Buzsáki - Rhythms of the Brain
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Buzsáki; Rhythms of the Brain 10 Self-organization is a fundamental brain operation.
Buzsáki; Rhythms of the Brain 11 Representation of external reality is a continual adjustment of the brain's self generated patterns by outside influences.  [recursion]  [Bayesian inference]  [Llinás;  brain operates as a reality emulator.] 1
Buzsáki; Rhythms of the Brain 11 Systems with features such as "self-organized" and "emergent" are often called "complex." 0
Buzsáki; Rhythms of the Brain 11 The term "complex" does not simply mean complicated but implies a nonlinear relationship between constituent components.  As a result, very small perturbations can cause large effects or no effect at all. 0
Buzsáki; Rhythms of the Brain 13 Complex systems live by the rules of nonlinear dynamics, better known is chaos theory. 2
Buzsáki; Rhythms of the Brain 13 Complexity can be formally defined as nonlinearity, and from nonlinear equations, unexpected solutions emerge. 0
Buzsáki; Rhythms of the Brain 13 Complex behavior of a dynamic system cannot easily be predicted or deduced from behavior of individual lower-level entities. 0
Buzsáki; Rhythms of the Brain 13 Emergent order and structure arise from the manifold interaction of numerous constituents. 0
Buzsáki; Rhythms of the Brain 13 Emergent self-organized dynamic, for example, a rhythm, imposes contextual constraints on its constituents, thereby restricting their degrees of freedom. 0
Buzsáki; Rhythms of the Brain 14 The evolution of complex systems is based upon cooperation and competition among its parts, and in the process certain constituents gain dominance over the others.  This dominance is called the "attractor" property in chaos theory. 1
Buzsáki; Rhythms of the Brain 14 Spontaneously organized brain patterns 0
Buzsáki; Rhythms of the Brain 30 Basic circuit -- hierarchy of multiple parallel loops. 16
Buzsáki; Rhythms of the Brain 30 A universal function of all brains is to move the body. 0
Buzsáki; Rhythms of the Brain 30 Neuronal loops are the principal organization at nearly all levels, comprising a multilevel, self-similar organization -- a fractal of loops. 0
Buzsáki; Rhythms of the Brain 31 Brain is organized in a hierarchy of multiple parallel loops (diagram) 1
Buzsáki; Rhythms of the Brain 31 In addition to multiple parallel loops, links between lower and higher layers are formed, generating a hierarchical form of organization among the parallel loops. 0
Buzsáki; Rhythms of the Brain 31 "New" brains are modified versions of older ones, and the new brain carries the major features of all previous versions. 0
Buzsáki; Rhythms of the Brain 31 Oldest circuits of the brain are located at the bottom. Subsequently developed levels rest in an intermediate position, while the most recently developed structures a situated on top. 0
Buzsáki; Rhythms of the Brain 32 In simple brains there are few neuronal steps between sensation and action. 1
Buzsáki; Rhythms of the Brain 32 An unexpected loud noise produces a startle reflex, which involves a sudden contraction of many of our muscles. 0
Buzsáki; Rhythms of the Brain 32 Sound waves in our ears may trigger a neuronal representation of memorable musical performances.  The neural circuitry involved in this process is quite elaborate and not well understood. 0
Buzsáki; Rhythms of the Brain 32 The neuronal loop connections between sensors and output are calibrated by experience so that the actions directed by senses can be meaningful and effective.   [Stereotyped motor programs]  [FAPs] 0
Buzsáki; Rhythms of the Brain 33 The result of a calibration-teaching process is that from past experience the brain can calculate the potential outcomes and convey this prediction to the effectors (e.g. skeletal muscles).   [Stereotyped motor programs]  [FAPs] 1
Buzsáki; Rhythms of the Brain 33 Human brain has about 100 billion (1011) neurons with an estimated 200 trillion (2 x 1014) contacts between them. 0
Buzsáki; Rhythms of the Brain 33 Although neurons are sparsely connected, they are within a few synaptic steps from all of the neurons. 0
Buzsáki; Rhythms of the Brain 34 Frequency bands of the various brain oscillators are relatively constant throughout mammalian evolution. 1
Buzsáki; Rhythms of the Brain 34 Scaling problems in brains of various sizes. 0
Buzsáki; Rhythms of the Brain 35 Axons occupy much more volume in the brain than do the cell bodies, dendrites, and spines combined. 1
Buzsáki; Rhythms of the Brain 36 Most connections among neurons are local in most brain structures. 1
Buzsáki; Rhythms of the Brain 37 Two organization principles -- (1) the degree of local clustering and (2) the degree of separation between distant parts of the brain (call it synaptic path length) -- compete with each other. 1
Buzsáki; Rhythms of the Brain 37 The "optimal" ratio of short and long-range connections has yet to be discovered. 0
Buzsáki; Rhythms of the Brain 39 Connections in scale-free networks obey a statistical  rule called the power law. 2
Buzsáki; Rhythms of the Brain 39 Scale-free systems are governed by Power Laws. 0
Buzsáki; Rhythms of the Brain 44 Cortical column diagram. 5
Buzsáki; Rhythms of the Brain 47 Rorschach inkblot test, developed by Hermann Rorschach. 3
Buzsáki; Rhythms of the Brain 53 Complexity of wiring in the neocortex. 6
Buzsáki; Rhythms of the Brain 55 Giulio Tononi, Olaf Sporns, and Gerald Edelman from the Neurosciences Institute in La Jolla, California searched for a structure-based metric that could objectively define "neuronal complexity," and capture the relationship between functional segregation and global integration of function in the brain.  Using the concepts of statistical entropy and mutual information, they estimated the relative statistical independence of model systems with various connectivity structures. 2
Buzsáki; Rhythms of the Brain 55 Statistical independence is low when the system constituents are either completely independent (segregated) or completely dependent (integrated). 0
Buzsáki; Rhythms of the Brain 56 Complexity reaches a maximum when a large number of assemblies of varied sizes are combined.  This feature is a hallmark of scale-free systems, governed by a power laws. 1
Buzsáki; Rhythms of the Brain 61 Diversity of cortical functions is provided by inhibition. 5
Buzsáki; Rhythms of the Brain 62 Inhibitory networks generate nonlinear effects. 1
Buzsáki; Rhythms of the Brain 65 Interneurons multiply the computational ability of principal cells. 3
Buzsáki; Rhythms of the Brain 65 Some interneurons do project as far as principal cells. 0
Buzsáki; Rhythms of the Brain 67 Interneuron networks are the backbone of many brain oscillators. 2
Buzsáki; Rhythms of the Brain 67 Five main principle-cell types have distinct functional properties. 0
Buzsáki; Rhythms of the Brain 67 Distinct functional properties of principle-cell types result from the unique combination of ion channels in the membrane and from their morphological individuality. 0
Buzsáki; Rhythms of the Brain 68 Diversity of cortical interneurons. 1
Buzsáki; Rhythms of the Brain 68 Thalamus, basal ganglia, and cerebellum have low variability in their neuron types. 0
Buzsáki; Rhythms of the Brain 68 Cortical structures have evolved not only five principle-cell types but also numerous classes of GABAergic inhibitory  interneurons. 0
Buzsáki; Rhythms of the Brain 68 Every surface domain of cortical principle cells is under the specific control of a unique interneuron class. 0
Buzsáki; Rhythms of the Brain 68 Using numerous classes of GABAergic inhibitory interneurons enormously multiplies the functional repertoire of principle cells, using mostly local interneuron wiring. 0
Buzsáki; Rhythms of the Brain 68 Adding novel interneuron types, even in small numbers, offers a nonlinear expansion of qualitatively different possibilities. 0
Buzsáki; Rhythms of the Brain 69 Scientific understanding of cortical interneurons has changed dramatically in the decade spanning the year 2000.  Interneurons are now understood to be a large family of intrinsically different cells with unexpectedly complex circuit wiring. 1
Buzsáki; Rhythms of the Brain 69 Different domains of principle cells have different functional dynamics. 0
Buzsáki; Rhythms of the Brain 70 Dendrite-targeting interneuron family displays the largest variability. 1
Buzsáki; Rhythms of the Brain 70 Interneurons also innervate each other by an elaborate scheme and affect each other's biophysical properties. 0
Buzsáki; Rhythms of the Brain 70 Long-range interneurons -- axon trees span two or more anatomical regions, some axon collaterals cross the hemispheric midline and/or innervate subcortical structures. 0
Buzsáki; Rhythms of the Brain 70 Long-range interneurons with distant clouds of terminal boutons are separated by myelinated axon collaterals that provide fast conduction speed for temporal synchrony of all terminals. 0
Buzsáki; Rhythms of the Brain 70 Widely-projecting, long-range interneurons are rare. 0
Buzsáki; Rhythms of the Brain 71 Long-range interneurons provide the necessary conduit for synchronizing distantly operating oscillators and allow for coherent timing of large numbers of neurons that are not directly connected with each other. 1
Buzsáki; Rhythms of the Brain 71 The axons of some interneurons avoid principle cells and contract exclusively other interneurons. 0
Buzsáki; Rhythms of the Brain 71 Existence of interneuron-specific interneurons provides support for a unique organization of the inhibitory system. 0
Buzsáki; Rhythms of the Brain 71 Interneuron-specific family also overlaps with the long-range interneuron subclass, emphasizing the importance of interregional synchronization of inhibition, and consequent coherent oscillatory entrainment of their target principle-cell populations. 0
Buzsáki; Rhythms of the Brain 75 Because interneurons connected by GABAA receptors are ubiquitous throughout the brain, gamma frequency oscillation can arise in almost every structure. 4
Buzsáki; Rhythms of the Brain 75 In "gamma clocks," no single neuron is responsible for initiating or maintaining the oscillation, yet all of the neurons contribute to the rhythm whenever they fire.  The responsibilities are distributed, and the result depends on cooperation.  Once a collective pattern arises, it constrains the timing of the action potentials of the individual cells because of the collectively generated inhibition. 0
Buzsáki; Rhythms of the Brain 75 In gamma clocks, firing and connectivity are essential, but the exact wiring is not critical as long as enough convergence and divergence are present. 0
Buzsáki; Rhythms of the Brain 77 The least numerous cells belong to the long-range interneuron family 2
Buzsáki; Rhythms of the Brain 78 Synaptic path length and, consequently, synaptic and conduction delays become excessively long for synchronization in larger networks. 1
Buzsáki; Rhythms of the Brain 78 Long-range interneurons connect local interneurons residing in different cortical regions. 0
Buzsáki; Rhythms of the Brain 78 The same physiological function in different-sized mammalian brains is supported by circuits with different compositions of neuronal proportions and connectivity. 0
Buzsáki; Rhythms of the Brain 79 Balance between excitation and inhibition is often accompanied by oscillations. 1
Buzsáki; Rhythms of the Brain 79 Connections among interneurons, including electrical gap junctions, are especially suitable for maintaining clocking actions. 0
Buzsáki; Rhythms of the Brain 79 Cerebral cortex is not only a complex system with complicated interactions among identical constituents but also has developed a diverse system of components. 0
Buzsáki; Rhythms of the Brain 81 Recording EEG traces from a few sites is sufficient to determine whether the brain is alive or dead or whether it is the sleeping or awake. 2
Buzsáki; Rhythms of the Brain 81 Scalp electrodes placed too close together will sense pretty much the same electrical fields. 0
Buzsáki; Rhythms of the Brain 81 In contrast to the excellent temporal resolution, scalp recording EEG methods have serious spatial resolution problems. 0
Buzsáki; Rhythms of the Brain 84 Magnetoencephalography 3
Buzsáki; Rhythms of the Brain 84 The magnetic fields that emanate from the brain are only one 100 millionth to one billionth of the strength of the Earth's magnetic field. 0
Buzsáki; Rhythms of the Brain 84 The sensor that can detect the weak magnetic signals emanating from the brain is known as a SQUID (superconducting quantum interference device), operating at a temperature of -270° C. 0
Buzsáki; Rhythms of the Brain 84 Liquid helium in the SQUID cools the coils to superconducting temperatures. 0
Buzsáki; Rhythms of the Brain 84 For magnetoencephalography, need many sensors around the head to increase spatial resolution. 0
Buzsáki; Rhythms of the Brain 84 For magnetoencephalography, detector coils are placed as close to each other as possible, forming a spherical honeycomb-like pattern concentric with the head. 0
Buzsáki; Rhythms of the Brain 84 Magnetoencephalographic (MEG) signal reflects mostly intracellular currents. 0
Buzsáki; Rhythms of the Brain 84 Spatial resolution of MEG is better than EEG mainly because the magnetic fields are not scattered and distorted by inhomogeneities in the skull and scalp. 0
Buzsáki; Rhythms of the Brain 86 Neurons Communicate with Spikes 2
Buzsáki; Rhythms of the Brain 88 Synaptic Potentials 2
Buzsáki; Rhythms of the Brain 89 Extracellular Currents 1
Buzsáki; Rhythms of the Brain 92 Functional Magnetic Resonance Imaging (fMRI) 3
Buzsáki; Rhythms of the Brain 94 Positron Emission Tomography (PET) 2
Buzsáki; Rhythms of the Brain 99 Triangulation of Neurons by Tetrodes 5
Buzsáki; Rhythms of the Brain 107 Forms of Oscillatory Synchrony 8
Buzsáki; Rhythms of the Brain 111 A System of Rhythms -- From Simple to Complex Dynamics 4
Buzsáki; Rhythms of the Brain 111 Not all neurons and connections are used all the time. The dynamically changing functional or effective connectivity gives rise to short lived oscillations that are perpetually created and destroyed by the brain's internal dynamics. 0
Buzsáki; Rhythms of the Brain 111 Brain dynamics constantly shift from the complex to the predictable.  Neuronal ensemble activity shuttle back and forth between the interference-prone complexity and robust predictable oscillatory synchrony. 0
Buzsáki; Rhythms of the Brain 112 Oscillations have been documented in the brains of numerous mammalian species, ranging from very slow oscillations with periods of minutes to very fast oscillations with frequencies reaching 600 Hz. 1
Buzsáki; Rhythms of the Brain 112 Frequency coverage of the traditional bands was confined by the EEG recording technology. 0
Buzsáki; Rhythms of the Brain 112 Hippocampal theta oscillation was discovered in the anesthetized rabbit. 0
Buzsáki; Rhythms of the Brain 112 The exact mechanisms of most brain oscillations are not known. 0
Buzsáki; Rhythms of the Brain 113 Relationship among three hippocampal rhythms observed in the rat -- theta (4 -- 10 Hz) and gamma (30 -- 80 Hz) rhythms and fast oscillation (140 -- 200 Hz).  These rhythms are independently generated, because the gamma oscillations persist without theta oscillations and compete with the fast oscillation. 1
Buzsáki; Rhythms of the Brain 113 The theta, gamma, and fast oscillation relate to each other on a natural logarithmic scale. 0
Buzsáki; Rhythms of the Brain 113 Discrete oscillation bands form a geometric progression on a linear frequency scale and a linear progression on a natural logarithmic scale. 0
Buzsáki; Rhythms of the Brain 113 All frequencies from 0.02 Hz to 600 Hz are continuously present, covering more than four orders of magnitude of temporal scale. 0
Buzsáki; Rhythms of the Brain 113 At least 10 postulated distinct mechanisms are required to cover the large frequency range. 0
Buzsáki; Rhythms of the Brain 113 Because a single structure does not normally generate all oscillatory classes, structures must cooperate to cover all frequencies. 0
Buzsáki; Rhythms of the Brain 113 Different mechanisms in different brain structures can give rise to the same oscillatory band, but there should be at least one distinct mechanism for each oscillation class. 0
Buzsáki; Rhythms of the Brain 113 There is a definable relationship among all the brain oscillators -- a geometrical progression of mean frequencies from band to band with a roughly constant ratio of e = 2.17 -- the base for the natural logarithm. 0
Buzsáki; Rhythms of the Brain 113 Sinse e is an irrational number, the phase of coupled oscillators of the various bands will vary on each cycle forever, resulting in a nonrepeating, quasi-periodic weakly chaotic pattern -- this is the main characteristic of the EEG. 0
Buzsáki; Rhythms of the Brain 115 A number of psychological phenomena argue in favor of the idea that cognitive events require hierarchical processing.  Separate processing requires the engagement of neuronal networks and multiple spatial scales. 2
Buzsáki; Rhythms of the Brain 115 Each oscillatory cycle is a temporal processing window. 0
Buzsáki; Rhythms of the Brain 115 The brain does not operate continuously but discontiguously, using temporal packages or quanta. 0
Buzsáki; Rhythms of the Brain 115 Networks with cycles have orders of magnitude larger capabilities than networks without cycles (e.g. a feedforward net) 0
Buzsáki; Rhythms of the Brain 115 The wavelength of the oscillatory category determines the temporal windows of processing, and, indirectly, the size of the neuronal pool involved. 0
Buzsáki; Rhythms of the Brain 115 In general, slow oscillators can involve many neurons in large brain areas, whereas the short time windows of fast oscillators facilitate local integration, largely because of the limitations of the axon conduction delays. 0
Buzsáki; Rhythms of the Brain 119 Brain oscillators should be considered as a system of oscillators with an intricate relationship between the various rhythmic components. 4
Buzsáki; Rhythms of the Brain 119 Synaptic activity in the brain can lead to a complex system organized at multiple timescales. 0
Buzsáki; Rhythms of the Brain 119 Slow rhythms involve very large numbers of cells and can be "heard" over a long distance, whereas localized fast oscillations involving only a small fraction of neurons may be conveyed only to a few partners. 0
Buzsáki; Rhythms of the Brain 119 Power spectrum of the EEG is a straight line on a log-log plot, the hallmark of scale-free systems (i.e. systems that obey power laws) 0
Buzsáki; Rhythms of the Brain 119 The amplitude of the EEG power spectrum increases as the frequency decreases.  This inverse relationship is expressed as the "one over f" power spectrum (also called "pink" noise). 0
Buzsáki; Rhythms of the Brain 120 A critical aspect of brain oscillators is that the mean frequencies of the neighboring oscillatory families are not integers of each other. Adjacent bands cannot simply lockstep because the prerequisite for stable temporal locking is phase synchronization. 1
Buzsáki; Rhythms of the Brain 120 The 2.17 ratio between adjacent oscillators can give rise only to transient or metastable dynamics, a state of perpetual fluctuation between unstable and transient phase synchrony, as long as the individual oscillators can maintain their independence and do not succumb to the duty cycle influence of a strong oscillator. 0
Buzsáki; Rhythms of the Brain 120 Multiple oscillators that perpetually engage and disengage each other. 0
Buzsáki; Rhythms of the Brain 120 Locally emerging stable oscillators in the cerebral cortex are constantly being pushed and pulled by the global dynamics. 0
Buzsáki; Rhythms of the Brain 120 Despite the chaotic dynamics of the transient coupling of the oscillators at multiple spatial scales, a unified system with multiple time scales emerges. 0
Buzsáki; Rhythms of the Brain 121 The inverse relationship between frequency and its power is an indication that there is a temporal relationship between frequencies -- perturbations of slow frequencies cause a cascade of energy dissipation at all frequency scales. 1
Buzsáki; Rhythms of the Brain 121 Long-term scalp recordings confirm power-law scaling behavior for all frequencies tested and expand the temporal scale of the 1/f line beyond a minute. 0
Buzsáki; Rhythms of the Brain 121 An alpha wave at this instant in your occipital cortex can influence the amplitude of another alpha wave a thousand cycles later and all waves in between. 0
Buzsáki; Rhythms of the Brain 121 The scale-invariant feature of the EEG is the mathematical telltale sign of self-organization. 0
Buzsáki; Rhythms of the Brain 121 The speed at which the power decreases from low to high frequencies measures the length of the correlations or, using another phrase, the "temporal memory effects" of the signal. 0
Buzsáki; Rhythms of the Brain 121 If there were no relationship among the frequency bands, the power density would be constant over a finite frequency range, and the spectrum would be flat -- 1/f0.  Physicists call this pattern "white noise." 0
Buzsáki; Rhythms of the Brain 121 Brownian motion -- "brown noise," the power density decreases much faster with frequency (1/f2) than is the case for pink noise.  Brown noise is random at longer intervals but is easily predictable and strongly correlated at short intervals. 0
Buzsáki; Rhythms of the Brain 122 The cerebral cortex with its most complex architecture generates the most complex noise known to physics. 1
Buzsáki; Rhythms of the Brain 122 Brain oscillators are not independent.  The same elements, neurons, and neuronal pools are responsible for all rhythms. 0
Buzsáki; Rhythms of the Brain 122 When brain rhythm is fast, only small groups can follow the beat perfectly, because of the limitations of axon conductance and synaptic delays. 0
Buzsáki; Rhythms of the Brain 122 Slow oscillations, spanning numerous axon conduction delay periods, allow the recruitment of very large numbers of neurons. 0
Buzsáki; Rhythms of the Brain 122 The slower the oscillation, the more neurons can participate. 0
Buzsáki; Rhythms of the Brain 122 With local connections only, an emerging rhythm at one place would aggressively invade neighboring territories, resulting in traveling waves. 0
Buzsáki; Rhythms of the Brain 122 When rhythms emerge simultaneously in several locations, they might be synchronized by the intermediate and long-range connections. 0
Buzsáki; Rhythms of the Brain 122 The inevitable delays and the time-limited recruitment of neuronal pools can account for a good part of the 1/f functionality. 0
Buzsáki; Rhythms of the Brain 123 The firing patterns of single cells depend not only on on their instantaneous external inputs but also on the history of their firing patterns and the state of the network in which they are embedded. 1
Buzsáki; Rhythms of the Brain 123 The power (loudness) fluctuations of brain generated and perceived sounds, like music and speech, and numerous other time related behaviors, exhibit 1/f power spectra. 0
Buzsáki; Rhythms of the Brain 123 Perhaps what makes music fundamentally different from (white) noise for the listener is that music has temporal patterns that are tuned to the brain's ability to detect them, because it is another brain (the composer) that generates these patterns. 0
Buzsáki; Rhythms of the Brain 123 The long-time and large-scale note structure of Bach's First Brandenburg Concerto is quite similar to the latest hit played by rock station or to Scott Joplin's Piano Rags. 0
Buzsáki; Rhythms of the Brain 123 High temporal predictability, such as the sound of dripping water, and the total lack of predictability,  such as John Cage's stochastic music (essentially white noise) are quite annoying to most people. 0
Buzsáki; Rhythms of the Brain 123 If self-generated brain dynamics have a link to the spectral composition of speech and music, one might expect that the same dynamics would influence a plethora of other behaviors. 0
Buzsáki; Rhythms of the Brain 123 Dynamics of cortical patterns in all mammals exhibit 1/f spectra. 0
Buzsáki; Rhythms of the Brain 126 Fractal Nature of EEG 3
Buzsáki; Rhythms of the Brain 126 The spectral content and frequency bands of the human EEG and electrocardiogram are remarkably similar to those of mice, rats, guinea pigs, rabbits, cats, dolls, and monkeys. 0
Buzsáki; Rhythms of the Brain 126 The long-term temporal structure of the macroscopic neuronal signal, reflecting the collective behavior of neurons that give rise to it, is macroscopically similar in virtually all cortical structures and in brains of various mammalian species. 0
Buzsáki; Rhythms of the Brain 126 A collective pattern recorded from a small portion of the cortex looks like the pattern recorded from the whole.  This "scale invariance" or "self-similarity" is a decisive characteristic of fractals. 0
Buzsáki; Rhythms of the Brain 126 Fractal dynamic processes -- such as pink noise -- are self-similar in that any piece of the fractal design contains a miniature of the entire design. 0
Buzsáki; Rhythms of the Brain 127 Macroscopic EEG and EEG patterns describe the large-scale functions of neuronal networks as a unified whole,.  independent of the details of the dynamic processes governing the subunits that make up the whole. 1
Buzsáki; Rhythms of the Brain 127 The concept that physical systems, made up of a large number of interacting subunits, obey universal laws that are independent of the microscopic details is a relatively recent breakthrough in statistical physics. 0
Buzsáki; Rhythms of the Brain 127 The scale freedom of spatial and temporal dynamics in the cortex has emerged as a useful direction of research. 0
Buzsáki; Rhythms of the Brain 127 The seductively simple 1/fα function is, in fact, very complex.  Every new computation takes into consideration the entire past history of the system. [Recursion]  [Bayesian inference] 0
Buzsáki; Rhythms of the Brain 127 The response of a neuron depends on the immediate discharge history of the neuron and the long-term history of the connectivity of the network in which it is embedded. 0
Buzsáki; Rhythms of the Brain 127 Even a weak transient local perturbation can invade large parts of the network and have a long-lasting effect, whereas myriads of other inputs remain ignored. 0
Buzsáki; Rhythms of the Brain 127 Although neuronal networks of the brain are in perpetual flux, due to their time-dependent state changes, the firing patterns of neurons are constrained by the past history of the network.  Complex networks have memory. 0
Buzsáki; Rhythms of the Brain 134 Most oscillations are transient but last long enough to provide stability for holding and comparing information at linear time scales. 7
Buzsáki; Rhythms of the Brain 135 Scale-free dynamics generate complexity, whereas oscillations allow for temporal predictions. 1
Buzsáki; Rhythms of the Brain 135 Order in the brain does not emerge from disorder.  Instead, transient order emerges from halfway between order and disorder, from the territory of complexity. 0
Buzsáki; Rhythms of the Brain 135 The dynamics in the cerebral cortex constantly alternate between the most complex metastable state and the highly predictable oscillatory state. 0
Buzsáki; Rhythms of the Brain 135 Neural networks can shift quickly from a highly complex state to act as predictive coherent units due to the deterministic nature of the oscillatory order. 0
Buzsáki; Rhythms of the Brain 159 Hebb's cell assembly is a transient coalition of neurons, much like the dynamic interactions among jazz musicians. 24
Buzsáki; Rhythms of the Brain 159 Information reverberates within the assembly, and the direction of flow is determined by the synaptic strengths. 0
Buzsáki; Rhythms of the Brain 159 Hebb believed that activity reverberates in loops of synaptically connected chains of neurons. 0
Buzsáki; Rhythms of the Brain 159 The reverberation explains why activity can outlast the physical presence of an input signal. 0
Buzsáki; Rhythms of the Brain 160 In the cell recordings of behaving rats, the receptive fields of hippocampal neurons are characterized by the animal's position in the environment. 1
Buzsáki; Rhythms of the Brain 163 For a hippocampal population of neurons, the optimal window for cell assembly was found to be between 10 and 30 ms.  This time scale may be of particular functional significance because many physiological variables share this time window. 3
Buzsáki; Rhythms of the Brain 163 The time constant of pyramidal cells is perhaps most important, because this is the window that determines a cell's integration ability. 0
Buzsáki; Rhythms of the Brain 163 The cell assembly time-window also matches the time period of gamma frequency oscillations. 0
Buzsáki; Rhythms of the Brain 163 We can conclude that cell assemblies are synchronized within the time window of gamma oscillation, because this allows an assembly to exert the largest possible impact on their downstream targets. 0
Buzsáki; Rhythms of the Brain 163 Duration of excitatory postsynaptic potentials in pyramidal cells in vivo is also in the 10 -- 30 ms range. 0
Buzsáki; Rhythms of the Brain 163 The 10 -- 30 ms range temporal window is most critical for spike-timing dependent plasticity of synapses. 0
Buzsáki; Rhythms of the Brain 175 Rest and sleep are the best examples of self-organized operations within neuronal circuits and systems. 12
Buzsáki; Rhythms of the Brain 176 Sleep is an excellent model of evolving brains states because it occurs without outside influence -- evolves from within. 1
Buzsáki; Rhythms of the Brain 176 Virtually every psychiatric ailment is associated with some kind of alteration of sleep duration and pattern. 0
Buzsáki; Rhythms of the Brain 176 Thalamus -- A Partner for Neocortex 0
Buzsáki; Rhythms of the Brain 176 In large systems with complex connectivity, it is often difficult to draw boundaries.  This is the case with in neocortical mantle, with its myriads of cortical modules and high density local  connectivity, supplied by neurons whose biophysical features do not vary greatly across the cortex. 0
Buzsáki; Rhythms of the Brain 177 A very large part of the thalamocortical circuits do not have much to do with the primary sensory information. 1
Buzsáki; Rhythms of the Brain 177 There are important inputs to the thalamocortical circuits from the cerebellum and the basal ganglia, but the bulk of the afferents are supplied by the neocortex. 0
Buzsáki; Rhythms of the Brain 177 Clustering of long-range connections provide some anatomical clues for subdivisions of the neo-cortex and justifies designations of cortical systems as visual, auditory, somatosensory, motor, language-related, spatial, or other. 0
Buzsáki; Rhythms of the Brain 177 Further segregation of neocortical functions as well is integration of information across the distant regions derives from the main afferent and efferent expansion -- the thalamus. 0
Buzsáki; Rhythms of the Brain 177 The thalamus is a football-shaped structure located in the origin of the two neocortical hemispheres, like the central atom of the large molecule. 0
Buzsáki; Rhythms of the Brain 177 The function of the thalamus geometrical arrangement could be that being equidistant from all cortical areas demands the least length of reciprocal wiring and provides the fastest axonal communication. 0
Buzsáki; Rhythms of the Brain 177 A very large part of the thalamocortical circuits do not have much to do with primary sensory information.  There are important inputs from the cerebellum and the basal ganglia, but the bulk of the afferents are supplied by the neocortex. 0
Buzsáki; Rhythms of the Brain 178 The importance of the cortical feedback to the thalamus is best illustrated by the fact that the thalamus is the only corticofugal target of the layer 6 pyramidal cell population, and these neurons  innervate virtually all thalamic nuclei. 1
Buzsáki; Rhythms of the Brain 178 Collaterals of layer 5 pyramidal cells, whose fast-conducting main axons are destined for the brainstem, target those thalamic nuclei that did not receive primary sensory or motor information. 0
Buzsáki; Rhythms of the Brain 178 Thalamocortical circuits are associated with thalamic divisions "higher order" nuclei, as opposed to the "first-order" nuclei with specific sensory motor information. 0
Buzsáki; Rhythms of the Brain 178 Afferents from higher-order cortical nuclei send widespread projections to cortical areas, disseminating their thalamocortical information via extensive axon harbors and larger cortical coverage. 0
Buzsáki; Rhythms of the Brain 179 The pattern of thalamic connectivity coevolved with the neocortex. 1
Buzsáki; Rhythms of the Brain 179 The number of thalamocortical neurons in the mouse is only 1/10 the number of target neurons in the cortex, where is in the human brain to ratio is less than 1/1000. 0
Buzsáki; Rhythms of the Brain 179 In partnership with the cortex, the reciprocal excitatory connections of the thalamus are prone to oscillation, and such a mechanism is perfectly poised to mix thalamocortical information. 0
Buzsáki; Rhythms of the Brain 179 Cytoarchitectural organization of the thalamus is unique.  Most GABAergic interneurons in the thalamus reside in the thin shell surrounding the thalamic chamber, call the reticular nucleus, and some other subcortical nuclei. 0
Buzsáki; Rhythms of the Brain 180 Rudolfo Llinás and colleagues (1984) discovered that some neuron types, such as thalamocortical cells, can be discharged not only by excitation but also by releasing the neuron from inhibition, releasing a "burst" of spikes at intervals of 3 -- 5 ms. 1
Buzsáki; Rhythms of the Brain 181 Thalamocortical cells can fire in two qualitatively different ways. -- (1) Depolarization can induce rhythmic single spikes, similar to those observed in neocortical pyramidal cells.   (2) When released from hyperpolarization, the slow calcium spike is depolarizing and lasts for tens of milliseconds, typically with a series of fast spikes riding on it. 1
Buzsáki; Rhythms of the Brain 181 Every thalamocortical neuron can be converted into a delta frequency clock when properly hyperpolarized. 0
Buzsáki; Rhythms of the Brain 182 Single-cell Oscillation in a Thalamocortical Neuron (diagram) 1
Buzsáki; Rhythms of the Brain 183 Brain evolution adopted a channel from the heart just to sustain oscillations during sleep. 1
Buzsáki; Rhythms of the Brain 183 When coordinated across multiple thalamocortical neurons, the single-cell properties can provide a delta-frequency pacing of their cortical targets. 0
Buzsáki; Rhythms of the Brain 183 Inhibition-induced rebound spikes are not elicited by any specific sensory input.  Because they are triggered by inhibition, they are prime examples of self-generated  spike patterns that communicate to downstream neurons primarily determined by the state of the thalamic network. 0
Buzsáki; Rhythms of the Brain 183 Reticular neurons are similar to thalamocortical cells; however, reticular neurons are not critical players in delta oscillations. 0
Buzsáki; Rhythms of the Brain 184 Numerous rhythms have been described in a resting sleeping thalamocortical system, including alpha waves (8 -- 12 Hz), mu rhythm (8 -- 12 Hz), sleep spindles (10 -- 20 Hz) and associated ultrahigh frequency oscillations (300 -- 600 Hz), delta waves (1 -- 4 Hz), and slow 1 to 4 slow rhythms (0.05 -- 1 Hz). 1
Buzsáki; Rhythms of the Brain 184 A common feature of all self-governed thalamocortical oscillations is that they bring about constraints regarding whether and when information about the outside world, detected by the peripheral senses, can pass through the thalamus and be distributed for further processing in cortical networks or is ignored outright. 0
Buzsáki; Rhythms of the Brain 185 At sleep onset, subcortical neurons, releasing acetylcholine, serotonin, norepinephrine, and histamine, decrease their firing rates.  So do specific thalamic afferents and primary sensory cortical neurons. 1
Buzsáki; Rhythms of the Brain 185 Generally, slower frequencies involve more extensive synchronous activation of the neuronal pool. 0
Buzsáki; Rhythms of the Brain 185 In contrast to the rigid interarea corticocortical connections, with progressively increasing axon conduction delays, the transthalamic "shortcuts" are nearly equidistant from all neocortical areas. 0
Buzsáki; Rhythms of the Brain 185 With the thalamus as a matchmaker, the effective connectivity between local neocortical populations can be changed according to current computational needs. 0
Buzsáki; Rhythms of the Brain 185 The key ingredient in the cortical globalization process is the ability of the oscillatory mechanisms to recruit anatomically distant cortical neurons into temporal coalitions. 0
Buzsáki; Rhythms of the Brain 185 In addition to the long-range connections among the various cortical regions, the thalamus provides additional radial "shortcuts" necessary for reducing the synaptic path lengths between the various cortical areas. 0
Buzsáki; Rhythms of the Brain 185 Weak connections can be amplified by phase modulation, due to the resonant properties of the thalamic and cortical modules involved. 0
Buzsáki; Rhythms of the Brain 185 Modules with resonant relations between their frequencies can exchange information more easily than modules with nonoscillating properties or dissimilar frequencies. 0
Buzsáki; Rhythms of the Brain 186 The thalamus is no longer viewed as a gigantic array of independent relays, but as a large communication hub that assists in linking large cortical areas in a flexible manner.  The principal mechanism of the cortical-thalamic-cortical flow of activity is self-sustained oscillations. 1
Buzsáki; Rhythms of the Brain 186 Oscillatory Patterns of Sleep 0
Buzsáki; Rhythms of the Brain 187 Unlike most body parts, the brain is busy at night. 1
Buzsáki; Rhythms of the Brain 187 In humans, at least five stages of sleep with progressively higher wakening thresholds can be distinguished, with the deepest stage being a rapid eye movement (REM) phase. 0
Buzsáki; Rhythms of the Brain 187 Separation of the first four stages of sleep, known collectively as non-REM sleep, is based mostly on the relative number of sleep spindles and delta waves. 0
Buzsáki; Rhythms of the Brain 187 Stage one is the phase transition between wake and sleep. 0
Buzsáki; Rhythms of the Brain 187 Stage two is heralded by the emergence of sleep spindles. 0
Buzsáki; Rhythms of the Brain 187 Stage three is a mixture of spindles and delta waves. 0
Buzsáki; Rhythms of the Brain 187 Stage four is characterized by the dominance of delta activity with only traces of spindles. 0
Buzsáki; Rhythms of the Brain 187 Approximately half of sleep consists of stages 2 and 3, stage 4 composes only 5 --15 percent of total sleep time and may be completely missing after 40 years of age. 0
Buzsáki; Rhythms of the Brain 187 Stages 3 and 4 are often referred to as slow wave or delta sleep. 0
Buzsáki; Rhythms of the Brain 187 Stage 5, REM sleep, is characterized by a waking-type EEG, rapid eye movements, loss of muscle tone, and dreaming. 0
Buzsáki; Rhythms of the Brain 187 REM sleep composes usually 20 -- 25% of total sleep time in humans adults, and is an indication of the end of a non-REM/REM sleep cycle. 0
Buzsáki; Rhythms of the Brain 187 Typically, four or five non-REM/REM cycles with a period of 70 -- 90 minutes each, occur within a night. 0
Buzsáki; Rhythms of the Brain 188 Sleep spindles are the hallmark of natural non-REM sleep. 1
Buzsáki; Rhythms of the Brain 189 All that is needed for the emergence of oscillation is a seed of enough synchrony so that some reticular neurons discharge, preferably a synchronous burst of spikes. 1
Buzsáki; Rhythms of the Brain 189 Discharging reticular cells hyperpolarize the same and more thalamocortical neurons because their axon collaterals diverge onto many thalamocortical neurons. 0
Buzsáki; Rhythms of the Brain 194 Recurrent and lateral excitation is the main mechanism through which excitation can spread.  This process takes time, given the low velocity of axon conductance. 5
Buzsáki; Rhythms of the Brain 195 Origin of Delta Waves 1
Buzsáki; Rhythms of the Brain 200 Origin of Alpha Rhythms 5
Buzsáki; Rhythms of the Brain 201 Occipital alpha rhythm is prominent in animals with saccadic eye movements, large visual cortex, and binocular frontal vision, but is virtually absent in the rat and other nocturnal species. 1
Buzsáki; Rhythms of the Brain 202 In contrast to vision, rodents have an elaborate somatosensory representation.  The face whisker system has an orderly and large representation in both the thalamus and the sensory cortex. 1
Buzsáki; Rhythms of the Brain 203 Occipital alpha and auditory cortical tau oscillations may arise as a result of complex interaction between the GABAergic thalamic neurons and thalamocortical neurons combined with neocortical amplification of the thalamic signals. 1
Buzsáki; Rhythms of the Brain 203 The extent of alpha oscillations is an indication of the cortical disengagement from inputs of the body and the environment. 0
Buzsáki; Rhythms of the Brain 203 The alpha peak in the human scalp EEG power spectrum is prominent under virtually all waking conditions, not only when eyes are closed and muscles are relaxed, although these conditions robustly increase the power in alpha band. 0
Buzsáki; Rhythms of the Brain 204 Sleep and rest-associated oscillations are the best examples of self-organized operations in the brain. 1
Buzsáki; Rhythms of the Brain 205 The thalamus is a hub for the neocortex that provides functional shortcuts between the vast areas of the cerebral hemispheres and reduces the synaptic pathways between various cortical areas. 1
Buzsáki; Rhythms of the Brain 205 Both the excitatory thalamocortical and the inhibitory neurons of the reticular nucleus are endowed with various intrinsic conductances, which promote oscillations at various temporal and spatial scales. 0
Buzsáki; Rhythms of the Brain 205 First-order and higher order nuclei of the thalamus have reciprocal relationships with sensory and associational cortices, respectively. 0
Buzsáki; Rhythms of the Brain 205 In the absence of environmental inputs, the brain gives rise to self-organized activity that follows a complex trajectory in time and neuronal space during sleep. 0
Buzsáki; Rhythms of the Brain 205 The isolated neocortex or small pieces of the neocortex alone can sustained self-organized patterns. 0
Buzsáki; Rhythms of the Brain 205 The most prominent oscillation of the waking brain is the family of alpha rhythms that occur selectively in every sensory and motor thalamocortical system in the absence of sensory inputs. 0
Buzsáki; Rhythms of the Brain 228 Ambiguous figures such as the Necker cube -- a critical element in perception is the object's continual surveillance by eye movements.  Seeing (i.e. perception) is an active exploration of the environment. 23
Buzsáki; Rhythms of the Brain 229 Metastability of ambiguous figures such as the Necker cube involve perceptual shifts initiated by eye movements. 1
Buzsáki; Rhythms of the Brain 229 Sleep is the default state of the brain -- it develops as a self-organized or spontaneous state without an external input. 0
Buzsáki; Rhythms of the Brain 231 Invention of functional imaging of the intact human brain in the early 1990s. 2
Buzsáki; Rhythms of the Brain 231 Society for Neuroscience meeting in Washington, DC,  fall of 1993, Wolf Singer, Max Planck Institute, Frankfurt-am-Main, Germany. 0
Buzsáki; Rhythms of the Brain 232 Representation of the various attributes of the visual world by distributed neuronal assemblies can be bound together harmoniously in the time domain through oscillatory synchrony. 1
Buzsáki; Rhythms of the Brain 232 Features processed in separate parts of the cortex by different sets of neurons are bound into a complex representation in a matter of 200 ms or so. 0
Buzsáki; Rhythms of the Brain 237 The existence of rhythms in the visual system, such as the prominent alpha waves, is a physiological telltale sign of excitatory feedback loops in action. 5
Buzsáki; Rhythms of the Brain 238 Binding by Temporal Coherence. 1
Buzsáki; Rhythms of the Brain 238 Peter Millner and Christoph von der Malsburg -- spatially distributed cell groups should synchronize their responses when activated by a single object. 0
Buzsáki; Rhythms of the Brain 238 Systems with emergent features require feedback. 0
Buzsáki; Rhythms of the Brain 238 Feedback loops are likely to be very important in processing sensory information or combine the sensory inputs with past experience. 0
Buzsáki; Rhythms of the Brain 239 Oscillation as a linking mechanism -- synchronization by oscillation is effective even through a few and weak links. 1
Buzsáki; Rhythms of the Brain 240 Gamma bursts, lasting from tens to thousands of milliseconds, are rarely observed spontaneously, but are reliably induced by visual stimuli. 1
Buzsáki; Rhythms of the Brain 240 Research results show that oscillatory dynamics in the brain is not directly related to the stimulus, but are added on by the brain.  Gamma oscillation in the activated neural cortex has a function. 0
Buzsáki; Rhythms of the Brain 240 Neurons with overlapping receptive fields    and similar response properties,    synchronize robustly with zero time lag,    whereas neurons that do not share the same receptive fields    do not synchronize. 0
Buzsáki; Rhythms of the Brain 240 It is the response features of the neurons,    rather than their spatial separation,    that determined the vigor of synchrony. 0
Buzsáki; Rhythms of the Brain 240 Neurons several millimeters apart    in the same or different stages of the visual system,    and even across the two cerebral hemispheres,    have been shown to come together in time transiently    by gamma frequency synchronization. 0
Buzsáki; Rhythms of the Brain 243 Attributes of an object    are not in the object;    they're generated by the observer's brain. 3
Buzsáki; Rhythms of the Brain 243 Gestalt psychologists have long known that the whole is often faster recognized than its parts,    indicating that object recognition    is not simply representation of elementary features,    but the result of bottom-up and top-down interactions,    in harmony with the architectural organization of the cerebral cortex. 0
Buzsáki; Rhythms of the Brain 243 Binding by gamma oscillation hypothesis. 0
Buzsáki; Rhythms of the Brain 243 Although the binding problem was originally formulated in terms of visual object recognition,    the idea of various attributes making up a whole is quite general    and should apply to all modalities. 0
Buzsáki; Rhythms of the Brain 243 Every part of the cortex should be able to support gamma oscillations under the right conditions. 0
Buzsáki; Rhythms of the Brain 243 Consciousness is a state that requires linking global features of the brain-body-environment interface. 0
Buzsáki; Rhythms of the Brain 243 Coherence measurements of MEG signals    over the whole extent of the cerebral hemispheres    indicates that significant coupling in the gamma frequency band    is present in the waking brain as well is during REM sleep. 0
Buzsáki; Rhythms of the Brain 243 Sensory perturbation    can easily reset gamma rhythm in the waking state,    whereas the same stimulus is largely ineffective during REM sleep. 0
Buzsáki; Rhythms of the Brain 244 Gamma oscillation    is not ubiquitous    but localized temporarily    to areas engaged in a particular operation. 1
Buzsáki; Rhythms of the Brain 244 Gamma frequency power    has been observed in motor areas during,    but more typically prior to,    voluntary movement in sensory-motor tasks. 0
Buzsáki; Rhythms of the Brain 244 Significant difference in gamma power    was reported between patterns induced by words versus pseudowords    in both visual and auditory tasks. 0
Buzsáki; Rhythms of the Brain 244 Induced gamma activity emerges at a variable latency between 150 and 300 ms after stimulus onset,    approximately at the time when stimuli acquire meaning. 0
Buzsáki; Rhythms of the Brain 245 Research observations indicate that a coherent perception of an object involves synchronization of large cortical areas. 1
Buzsáki; Rhythms of the Brain 245 Low spatial resolution of scalp recordings. 0
Buzsáki; Rhythms of the Brain 245 Gamma oscillations should be confined to discrete active locations rather than being diffusely present over a wide cortical region. 0
Buzsáki; Rhythms of the Brain 245 Recording sites as close as 3--4 mm from each other in the visual cortex yielded quite different amplitudes of gamma oscillations. 0
Buzsáki; Rhythms of the Brain 245 Short bouts of oscillations detected by scalp electrodes correspond to localized events that are integrated over time and space. 0
Buzsáki; Rhythms of the Brain 245 Gamma oscillations are used in the brain for temporally segmenting representations of different items. 0
Buzsáki; Rhythms of the Brain 246 Neuronal assemblies in the waking brain self-organize themselves into temporal packages of 15 -- 30 ms. 1
Buzsáki; Rhythms of the Brain 246 Temporal integration abilities of individual pyramidal cells. 0
Buzsáki; Rhythms of the Brain 246 Neuronal connections are subject to use-dependent modification. 0
Buzsáki; Rhythms of the Brain 246 Two fundamental ways in which neuronal coalitions can be altered -- (1) forming physical connections between neurons or eliminating them, (2) changing the synaptic strengths of existing connections. 0
Buzsáki; Rhythms of the Brain 247 Two fundamental requirements for affecting synaptic strength --  (1) sufficiently strong depolarization of the postsynaptic neuron, (2) appropriate timing between presynaptic activity and the discharge of the postsynaptic neuron. 1
Buzsáki; Rhythms of the Brain 247 Because mechanisms for affecting synaptic strength of neuronal coalitions are affected by the gamma-oscillation-mediated synchronization, adjustment of synaptic strength is a perpetual process in the cortex. 0
Buzsáki; Rhythms of the Brain 247 Every time a postsynaptic neuron fires in a manner that the discharge leads to an increase of free Ca2+ in the dendrites, the previously or subsequently active presynaptic connections are modified. 0
Buzsáki; Rhythms of the Brain 247 The critical temporal window of plasticity for pre-synaptic connection modification corresponds to the length of the gamma cycle. 0
Buzsáki; Rhythms of the Brain 247 Spike-timing-dependent plasticity highlights the essential role of spite timing in modifying network connectivity, a fundamental brain mechanism. 0
Buzsáki; Rhythms of the Brain 247 Gamma oscillation remains a central timing mechanism essential for synaptic plasticity. 0
Buzsáki; Rhythms of the Brain 247 Synchronization by gamma oscillations results in not only perceptual binding but, inevitably, modification of connections among the neurons involved. 0
Buzsáki; Rhythms of the Brain 247 The assembly bound together by gamma-oscillation-induced synchrony can reconstruct patterns on the basis of partial cues because of the temporally fortified connections among neuron assembly members. 0
Buzsáki; Rhythms of the Brain 277 Perceptions of natural scenes, speech, music, and body image as well as our occasional illusions can be attributed largely to the unique organization of the iso-cortex. 30
Buzsáki; Rhythms of the Brain 278 The implicit experience of learning how to walk comfortably in high heeled shoes or ignoring the annoying sound of the air-conditioner in your office does not require that we be aware of the process. 1
Buzsáki; Rhythms of the Brain 280 The best way to start speculating about the functions of brain structure is to inspect the anatomical organization carefully.  The dictum "structure defines function" never fails. 2
Buzsáki; Rhythms of the Brain 281 The "limbic" system derives from the ringlike arrangement of allocortical structures, including the amygdala, hippocampus, entorhinal cortex, and hypothalamus, that provide a relative distinct border separating the brain stem from the new cortex. 1
Buzsáki; Rhythms of the Brain 284 The entire hippocampus can be conceived as a single giant cortical column.  (diagram) 3
Buzsáki; Rhythms of the Brain 284 One important entry point to the hippocampus is the granule cells of the dentate gyrus. 0
Buzsáki; Rhythms of the Brain 284 The axon terminals of granule cells excite about half of the hippocampal pyramidal cells; these reside in the CA3 region. 0
Buzsáki; Rhythms of the Brain 284 The CA3 region is actually two layers with a continuous transition.  Pyramidal cells in the portal area engulfed by the granule cells send their main collaterals to the CA1 pyramidal cells.  The remaining CA3 and Ca2 neurons compose a strongly recursive network. 0
Buzsáki; Rhythms of the Brain 284 The major difference between neocortical and hippocampal organizations lies mainly in the manner in which the two systems grew during the course of the mammalian evolution. 0
Buzsáki; Rhythms of the Brain 285 The hippocampus grows as a single large multilayer space.  The evolutionary advantage of such an architectural solution is the creation of a giant random connections space, a requisite for combining arbitrary information. 1
Buzsáki; Rhythms of the Brain 285 The hippocampus is the neocortex's librarian. 0
Buzsáki; Rhythms of the Brain 289 The computational properties of recursive organization, such as the extensive CA3 recurrent system, meet the requirements of an "autoassociator." 4
Buzsáki; Rhythms of the Brain 289 An autoassociator is a self-correcting network that can recreate a previously stored pattern that most closely resembles the current input pattern, even if it is only a fragment of the stored version. 0
Buzsáki; Rhythms of the Brain 289 Give the autoassociative network part of the content, and it returns the whole. 0
Buzsáki; Rhythms of the Brain 289 The performance of an associative network is characterized by the memory capacity and content addressability. 0
Buzsáki; Rhythms of the Brain 289 Content addressability refers to an ability to recall a whole episode from a retrieval cue, consisting of only a small part of the original information. 0
Buzsáki; Rhythms of the Brain 289 The extensive axon arbors of the CA3 pyramidal cells indicate that the probability of connecting to nearby or distant CA3 neurons is approximately the same. 0
Buzsáki; Rhythms of the Brain 290 Anatomical data and computational modeling have provided guidelines for the assessment of storage capacity and content addressability of networks. 1
Buzsáki; Rhythms of the Brain 290 The coding of a memory trace needs a sparse and distributed memory. 0
Buzsáki; Rhythms of the Brain 290 Sparse representation means that only a fraction of the trace is represented at one physical storage location. 0
Buzsáki; Rhythms of the Brain 290 The anatomy of the hippocampus meets the requirements a sparse representation.  Unlike the primary sensory cortices, cell assemblies in the hippocampus, representing the same information, consists of neurons that are distributed virtually randomly over the entire CA3 -- CA1 regions. 0
Buzsáki; Rhythms of the Brain 290 Spreading memory traces in a large coding space reduces overlaps among the stored patterns. 0
Buzsáki; Rhythms of the Brain 292 Episodic memory is claimed to be uniquely human, a mental travel back in time that endows the individual with the capacity to reference personal experiences in the context of both time and space. 2
Buzsáki; Rhythms of the Brain 292 It is these lifelong experiences, representing unique events through space-time, that give rise to the feeling of the self and are the sources of individuality. 0
Buzsáki; Rhythms of the Brain 292 Semantic knowledge is largely a context-free form of information.  It is the "meaning" of things. 0
Buzsáki; Rhythms of the Brain 292 Forward associations are stronger than backward associations. 0
Buzsáki; Rhythms of the Brain 293 Recall of a fragment of the episode recreates the temporal context of the episode, and the temporal context facilitates sequential free recall. 1
Buzsáki; Rhythms of the Brain 308 Theta rhythm, the major temporal organizer of the hippocampal -- entorhinal cortex. 15
Buzsáki; Rhythms of the Brain 308 It is the theta oscillation through which one can understand the relationship between one-dimensional and two-dimensional navigation and between episodic and semantic memory. 0
Buzsáki; Rhythms of the Brain 308 Hippocampal theta oscillations (6 -- 10 Hz in the rat and somewhat slower in higher species) is a sustained rhythm in the sense that as long as the animal is engaged in the same behavior, theta waves occur continuously. 0
Buzsáki; Rhythms of the Brain 308 Neurons in many structures can fire phase-locked to hippocampal theta oscillations, although the extent of the phase entrainment depends on the structure, cell type, and task. 0
Buzsáki; Rhythms of the Brain 309 In the strongly interconnected system of the brain with multiple loops, identifying the key ingredient responsible for the emergence of theta rhythm is not trivial. 1
Buzsáki; Rhythms of the Brain 310 Although hippocampal pyramidal cells do not typically  oscillate in isolation, they have resonant properties at theta frequency, due mainly to the time constants of currents flowing through ion channels. 1
Buzsáki; Rhythms of the Brain 310 Layer 2 entorhinal cortical neurons (the grid cells), are endowed with subthreshold oscillations at theta frequency. 0
Buzsáki; Rhythms of the Brain 310 Evolution has dedicated a consortium of mechanisms to secure a precise timing mechanism at the theta time period. 0
Buzsáki; Rhythms of the Brain 311 Timing of principle cell action potentials is secured by a coordinated action of interneuron classes. (diagram) 1
Buzsáki; Rhythms of the Brain 312 Single-cell properties perfectly match circuit features in both principle cells and interneurons. 1
Buzsáki; Rhythms of the Brain 312 Multiple theta oscillations mechanisms can contribute to the computational properties of hippocampal -- entorhinal neurons in complex ways. 0
Buzsáki; Rhythms of the Brain 312 Generation of theta oscillation currents. 0
Buzsáki; Rhythms of the Brain 312 Theta currents arise primarily from the laminarly-arranged pyramidal cells and granules cells. 0
Buzsáki; Rhythms of the Brain 312 Theta currents have been most extensively studied in the CA1 region. 0
Buzsáki; Rhythms of the Brain 312 The largest amplitude theta is observed at the distal apical dendrites of the CA1 pyramidal cells, the layer where the afferents from layer 3 entorhinal cortial cells and the thalamic reunions nucleus terminate. 0
Buzsáki; Rhythms of the Brain 313 The basket family of interneurons also appears critical  because they fire rhythmic bursts of spikes at theta frequency, thereby inducing inhibitory currents in the perisomatic region 1
Buzsáki; Rhythms of the Brain 313 Although nearly all interneuron types are entrained to the theta rhythm, their maximum activity referenced to the phase of the theta cycle differs systematically. 0
Buzsáki; Rhythms of the Brain 314 The interference of two oscillators beating at slightly different frequencies and acting on the same neurons can systematically affect spike timing. 1
Buzsáki; Rhythms of the Brain 314 Spikes of a place cell shifts systematically relative to the phase of the ongoing theta oscillation.  This phenomenon is called "phase precession." 0
Buzsáki; Rhythms of the Brain 314 There is a unique and systematic relationship between spikes and theta phase. 0
Buzsáki; Rhythms of the Brain 314 The phase of spikes and animal's position on the track are correlated. 0
Buzsáki; Rhythms of the Brain 315 The phase precession demonstration was the first convincing example of a long suspected temporal "code," and it has remained the most compelling evidence in support of the critical role of oscillations in brain function. 1
Buzsáki; Rhythms of the Brain 315 With the discovery of phase precession, timing directly entered the field of place-cell research, offering the opportunity to combine space and time in the service of episodic memory. 0
Buzsáki; Rhythms of the Brain 315 Navigation in rats and episodic memory in humans. 0
Buzsáki; Rhythms of the Brain 318 The discovery of temporal coordination of neuronal spikes by theta oscillations offered new insights into the assembly functions of hippocampal neurons. 3
Buzsáki; Rhythms of the Brain 318 Transient phase coupling of two or more oscillators with different frequencies is an effective method for producing a continuously moving phase vector. 0
Buzsáki; Rhythms of the Brain 318 The discovery of phase precession in hippocampal place cells arose from the idea of two interfering oscillators, tentatively identified with the entorhinal input (noncholinergic) and the intrahippocampal CA3 (cholinergic) theta oscillators. 0
Buzsáki; Rhythms of the Brain 320 Hippocampal neurons, like members of an orchestra, are embedded in an interactive synaptic environment, and the timing of the action potentials is biased not only by theta oscillation pacing but also by their synaptically connected spiking peers. 2
Buzsáki; Rhythms of the Brain 320 The key idea is that sequentially activated cell assemblies in the hippocampus are connected by synaptic links, and the strengths of these links are reflected by the temporal relations between them. 0
Buzsáki; Rhythms of the Brain 321 Compression of items into theta cycles is reminiscent of the mnemonic technique called "chucking." 1
Buzsáki; Rhythms of the Brain 324 Functional connections within the feedforward CA3 -- CA1 system and the CA3 excitatory recurrent system is able to maintain self-organized activity, with the emergence of theta like oscillation. 3
Buzsáki; Rhythms of the Brain 324 Excitation and inhibition build up and die in a relatively parallel matter during the theta cycle in CA3 region. 0
Buzsáki; Rhythms of the Brain 324 The buildup of excitation and inhibition in the CA3 region also gives rise to a transient gamma oscillation, associated with the increased gamma-cycle-locked oscillation of basket and chandelier cells. 0
Buzsáki; Rhythms of the Brain 326 Distance information between positions on a linear track is stored by synaptic weights among neurons in the CA3 -- CA1 collateral system. 2
Buzsáki; Rhythms of the Brain 326 During each theta cycle, the large synaptic space of the CA3 -- CA1 collateral system is searched, recalling several temporally linked cell assemblies. 0
Buzsáki; Rhythms of the Brain 327 Research work in humans suggests that the hippocampal -- entorhinal system is involved in both episodic and semantic memories. 1
Buzsáki; Rhythms of the Brain 328 Understand how a useful neuronal mechanisms that evolved in a small-brain animal (e.g. navigation in physical space) can be exploited for another purpose (e.g. memory storage and retrieval) at later stages of the brain evolution. 1
Buzsáki; Rhythms of the Brain 329 Free recall is essentially a pattern-completion problem. 1
Buzsáki; Rhythms of the Brain 329 The asymmetric nature of the recursive CA3 -- CA3 and CA3 -- CA1 connections, combined with temporal ordering of cell assemblies and spike timing dependent plasticity, favor temporally forward associations. 0
Buzsáki; Rhythms of the Brain 329 Similar to the physical distances on a linear track, positional distances among items of an episodic list can be coded by the synaptic strengths between cell assemblies, which represent the items. 0
Buzsáki; Rhythms of the Brain 329 Because distance representations are brought together into the cycle time of theta, not only temporally adjacent but also noncontiguous items can be linked together by synaptic plasticity. 0
Buzsáki; Rhythms of the Brain 329 The higher order links of noncontiguous items can be established because the probability of anatomical connections among any cell pairs is similar in the hippocampus. 0
Buzsáki; Rhythms of the Brain 329 It is the timing rule of synaptic plasticity that functionally connects assembly A more strongly to assembly B than to assembly C in a sequence. 0
Buzsáki; Rhythms of the Brain 330 Multiple overlapping observations with common junctions are the source of semantic knowledge. 1
Buzsáki; Rhythms of the Brain 330 Seeing a dog for the first time in life is an episode.  After seeing many different dogs and pictures of dogs, the universal features assume a semantic meaning -- a common name. 0
Buzsáki; Rhythms of the Brain 330 Although episodic memories are the prerequisite of semantic information, storage of consolidated semantic knowledge may no longer required the large combinatorial associational network provided by the hippocampus. 0
Buzsáki; Rhythms of the Brain 330 Once semantic information is solidified, it can be transferred in neocortical destinations. 0
Buzsáki; Rhythms of the Brain 331 The hippocampus is the ultimate search engine for the retrieval of archived information. 1
Buzsáki; Rhythms of the Brain 331 Hippocampal theta oscillations are related to episodic and semantic memory. 0
Buzsáki; Rhythms of the Brain 331 Episodic memory and semantic memory consolidation have been associated with the hippocampal -- entorhinal system, primarily on the basis of lesion cases in humans and research studies in smaller animals. 0
Buzsáki; Rhythms of the Brain 331 The hippocampus and associated structures are organized in multiple loops in a part of the allocortex, with reciprocal connections to the neocortex. 0
Buzsáki; Rhythms of the Brain 331 The most prominent collected pattern of hippocampal neurons is theta oscillation, a sustained rhythm associated with it would explorative navigation. 0
Buzsáki; Rhythms of the Brain 331 A consortium of circuit and single-cell properties supports theta oscillations, which provides timing for individual hippocampal pyramidal and granule cells and the principal cells of the limbic system. 0
Buzsáki; Rhythms of the Brain 331 The major theta current generator in the hippocampus is the entorhinal input to the distal apical dendrites of CA1 pyramidal cells. 0
Buzsáki; Rhythms of the Brain 331 The medial septum is a key rhythm generator of theta cycles, but the recurrent CA3 system can also generate theta oscillations. 0
Buzsáki; Rhythms of the Brain 331 Interactions between CA3 pyramidal cells and basket interneurons also give rise to gamma frequency oscillations, phase-locked to the slower theta rhythm. 0
Buzsáki; Rhythms of the Brain 331 Inhibition and gamma power are built up simultaneously in the CA3 and CA1 regions, the consequence of which is that pyramidal cells in these sectors, on average, discharge on the opposite phases of the theta cycle. 0
Buzsáki; Rhythms of the Brain 331 The various theta oscillation mechanisms are responsible for the temporal organization of pyramidal neurons. 0
Buzsáki; Rhythms of the Brain 332 Similar to the theta cycle representation of physical distances in one-dimensional tasks, positional "distances" among items of an episodic list can be coded by the synaptic strengths between cell assemblies, representing the items of the episode. 1
Buzsáki; Rhythms of the Brain 332 Higher order links can be established because the probability of anatomical connections among cell pairs is similar in the hippocampus. 0
Buzsáki; Rhythms of the Brain 332 An ideal structure for episode coding and recall is an autoassociator with a large random synaptic space, since free recall is essentially a pattern completion problem. 0
Buzsáki; Rhythms of the Brain 332 The extensive axon arbors of CA3 pyramidal cells and their recursive CA3 -- CA3 and CA3 -- CA1 connections are ideal for storing large numbers of episodic memories and for retrieving them efficiently. 0
Buzsáki; Rhythms of the Brain 333 Episodic and semantic memory representations may have evolved from mechanisms serving dead-reckoning and map-based navigation, respectively. 1
Buzsáki; Rhythms of the Brain 334 Coupling of Systems by Oscillations 1
Buzsáki; Rhythms of the Brain 334 A purely feedforward scheme is an exception in cortical systems; the typical connectivity is reciprocal and recurrent innervation. 0
Buzsáki; Rhythms of the Brain 334 There is no real structural top in neuronal hierarchy. 0
Buzsáki; Rhythms of the Brain 334 The top end of computation in neural networks is generally heralded by time, marked by inhibition of activity, rather than by some defined anatomical boundary. 0
Buzsáki; Rhythms of the Brain 334 Neuronal information is propelled in parallel and multiple juxtaposed and superimposed loops, making the distinction between top and bottom processing very difficult. 0
Buzsáki; Rhythms of the Brain 334 A candidate physiological mechanism of attention is gain control, which is a quantitative rather than a qualitative change, reflecting and enhance sensitivity of the processing circuits to inputs. 0
Buzsáki; Rhythms of the Brain 334 Enhanced gain in neuronal networks can be achieved mainly by subcortical neurotransmitters, such as acetylcholine and norepinephrine, which enhance cortical gamma oscillations. 0
Buzsáki; Rhythms of the Brain 335 Cortical activity is in perpetual motion, and every motor and cognitive act is a synthesis of self-generated, circuit maintained activity and environmental perturbation. 1
Buzsáki; Rhythms of the Brain 335 Invariant responses of the brain, irrespective of its state is true only for elementary reflexes involving short loops. 0
Buzsáki; Rhythms of the Brain 335 In most situations, the brain's reaction to environmental changes is not invariant but depends on the outcome of previous reactions in similar situations and on the brain's current state, determined by the multiple interactions among various oscillators. 0
Buzsáki; Rhythms of the Brain 335 If different brain areas and systems constantly generate their autonomous self-organized patterns, the fundamental basis of communication and exchange of information between them is oscillatory phase locking. 0
Buzsáki; Rhythms of the Brain 335 In reciprocally interconnected systems, temporal ordering of neuronal activity by way of phase locking can direct the flow of excitation. 0
Buzsáki; Rhythms of the Brain 335 Neurons that discharge earlier can drive the neurons of the trailing oscillator. 0
Buzsáki; Rhythms of the Brain 335 By simply reversing the phase of offset, the direction of drive can be reversed. 0
Buzsáki; Rhythms of the Brain 335 Because it is largely past experience that determines the brain's response to environmental inputs, it is expected that the dialogue between the hippocampus and the relevant parts of the neocortex is virtually continuous. 0
Buzsáki; Rhythms of the Brain 335 Hippocampal theta oscillations are among the rare sustained rhythms in the brain. 0
Buzsáki; Rhythms of the Brain 336 Various neocortical regions are capable of generating their own local theta oscillations under the right conditions, such that hippocampal and neocortical theta oscillators entrain each other. 1
Buzsáki; Rhythms of the Brain 336 Stochastic resonant properties of neocortical local circuits can extract the data-coding message. 0
Buzsáki; Rhythms of the Brain 337 The advantages of hippocampal theta engagement of neocortical circuits are that coupling can be established by very weak links, and many cortical assemblies can be entrained with short time lags after just one cycle such that their joint outputs would be synchronized with minimal delays. 1
Buzsáki; Rhythms of the Brain 337 Distant cortical networks with nonexistent or weak anatomical connections can orchestrate their activity in such a way that their temporally locked outputs can select common downstream assemblies. 0
Buzsáki; Rhythms of the Brain 337 Overall, the temporally-locked neural mechanisms, in isolation or combination, would allow top-down hippocampal neural cortical communication at a pace determined by the hippocampal theta oscillations. 0
Buzsáki; Rhythms of the Brain 337 Entorhinal cortex, the main hub between the hippocampal system and neocortex. 0
Buzsáki; Rhythms of the Brain 337 The relative phase-delayed activity of neurons in the hippocampus or entorhinal cortex determine the direction of neuronal communication between the two structures, and the direction of impulse flow changes as a result of experience. 0
Buzsáki; Rhythms of the Brain 338 Training-reversed direction of information.  Time courses of perceptual and memory retrieval signals. 1
Buzsáki; Rhythms of the Brain 338 Perceptual signal reached the temporal cortex before the perirhinal cortex, confirming its forward propagation. 0
Buzsáki; Rhythms of the Brain 338 Memory retrieval signals appeared earlier in the perirhinal cortex, and neurons in the temporal cortex where gradually recruited to represent the sought target. 0
Buzsáki; Rhythms of the Brain 338 Coupling by theta oscillations has also been reported in the amygdalalohippocampal circuit. 0
Buzsáki; Rhythms of the Brain 338 As a result of fear conditioning, theta oscillations emerge in the amygdala of mice, with waves in synchrony with hippocampal theta oscillations. 0
Buzsáki; Rhythms of the Brain 338 Temporal coordination may allow fear signals conveyed by the amygdala to to be associated with the environmental context provided by spatial inputs to the hippocampus. 0
Buzsáki; Rhythms of the Brain 338 Scalp recordings of EEG in humans has provided indirect support for the role of theta oscillations in memory functions. 0
Buzsáki; Rhythms of the Brain 338 Sensory stimuli and semantic memory performance are best correlated with a decrease of the high alpha power ("desynchronization"), whereas increased theta power above the occipital region is associated with encoding of new information. 0
Buzsáki; Rhythms of the Brain 339 In working memory studies, using either verbal or visiospatial stimuli, an increase in theta coherence was observed between the prefrontal cortex and posterior association areas. 1
Buzsáki; Rhythms of the Brain 339 In a working memory task, both encoding and retrieval items reset the MEG theta signal, the dipole source was attributed to be the anterior hippocampus. 0
Buzsáki; Rhythms of the Brain 340 Although task related modulation of power occurred simultaneously in hippocampal and neocortical sites, the induced oscillations were rarely phase coherent. 1
Buzsáki; Rhythms of the Brain 340 Coherence was also rare among cortical sites, and it decreased and the power law function of distance. 0
Buzsáki; Rhythms of the Brain 340 The simultaneous appearance of oscillations in the theta frequency without phase coherence across structures poses challenging questions regarding the functional role and origin. 0
Buzsáki; Rhythms of the Brain 340 Alpha oscillations do not necessarily reflect idling of cortical networks but rather indicate an active disengagement from environmental inputs with an emphasis on an internal mental operations. 0
Buzsáki; Rhythms of the Brain 341 Simultaneous recordings of hippocampal and neocortical cell assemblies in rats lend support to the idea that at least some forms of the dialogue between hippocampus and neocortex occur in the packages of theta oscillatory waves. 1
Buzsáki; Rhythms of the Brain 341 Phase-locked action potentials of the medial prefrontal neurons are delayed by approximately 50 ms, indicating the hippocampoprefrontal directionality. 0
Buzsáki; Rhythms of the Brain 341 Theta phase-locked discharge of neurons in anatomically direct targets of the hippocampal system is perhaps not so surprising.  But can neurons in other areas of the neocortex, several synapses away from the hippocampus, display theta phase-locking, if even transiently? 0
Buzsáki; Rhythms of the Brain 341 The majority of the phase-locked somatosensory neurons transiently coherent with theta oscillations were inhibitory neurons, some of which fire rhythmic bursts at theta frequency. 0
Buzsáki; Rhythms of the Brain 341 Induced fields at various cortical sites in episodic memory tasks are not necessarily coherent with hippocampal theta oscillations. 0
Buzsáki; Rhythms of the Brain 342 If the hippocampal output manages to temporally bias the firing patterns of distant cortical sites by polysynaptically entraining some of their interneurons, well timed messages from those saying cortical areas will be treated preferentially over others in the hippocampus. 1
Buzsáki; Rhythms of the Brain 342 A temporally specified "call-up" mechanism can be an effective solution for top-down selection of bottom-up inputs. 0
Buzsáki; Rhythms of the Brain 343 Gamma oscillations tie together the hippocampal CA3 and CA1 regions. The CA3 autoassociator generates an intrinsic theta rhythm.  Both theta and gamma oscillations are affected by the oscillatory pattern of the dentate gyrus. 1
Buzsáki; Rhythms of the Brain 343 The activity of the neocortex under various anesthetics alternates between neuronal silence with nearly all neocortical principle cells sitting at a hyperpolarized level (down state) and the up state, with many neurons spiking. 0
Buzsáki; Rhythms of the Brain 344 In the dentate region, gamma activity is the most conspicuous pattern. 1
Buzsáki; Rhythms of the Brain 345 Self-organized hippocampal activity can invade large cortical areas.  (diagram) 1
Buzsáki; Rhythms of the Brain 345 In the approximately 100 ms time window of a hippocampal sharp wave, 50,000 -- 100,000 neurons discharge together in the CA3 -- CA1 -- subicular complex -- entorhinal axis of the rat, qualifying it as the most synchronous network pattern in the brain. 0
Buzsáki; Rhythms of the Brain 363 Circuit Plan of the Cerebellum 18
Buzsáki; Rhythms of the Brain 363 All vertebrate animals have a cerebellum with highly preserved phylogenetic homology, and it continues to serve identical functions. 0
Buzsáki; Rhythms of the Brain 363 Computation in the cerebellar cortex is carried out cooperatively by four types of GABAergic inhibitory cells -- the Purkinje cells, basket cells, stellate cells, and Golgi cells -- and excitatory granule cells. 0
Buzsáki; Rhythms of the Brain 363 Purkinje cells are the principal computational neurons of the cerebellum and exhibit many differences from the pyramidal cells of the cerebrum. 0
Buzsáki; Rhythms of the Brain 364 Cerebellum is organized as multiple parallel loops without interloop communication. (diagram) 1
Buzsáki; Rhythms of the Brain 364 The extensive dendrite arborization of the Purkinje cells is the most elaborate in the brain. 0
Buzsáki; Rhythms of the Brain 364 In contrast to the cortical pyramidal cells that have cylindrical dendrite arbors and extensive mutual overlap with thousands of other nearby pyramidal cells, Purkinje cells are flat, and their dendrites hardly touch each other. 0
Buzsáki; Rhythms of the Brain 364 The cerebellar organization provides maximum autonomy for each Purkinje cell. 0
Buzsáki; Rhythms of the Brain 365 Circuit Plan of the Basal Ganglia 1
Buzsáki; Rhythms of the Brain 366 Inhibitory loops of the basal ganglia (diagram) 1
Buzsáki; Rhythms of the Brain 366 The collective term "basal ganglia" refers to the serially connected striatum, globus pallidus external segment, globus pallidus internal segment, substantia nigra. 0
Buzsáki; Rhythms of the Brain 366 What makes the basal ganglia so special is that nearly all of their neurons use GABA as neurotransmitter. 0
Buzsáki; Rhythms of the Brain 366 The ventral thalamic nuclei provide the cerebellum a link to the basal ganglia. 0
Buzsáki; Rhythms of the Brain 367 The striatum receives its major excitatory inputs from the neocortex and allocortex. 1
Buzsáki; Rhythms of the Brain 367 The similarity between cerebellar and basal ganglia architectural organizations is striking. Very large numbers a parallel inhibitory loops are funneled back into a relatively small, excitatory hub with widespread projections. 0
Buzsáki; Rhythms of the Brain 368 A fundamental difference between the in inhibition dominated cerebellum and basal ganglia circuits and the cortical networks is the inability of the cerebellum and basal ganglia circuits to support large-scale, self-organized spontaneous patterns. 1
Buzsáki; Rhythms of the Brain 368 Supersynchronous, epileptic discharges never arise from the GABAergic-neurotransmission-dominated cerebellar and basal ganglia networks. 0
Buzsáki; Rhythms of the Brain 368 The computation and locally organized networks of the cerebellum and basal ganglia represent an antithesis of cortical performance, which is characterized by perpetual spontaneous activity and temporally coordinated patterns over wide spatial domains. 0
Buzsáki; Rhythms of the Brain 368 The inferior olive provides a rhythmic input in the range of 5 -- 13 Hz to the Purkinje cells  of the cerebellum by way of the climbing fibers. 0
Buzsáki; Rhythms of the Brain 369 Individual neurons in the cerebellar nuclei fire remarkably rhythmically between 20 and 150 Hz during both waking and sleep states, but they seldom show population synchrony. 1
Buzsáki; Rhythms of the Brain 369 Coordinated network activity in the basal ganglia neurons is provided by the cortical inputs, but oscillatory patterns remain highly localized. 0
Buzsáki; Rhythms of the Brain 369 Only structures that display persistent neuronal activity and involve large neuron pools support consciousness. 0
Buzsáki; Rhythms of the Brain 369 Although oscillations can arise from many types of networks, only special architectures, such is the cerebral cortex, can support spatially widespread oscillations at multiple temporal scales and with the consequent 1/f-type, self-organized criticality features. 0
Buzsáki; Rhythms of the Brain 370 Regenerative activity requires positive, excitatory feedback, a critical ingredient conspicuously absent in cerebellar and basal ganglia circuits. 1
Buzsáki; Rhythms of the Brain 370 Regenerative feedback can incorporate the past into the system's present state, and it threads the system through both time and space, thereby allowing input-induced perturbations to be compared with the effects of previous similar encounters. 0
Buzsáki; Rhythms of the Brain 370 It is the reconstructive feedback and a sustained neuronal activity it supports that can place the inputs into context. 0
Buzsáki; Rhythms of the Brain 370 The most striking, yet perhaps the least appreciated, behavior of cortical networks is their regenerative, spontaneous activity.  Every spike, sensory evoked or spontaneous, in cortical principles cells can reach distant neurons. 0
Buzsáki; Rhythms of the Brain 370 The spontaneous, self-organizing ability of cortical networks is what gives rise to originality and freedom in the brain. 0
Buzsáki; Rhythms of the Brain