Scientific Understanding of Consciousness
Consciousness as an Emergent Property of Thalamocortical Activity

Synchronization of Neuronal Activity by Interneurons

 

Nature 378, 75 - 78 (02 November 1995);

Synchronization of neuronal activity in hippocampus by individual GABAergic interneurons

S. R. Cobb, E. H. Buhl, K. Halasy^*, O. Paulsen & P. Somogyi

^* MRC Anatomical Neuropharmacology Unit, University Department of Pharmacology, Mansfield Road, Oxford 0X1 3TH, UK
^†Department of Zoology & Cell Biology, Jozsef Attila University, Szeged H-6722, Hungary

(paraphrase)

SYNCHRONIZATION of neuronal activity is fundamental in the operation of cortical networks. With respect to an ongoing synchronized oscillation, the precise timing of action potentials is an attractive candidate mechanism for information coding. Networks of inhibitory interneurons have been proposed to have a role in entraining cortical, synchronized 40-Hz activity. Here we demonstrate that individual GABAergic interneurons can effectively phase spontaneous firing and subthreshold oscillations in hippocampal pyramidal cells at theta frequencies (4–7 Hz). The efficiency of this entrainment is due to interaction of GABA_A-receptor-mediated hyperpolarizing synaptic events with intrinsic oscillatory mechanisms tuned to this frequency range in pyramidal cells. Moreover, this GABAergic mechanism is sufficient to synchronize the firing of pyramidal cells. Thus, owing to the divergence of each GABAergic interneuron, more than a thousand pyramidal cells may share a common temporal reference established by an individual interneuron.

(end of paraphrase)

 

 

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