Gating of Social Reward

by Oxytocin in the Ventral Tegmental Area

 

Science  29 Sep 2017: Vol. 357, Issue 6358, pp. 1406-1411

Gating of social reward by oxytocin in the ventral tegmental area

Lin W. Hung, et.al.

Nancy Pritzker Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA.

The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.

Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA.

Department of Biology, Stanford University, Stanford, CA, USA.

Departments of Bioengineering and Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA.

Department of Neuroscience, Johns Hopkins University, Baltimore, MD, USA.

[paraphrase]

Positive prosocial experiences are critical for cooperative and productive interactions between members of a group. Conversely, the inability to experience reinforcement from social interactions (henceforth, “social reward”) is a symptom of neuropsychiatric disorders, notably autism. Over the past decade, evidence has accumulated that the neuropeptide oxytocin (OXT) plays a critical role in social behaviors and may have therapeutic utility for the treatment of social behavior deficits. An important clue that OXT exerts some of its actions by influencing the brain’s reward circuitry came from work demonstrating that OXT receptors (OXTrs) in the nucleus accumbens (NAc) of prairie voles were critical for pair bonding. Subsequent work suggested that OXT action in the NAc is also important for social reward in mice.    OXT action in the ventral tegmental area (VTA), another key node of reward circuitry, may also be critical for regulating social interaction cues and social reward. Although social interactions in mice are accompanied by increases in activity in NAc-projecting VTA dopamine (DA) neurons, which are critical for motivated behaviors, the mechanism by which VTA DA neuron activity is gated during social behaviors is unknown.

The reward generated by social interactions is critical for promoting prosocial behaviors. Here we present evidence that oxytocin (OXT) release in the ventral tegmental area (VTA), a key node of the brain’s reward circuitry, is necessary to elicit social reward.

Link to — Diagram of Gating of Social Reward by Oxytocin in the Ventral Tegmental Area

Link to — Rewarding Nature of Social Contact

During social interactions, activity in paraventricular nucleus (PVN) OXT neurons increased. Direct activation of these neurons in the PVN or their terminals in the VTA enhanced prosocial behaviors. Conversely, inhibition of PVN OXT axon terminals in the VTA decreased social interactions. OXT increased excitatory drive onto reward-specific VTA dopamine (DA) neurons. These results demonstrate that OXT promotes prosocial behavior through direct effects on VTA DA neurons, thus providing mechanistic insight into how social interactions can generate rewarding experiences.

[end of paraphrase]

 

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