A neural circuit mechanism for monitoring and controlling ingestion

摘要

Stress disrupts gamma oscillations in the rat nucleus accumbens during spontaneous social interaction Alteration in social behavior is one of the most debilitating symptoms of major depression as well as in other stress-related neuropsychiatric disorders. The reward system - which regulates social behavior, is impaired in depressive patients and particularly the activity of the nucleus accumbens is affected. Furthermore, gamma oscillations in the nucleus accumbens seem to be associ- ated with reward processing; furthermore, their role in depression remain unknown. In this scenario, we hypothesized that gamma oscillations in the rat nucleus accumbens are sensitive to the effects of social distress. Male Sprague-Dawley rats were subjected to chronic social defeat stress. A control group was left undis- turbed. Afterward, a microelectrode array was implanted in the nucleus accumbens of all animals. Local field potential activity was acquired using a wireless recording system in a social condition and non-social (open field). In the social condition, the implanted rats interacted freely and continuously with an unfamiliar conspecific in an ecological manner. We found that high-gamma band power in the nucleus accumbens of control rats was higher during the social condition compared to the non-social condition. Conversely, in socially-stressed rats, we did not find significant differences at this level between both conditions. These findings suggest that high-gamma oscillations are involved in social behavior and alter- ations at this level could be an electrophysiological signature of the effect of chronic social stress on reward processing.