The nucleus accumbens is considered to be very important in the control of reward responses, motivation, and mood, but the neuronal cell types underlying these processes are not yet known. Identification of the neuronal cell types that regulate depression-like states is important for understanding the biological basis of mood and its regulation by diseases like major depressive disorder. Taking advantage of recent findings demonstrating that the serotonin receptor chaperone, p11, is an important molecular regulator of depression-like states, the authors of this study identified cholinergic interneurons as a primary site of action for p11 in the nucleus accumbens. The authors present evidence to suggest that cholinergic neuronal activity in the nucleus accumbens regulates depression-like behaviors and is important in regulation of mood and motivation.

Warner-Schmidt JL, Schmidt EF, Marshall JJ, Rubin AJ, Arango-Lievano M, Kaplitt MG, Ibañez-Tallon I, Heintz N and Greengard P: Cholinergic interneurons in the nucleus accumbens regulate depression-like behavior. Proc. Natl. Acad. Sci. USA [Epub ahead of print, June 25, 2012, doi: 10.1073/pnas.1209293109]

http://www.pnas.org/content/early/2012/06/22/1209293109.abstract