| dc.description.abstract | Neuropeptides exert complex regulation of neural circuits in order to promote adaptive behavior. Here, I detail the roles of two neuropeptides, BigLEN and Neuropeptide Y, on nucleus accumbens physiology and motivated behavior. BigLEN, a hunger-driven neuropeptide, inhibits a cholinergic microcircuit to dampen nucleus accumbens output to the lateral hypothalamus. This mechanism underlies increased unrewarded persistence in food-deprived animals, while being dispensable for increased effortful food-seeking. These results show that hunger mobilizes modulatory systems that target specific aspects of behavior strategy, opening up the possibility for treatments targeted at these deficits without impacting motivation broadly. Neuropeptide Y (NPY) engages multiple receptors medium spiny neuron synapses to shape excitatory transmission. The ultimate effect of NPY on excitatory synaptic transmission in the nucleus accumbens depends on the activity of dipeptidyl peptidase IV, which degrades NPY to produce a pharmacologically distinct metabolite. Exogenous infusion of neuropeptide Y or a Y1 receptor agonist into the nucleus accumbens results in increased social interaction. These findings show that NPY regulates the nucleus accumbens at multiple nodes, and that the metabolism of NPY determines the character of this modulation. | |
