UCLA

Reward-seeking behaviors can be guided by both internal and external factors. Dopaminergic signaling within the nucleus accumbens core (NAc) has been heavily implicated in reward-related learning and motivation. However, it was unclear what dopaminergic release profile occurs with learning a sequence of actions in which sustained motivation is required to complete the task and procure a reward. Investigation revealed a ramp-like profile that corresponded with learning and motivational aspects of the task. In addition to self-guided reward seeking, external cues that predict reward are also capable of motivating reward seeking. NAc dopamine signaling has been highly implicated in this as well, but additional modulators within the NAc, such as acetylcholine, are poorly understood. Therefore, I investigated the role of the NAc cholinergic system in regulating cue-motived reward seeking. Results suggest that the cholinergic system acts as a regulatory gate over cue-motivated reward seeking, with increases in activity suppressing, and decreases augmenting, this behavior. Additionally, evidence indicates that the NAc cholinergic system provides this suppressatory gate on cue-motivated behavior, at least in part, via terminal modulation of dopamine release.