IMB Seminar: Mitchell Roitman

Mitchell Roitman
Department of Psychology
University of Illinois

Mesolimbic encoding of affective stimuli: Tuning by physiological state and its proxies

The mesolimbic dopamine system has long been synonymous with the brain’s ‘reward system.’ Yet debate continues over the nature of dopamine signaling with some current literature suggesting that it also signals aversive outcomes. Work from my laboratory takes advantage of real-time recording techniques in behaving subjects and reveals dichotomous dopamine responses to rewarding and aversive stimuli. The physiological state of an organism can change the affective value of stimuli. We have shown that physiological state also tunes the dopamine response to a given stimulus. We are beginning to understand how dopamine neurons integrate peripheral and central peptide signals that relate physiological state throughout the central nervous system to drive dopamine signaling to stimuli selectively and when the stimulus matches physiological need. Finally, non-nutritive stimuli (e.g. cocaine) potently drive mesolimbic activity. Peptide receptors also regulate drug-induced dopamine signaling. Thus, the signals that relate physiological state to the central nervous system may serve as viable targets to regulate the dopamine signaling that contributes to maladaptive approach behavior underlying affective disorders such as obesity and drug addiction.


The talk will begin at 12pm. A pizza lunch will be served at 11:45am.