David Gabbert

Year: Junior

Major(s):  Biology

Mentor: Steidl, Stephan

Department: Psychology

Project Title: Role of the pedunculopontine tegmental nucleus in reward-seeking behaviors

Project Abstract: Release of the neurotransmitter dopamine (DA) in the brain is associated with the rewarding effects of food, sex, and psychoactive drugs. The receipt of rewards is often paired with initially non-rewarding neutral stimuli (e.g. drug paraphernalia). With experience the presentation of these stimuli comes to predict receipt of the reward, activating the dopamine system and inducing reward-seeking behaviors. How reward-predictive cues activate the dopamine system is not known. Our study will examine the role of the pedunculopontine tegmental nucleus (PPTg), which provides input to the ventral tegmental area (VTA) and activates dopamine neurons in this area, in an animal model of reward-seeking behavior We will test the contributions of the PPTg to reward-seeking behaviors by transiently chemically inactivating the PPTg immediately prior to a test of reward-seeking behavior. We expect that this manipulation will inhibit the ability of the PPTg to relay reward-predictive information to VTA dopamine neurons and ultimately will reduce reward-seeking behaviors. These experiments are expected to define the PPTg as part of the brain circuitry through which reward-predictive cues access the dopamine system and help identify this circuitry as an important target in the treatment of substance abuse, where relapse associated with exposure to drug-predictive cues following periods of abstinence is associated with craving and relapse.