Ekamjeet Dhillon

Year: Senior

Major(s):  Psychology, Biology

Mentor: Steidl, Stephan

Department: Psychology

Project Title: Role of ventral tegmental area cholinergic receptors in opiate-induced locomotion

Project Abstract: The objective of this study is to investigate the mechanism by which opiates activate the brain¿s reward and pleasure systems and to identify potential treatment targets in opiate addiction. Thirty-two C57BL/6 mice will be divided into four groups, and each mouse will be tested in the open-field (OF) paradigm after receiving treatment. The OF quantizes rodent exploratory activity, such as the extent of forward locomotion. The second group will receive morphine. The first group will serve as its control and receive saline. We hypothesize that infusions of morphine into the ventral tegmental area (VTA) in the midbrain will increase forward locomotion, which is a reliable behavioral indicator of increased dopamine activity. The third group will receive atropine, a muscarinic cholinergic receptor blocker, followed by morphine. The fourth group will serve as its control and receive atropine. We hypothesize that pretreatment of the VTA with atropine will reduce locomotion induced by the subsequent infusion of morphine into the VTA. If our hypotheses are true, we can conclude that muscarinic cholinergic receptors are heavily involved in mediating opiate effects on the midbrain dopamine system and are important treatment targets for opiate addiction.