Abstracts - Speakers

First Annual Waggoner Center Advance - March 22, 2013



Hitoshi Morikawa, MD/PhD

Associate Professor of Neurobiology

Synpatic Plasticity and Metaplasticity in VTA Dopamine Neurons: Drugs, Stress, and Junk Food

Daily life experiences affect an individual's risk of developing addiction both concurrently and in the future. Development of addiction involves a maladaptive form of learning and memory in which drug-related experiences are remembered powerfully, resulting in persistent and uncontrollable drug seeking behavior. We have previously described long-term potentiation (LTP) of NMDA receptor (NMDAR)-mediated glutamatergic transmission in midbrain dopamine neurons. This form of synaptic plasticity is induced using a synaptic stimulation-burst pairing protocol that is designed to emulate the neural activity experienced during stimulus-reward conditioning. In this talk, I will show our recent data demonstrating how various experiences, such as repeated drug exposure, social isolation, acute and repeated stress, or even prolonged consumption of high-calorie foods, enhance NMDAR LTP in the ventral tegmental area (VTA). I will further discuss how this enhanced VTA synaptic plasticity may promote the learning of the appetitive valence of drug-associated environmental stimuli. NMDAR plasticity in the VTA may represent a neural substrate by which daily life experiences influence addiction vulnerability.