Learning and Addiction

Phasic dopamine in reward-based learning and addiction
2007 Seed Grant
Xiaoxi Zhuang, Ph.D.
The University of Chicago

Dopamine is the common chemical mediator in the brain that mediates all addictive drugs’ rewarding properties. However, the exact role of dopamine in the two key components of reward, incentive motivation and reinforcement learning, has not been determined. This problem has significant implications in prevention and treatment of drug abuse. If dopamine mediates learning, prevention and treatment should involve extinction of learning. If dopamine mediates motivation, prevention and treatment should involve manipulation of the homeostatic motivational system. The proposed project uses a genetic approach in transgenic mice to test the hypothesis that two different activities of dopamine, the baseline tonic activity and the induced phasic activity, mediate motivation and learning respectively.

The total economic cost of drug abuse is more than half a trillion dollars annually. The most cost effective way to reduce that is prevention of drug abuse, treatment of drug abuse and prevention of relapse rather than law enforcement. That requires the understanding of the neurobiological and behavioral basis of drug abuse. One main roadblock in that aspect has been the controversy over the exact role of dopamine in addiction. The proposed project will for the first time test a key hypothesis central to such a controversy and aims to solve such a controversy. These studies will provide essential information needed to guide preventive and treatment approaches. Moreover, our studies will identify a molecular pathway and molecular targets that can be used for the development of pharmacotherapies.

Other Grants

Rebekah C. Evans, Ph.D., Georgetown University
In Vivo and Ex Vivo Dissection of Midbrain Neuron Activity During Exercise
Exercise is important for the health of the body and the mind. Exercise promotes learning and reduces symptoms of brain-related diseases such as Parkinson’s disease and Alzheimer’s disease. However, it…
William J. Giardino, Ph.D. Stanford University
Deciphering the Neuropeptide Circuitry of Emotional Arousal in Narcolepsy
This research project aims to investigate the neural mechanisms of a specific type of brain cell called neuropeptide neurons within a region of the brain’s amygdala network called the bed…
Howard Gritton, Ph.D., University of Illinois
Attention Mechanisms Contributing to Auditory Spatial Processing.
Our world is composed of a rich mixture of sounds. We often process sounds including speech in the presence of many other competing auditory stimuli (e.g., voices in a crowded…
Nora Kory, Ph.D., Harvard University
Elucidating the Fates and Functions of Lactate in the Brain
The human brain requires significant energy to function. Despite accounting for only 2% of our body weight, the brain consumes a substantial 20% of the body’s energy, relying on a…