Volume 19, Number 4, December 2008
Donita Robinson, Ph.D.
Bowles Center for Alcohol Studies Researcher Donita Robinson, Ph.D., recently received her first Research Project Grant (R01) from the National Institutes of Health’s National Institute on Alcohol Abuse and Alcoholism. Totaling just over a million dollars, the five-year project will examine dopamine release and neural activity in rat models of habitual alcohol drinking and cue-induced relapse.
The project, titled ‘Habits and cues in alcohol drinking: Dynamic striatal activity,’ will look at the major factors that contribute to habitual alcohol drinking, such as the learning processes underlying habit formation and the degrees to which habits versus goal-directed behaviors may influence the susceptibility to relapse.
“Alcoholism is a chronic disorder that typically spans several decades and may be perpetuated by learned, habitual behavior. Studies in rats can model the contribution of habit to alcohol drinking and allow direct measurement of brain function during these behaviors,” said Robinson.
Dopamine is a neurotransmitter, important in many functions, including learning, movement, attention and reward. Robinson is focused on the key role of dopamine in the association between cues and drug experience. Addiction links cues and drug experiences leading to cues, e.g. seeing an alcohol advertisement or establishment prompts hunger for the reward, e.g. craving for drug. Psychologists have found that addicted individuals respond to cues that they learned were rewarding when first experimenting with drugs, even after they stop being rewarding, e.g. continued drug seeking in the absence of reward (and likely presence of negative consequences). The psychological shifts from goal-directed behavior to automatic habitual behavior are thought to be based on changes in dopamine neurotransmission.
Robinson can measure neuronal activity in brain in subsecond time spans that follow synaptic transmission in moving, behaving rats. This allows the determination of brain region-specific synaptic plasticity, and neuronal activity being related to behavior at various stages of alcohol experience, experimentation, learning use, dependence, abstinence and relapse She will test the overall hypothesis that subsecond dopamine release and ongoing neuronal activity differ in the brain areas active during goal-directed alcohol reinforcement compared to the areas preferentially active during habitual alcohol reinforcement and cue-induced relapse.
Data from this study will provide important information on how the brain differentially encodes goal-directed versus habitual alcohol drinking. Robinson thinks that these studies could potentially identify novel mechanisms that would be of crucial importance to understand the development and treatment of alcohol abuse and alcoholism.