Cognitive Dysfunction and Corticostriatal Networks in Alcohol Dependence
Principal Investigator: Judson Chandler, Ph.D.
Co-Principal Investigator: Marcelo Lopez, Ph.D.
Co-Investigator: Ron See, Ph.D.
Alcoholism is a disorder characterized by a loss of control over drinking and relapse. While the rewarding effects of alcohol are essential for some aspects of drinking, recent findings suggest that heavy drinking is a maladaptive, persistent habit involving a transition from decision-based to habit-based actions. This suggests that there are changes in prefrontal and dorsal striatal circuits in the brain that underlie these different types of behaviors. Support for this hypothesis comes from imaging studies that reveal alterations in prefrontal and striatal brain regions in alcoholic subjects as compared to non-alcoholic controls.
Studies in this research component examine how changes in corticostriatal neural networks may underlie the transition from controlled, decision-based drinking to compulsive and habitual alcohol consumption. These studies use a well-characterized animal model of dependence that involves repeated cycles of chronic intermittent ethanol (CIE) exposure and withdrawal that results in escalation of alcohol self-administration. Advanced recording procedures are used to measure neuronal population activity within discrete corticostriatal networks during performance of cognitive behavioral tasks that engage prefrontal networks.
We hypothesize that repeated cycles of CIE exposure alters the dynamics of prefrontal cortical networks leading to impaired executive function and ultimately loss of inhibitory control by the prefrontal cortex over drinking. This hypothesis will be tested using four specific aims that will: 1) Determine whether CIE exposure-induced escalations in drinking are associated with the transition from goal-directed to habitual control; 2) Determine whether CIE exposure-induced escalation in drinking is associated with the development of deficits in working memory as an index of executive dysfunction; 3) Use advanced recording procedures to assess alterations in corticostriatal networks during repeated cycles of CIE exposure; and 4) Determine whether aripiprazole, a compound previously demonstrated to reduce drinking in both animals and humans, reverses CIE exposure-induced deficits in working memory.
The results of these studies will fundamentally advance our understanding of the role of neuroadaptive changes in corticostriatal networks in the development of alcohol addiction and dependence, and will lay the groundwork for future studies targeting executive function as a new pharmaco-therapeutic approach for more effective treatment of this devastating disorder.