Chronic exposure to alcohol results in neuroadaptive phenomena, including tolerance, sensitization, dependence, withdrawal, loss of control of drinking, and relapse that contribute to the development of excessive alcohol consumption. The goal of the INIA (Integrative Neuroscience Initiative on Alcoholism) Consortium is to identify the molecular, cellular, and behavioral neuroadaptations that occur in the brain reward circuits associated with the extended amygdala and its connections. It is hypothesized that genetic differences and/or neuroadaptations in this circuitry are responsible for the individual differences in vulnerability to the excessive consumption of alcohol. We propose to use quantitative proteomics to dissect the molecular mechanisms contributing to the behavioral phenotype of differential and excessive drinking (both baseline drinking and withdrawal induced drinking) in two animal models: 1) Adenylyl Cyclase 7 (AC7) transgenic animals - changes in the copy number of the AC7 gene produces changes in drinking phenotype using the Withdrawal Induced Drinking (WID) paradigm and 2) High Alcohol Preference (HAP)/Low Alcohol Preference (LAP) animals - animals selectively bred for differences in free-choice alcohol consumption by the 2 Bottle-Choice (2BC) paradigm - the selected genotype (changes in multiple genes) contributes to differential baseline drinking. Our goals are 1) to develop and optimize proteomic methodology for the quantitative analysis of enriched brain fractions, 2) to identify global differences in baseline protein expression between selected lines of the two animal models [AC7 transgenic model (AC7 transgenic versus wildtype) and HAP/LAP selective breeding model (HAP versus LAP)], and 3) to globally compare longitudinal changes in protein expression between animals (AC7 transgenic versus wildtype and HAP versus LAP) at selected time points during WID-2BC to identify proteins that contribute to the differential and excessive drinking behaviors.
