Adolescent alcohol abuse is a growing national health concern. Recent data from the Department of Health and Human Services: Substance Abuse and Mental Health Services Administration (2005) showed that over 90% of alcohol consumption by youth follows a binge pattern, defined as consuming enough alcohol in a 2- hour time span to raise the blood alcohol concentrations above the legal limit of 0.08%. Moreover, they report that approximately 2, 8, 20, and 50% of teenagers aged 12, 14, 16, and 18 years, respectively, engaged in binge drinking behavior in the month prior to the survey. The adolescent period is marked by formative changes in neuronal structure and function; therefore, alcohol abuse during this vulnerable time period can result in permanent neurological damage and adult behavioral deficits. The overall goals and specific aims of these proposed studies will 1) elucidate the specific mechanistic pathways by which alcohol exposure during adolescence modifies gene expression in the brain, 2) determine how these modifications persist through adulthood, and 3) ascertain how they are transferred by epigenetic inheritance to the next generation. The experiments will utilize both animal models (rat) of adolescent binge drinking and neuronal cell culture studies to determine the effects of alcohol on the developing adolescent brain.
Aim 1 employs proteomic techniques, including 2-D fluorescence difference gel electrophoresis combined with electrospray ionization (MSn) mass spectrometry, to identify specific proteins that associate with the glucocorticoid receptor (GR) after alcohol exposure. In addition, functional assays will determine how these protein:protein interactions alter GR target genes responsible for regulating the stress response.
Aim 2 employs techniques to quantify and identify epigenetic changes in the DNA methylation patterns of stress-related genes that are induced by adolescent alcohol exposure. Finally, Aim 3 will examine the offspring of animals exposed to alcohol during adolescence to determine the extent that the epigenetic changes associated with adolescent alcohol abuse are transferred to the offspring. The general research strategy for all of the aims will employ both cutting-edge proteomic and epigenetic techniques, along with classical social behavior tasks, to gain a broad mechanistic understanding of how alcohol can produce long-term, possibly permanent changes in the adolescent and adult stress response. These proposed studies fall within the larger scope of the NIH mission to understand how alcohol abuse produces functional changes in the central nervous system to adversely affect human health. Furthermore, these studies conform to the 5-year strategic plan of the National Institutes of Alcoholism and Alcohol Abuse (NIAAA) to take a lifespan perspective on alcohol abuse and determine how alcohol abuse can produce different physiological outcomes dependent upon specific biological life stages.
Mood disorders are often the result of a dysfunctional stress/coping response. Adolescent alcohol abuse results in damage to brain regions that are associated with maintaining a healthy stress response. These studies will establish how adolescent alcohol abuse disrupts the stress response and also, determine the mechanism for how these detrimental effects can persist throughout adulthood.
