The vast majority of American children begin consuming alcohol prior to high school graduation and episodes of heavy ethanol consumption increase over time (Johnson et al., 1999, 2009). A family history of alcoholism increases the risk that adolescent alcohol consumption is associated with adult alcoholism (Agrawal et al., 2009). Periadolescent ethanol consumption by alcohol-preferring (P) rats increases the reinforcing properties of EtOH in the posterior ventral tegmental area (pVTA) during adulthood (Toalston et al., 2014). NADIA- generated research has indicated that adolescent intermittent ethanol (AIE) exposure results in persistent alterations in neuroimmune factors, choline acetyltransferase (ChAT), increased anxiety, and changes in histone acetylation altering neurocircuitry (Vetreno et al., 2014; Sakharkar et al., 2014). As a new component of the NADIA Consortium, the long-range objectives of this study are to determine the effects of AIE on the motivational, reinforcing and anxiolytic properties of EtOH during adulthood within the pVTA and central nucleus of the amygdala (CeA). The impact of a genetic predisposition to high alcohol consumption on the effects of AIE will be determined by making assessments in P rats. The overall hypothesis is that AIE results in lasting neurotransmitter system, epigenetic, and structural alterations in regions critical for motivation, reinforcement, and anxiety. The goals of the application are 1) to assess alterations in the reinforcing properties of EtOH in the pVTA and CeA produced by AIE, 2) to evaluate the neurochemical response to EtOH in the pVTA induced by AIE, 3) to determine if histone deacetylase (HDAC) inhibitor treatment reverses the alterations produced by AIE, 4) to determine the impact of AIE on probabilistic decision-making.
In Aim 1, we will test the hypothesis that AIE induced neuroadaptations within the pVTA alter EtOH reinforcement and the neurochemical response to EtOH during adulthood.
In Aim 2, we will test the hypothesis that AIE induced neuroadaptations within the pVTA can be reversed by site specific administration of HDAC inhibitor during adulthood.
In Aim 3, we will test the hypothesis that AIE induced neuroadaptations within the CeA alter the reinforcing and anxiolytic properties of EtOH during adulthood.
In Aim 4, we will test the hypothesis that AIE has altered the probabilistic decision-making (an animal model of impulsivity) during adulthood. This is a highly significant project that will attempt to elucidate the complex factors that underlie the effects of AIE on adult EtOH usage.
Adolescent alcohol drinking greatly increases the rate of adult alcoholism and increase rate of other drug addiction. To date, the long term consequences of adolescent alcohol drinking on the adult brain has not been elucidate. The current grant is designed to examine the consequences of adolescent alcohol consumption within the drug reward pathway.
