ETHANOL CONSUMPTION IN ADOLESCENTS RATS RESULTING FROM SELECTIVELY BRED, HIGH AND LOW ETHANOL CONSUMERS, LINES

MACARENA FERNÁNDEZ; BAEZ,BARBARA ; ESPINOSA, L.; BORDÓN, ANA; MARTINEZ, ELIANA ; FABIO M.C.; PAUTASSI R

Mar del Plata

Congreso; XXX Congreso Anual de la Sociedad Argentina de Investigación en Neurociencias; 2015

Sociedad Argentina de Investigacion en Neurociencias

Adolescence is a developmental stage in which the onset and escalation of alcohol consumption is highly prevalent. This developmental stage also features the highest rates of alcohol abuse and dependence. The reasons underlying these phenomena remain largely unknown. One way to identify features related to problematic use of alcohol is to analyze ethanol reactivity in rats selectively bred across generations for their high consumption of alcohol (e.g., the "alcohol-preferring? or ?P? rats, of Indiana University, USA). Studies conducted in these rats have found an association between lower sensitivity to the aversive motivational (Stewart, Murphy, McBride, Lumeng, Li, 1996) and sedative effects of alcohol (Schechter, 1992), and heightened intake of this drug. The P and other selected strains are generated by crossing males and females exhibiting high preference for 10% alcohol during adulthood, for 30, 40 or 70 generations. It is still uncertain, however, how motivational and consummatory responses to ethanol diverge (or not) during the initial generations. Moreover, none of these lines have been selected for exhibiting high alcohol intake and preference during adolescence.The aim of this work was to generate lines of Wistar rats with high or low predisposition for ethanol intake, via selective breeding of high and low ethanol consumers during adolescence, which is the developmental stage in which ethanol use disorders emerge and are likely determined. These lines should be a valuable tool to analyze the relationship between motivational sensitivity toethanol and ethanol intake. In the present communication, we present data of ethanol intake and preference in the first two generations derived from our short-term selection process.The experiment began with 120 adolescent Wistar Rats (male and female, original nucleus derived from 12 litters), derived from one of the vivariums of the Instituto Ferreyra (INIMEC-CONICET-UNC). These animals were evaluated for ethanol intake and preference throughout adolescence (postnatal days 32-57, approximately), by means of an intermittent intake protocol. Specifically, animals had individual access to a bottle of 5% ethanol v/v and a bottle containing tap water. Bottles were introduced in the homecage on Mondays, Wednesdays and Fridays; and each session lasted 24 h. Absolute (g/kg) and percent ethanol preference were measured. Low or high average alcohol preference at week 4 served as criteria for selection of high and low intake animals, within each sex. Also, rats had to drink more than 4.0 g/kg of alcohol at week 4 to be included as "high consumers". In the founding generation, twelve high consumers females were crossed with 12 high consumers males, and a similar crossing was done in rats exhibiting low ethanol preference and consumption. Inbreeding was avoided. This mating resulted in 120 subjects of the first generation (F1) of the high alcohol consumption line (HAC,) and 120 of the low alcohol consumption line (LAC). Eighty of these subjects (forty of each line) were assessed for alcohol intake test during adolescence, as described, to generate F2 generations of each line.Ethanol intake (g/kg and %) was analyzed via repeated measures ANOVA (generation x line x sex x days). The results were very similar in both variables. The ANOVAs revealed significant main effects of generation (F1, 148 = 13,989, F 1,150 = 14,465, ps