poster abstractThe discounting of delayed rewards, a specific type of impulsive behavior, has been associated with
alcohol use disorders. However, the way in which this characteristic is related to the genetic and
behavioral paths which lead to high-drinking is a newly emerging area of alcohol research. Rodents
selectively bred for extreme high vs. low alcohol preference have shown parallel patterns of delay
discounting. This study investigated whether or not delayed discounting is preferentially related to
ethanol-seeking vs. consumption. Alcohol preferring rats (P; n=5), High Alcohol Drinking rats (HAD2;
n=15), and Long Evans rats (LE; n=11) were used and have previously been identified as high
seeking/high drinking, moderate seeking/high drinking, and moderate seeking/moderate drinking,
respectively. Six levels of delay (0, 2, 4, 8, 12 and 16 seconds) were assessed using a sucrose reinforcer.
The average indifference points for each delay were then fitted to hyperbolic equations to yield a single
parameter (k). An ANOVA for those values, along with post hoc testing, revealed Ps to have larger k
values than both HAD2s and LEs. However, the HAD2s and LEs were not different from each other. A
mixed ANOVA for indifference points showed a main effect of Delay (p<.01), Group (p<.01), and no
group/delay interaction (p=.08). The main effect of group revealed the same pattern of findings for the
indifference points as for the k values. Both the higher k values and the lower indifference points of the
Ps indicate their steeper discounting in comparison to both HAD2s and LE. These results suggest that this
measure of impulsivity could be associated with the quantity of ethanol-seeking, and not just with the
inclination to consume ethanol. These results extend previous findings, and as all animals were ethanol
naïve, these results support the idea that increased impulsivity is a characteristic that precedes addictive
disorders
