Ethanol effects on freezing and conspecific attack in rats previously exposed to a cat

Male rats under saline or three levels of ethanol were briefly exposed to a cat or to a control stimulus and then presented with a male conspecific in the same ssituation. Cat exposure produced prolonged freezing and a suppression of aggression for the saline group. However, while groups receiving ethanol showed a systematic and reliable reduction in freezing as a function of increasing dose levels, male attack behavior did not show a corresponding (opposite) set of changes: Although freezing was reliably reduced at 0.6 and 1.2 g/kg ethanol an increase in offensive behavior at the 0.6 dose level was not reliable, while offense reliably declined at the higher level. Correlations between freezing changes and offense were significant only for the 0.3 g/kg dose level groups, for which neither freezing nor attack was reliably different from the saline level. The partial disassociation of freezing and the suppression of male attack on a conspecific is not congruent with a view that the effects of ethanol on aggression are mediated by an ethanol-based suppression of fear. However, these results do suggest that the offense and fear-related changes may be linked at very low ethanol doses.