Escape from fear under alcohol: Fear inhibits alcohol-enhanced responding

Abstract

Ethanol’s influence on the fear-arousing properties of a Pavlovian conditioned stimulus was assessed in an escape-from-fear paradigm. During the first phase, half of the rats were given tone-shock pairings (paired groups), and half received an equal number of tones and shocks in an unpaired manner (unpaired-control groups). Fear of the tone was assessed later by permitting rats to learn a locomotor response to escape a chamber in which the tone was presented. Type of fear conditioning was combined factorially with presence or absence of alcohol both during fear conditioning and during escape testing. Although initially slower than controls, paired groups increased their running speeds over test trials and eventually surpassed the control groups. Drug state during conditioning had no effect upon test performance, but the presence of alcohol during testing increased running speeds in both the paired and unpaired groups. Moreover, fear elicited by the tone in paired groups inhibited the arousing effect of alcohol on early test trials. These data do not support the hypothesis that alcohol reduces conditioned fear.