Comparison of alcohol-preferring (P) and nonpreferring (NP) rats on tests of anxiety and for the anxiolytic effects of ethanol.
Rats of the selectively bred alcohol-preferring P and alcohol-nonpreferring NP lines were evaluated using three different behavioral measures of anxiety. Compared with NP rats, P rats (1) showed greater footshock-induced suppression of operant responding in an approach-avoidance conflict test; (2) spent less time in the open arms of an elevated plus maze; and (3) took longer in a passive avoidance test to step down from a platform to a grid floor where footshock was received 24 hours earlier. These findings indicate a greater degree of anxiety in the P than in the NP line of rats in these situations. Pretreatment with intraperitoneal (IP) ethanol (0.5-1.0 g/kg) injections produced anticonflict or anxiolytic effects in P but not in NP rats. However, the anticonflict effects of ethanol were small relative to those produced by chlordiazepoxide (CDP, 7.5 mg/kg) in both lines. The results demonstrate that selective breeding for divergent oral ethanol preference has produced associated differences between the P and NP lines of rats in behavioral tests of anxiety and in the anxiolytic effects of ethanol.
Stewart
R B
RB
Department of Psychiatry, Indiana University School of Medicine, Indianapolis 46205.
Gatto
G J
GJ
Lumeng
L
L
Li
T K
TK
Murphy
J M
JM
D000428:Alcohol Drinking / Q000523:psychology*; D000704:Analysis of Variance; D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology*; D001007:Anxiety / Q000175:diagnosis* / Q000523:psychology*; D001362:Avoidance Learning / Q000187:drug effects; D002707:Chlordiazepoxide / Q000494:pharmacology; D003220:Conflict, Psychological; D000431:Ethanol / Q000494:pharmacology*; D005260:Female; D051381:Rats; D011930:Reaction Time / Q000187:drug effects; D012701:Serotonin / Q000502:physiology
D014151:Anti-Anxiety Agents; D012701:Serotonin; D000431:Ethanol; D002707:Chlordiazepoxide