THE ATTENUATION OF SUPPRESSION OF MOTILITY BY TRIAZOLAM IN THE CONDITIONED FEAR STRESS TASK IS EXACERBATED BY ETHANOL IN MICE

We investigated whether triazolam attenuated the suppression of motili ty in the conditioned fear stress task in mice and whether ethanol mod ified the effects of triazolam. When mice were placed 24 hours later ( retention test) in the same environment in which they had previously b een exposed to an electric foot shock (training), they exhibited a mar ked suppression of motility (conditioned Fear stress). Triazolam (0.01 -0.1 mg/kg, s.c.), administered before training, attenuated the suppre ssion of motility in the conditioned fear stress task in a dose-depend ent manner. without affecting the sensitivity to an electric foot shoc k. The doses of triazolam that attenuated the suppression of motility were much lower that those of chlordiazepoxide (5-10 mg/kg, s.c.). Nei ther drug, administered before the retention test, attenuated the supp ression of motility in the conditioned fear stress task. These results suggest that both benzodiazepines may inhibit the process of acquisit ion, but not the process of recall, of memory. Ethanol (1 g/kg, p.o.), which, by itself, did not affect either the suppression of motility o r the sensitivity to an electric fool shock, exacerbated the attenuati on of the suppression of motility in the conditioned fear stress task induced by both triazolam (0.01 mg/kg) and chlordiazepoxide (5 mg/kg). These results suggest that ethanol exacerbates the effects of benzodi azepines.