We investigated whether
triazolam attenuated the suppression of motility in the conditioned fear stress task in mice and whether
ethanol modified the effects of
triazolam. When mice were placed 24 hours later (retention test) in the same environment in which they had previously been exposed to an electric foot
shock (training), they exhibited a marked suppression of motility (conditioned fear stress).
Triazolam (0.01-0.1 mg/kg, s.c.), administered before training, attenuated the suppression of motility in the conditioned fear stress task in a dose-dependent manner, without affecting the sensitivity to an electric foot
shock. The doses of
triazolam that attenuated the suppression of motility were much lower that those of
chlordiazepoxide (5-10 mg/kg, s.c.). Neither
drug, administered before the retention test, attenuated the suppression of motility in the conditioned fear stress task. These results suggest that both
benzodiazepines may inhibit the process of acquisition, 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 or the sensitivity to an electric foot
shock, exacerbated the attenuation 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
benzodiazepines.