Microgram doses of diazepam do not induce proconvulsant or proconflict effects in rodents.

Cooper (1983, 1985) observed an inhibition of ambulation and fluid intake in rats following diazepam in the microgram dose range. The present study aimed at investigating the effects of microgram doses of this benzodiazepine on i) the threshold doses of either pentylenetetrazole, picrotoxin or bicuculline required to induce seizures in mice and ii) the suppression of lever pressing for food induced by the delivery of one electric footshock every ten presses in rats pretreated or not with isoniazid (64 mg/kg IP). Diazepam 4-32 micrograms/kg IP) neither reduced seizure threshold doses of either convulsant studied nor did this drug (16-128 micrograms/kg IP) reliably decrease the number of lever presses under the punishment schedule. The present study provides no further evidence for a dose-related biphasic effect of diazepam which could give new insight into the functioning of benzodiazepine-coupled brain processes.