[Comparative study of the action of tranquilizers on reinforcement systems].

In experiments on rats the benzodiazepine tranquilizers diazepam (0.5 -- 1 mg/kg), nitrazepam (0.5 -- 5 mg/kg), phenazepam (0.5 -- 5 mg/kg) and grandaxin (5 mg/kg) facilitated the reaction of self-stimulation (RS), with electrodes implanted in the area of the lateral hypothalamus and medial fascicle of the forebrain. Increased doses of the tranquilizers (up to 10 mg/kg) depressed RS, diminished the searching activity and muscle tone. The tranquilizer elroquil belonging to the phenothiazine series depressed RS in doses 15--35 mg/kg. Diazepam (0.2 and 1 mg/kg), nitrazepam (0.2 and 0.5 mg/kg) and phenazepam (0.2 and 1 mg/kg) reduced the latent period of the reaction of active avoidance (RA) during aversive electric stimulation of the medial lemnisk. In doses of 10 mg/kg the drugs inhibited RA. Elroquil and grandaxin raised the latent period of RA within the dosage range studied. The drug effects and efficacious dose ranges varied among the tranquilizers.