Differential effects of diazepam (valium) on brain stimulation reward sites

The effect of diazepam on electrical self-stimulation of the dorsolateral hippocampus was tested in 19 male rats. Two mg/kg of diazepam significantly suppressed lever pressing rates at both high and low current intensities, whereas 1 mg/kg did so only at the low current intensity. The lowest dose (0.5 mg/kg) of diazepam had no significant effect. The second experiment tested the generality of the effect of diazepam on self-stimulation using electrodes in the lateral hypothalamus. A significant increase in lever pressing rates was observed at all dose levels.