Treatment with anticonvulsant drugs retards the development of brain-stimulation reward in the prefrontal cortex.

Electrical stimulation of the medial prefrontal cortex in rats daily for nine days caused a marked improvement in the rate of acquisition of a self-stimulation response. Diazepam (1 mg/kg, IP) or phenobarbital (15 mg/kg), but not phenytoin (25 mg/kg), administered during the nine day period of electrical stimulation, attenuated this facilitatory effect. However, diazepam or phenobarbital in the same dosages administered to self-stimulating rats (i.e., after acquisition) failed to alter responding. It was suggested that a kindling-like mechanism may underlie the development of self-stimulation of the prefrontal cortex.