The effect of some neuroleptics on the interaction of cortically and nigrally evoked potentials in the rat striatum.

The interaction of cortico- and nigrofugal inputs to the striatum of the rat was investigated using the technique of evoked potentials. Repetitive, unilateral stimulation of the substantia nigra inhibited potentials which were evoked from the ipsilateral rostral cortex and recorded from the ipsilateral striatum. The inhibition was antagonized by low doses of various intraperitoneally administered neuroleptics such as: pimozide (0.1 - 0.2 mg/kg), haloperidol (0.1 - 0.5 mg/kg), chlorpromazine (0.5 - 2.0 mg/kg) and thioridazine (0.5 - 4.0 mg/kg). These findings are discussed in view of the existing controversy regarding the mode of action of dopamine in the striatum.