Effects of trifluoperazine on the central nervous system of the cat

Abstract

The effects of accumulative doses of trifluoperazine (0[middle dot]125-8 mg/kg) on the patellar and linguomandibular reflexes and segmentally evoked monosynaptic and polysynaptic spinal cord potentials were determined in the intact cat preparation. Doses of 1-8 mg/kg of trifluoperazine were necessary to depress these reflexes significantly. Reticular evoked facilitation of the patellar reflex was not depressed significantly until the accumulative dose of trifluoperazine reached 8 mg/kg. On the other hand, reticular evoked inhibition was resistant to all administered doses of trifluoperazine (0[middle dot]125-8 mg/kg). The rigid condition of the Sherrington (gamma-motor driven) decebrate animal was depressed by 4 mg/kg and abolished by 8 mg/kg of trifluoperazine. These studies were interpreted to indicate a brainstem site and a possible spinal cord site of motor depressant action of large doses of trifluoperazine.The EEG discharge of subcortical structures in chronically implanted cats was only minimally depressed by 4-16 mg/kg of trifluoperazine. In addition, hypersynchronous discharge and behavioral responses produced by electrical stimulation of the basolateral amygdala were prolonged following doses of trifluoperazine (4-16 mg/kg).The mean arterial blood pressure was not significantly reduced unless doses of 4-8 mg/kg of trifluoperazine were administered. Trifluoperazine and chlorpromazine (CPZ) were compared in several experiments and possible mechanisms of action discussed.