A COMPARISON OF THE EFFECTS OF PHENOBARBITAL AND PENTOBARBITAL ON MOTOR CORTICAL THRESHOLD AND RIGHTING REFLEX RESPONSE IN THE CAT

¹ Department of Pharmacology, College of Medicine, University of Iowa, Iowa City, Iowa

Phenobarbital was compared to pentobarbital as to its potency in increasing the threshold for motor cortical seizures and in producing loss of righting reflex. A chronic cat preparation was used. Pentobarbital was 2.2 times as potent as phenobarbital in elevating motor cortical thresholds and 5.5 times as potent in producing loss of righting reflex. The confidence limits for the two potency ratios did not overlap. It was concluded that phenobarbital was more selective than pentobarbital in increasing motor cortical thresholds.