Effects of pentobaribtal and ketamine on brain stem auditory potentials. Latency and amplitude intensity functions after intraperitoneal administration.

Latency and amplitude intensity functions of two short latency (less than 5 ms) components (I and IV) of the brain stem auditory potentials were recorded from scalp electrodes in 18 paralyzed, hooded rats breathing with the assistance of artificial respirators. Averaged responses were obtained in three groups of rats before and 30 minutes after intraperitoneal injections of saline, ketamine hydrochloride (Ketalar), and pentobarbital sodium. Although both ketamine and pentobarbital significantly decreased heart rate and altered the gross EEG, they did not significantly change the latency or amplitude intensity functions of the two evoked-potential components.