Effect of amphetamine and pentobarbital on sleep-wake patterns of cats with basal forebrain lesions.

The effects of amphetamine and pentobarbital upon electrographic state were studied in naive cats and cats with forebrain lesions that induce insomnia. Amphetamine increased alertness and decreased both slow wave sleep (SWS) and rapid eye movement (REM) sleep states for up to 12 h in both intact animals and cats with lesions. Pentobarbital inhibited REM sleep and alert states while increasing SWS and drowsy states in naive cats. The effect was mainly restricted to the first 8 h. In cats with forebrain lesions, the effects were similar except that the amount of REM sleep was significantly elevated. During a portion of the first 8 h, the tracing cannot be distinguished from a normal control sample. It is hypothesized that pentobarbital mimics the normal inhibitory influence of the intact forebrain and either induces or facilitates 'normal' sleep patterns in cats with forebrain lesions.