Demonstration of ponto-geniculo-occipital waves in the albino rat

Abstract

Monophasic waves that resemble the ponto-geniculo-occipital (PGO) waves recorded in cats were electrophysiologically recorded in the albino rat. These waves were most prominent within rapid eye movement (REM) sleep episodes and in the segments of slow-wave sleep just preceding both REM sleep periods and spontaneous awakenings. Administration of para-chlorophenylalanine (300 mg/kg) caused a change in distribution of the waves—an increase in the proportion occurring in waking and a decrease in REM sleep. REM sleep deprivation carried out by hand awakenings caused an increase in the proportion of waves occurring prior to REM sleep onset as well as a decrease in the proportion of waves in REM sleep. The waves recorded in the albino rat were so similar in their appearance to the PGO waves recorded in the cat as well as in their temporal distribution, and susceptibility to manipulation, that this activity appeared to constitute the rat homolog of PGO waves.