Metencephalic localization of ponto-geniculo-occipital waves in the albino rat

The dorsal pontine tegmentum was the center of an investigation of the metencephalic loci in which ponto-geniculo-occipital (PGO) waves were recorded in the albino rat. The characterization of electrophysiologic activity recorded from 45 electrodes was anatomically mapped on schematic coronal sections of the rat brain. The region of the nucleus locus ceruleus and nucleus tractus mesencephali consistently yielded PGO activity and the region immediately surrounding did not. Other sites where PGO activity was recorded include the lateral and dorsal aspects of the fasciculus longitudinalis medialis, the nucleus tegmenti ventralis von Gudden, and the anterior lobe of the cerebellum. These data demonstrate a widespread yet sometimes discrete set of loci for PGO activity and indicate that the mechanisms responsible for its appearance have widespread yet discrete influence.