Reversible suppression of ponto-geniculo-occipital waves by localized cooling during paradoxical sleep in cats

Abstract

A new technique of localized moderate cooling is utilized to perform reversible lesions in cats. These results show: that reversible suppression of ponto-geniculo-occipital activity, at the level of the lateral geniculate nuclei, by bilateral cooling at the level of the ponto-mesencephalic isthmus, is effective under prescribed conditions of position and tip temperature of the thermodes; that unilateral isthmic cooling suppresses only one of the two components of ponto-geniculo-occipital waves; and that ponto-geniculo-occipital waves of paradoxical sleep and eye movement potentials are suppressed in parallel by cooling. From these data it arises that a set of fibers, whose topography is not entirely identical with the intermediate bundle stemming from the nucleus subcoeruleus, might be involved in the conduction of information for ponto-geniculo-occipital waves and eye movement potentials. The nature of this set of fibers is discussed. Furthermore, reversible suppression of one of the components of the ponto-geniculo-occipital wave by unilateral isthmic cooling, supports the initial hypothesis concerning pontine “generators.”