Optokinetic visual detection in the rat visual centres a [14C]-2-deoxy-D-glucose study

Abstract

Following forty-five min of binocular optokinetic stimulation (OKS) the autoradiographic maps of [14C]-2-deoxy-D-glucose (2DG) assumption of Long-Evans brain reveal clearly different patterns of optical density within visual centres. The most superficial layers of superior colliculus (SC) and a pretectal area including the nucleus of the optic tract (NOT) appear symmetrically, strongly darker than other visual structures such as lateral geniculate nucleus (LGN) and visual cortex (VC). Whereas the lack of metabolic increase at LGN and VC levels entirely confirms the non-involvement of the geniculo-cortical path in mediating the optomotor response following OKS in Rodents, it is postulated that the symmetrical increase of 2DG uptake even upon unidirectional OKS found even at pretectal level may represent a commissural transfer of visual information between homologous pretectal areas like the nuclei of the optic tract.