A 2-DG Analysis Of The Effects Of Monocular Deprivation On The Rat Visual System

Abstract

Six weeks of monocular lid-suture (MD) early in life (but not later) led to greater 2-deoxyglucose (2-DG) uptake in the deprived as compared to the undeprived parts of the visual system of pigmented rats when they were binocularly stimulated with either gratings or diffuse light. Electrophysiological studies would predict lesser 2-DG uptake in the deprived visual structures. The greater 2-DG uptake in deprived cortex with diffuse light stimulation suggested that the deprived cortical cells lacked spatial tuning, responded indiscriminately, and therefore were more active than their more spatially tuned normal counterparts. The appearance of the deprivation-induced elevation in the lateral geniculate nucleus (LGN) also suggested that an increase in the drive to cortical cells could have contributed to the effect in deprived area 17. It was also hypothesized that lid-suture increased retinal sensitivity and that this had led to the greater uptake in the LGN and superior colliculus. The 2-DG technique provides a new perspective on the effects of early MD. Like the electrophysiological studies the 2-DG technique indicates that early lid-suture results in a reduction in spatial information processing capacity. In addition, however, the metabolic method suggests that the deprived visual system increases its capacity to process intensity information.