Depression and recovery of metabolic activity in rat visual system after eye removal

To examine the anterograde metabolic effects of visual system damage, unilateral eye enucleation was carried out in 19 black-hooded rats, and the animals were injected with 2-deoxy[14C]glucose at postoperative survival times ranging from 1 h to 91 days. Metabolic depression followed by recovery to near-normal resting levels of activity was seen contralateral to the enucleation in the superior colliculus and the dorsal and ventral lateral geniculate nucleus (primary effects), and in the lateral posterior nucleus, in layer IV, and the infragranular layers of visual cortex (secondary effects). Diaschisis, defined as a temporary depression in neural activity after denervation, appears to be a characteristic response of the damaged visual system.