UC Irvine

The effect of unilateral visual deprivation on the vascular system of brain regions has been studied in the chick where the visual pathways are totally crossed. We injected 125I-iodantipyrine or 125I-iodinated albumin into the hearts of chicks at various times after monocular eyelid suture or unilateral eye extirpation. Radioactivity within optic lobes and cerebral hemispheres was assayed, to estimate the velocity of blood flow or the plasma volume. As early as 1 hr after monocular deprivation by eyelid suture or by enucleation, significant deficits in the velocity of the circulation through the contralateral brain regions were observed. These effects were maintained for at least 6 days and were of similar magnitude in contralateral optic lobes (which are directly innervated by the optic nerve) and the contralateral cerebral hemispheres (which receive no primary innervation from the optic nerve). After 1 hr of either form of monocular deprivation, a reduced plasma volume was found in contralateral optic lobes but not in cerebral hemispheres. These data suggest that maintenance of optimal cerebral vascular supply may be dependent on a patterned sensory input to the brain. A deficiency in the complexity of cerebral afferentation in the young animal may impair adequate vascularity and thus retard maturation. © 1971.