ABSTRACTCommon carotid occlusion in the rat significantly decreases the density of,-adrenergic receptors in preparations of microvessels obtained from ipsilateral and contralateral cerebral cortices. The disruption of nerve pathways connecting the hemispheres (callosal transection) partially reverses the effect of common carotid occlusion on /3-adrenergic receptor density in capillaries of the contralateral cortex. In addition, the destruction of the central noradrenergic system by intraventricular injection of 6-hydroxydopamine abolishes the effect of ischemia on capillary,3-adrenergic receptor function in both hemispheres. The results suggest that /3-adrenergic receptors located on microvessels are partially regulated by neuronal pathways and that focal ischemia induces neurochemical and functional changes in remote areas of the brain.