Pattern-reversal visual evoked potentials in rabbits are resistant to occlusion of the carotid artery

Contrast (pattern-reversal) visual evoked potentials (VEPs) were examined in the awake rabbit to test the possibility that carotid occlusion would disrupt sensory transmission in the visual pathways. Rabbits were operated to ligate one carotid and to chronically transplant another one into a skin flap. VEPs to checkerboard stimuli reversing with a rate of 2/s were recorded from the visual cortex. No significant changes in latency, amplitude and waveshape of VEPs were noted after 3-30 min of carotid occlusion. Apparently, blood flow from the basilar system can be easily shunted via the circle of Willis to the territory of the internal carotid.