Abstract
Visual evoked potential (VEP) was studied in five adult male guinea pigs weighing 350-750 g. VEPs were recorded with chronically implanted electrodes. Photic stimulation was presented in the following order: binocular, left eye, right eye, and screened binocular. The averages of the responses were made from 140 samples. When a single eye was exposed to photic stimulation, the ipsilateral VEP was different from the contralateral VEP; the peaks N140 and P200 disappeared, and the peak latencies of N75 and P100 were significantly (P<0.05) longer than those in the contralateral hemisphere. Peak-to-peak amplitude N40-P55 in the ipsilateral VEP was significantly (P<0.05) lower than that in the contralateral VEP. The contralateral VEP by monocular stimulation was generally indistinguishable from the response to binocular stimulation. As described above, when only a single eye was exposed to flashes, the ipsilateral dural VEP was different from the contralateral dural VEP.
