Flash visual evoked potentials in diurnal birds of prey
Visual evoked potentials (VEP) in response to flashes of white light were recorded from 15 adult beagles of both sexes to provide a normative data base. Separate recordings were taken by stimulating each eye of every dog. Responses were recorded from a needle electrode placed over the nuchal crest referenced to an electrode just caudal to the eyes. Five positive and negative peaks were present in each VEP; P1, N1, P2, N2, and P3. Peak P2 was the most prominent. Mean (+/- standard deviation [SD]) latencies for peaks P1, N1, P2, N2, and P3 were 14.3 +/- 2.4, 29.2 +/- 2.2, 54.5 +/- 7.4, 78.0 +/- 13.1, and 98.1 +/- 12.6 msec, respectively. Peak-to-peak mean amplitudes ranged from 5.88 to 13.30 microV. Recordings were accomplished without sedation, anesthesia, or mydriatic drugs.