Sex and strain differences in the visual evoked potentials of albino and hooded rats.

Visually evoked potentials were recorded n male and female rats from albino and hooded strains. Recordings were made at 4 different flash intensities in unanesthetized animals. Clear sex and strain differences were observed. Females had larger amplitude P1-N1 and N1-P2 components and shorter latency N1 peaks than males. Albino rats had larger amplitude P1-N1, N2-Pe and P3-N3 components and longer latency P2 and P3 peaks than hooded rats. Variations in flash intensity produced greater alterations in latencies and N1-P2 amplitudes in hooded rats than in albino rats, but greater alterations in N1, N2 and P3 latencies in albino rats than in hooded rats. Hooded rats are recommended as more valuable for studies of chemically induced change in the visual evoked potential.