Relation of albinism and drugs to the visual evoked potential of the mouse.

The individual and combined influences of pentobarbital and chlorprothixene on the early components of the cortical visual evoked potential (VEP) were examined in the C57BL/6 mouse. Pentobarbital produced a large increase in latency, and chlorprothixene resulted in a smaller latency increase. When these agents were combined, their effects on the VEP latency were antagonistic. The effects of pentobarbital on VEP amplitude varied as a function of flash intensity, and this barbiturate anesthetic also produced qualitative VEP waveform changes. When the congenic albino (c/c) C57BL/6 was compared with the black (+/+) C57BL/6 mouse; pentobarbital anesthesia produced a decrease of latency with increasing stimulus intensity only in the c/c genotype, whereas VEP amplitudes were similarly affected by pentobarbital in both genotypes.