Postnatal development of visual evoked potentials in Japanese black calves

The visual evoked potential (VEP) was recorded in six Japanese Black calves from 1 to 10 weeks after birth. The VEP waveform recorded at the 1st week was consisted of three positive and three negative peaks. The VEP showed little postnatal changes except for the shortening of the peak latencies of P1 and N3 and the increase of the peak-to-peak amplitudes of P1-N1 and P2-N2 (significant between the 1st and 10th week of age). The visual function associated with generation of the flash VEP is suggested to have almost developed at birth in the calf. The postnatal measurement of the VEP would be useful for evaluating the neurologic disorders of the visual system in young calves.