AIM: To detect the visual electrophysiological function and observe the ultrastructure in the visual cortex of sensitive period monocular deprivation rats.

METHODS: Totally 20 SD rats of 14-day-old were randomly divided into two groups, ten for each group. Rats of experimental group were sutured unilateral eye as monocular deprivation animal models and reared in the same natural light environment with the control group for 45 days. Both two groups received electrophysiological testing, visual cortex ultrastructure was observed by the transmission electron microscope.

RESULTS: Electrophysiologic study on ocular deprived animal model, F-VEP showed typical NPN wave form in normal rats, P1 wave peak latency was short, wave crest was steep and straight. Detection in ocular deprived rats showed that P1 wave peak latency lengthened obviously, wave crest depressed significantly. Observation of ultrastructure of visual cortical neurons in monocular deprived animals by electron microscope showed that it was destroyed seriously.

CONCLUSION: Monocular deprivation can affect rats' visual electrophysiological function. It makes F-VEP P1 wave peak latency of model rats obviously lengthen, amplitude of vibration significantly degrades. Monocular deprivation can destroy rats' visual cortex neurons ultrastructure and this change is the morphological basis of monocular deprivation amblyopia.