The Effects Of Early Binocular Form Deprivation On The Electrophysiological Properties Of Visual Pathway In Rats

Objective This study aimed to investigate the impact of binocular form deprivation on the electrophysiological characteristics of the visual pathway of postnatal rats.Methods 50 Wistar rats of 8 postnatal days were randomly divided into binocular form deprivation group(B group) and normal control group(N group). In these two groups, all of rats were housed in the same condition with reversed 12h/12 h light/dark cycles. The latency and amplitude of P100-wave in these two groups were recorded by pattern visual evoked potential technique in postnatal 38-44 days when visual development was at the end of the critical period. Meanwhile, intrinsic membrane properties of single visual cortical neuron of rats in these two groups were also recorded through whole cell patch clamp technique for comparative analysis.Results The latency of the P100-wave in B group(95.67±14.67)ms was is longer than that in N group(83.66±10.82)ms significantly(P=0.002,t=-3.338),while the peak amplitude of P100 wave in B group(3.02±1.02)?V was much lower than that in N group(7.42±1.65)?V significantly( P=0.000,t=11.275).There was no statistical significance between the B group and N group in aspect of membrane capacitance((45.18±19.09)p F in N versus(50.01±15.86)p F in B)? membrane resistance((55.84±12.03)M? in N versus(58.85±14.15)M? in B)?time constant((37.52±10.84)ms in N versus(43.60±12.09)ms in B) of visual cortical neurons(P>0.05,t=-1.534),(P>0.05,t=0.688),(P>0.05,t=-1.103).Conclusion The postnatal deficiency of binocular form leads to delayed signal induction of visual pathway, but it has no effect on the intrinsic electrophysiological properties of visual cortical neurons.