| [Abstract] Objective To inestigate and discuss the mechanism of PVEP for Neurotrophins(BDNF and CNTF) to Assist the optic nerve(ON) in repairment and regeneration after its’Hemi-Injury. To search new way for functional and effective optic nerve regeneration. Methods The cats act as the experimental object Before operation, the animals were randomly divided into 4 groups,10 cats are used as normal contrast group(N);10 cats for ON1/2 semidiameter Incision Group(ON1/2I);10 cats act as ON1/2 Incision and Injection Physiological Saline water into intraocular vitreous Group(ON1/2I+PS)；10 cats are as ON1/2 Incision, at the same intraocular vitreous Injecting Ciliary Neurotrophic Factor(CNTF) and Brain-Derived Neurotrophic Factor Group(BDNF), (ON1/2I+BF)。After the experimental cats were operated to make the models of ON semidiameter Incision (ON1/2I) and those animals were fed for four weeks, sixteen weeks and thirty-two weeks respectively under the same condition of visual environment, N, ON1/2I, ON1/2I+PSW and ON1/2I+BF were examined with Pattern Visual Evoked Patential (PVEP) for three times(in the 1st , 4th , 8th month). Then, the results of PVEP from the eyes in the normals and animal models were analysed and investigated with two pair T-test. Results The first month after the optic nerve was injuried at1/2 semidiameter, compared with N, PVEP of N1-P1 amplitude lowered and P1 latency delayed for all of ON1/2 injuried groups. Also, compared as ON1/2I+BF, PVEP of N1-P1 amplitude lowered and P1 latency delayed of ON1/2I and ON1/2I+PS. The fourth month after the optic nerve was injuried at 1/2 diameter, ON1/2I and ON1/2I+PS are compared with N in N1-P1 amplitude and P1 latency of PVEP, there are not significantly recovered. Also, their N1-P1 amplitude and P1 latency of PVEP had lowered and delayed Compared with ON1/2I+BF. In addition, while ON1/2I+BF was compared with N, there are also significant difference in the N1-P1 amplitude and P1 latency of PVEP. But it is curve lines of the N1-P1 amplitude and P1 latency of PVEP on ON1/2I+BF that showed to have recovered comparing with while it was at the first month. The eighth month after the optic nerve was injuried at 1/2 of diameter, compared as N, PVEP of N1-P1 amplitude has yet lowered and P1 latency delayed in ON1/2 and ON1/2I+PS. The curve of the N1-P1 amplitude and P1 latency of PVEP on ON1/2 and ON1/2I+PS was not found to have recovered significantly by analysed the results of PVEP examination when they were compared with while they were at the first month. Also, there are not significnat difference Bewteen ON1/2I+BF and N when ON1/2I+BF was compared with N for PVEP of P1 latency. But N1-P1 amplitude has yet droped to be compared with that of N, there is significant difference(P<0.05). and However, there is also significant difference (P<0.01) when ON1/2I+BF was compared with ON1/2 and ON1/2I+PS. There is significant difference (P<0.01) bewteen ON1/2I+BF in the eighth month and in the fourth month for PVEP of N1-P1 amplitude and P1 latency. Its` curve lines of the N1-P1 amplitude and P1 latency of PVEP in the eighth month showed to have recovered. Conclusion There is dynamic changes on visual electrophysiology before and after optic nerve injury and periods of regeneration, which shows that P1 latency of PVEP has delayed heavily and N1-P1 amplitud has cut largely down after early period of the optic nerve was injuried at 1/2 of diameter. However, the first, the fourth and eighth month after we apply neurotrophic factors to resist side-effect on optic nerve injury, it shows that P1 latency of PVEP shorten and N1-P1 amplitud rise up gradualy. The results of changes for PVEP proved that injuried ON recoveries function of conduction for visual information and has an effective regeneration. it is effect for compound liquefacient of BDNF and CNTF injection into vitreous body on time to assist optic nerve in regenerating after optic nerve was cut down at 1/2.injury. It is possible for ON to be assisted in regeneration after the optic nerve was injuried at 1/2 in diameter by .offering a constantly artificial environment or external neurotrophic condition. Compound of BDNF and CNTF has an effective to promote regeneration of injuried optic nerve and regulate micro-environment on injuried point of optic nerve as well as supplementary affect.
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