| Objective:To study the effects of repeated periorbital alternating current stimulation(rPACS)intervention on the plasticity of visual cortex in amblyopia mice after critical period by pattern visual evoked potentials(PVEP).Methods:1.24 P26 C57 mice were randomly divided into 5 groups: normal group 1(N1group,n=5),normal group 2(N2 group,n=5),monocular deprivation(MD)group 1(MD1 group,n = 5),MD2 group(n = 5),MD+rPACS group(MD+PACS group,n=4).N1 group and N 2 group were not given any intervention measures.MD1 group,MD2 group and MD+PACS group were deprived of right eye at the age of P26 days,and then the eyelids were opened on P32 days.The MD+PACS group was treated with rPACS at the age of P36~P42 for 7 days.The N1 group,MD1 group mice were recorded PVEP at the age of P36 days,N2 group,MD2 group,MD+PACS group were recorded PVEP at P43 days of age.The amplitude and peak-time of P100 waveform of binocular PVEP in all mice were measured,and the ocular dominance value(C/I ratio)was calculated.The difference of amplitude and peak-time of P100 waveform of the right eye or the deprived eye PVEP and the difference of C/I ratio in each group were compared.2.19 P26 C57 mice were randomly divided into 4 groups: normal group(N group,n=5),monocular deprivation group(MD group,n=5),MD+rPACS group(MD+rPACS group,n = 4)and MD+enriched environment group(MD+EE group,n= 5).No intervention were given to the N group(same as the first part).The MD group,MD+PACS group and MD+EE group were deprived of the right eye at the age of P26 days,and then the eyelids were opened on P32 days.The mice in N group,MD group and MD+PACS group were fed in standard environment(SE).The MD+EE group began to be fed in EE on P36 days for 7 days,PVEP were recorded at P43 days of age.The methods of intervention and PVEP for the other groups were same as the first part.The amplitude and peak-time of P100 waveform of binocularPVEP in all mice were measured,and the ocular dominance value(C/I ratio)was calculated.The difference of amplitude and peak-time of P100 waveform of the right eye or the deprived eye PVEP and the difference of C/I ratio in each group were compared.3.24 P26 C57 mice were randomly divided into 5 groups: normal group(N group,n=5),monocular deprivation group(MD group,n=5),MD+rPACS group(MD+rPACS group,n = 4),MD+enriched environment group(MD+EE group,n = 5)and MD+enriched environment combined with rPACS group(MD+EE+PACS group,n = 5).No intervention were given to the N group(same as the first part).The MD group,MD+PACS group,MD+EE group and MD+EE+PACS group were deprived of the right eye at the age of P26 days,and then the eyelids were opened on P32 days.The mice in N group,MD group and MD+PACS group were fed in standard environment(SE).The MD+EE group and MD+EE+PACS group began to be fed in EE on P36 days for 7 days,PVEP were recorded at P43 days of age.The methods of intervention and PVEP of the other groups were same as the first part.The amplitude and peak-time of P100 waveform of binocular PVEP in all mice were measured,and the ocular dominance value(C/I ratio)was calculated.The difference of amplitude and peak-time of P100 waveform of the right eye or the deprived eye PVEP and the difference of C/I ratio in each group were compared.Results:1.There was significant difference in the amplitude of P100 waveform of the right eye or the deprived eye PVEP in the N1 group,N2 group,MD1 group and MD2group(F=13.647,P=0.000),but there was no significant difference in the amplitude of P100 waveform of the left eye or the non-deprived eye PVEP waveform(F=0.600,P=0.624).There was no significant difference in the amplitude of P100 waveform of the right eye or the deprived eye PVEP between the N1 group and the N2 group(t=0.137,P=0.892).There was no significant difference in the amplitude of the right eye or the deprived eye PVEP P100 waveform between the MD1 group and the MD2group(t=0.398,P=0.695).The amplitude of the right eye or the deprived eye P100 waveform in the MD1 group was lower than that in the N1 group,the difference is statistically significant(t=4.384,P=0.000),and the amplitude of P100 waveform ofthe right eye or the deprived eye in the MD2 group was lower than that in the N2 group,the difference is statistically significant(t=4.645,P=0.000).There was significant difference in peak-time of the right eye or the deprived eye PVEP waveform in the N1 group,N2 group,MD1 group and MD2 group(F=7.810,P=0.002).There was no significant difference in peak-time of PVEP waveform p100 in the left eye or the non-deprived eye(F=1.137,P=0.364).There was no significant difference in the right eye or the deprived eye P100 waveform peak-time between the N1 group and the N2 group(t=0.417,P=0.682).There was no significant difference in the peak-time of the right eye or the deprived eye PVEP P100 waveform between the MD1 group and the MD2 group(t=-0.388,P=0.703).The peak-time of P100 waveform in the MD1 group was longer than that in the N1 group,the difference is statistically significant(t=3.883,P=0.001).The peak-time of P100 waveform in the MD2 group was longer than that in the group N2,the difference is statistically significant(t=2.359,P=0.031).There was significant difference in C/I ratio in the N1 group,N2 group,MD1 group and MD2 group(F=13.540,P=0.000).There was no significant difference in C/I ratio between group the N1 and the group N2(t=-1.054,P=0.307).There was no significant difference in the C/ I between the MD1 group and the MD2 group(t=-0.388,P=0.703).The C/I in the MD1 group was lower than that in the N1 group,the difference is statistically significant(t=4.103,P=0.001),and C/I in the MD2 group was lower than that in the N2 group,the difference is statistically significant(t=4.769,P=0.000).There was significant difference between the amplitude of the right eye or the deprived eye P100 waveform of the N2 group and the MD2 group,MD+PACS group(F=6.675,P=0.013),.but there was no significant difference in the amplitude of P100 waveform of PVEP waveform in the left eye or the non-deprived eye(F=0.350,P=0.712).The amplitude of P100 waveform of the right eye or the deprived eye in the MD2 group was lower than that in the N2 group,the difference is statistically significant(t=3.653,P=0.004).The amplitude of the deprived eye PVEP in the MD+PACS group was higher than that in the MD2 group,but there was no significant difference(t=1.665,P=0.606),and there was no significant difference between the MD+PACS group and the N2 group(t=1.778,P=0.423).There was significant difference between the peak-time in the right eye orthe deprived eye of the N2 group and MD2 group,MD+PACS group(F=4.452,P=0.038),.but there was no significant difference in the peak-time in the left or the non-deprived eye(F=0.222,P=0.804).The peak-time of P100 waveform of the right eye or the deprived eye in the MD2 group was longer than that in the N2 group(t=-2.714,P=0.020).The MD+PACS group was longer than that in the MD2 group(t=2.372,P=0.037).There was significant difference among the N2 group,MD2 group,MD+PACS(F=7.869,p=0.008).The C/I ratio in the MD2 group was lower than that in the N2 group(P=0.003)and the MD+PACS group(P=0.016).There was no significant difference in the peak-time between the MD+PACS group and the N2group(t=0.187,P=0.855).There was significant difference between the C/I ratio of the N2 group and MD2 group,MD+PACS group(F=7.869,P=0.008).The C/I ratio in the MD2 group was lower than that in the N2 group,the difference is statistically significant(t=3.778,P=0.003).The C/I ratio in the MD+PACS group was higher than that in the MD2 group(t=2.845,P=0.016),and there was no significant difference between the MD+PACS group and the N2 group(t=0.717,P=0.488).2.There was no significant difference in the amplitude of P100 waveform in the right eye or the deprived eye between the N group and MD group,MD+PACS group,MD+EE group(F=2.173,P=0.134).There was no significant difference in the amplitude of P100 waveform of the left eye or the non-deprived eye in the N group and MD group,MD+PACS group,MD+EE group(F=0.587,P=0.633).The amplitude of P100 waveform of the right eye or the deprived eye in the MD+EE group had no significant difference with the N group(t=-0.316,P=0.756),MD+PACS group(t=0.836,P=0.416).The MD+EE group was higher than The MD group,but there was no significant difference(t=2.013,P=0.062).There was significant difference in the peak-time of P100 waveform of the right eye or the deprived eye in the N group and MD group,MD+PACS group,MD+EE group(F=3.963,p= 0.029).There was no significant difference in the peak-time of P100 waveform of the left eye or the non-deprived eye in the N group and MD group,MD+PACS group,MD+EE group(F=0.123,P=0.945).The peak-time of the right eye or the deprived eye P100 waveform in the MD+PACS group was shorter than the MD group(t=-2.696,P=0.017).The peak-time of P100 waveform in the MD+EE group had no significantdifference with the N group(t=1.674,P=0.115).The peak-time of P100 waveform in the MD+EE group was shorter than the MD group,but there was no significant difference(t=-1.411,P=0.179).There was significant difference in P43 day C/I ratio among the four groups(F=4.283,p=0.023).The C/I in the MD group was lower than that in the MD+PACS group(t=2.568,P=0.021).The C/I in the MD+EE group was higher than that in the MD group,but there was no significant difference(t=1.875,P=0.08).The C/I in the MD+EE group had no significant difference with the N group(t=-1.536,P=0.145),MD+PACS group(t=-0.800,P=0.436).3.There was significant difference in the amplitude of P100 waveform of the right eye or the deprived eye in the N group and MD group,MD+PACS group,MD+EE group,MD+EE+PACS group(F=2.770,P=0.057).There was no significant difference in the amplitude of P100 waveform of the left eye or the non-deprived eye in the N group and MD group,MD+PACS group,MD+EE group(F=1.287,P=0.310).The amplitude of P100 waveform of the right eye or the deprived eye in the MD+EE+PACS group was higher than that in the MD group(t=3.097,P=0.006),and the MD+EE+PACS group had no significant difference with the N group(t=0.815,P=0.425).The amplitude of P100 waveform in the MD+EE+PACS group was higher than that in the MD+PACS group(t=1.880,P=0.076),MD+EE+PACS group(t=1.125,P=0.275),but there was no significant difference.There was significant difference in the peak-time of P100 waveform of the right eye or the deprived eye in the N group and MD group,MD+PACS group,MD+EE group,MD+EE+PACS group(F=3.963,P=0.029).There was no significant difference in the peak-time of P100 waveform of the left eye or the non-deprived eye in the N group and MD group,MD+PACS group,MD+EE group(F=0.237,P=0.914).The peak-time of P100 waveform in the deprived eye in the MD+EE+PACS group was shorter than that in the MD group(t=-3.417,P=0.003).The peak-time of P100 waveform of right eye or the deprived eye in the MD+EE+PACS group had no significant difference with the N group(t=0.061,P=0.952).The peak-time of P100 waveform in the deprived eye in the MD+EE+PACS group was shorter than that in the MD+PACS group(t=0.289,P=0.775),MD+EE group(t=-1.882,P=0.075),but there was no significant difference.There was significant difference in P43 day C/I ratio among the N groupand MD group,MD+PACS group,MD+EE group,MD+EE+PACS group(F=4.151,P=0.014).The C/I ratio in the MD+EE+PACS group was higher than that in the MD group(t=3.006,P=0.007).The C/I ratio in the MD+EE+PACS group had no significant difference with the N group(t=-0.706,P=0.488).The C/I ratio in the MD+EE+PACS group was higher than that in the MD+PACS group(t=0.038,P=0.970),MD+EE group(t=0.965,P=0.346),but there was no significant difference.Conclusion:1.rPACS can improve the amplitude and peak-time of PVEP in amblyopia mice after critical period of visual development,promote the shift of ocular dominance from the non-deprived eye to the deprived eye,and reactivate the plasticity of visual cortex in amblyopia mice after critical period.2.rPACS is superior to EE in improving PVEP response and ocular dominance in amblyopia mice after critical phase of visual development.3.rPACS combined with EE intervention can further improve the PVEP response and ocular dominance of amblyopia mice after critical period of visual development,and the overall effect is close to the normal level.The reactivation effect of the combined intervention on the plasticity of visual cortex in amblyopia mice after critical period was more obvious than that of simple electrical stimulation,or EE. |
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