| Objective:To explore the intrinsic molecular mechanism of Wnt /β-catenin signaling pathway regulating synaptic plasticity in visual cortical neurons。Method:Sixty-four 14-day-old rats were divided into two groups according to a random number table: normal group and form deprivation group,The left eye of 32 rats in form deprivation group underwent eyelid suture。32 rats in normal group were treated without any treatment。Seven days after the deprivation of form,all rats were examined by F-VEP(Flash Visual Evoked Potential),and the latency and amplitude of P wave were recorded to determine if the amblyopia model was established successfully,After the test is completed,the left eye of the rats is stitched inform deprivation group。 In the deprivation time of 7 days,21 days,45 days,90 days at four time points were randomly treated two groups of eight rats,Hematoxylin Eosin(HE)staining was used to observe the morphological changes of the visual cortex neurons in the normal group and the deprivation amblyopia group,Immunohistochemistry was used to detect the expression of β-catenin,GSK-3β,NR2 A and NR2 B immunoreactive neurons in the visual cortex of the two groups and image acquisition.Result:F-VEP : Compared with normal rats,the latent period of P wave was significantly longer in F-VEP group(P = 0.00),the difference was statistically significant,P wave amplitude was significantly lower(P <0.05),the difference was statistically significant。 HE staining:Observed under optical microscope,the number of neurons in the normal cortex of rats in the visual cortex was large,with large volume,abundant cytoplasm,prominent cytoplasm,large nucleus and rich staining;Compared with the normal group,the number of cells in the deprivation group was significantly decreased,the volume was smaller,the cytoplasm was reduced,the nucleus became smaller,and the cell nucleus fragmentation,pyknosis and dissolution were observed.Immunohistochemistry:1)β-catenin:The comparison between the normal group and the form deprivation group showed that there were significant differences among the four time points(P <0.05);In the deprivation group,the four time points were statistically significant compared with each other(P <0.05);In the normal group,except for 45 days and 90 days,there was no significant difference(P> 0.05),The remaining four time points compared with each other was statistically significant(P <0.05)。2)GSK-3β:In the normal group,the expression increased with time and a small increase,the two groups at any two time compared with each other was not statistically significant(P> 0.05);GSK-3β in the deprivation group had statistical significance at 4 time points(P <0.05);The difference between the normal group and the shape deprivation group was statistically significant at four time points(P<0.05)。3)NR2A : In normal group,there was significant difference between 7 days deprivation and 21 days deprivation,45 days deprivation and 90 days deprivation(P <0.05);The deprivation of 21 days,deprivation of 45 days,deprivation of 90 days compared with each other,the difference was not statistically significant(P> 0.05);There were significant differences among the four time points in the deprivation group(P <0.05);The differences between the two groups at four time points were statistically significant(P <0.05)。4)NR2B:The normal group and the form deprivation group rats except between the time of 7 days deprivation,no significant difference between the two groups(P> 0.05),There were significant differences in the three time points of 21 days deprivation,45 days deprivation and 90 days deprivation(P <0.05);In the deprivation group and normal group,the results of the four time points were statistically significant(P <0.05)。Correlation test:In the normal group,β-catenin and GSK-3β in the visual cortex of rats were negatively correlated,but the correlation was not significant(r =-0.662,P <0.05),and had no significant correlation with NR2 A and NR2B(r = 0.101,P = 0.13;r = 0.166,P = 0.314)。There was no significant correlation between GSK-3β and NR2A(r =-0.206,P = 0.227)。There was a negative correlation between GSK-3β and NR2 B,but the correlation was not significant(r =-0.325,P <0.05)。In the deprivation group,there was a significant negative correlation between β-catenin and GSK-3β(r =-0.962,P = 0.00);There was a significant positive correlation between β-catenin and NR2A(r = 0.950,P = 0.00);There was a significant negative correlation between β-catenin and NR2B(r =-0.919,P = 0.00);There was a significant negative correlation between GSK-3β and NR2A(r =-0.876,P = 0.00).There was a significant positive correlation between GSK-3β and NR2B(r = 0.925,P = 0.00)。 Conclusion:1、The expression of β-catenin and NR2 A in the visual cortex of monocular deprivation amblyopic rats model was lower than that of normal rats。2、GSK-3β,NR2 B in the monocular deprivation amblyopia rat model visual cortex increased compared with normal rats。3、There was no significant correlation between the visual cortex β-catenin,GSK-3β,NR2 A and NR2 B in normal rats。In monocular deprivation amblyopic rats,there was a significant negative correlation between β-catenin and GSK-3β;there was a significant positive correlation between β-catenin and NR2 A,there was a significant negative correlation between β-catenin and NR2B;there was a significant negative correlation between GSK-3β and NR2 A,there was a significant positive correlation between GSK-3β and NR2B。4、Wnt / β-catenin signaling pathway may regulate the expression of NR2 A and NR2 B through GSK-3β during the critical period of visual developmental plasticity in rats,which may be involved in the plasticity of the visual cortex neurons in the critical period of visual development and thus participate in the formation of amblyopia。... |
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