Expression Of BDNF And SYN In Visual Cortex Of Form Deprivation Amblyopic Rats

ObjectiveThis experiment through detecting of F-VEP of form deprivation rat, proves short-term form deprivation can be form amblyopic. By immunohistochemistry test the dynamic expression of BDNF and SYN on visual cortex, study the correlation SYN and BDNF with age and the influence of form deprivation. Discussed the correlation of SYN and BDNF with visual development and visual experience from molecular level, in order to provided theoretical basis for the pathogenesis of amblyopic.Methods1. The newborn 21 SPF SD rats, male and female unlimited, only Nanhua University animal experiment center is offered, random distribute seven groups of three, normal (N) components NP21 NP14, NP45, NP120 group, monocular form deprived (MD) components MD45 MD21, MD120 group,. MD rats are sutured eyelid right after birth 14d to form amblyopic model. Will NP21 and MD21 rats in 21d after birth to be tested flash visual evoked potential (F - VEP) detection, record wave time of N1, P1, N2 and amplitude of N1P1 and P1N2. Using SPSS17.0 statistical analysis software, application of multivariable analysis of variance (Multivariate MANOVA), compare mean vector of more group.2. The rats when feeding to needed days are imposed abdomen hocus, perfusion, beheaded, take the brain, fixed. Conventional paraffin embedding, 4μm coronary continuous on biopsy, Nissl's staining and immunohistochemistry . Observe the expression of BDNF and SYN in the visual cortex by microscope, Olympus microscopic imaging system gathering pictures, image analysis software measure accumulative optical density (IOD). Each measurement data is( (x|—)±s)to mean said .SPSS17.0 statistical analysis software, the compares of development of different time between groups by the single factor analysis of variance, the same time difference between the group by independent sample t-test, the correlation of two kinds of protein expression by Pearson correlation analysis .The results1. F - VEP detection: compared with normal and not deprived eyes, the F-VEP of deprived eyes, P1, N1, N2 wave time lengthen, N1P1, P1N2 volatility reduce (P < 0.01). And before both the F-VEP, compare no significant difference (P > 0.05).2. (1) Nissl's staining: visual cortex neurons cytoplasm shaded to see clear cytoplasm protuberant, nuclear not shaded, widely distributed in cortex, distribution present ribbon. Compared with normal, visual cortex of corresponding deprive group, the number of neurons slightly reduce, size is uneven and nuclear shading slightly deepened.(2) The expression of BDNF in visual cortex: BDNF positive reaction products show brown granular distributed in neurons cytoplasm and protuberant, widely distributed on the cortex each layer. IOD of BDNF expression value is 5.66±0.99 on NP14, 12.50±1.38 on NP21, 12.10±1.56 on NP45, 4.62 + 0.90 on NP120. Overall differences between-group is significant (P = 0.000), P21=P45 > P14=P120. compared with NP group, BDNF expression in visual cortex of MD rats is reduce , difference was statistically significant, IOD value is: 4.78 + 0.70 (P = 0.000) in MD21, MD45 is 4.86 + 0.65 (P = 0.000), MD120 is 4.06 + 0.43 (P = 0.025). The expression of BDNF is effected by abnormal visual experience.(3) The expression of SYN in the visual cortex. SYN positive reaction products is tan-yellow granular, located in presynaptic, widely distributed in visual cortex,but perikaryon, blood vessels, and callosum there were no expression. The IOD value is 13.62±1.31on NP14, NP21 for 26.15±1.30, P45 for 29.30±1.07, NP120 for 11.95±0.92. Variance analysis significant between-group differences (P = 0.000), P45>P21>P14>P120(P=0.000). The expression of SYN in normal visual cortex is effected by development time. IOD value is 15.68±1.02 on MD21, MD45 is 15.38±0.83, and MD120 is 10.62 + 0.71. SYN expression on MD were lower than that of the NP group (P = 0.000), the expression of SYN is effected by visual experience.(4) BDNF association with the expression of SYN: separately do correlation analysis to the expression of SYN and BDNF on visual cortex of NP or MD group rats. NP group were significantly positive correlation (r = 0.927, P = 0.000), MD group were significantly positive correlation (r = 0.574, P = 0.000).Conclusion1. In rat visual development of early critical periods, short-term form deprivation (7d) can form amblyopic models.2. BDNF and SYN are expressed in visual cortex of all ages normal rats, but expression is age-related, as with visual development, confirmed they partake the process of development and mature of visual central after birth. Further research in amblyopic, in the key visual development during its expression were significantly lower than the normal development group, explain the expression of SYN and BDNF are adjusted by visual experience. They participate in the formation of amblyopic cases.