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Background Plasticity of visual system is one of the mechanisms of deprivation amblyopia.Our previous study showed that synapsin plays a role during visual developmental plasticity,and conventional protein kinase C-γ (cPKC-γ) probably is one of upstream kinases of synapsin.However,whether or how the cPKC-γ plays its effects on visual developmental plasticity is below understood.Objective This study was to investigate the dynamic expression of cPKC-γ in visual cortex of normal mice and explore the effects of abnormal visual experience on cPKC-γ expression.Methods The bilateral visual cortex tissues were obtained from 36 clean C57BL/6 mice at postnatal (P) 7,14,21,28,35,42 days respectively and 6 mice for each for the researching of cPKC-γ dynamical expression in visual cortex over aging.Other 24 C57BL/6 mice were randomized into developmental phase group and adult phase group,12 for each group.The monocular deprived (MD) models were established by suturing the upper and inferior eyelides in P14 mice for 14 days in 6 mice in the developmental phase group and 6 healthy mice served as controls,and MD models were established in the same way in 6 P60 mice in the adult phase group,and the same aged mice (6 mice) were used as controls.The mice were sacrificed and bilateral visual cortexes were obtained.The expression of cPKC-γ protein in the visual cortex was quantitatively detected using Western blot assay.The study protocol was approved by Ethic Committee of Tongren Eye Hospital.The use and care of the experimental mice followed the ARVO Statement.Results The cPKC-γ protein was faintly expressed in visual cortex in normal P7 mice,with the related expressing level of (39.74± 11.22)％ and (40.78± 10.37)％ in the left and right cortex,respectively.The expressing level of cPKC-γ protein was gradually increased over aging,with the peak value of (138.68±15.73)％ and (138.47±23.48)％ in P21 mice.A significant difference was found in the expression of cPKC-γ protein in various ages of mice (Fage =57.174,P =0.000),and the expression of cPKC-γ protein was not significantly different between the left and right visual cortexses (Flateral =0.059,P =0.809).No significant differences were found in the expression of cPKC-γ protein on bilateral visual cortexes among the mice of the developmental phase group and adult phase group (Fage =1.798,P =0.159) or among the MD group and normal control group (Fgroup =0.104,P=0.749).Conclusions The dynamic expression of cPKC-γ in the visual cortex of normal mice presents a consistant tend with the aging and development of visual critical period.MD does not affect the expression of cPKC-γ protein in bilateral visual cortexes.Further researches should be performed in the activity of cPKC-γ protein in MD mice.
RESUMO
Background It has not been reported that if the visual cortex M receptor changed during the development of myopia and how it changed if given acupuncture treatment.Objective The aim of this study was to observe the effect of electroacupuncture stimulation on the expression of acetylcholine receptors M1 (AchRM1) in visual cortex of guinea with lens-induced myopia (LIM).Methods Forty-eight three-week-old healthy guinea pigs were randomized into the normal control group,the LIM model group and the LIM electroacupuncture group.The right eyes of the guinea pigs were selected as the experimental eyes.LIM was created by monocularly wearing of-10 D lens for 4 weeks in the right eyes in the LIM model group and LIM electroacupuncture group,and then the acupuncture at the temple and hegu point was performed for 30 minutes per day for consequent 4 weeks,in the LIM electroacupuncture group.The fellow eyes of the guinea pigs were used as the self-control eyes.The refractive power and axial length were examined with retinoscopy and A-type sonography before and 4 weeks after modeling,respectively.The animals were sacrificed by excessive anesthesia at the fourth week after acupuncture and visual vertex tissue was obtained.The expression of M1 receptor mRNA in visual vertex was detected by fluorescence quantitative PCR,and the content of M1 receptor protein in visual vertex was assyed by ELISA.The study protocal was approved by Animal Ethic Committee of Shandong University of Traditional Chinese Medicine,and the use and care complied with Statement of the Association for Research in Vision and Ophthalmology.Results At the fourth week after modeling,the mean diopters were (-3.24±0.28) D and (-3.30±0.45) D in the LIM model group and the LIM eleetroacupuncture group,which were significantly higher than (0.83 ±0.86)D in the normal control group (both at P=0.000),and there was no significant difference in the diopter between the LIM model group and the LIM electroacupuncture group (t =0.200,P =0.659).The mean axial lengths were (8.67 ±0.14) mm and (8.60±0.06) mm in the LIM model group and the LIM electroacupuncture group,which were considerably increased in comparison with (8.33±0.08)mm in the normal control group (both at P＜0.05).The relative expression levels of AchRM1 mRNA in visual cortex were 0.79±0.18,1.36±0.23 and 1.13±0.13 in the normal control group,LIM model group and LIM electroacupuncture group,and the relative expression level of AchRM1 mRNA in the LIM electroacupuncture group was significantly higher than that of the normal control group and lower than that of the LIM model group (both at P＜0.05).In addition,the contents of AchRM1 receptor protein in the visual cortex were 248.00±33.31,455.17±42.40 and 396.17±47.57 in the normal control group,LIM model group and the LIM electroacupuncture group,with a similar pattern among the groups (both at P＜0.05).Conclusions A electroacupuncture stimmulation do not affect the myopic diopter and axial length in LIM model.The AchRM1 and AchRM1 receptor in the visual cortex up-regulate in LIM eyes,infering that electroacupuncture stimmulation can improve vision by decreasing the level of AchRM1 receptor in visual cortex in LIM eyes in guinea pigs.