Dynamic expression of conventional protein kinase C-γ with development of visual cortex and effect of monocular deprivation on it in mice

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 (F_age=57.174, P=0.000), and the expression of cPKC-γ protein was not significantly different between the left and right visual cortexses (F_lateral=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 (F_age=1.798, P=0.159) or among the MD group and normal control group (F_group=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.