SHENBingyan,WANG Min,FANG Yenan, et al. Dynamic changes in the number of retinal ganglion cells and axons after optic nerve crush in mice[J]. JOURNAL OF WEZHOU MEDICAL UNIVERSITY, 2023, 53(7): 532-539.
Abstract：Objective: To investigate the dynamic changes in the number of retinal ganglion cells (RGCs) and axons at different time points after optic nerve crush in mice, and to further assess the degree of optic nerve injury. Methods: Twenty 1-month-old C57BL/6J mice were randomly divided into four groups: normal control group and experimental groups at 3, 7, and 14 days after optic nerve injury. Fundus photography and optical coherence tomography were performed with the small-animal microscopic imaging system, and the thickness of the total retina and ganglion cell complex (GCC) were measured. Immunofluorescence staining and electron microscopy were used to assess the dynamic changes of the number of RGCs and axons. Results: Three days after optic nerve injury, the thickness of the GCC layer and the number of RGCs in different retinal regions were not significantly different from those in the normal control group (P>0.05), but the axonal survival rate was reduced (P<0.05). The thickness of the GCC layer, the number of RGCs in the peripapillary region and the lateral region of the retina, and the axonal survival rate on day 7 post-injury were reduced, compared with normal control group (P<0.05). The thickness of the GCC layer, the number of RGCs in the per retinal region, and the axonal survival rate on day 14 post-injury decreased significantly compared with other groups (P<0.05). Besides, the thickness of the GCC layer, the number of RGCs, and the axonal survival rate were all positively correlated (P<0.001). Conclusion: During the early stage of optic nerve injury (3 days post-injury), the survival rate of RGCs and axons is high. However, the survival rate of RGCs and axons gradually decreases during the middle and late stages of optic nerve injury (7 to 14 days post-injury). Therefore, prompt intervention during the early stage of optic nerve injury may be helpful to prevent further deterioration of visual function.
