Glaucoma is a leading cause of irreve rsible blindness wo rldwide,and previous studies have shown that,in addition to affecting the eyes,it also causes abnormalities in the brain.However,it is not yet clear how the pr...Glaucoma is a leading cause of irreve rsible blindness wo rldwide,and previous studies have shown that,in addition to affecting the eyes,it also causes abnormalities in the brain.However,it is not yet clear how the primary visual cortex(V1)is altered in glaucoma.This study used DBA/2J mice as a model for spontaneous secondary glaucoma.The aim of the study was to compare the electrophysiological and histomorphological chara cteristics of neurons in the V1between 9-month-old DBA/2J mice and age-matched C57BL/6J mice.We conducted single-unit recordings in the V1 of light-anesthetized mice to measure the visually induced responses,including single-unit spiking and gamma band oscillations.The morphology of layerⅡ/Ⅲneurons was determined by neuronal nuclear antigen staining and Nissl staining of brain tissue sections.Eighty-seven neurons from eight DBA/2J mice and eighty-one neurons from eight C57BL/6J mice were examined.Compared with the C57BL/6J group,V1 neurons in the DBA/2J group exhibited weaker visual tuning and impaired spatial summation.Moreove r,fewer neuro ns were observed in the V1 of DBA/2J mice compared with C57BL/6J mice.These findings suggest that DBA/2J mice have fewer neurons in the VI compared with C57BL/6J mice,and that these neurons have impaired visual tuning.Our findings provide a better understanding of the pathological changes that occur in V1 neuron function and morphology in the DBA/2J mouse model.This study might offer some innovative perspectives regarding the treatment of glaucoma.展开更多
Purpose:To characterizes the progression of glaucoma in DBA/2J mice by measuring intraocular pressure(IOP) and retinal ganglion cells(RGCs) numbers in mice of various ages. Methods:A quantitative assessment of the pat...Purpose:To characterizes the progression of glaucoma in DBA/2J mice by measuring intraocular pressure(IOP) and retinal ganglion cells(RGCs) numbers in mice of various ages. Methods:A quantitative assessment of the pathophysiology of the DBA/2J mice was performed and the C57/BL6 mice was used as control. The IOP was measured by the servo-null micropipette system; the regional patterns of the loss of RGCs were determined by cell count of retrogradely-labeled RGCs. Results:The baseline IOP for DBA/2J mice at 7 weeks was (16.6 ± 1.2)mm Hg.Then IOP increased extend to 12 months, with the peak of (25.2 ± 1.2)mm Hg at 6 months of age. Retinal ganglion cell numbers did not decrease relative to control until 12 months of age(P=0.006), when the loss was proportionally higher in peripheral regions(P<0.05). Conclusion:The elevation in IOP precedes the loss of RGCs by several months. RGCs cell loss occurs particularly in peripheral regions of the retina. These findings expand our understanding of the changes in DBA/2J mice and provide information for experiments design when they are used as a glaucoma model for future studies of RGCs degeneration in glaucoma.展开更多
BACKGROUND： Retinal microglia has been shown to reactivate in a murine model of pigmentary glaucoma. However, the relationship between microglial activation and intraocular pressure （lOP） elevation and retinal gang...BACKGROUND： Retinal microglia has been shown to reactivate in a murine model of pigmentary glaucoma. However, the relationship between microglial activation and intraocular pressure （lOP） elevation and retinal ganglion cell （RGC） death is still unclear. OBJECTIVE： To verify that microglial activation and tumor necrosis factor alpha （TNF-α） expression is involved in RGC death with elevated lOP and prolonged time of glaucomatous optic nerve lesion in a DBA/2J mouse model of glaucoma. DESIGN, TIME AND SETTING： This randomized, controlled, animal experiment was performed at the Peking University Third Hospital, Peking University Eye Center, China between December 2006 and May 2008.MATEFIiALS： DBA/2J mice and C57BL/6J mice （Jackson Laboratory, USA）, rat anti-mouse CD11 b monoclonal antibody （Serotec, UK）, and goat anti-TNF-α polyclonal antibody （Sigma, USA） were used in this study.METHODS： A total of 100 female, DBA/2J mice at 3, 6, 9, 12, and 14 months of age （20 mice per age group） were used for the glaucoma model, and 18 C57BL/6J mice at 3, 9, 14 months of age （6 mice per age group） were used as normal controls. The anterior segment of the eye was observed using a slit-lamp biomicroscope, lOP was measured using a microneedle system. Morphology and number of retinal microglia were observed using immunohistochemistry. RGCs were quantified using Nissl staining. Co-localization of TNF-α and microglia was observed using double-labeling immunofluorescence. Excavation of the optic nerve head was observed utilizing hematoxylin-eosin staining. MAIN OUTCOME MEASURES： The following parameters were measured： lOP levels, numbers of RGCs and activated microglia, and TNF-α expression. RESULTS： In 6-month-old DBA/2J mice, dispersed pigment was observed, and some mice developed increased IOP. At 9 months of age, lOP levels reached a peak. In 3-month-old DBA/2J mice, microglia were activated. In 6-month-old DBA/2J mice, the number of activated microglia was significantly increased and migrated to the outer retinal layer. In 9-month-old mice, TNF-a expression was co-localized with microglia. Significant RGC loss occurred in mice aged 9 to 14 months, with the presence of optic nerve fiber loss and optical nerve head excavation, lOP returned to normal levels at 12 months of age, but microglia remained activated, which was consistent with RGC loss. CONCLUSION： Retinal microglial activation was partially attributed to increased lOP. Activated microglia might be mainly responsible for RGC loss. TNF-α expression was evident in the inner retinal layer. However, the relationship between TNF-α and RGC loss remains poorly understood.展开更多
基金supported by the STI 2030-Major Projects 2022ZD0208500(to DY)the National Natural Science Foundation of China,Nos.82072011(to YX),82121003(to DY),82271120(to YS)+2 种基金Sichuan Science and Technology Program,No.2022ZYD0066(to YS)a grant from Chinese Academy of Medical Science,No.2019-12M-5-032(to YS)the Fundamental Research Funds for the Central Universities,No.ZYGX2021YGLH219(to KC)。
文摘Glaucoma is a leading cause of irreve rsible blindness wo rldwide,and previous studies have shown that,in addition to affecting the eyes,it also causes abnormalities in the brain.However,it is not yet clear how the primary visual cortex(V1)is altered in glaucoma.This study used DBA/2J mice as a model for spontaneous secondary glaucoma.The aim of the study was to compare the electrophysiological and histomorphological chara cteristics of neurons in the V1between 9-month-old DBA/2J mice and age-matched C57BL/6J mice.We conducted single-unit recordings in the V1 of light-anesthetized mice to measure the visually induced responses,including single-unit spiking and gamma band oscillations.The morphology of layerⅡ/Ⅲneurons was determined by neuronal nuclear antigen staining and Nissl staining of brain tissue sections.Eighty-seven neurons from eight DBA/2J mice and eighty-one neurons from eight C57BL/6J mice were examined.Compared with the C57BL/6J group,V1 neurons in the DBA/2J group exhibited weaker visual tuning and impaired spatial summation.Moreove r,fewer neuro ns were observed in the V1 of DBA/2J mice compared with C57BL/6J mice.These findings suggest that DBA/2J mice have fewer neurons in the VI compared with C57BL/6J mice,and that these neurons have impaired visual tuning.Our findings provide a better understanding of the pathological changes that occur in V1 neuron function and morphology in the DBA/2J mouse model.This study might offer some innovative perspectives regarding the treatment of glaucoma.
基金This work was supported by Guangdong Scientific researchfund (NO. 2006J1-C0051)
文摘Purpose:To characterizes the progression of glaucoma in DBA/2J mice by measuring intraocular pressure(IOP) and retinal ganglion cells(RGCs) numbers in mice of various ages. Methods:A quantitative assessment of the pathophysiology of the DBA/2J mice was performed and the C57/BL6 mice was used as control. The IOP was measured by the servo-null micropipette system; the regional patterns of the loss of RGCs were determined by cell count of retrogradely-labeled RGCs. Results:The baseline IOP for DBA/2J mice at 7 weeks was (16.6 ± 1.2)mm Hg.Then IOP increased extend to 12 months, with the peak of (25.2 ± 1.2)mm Hg at 6 months of age. Retinal ganglion cell numbers did not decrease relative to control until 12 months of age(P=0.006), when the loss was proportionally higher in peripheral regions(P<0.05). Conclusion:The elevation in IOP precedes the loss of RGCs by several months. RGCs cell loss occurs particularly in peripheral regions of the retina. These findings expand our understanding of the changes in DBA/2J mice and provide information for experiments design when they are used as a glaucoma model for future studies of RGCs degeneration in glaucoma.
基金the National Natural Science Foundation of China,No.30571986the Research Fund from Peking University Third Hospital
文摘BACKGROUND： Retinal microglia has been shown to reactivate in a murine model of pigmentary glaucoma. However, the relationship between microglial activation and intraocular pressure （lOP） elevation and retinal ganglion cell （RGC） death is still unclear. OBJECTIVE： To verify that microglial activation and tumor necrosis factor alpha （TNF-α） expression is involved in RGC death with elevated lOP and prolonged time of glaucomatous optic nerve lesion in a DBA/2J mouse model of glaucoma. DESIGN, TIME AND SETTING： This randomized, controlled, animal experiment was performed at the Peking University Third Hospital, Peking University Eye Center, China between December 2006 and May 2008.MATEFIiALS： DBA/2J mice and C57BL/6J mice （Jackson Laboratory, USA）, rat anti-mouse CD11 b monoclonal antibody （Serotec, UK）, and goat anti-TNF-α polyclonal antibody （Sigma, USA） were used in this study.METHODS： A total of 100 female, DBA/2J mice at 3, 6, 9, 12, and 14 months of age （20 mice per age group） were used for the glaucoma model, and 18 C57BL/6J mice at 3, 9, 14 months of age （6 mice per age group） were used as normal controls. The anterior segment of the eye was observed using a slit-lamp biomicroscope, lOP was measured using a microneedle system. Morphology and number of retinal microglia were observed using immunohistochemistry. RGCs were quantified using Nissl staining. Co-localization of TNF-α and microglia was observed using double-labeling immunofluorescence. Excavation of the optic nerve head was observed utilizing hematoxylin-eosin staining. MAIN OUTCOME MEASURES： The following parameters were measured： lOP levels, numbers of RGCs and activated microglia, and TNF-α expression. RESULTS： In 6-month-old DBA/2J mice, dispersed pigment was observed, and some mice developed increased IOP. At 9 months of age, lOP levels reached a peak. In 3-month-old DBA/2J mice, microglia were activated. In 6-month-old DBA/2J mice, the number of activated microglia was significantly increased and migrated to the outer retinal layer. In 9-month-old mice, TNF-a expression was co-localized with microglia. Significant RGC loss occurred in mice aged 9 to 14 months, with the presence of optic nerve fiber loss and optical nerve head excavation, lOP returned to normal levels at 12 months of age, but microglia remained activated, which was consistent with RGC loss. CONCLUSION： Retinal microglial activation was partially attributed to increased lOP. Activated microglia might be mainly responsible for RGC loss. TNF-α expression was evident in the inner retinal layer. However, the relationship between TNF-α and RGC loss remains poorly understood.
