Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia.
Invest Ophthalmol Vis Sci. 2013 Jul 12;54(7):4691-7. doi: 10.1167/iovs.13-12415.
To determine the presence and magnitude of the photopic negative response (PhNR) component of the electroretinogram (ERG) in the mouse eye and to test if it is altered by short-term elevation of intraocular pressure (IOP).
Photopic and scotopic ERGs were recorded from 12-month-old C57BL/6J mice and analyzed for photoreceptoral responses (a-wave), bipolar cell responses (b-wave), scotopic threshold responses (STRs), and PhNRs. Electroretinogram signals were measured before and after short-term subischemic elevation of IOP (50 mm Hg for 30 minutes) induced by cannulation of the anterior chamber. Retinas were subsequently assessed for signs of retinal stress and cell survival using immunohistochemistry and quantitative PCR.
The corneal negative PhNR of the photopic ERG was elicited in the mouse eye, and its amplitudes correlated with amplitudes of the positive STR (pSTR). Elevation of IOP significantly reduced amplitudes of both the PhNR and pSTR, while scotopic a-waves, scotopic b-waves, and photopic b-waves were unchanged. Pressure elevation was associated with upregulation of glial fibrillary acidic protein and heme oxygenase 1 expression in retinal macroglia in the absence of retinal cell death.
The PhNR component of the full-field ERG can be recorded in mice and is sensitive to elevation of IOP. Correlation between PhNR and pSTR signals before and after IOP elevation suggests that the PhNR depends on inner retinal integrity and provides a means for evaluating inner retinal function in mouse models.
确定小鼠眼电图（ERG）中光幻视负反应（PhNR）成分的存在和幅度，并检验其是否会因眼内压（IOP）短期升高而改变。
从 12 月龄 C57BL/6J 小鼠中记录明适应和暗适应 ERG，并对光感受器反应（a 波）、双极细胞反应（b 波）、暗适应阈值反应（STR）和 PhNR 进行分析。通过前房插管将 IOP 短暂升高至亚缺血水平（50mmHg 持续 30 分钟），在升高 IOP 前后测量 ERG 信号。随后通过免疫组织化学和定量 PCR 评估视网膜应激和细胞存活的迹象。
在小鼠眼中诱发了明适应 ERG 的角膜负 PhNR，其幅度与正 STR（pSTR）的幅度相关。IOP 升高显著降低了 PhNR 和 pSTR 的幅度，而暗适应 a 波、暗适应 b 波和明适应 b 波则保持不变。压力升高与视网膜大胶质细胞中胶质纤维酸性蛋白和血红素加氧酶 1 表达的上调有关，而无视网膜细胞死亡。
全视野 ERG 的 PhNR 成分可在小鼠中记录，并对 IOP 升高敏感。IOP 升高前后 PhNR 和 pSTR 信号之间的相关性表明 PhNR 依赖于内视网膜完整性，并为评估小鼠模型中的内视网膜功能提供了一种方法。
