Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, 03690 San Vicente del Raspeig, Alicante E-03080, Spain.
Exp Eye Res. 2010 Aug;91(2):273-85. doi: 10.1016/j.exer.2010.05.020. Epub 2010 Jun 1.
In adult albino mice the effects of increased intraocular pressure on the outer retina and its circuitry was investigated at intervals ranging 3-14 weeks. Ocular hypertension (OHT) was induced by cauterizing the vessels draining the anterior part of the mice eye, as recently reported (Salinas-Navarro et al., 2009a). Electroretinographic (ERG) responses were recorded simultaneously from both eyes and compared each other prior to and at different survival intervals of 2, 8 or 12 weeks after lasering. Animals were processed at 3, 9 or 14 weeks after lasering, and radial sections were obtained in the cryostat and further processed for immunocytochemistry using antibodies against recoverin, gamma-transducin, Protein Kinase C-alpha (PKC-alpha), calbindin or synaptophysin. The synaptic ribbons were identified using an antibody against the protein bassoon, which labels photoreceptor ribbons and nuclei were identified using TO-PRO. Laser photocoagulation of the perilimbar and episcleral veins of the left eye resulted in an increase in mean intraocular pressure to approximately over twice its baseline by 24 h that was maintained for approximately five days reaching basal levels by 1 week. ERG recordings from the different groups of mice showed their a-, b-wave and scotopic threshold response (STR) amplitudes, when compared to their contralateral fellow eye, reduced to 62%, 52% and 23% at 12 weeks after lasering. Three weeks after lasering, immunostaining with recoverin and transducin antibodies could not document any changes in the outer nuclear layer (ONL) but both ON-rod bipolar and horizontal cells had lost their dendritic processes in the outer plexiform layer (OPL). Sprouting of horizontal and bipolar cell processes were observed into the ONL. Fourteen weeks after lasering, protein kinase-C antibodies showed morphologic changes of ON-rod bipolar cells and calbindin staining showed abnormal horizontal cells and a loss of their relationship with their presynaptic input. Moreover, at this time, quantitative studies indicate significant diminutions in the number of photoreceptor synaptic ribbons/100 microm, and in the thickness of the outer nuclear and plexiform layer, when compared to their fellow eyes. Increased intraocular pressure in Swiss mice results in permanent alterations of their full field ERG responses and in changes of the inner and outer retinal circuitries.
在成年白化小鼠中，我们在 3-14 周的时间间隔内研究了眼内压升高对视网膜外段及其环路的影响。正如最近报道的那样（Salinas-Navarro 等人，2009a），通过烧灼小鼠眼前部血管来诱导高眼压（OHT）。在激光照射前和激光照射后 2、8 或 12 周的不同存活间隔内，同时从双眼记录视网膜电图（ERG）反应，并对其进行比较。在激光照射后 3、9 或 14 周对动物进行处理，并在 cryostat 中获得径向切片，然后使用针对 recoverin、gamma-transducin、蛋白激酶 C-alpha（PKC-alpha）、钙结合蛋白或突触小体蛋白的抗体进行免疫细胞化学处理。使用针对蛋白 bassoon 的抗体鉴定突触带，bassoon 标记光感受器带，使用 TO-PRO 鉴定核。对左眼的周边巩膜和脉络膜静脉进行激光光凝，导致平均眼内压在 24 小时内增加到基线以上约两倍，持续约五天，到 1 周时达到基础水平。与对侧眼相比，不同组别的小鼠的 ERG 记录显示其 a-、b-波和暗视阈反应（STR）幅度在激光照射后 12 周时降低至 62%、52%和 23%。激光照射后 3 周，用 recoverin 和转导蛋白抗体进行免疫染色不能证明外核层（ONL）有任何变化，但 ON-rod 双极细胞和水平细胞在外丛状层（OPL）中失去了树突过程。水平细胞和双极细胞的突起向 ONL 中延伸。激光照射后 14 周，蛋白激酶-C 抗体显示 ON-rod 双极细胞的形态变化，钙结合蛋白染色显示异常的水平细胞及其与突触前输入的关系丧失。此外，此时定量研究表明，与对侧眼相比，光感受器突触带/100 微米的数量以及外核和外丛状层的厚度显著减少。瑞士小鼠眼内压升高导致其全视野 ERG 反应永久改变，并导致内、外视网膜回路改变。
