Visual evoked potentials and MBP gene expression imply endogenous myelin repair in adult rat optic nerve and chiasm following local lysolecithin induced demyelination
Visual evoked potentials and MBP gene expression imply endogenous myelin repair in adult rat optic nerve and chiasm following local lysolecithin induced demyelination
复制标题
DOI：
10.1016/j.brainres.2010.07.026
复制
发表时间：
2010-09-10
期刊：
影响因子：
2.9
通讯作者：
Tiraihi, Taki
中科院分区：
文献类型：
--
作者：
Mozafari, Sabah;Sherafat, Mohammad Amin;Tiraihi, Taki
多发性硬化症(MS)患者可能患有视力障碍。毒素诱导的脱髓鞘经常被用来分别研究脱髓鞘和重新髓鞘形成过程的细胞和结构方面。本研究通过记录视皮层的视觉诱发电位(VEP)及其与病变部位髓鞘碱性蛋白(MBP)表达的关系，描述了溶血磷脂(LPC)对成年大鼠视神经损伤和视交叉的功能影响。分别于注射后第2、7、14、28天记录VEP。我们观察到，光刺激产生的VEP在损伤后的幅度和潜伏期方面都发生了逐渐变化，与对照组动物产生的VEP相比也是如此。通过检测成熟少突胶质细胞和雪旺细胞中表达的重要基因之一MBP的mRNA表达水平，证实了上述观察结果。注射溶血磷脂后，脱髓鞘交叉神经和视神经组织中MBP mRNAs的表达水平下降，第7天最低，第14天恢复到正常水平。然而，即使在那之后，它仍然继续增加，并在损伤后第28天达到最大水平。本研究结果表明，LPC注射于视交叉具有视神经和视交叉脱髓鞘障碍的功能和分子改变，并在损伤后28天恢复到对照动物的水平，这在髓鞘修复过程中是典型的。本文对毒素诱导的实验性视神经损伤模型提供了新的见解，该模型可用于评估不同修复策略后脱髓鞘视神经和视交叉的功能恢复。它似乎也有助于研究不同疗法的保护或重新髓鞘形成的效果，例如，受MS(C)2010 Elsevier B.V.影响更大的视觉器官。
Multiple sclerosis (MS) patients may suffer from optic disturbances. Toxin-induced demyelinations have frequently been developed to investigate the cellular and structural aspects of demyelination and remyelination processes, separately. The present study describes functional consequence of lysolecithin (LPC)-induced lesion in the adult rat optic nerves and chiasm by recording the visual evoked potentials (VEPs) from the visual cortex and its correlation with myelin basic protein (MBP) expression in lesion site. Records of VEP were obtained at 2, 7, 14 and 28 days post-injection. We observed that the VEPs generated by light stimuli progressively changed in both amplitude and latency after the lesion as well as in comparison with those generated in control animals. These observations were confirmed through measurement of mRNA expression level for MBP which is one of the important genes expressed in mature oligodendrocytes and Schwann cells. The level of MBP mRNAs in demyelinated chiasm and optic nerves decreased following lysolecithin injection with its least value on day 7, and then it increased to the control level 14 days post-lesion. However, it continued to increase even after that and reached a maximum level 28 days post lesion. Results of the present paper show that, LPC injection in the chiasm share functional and molecular alterations which are found in demyelinating disorders in both the optic nerves and chiasm and also these alterations were coming back to level of control animal on 28 days post lesion, which is typically seen in myelin repair process. The present paper provides new insights into the experimental toxin-induced models that may be useful for evaluating the functional recovery of demyelinated optic nerves and chiasm following various repairing strategies. It also seems to be useful for studying the protective or remyelinating effects of different therapies in e.g. optic apparatus which is more affected by MS. (C) 2010 Elsevier B.V. All rights reserved.