Faculty of Veterinary Medicine, Department of Basic Sciences, Shahid Chamran University of Ahvaz, Iran.
Stem Cell and Transgenic Technology Research Center, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
Brain Behav. 2022 Aug;12(8):e32723. doi: 10.1002/brb3.2723. Epub 2022 Jul 21.
Multiple sclerosis (MS) is the most common autoimmune disease. Progressive depletion of the brain and spinal cord tissue appears at the onset of the disease. Several studies have shown the increased size of the ventricles of the brain and decreases in the area of the corpus callosum and the width of the brain. Other important symptoms of this disease are cognitive, learning, and memory disorders.
The aim of this study was to compare morphometric, histological, and functional changes in the demyelination model in both sexes.
In this experimental study, male and female Wistar rats were studied in four experimental groups. Demyelination was induced by the injection of ethidium bromide in the ventricular region. The chronic effect of demyelination on spatial memory, movement, and coordination was investigated using the Morris Water Maze (MWM), and clinical and balance beam tests, respectively. Myelin degradation, cell death and neurogenesis were estimated using Luxol Fast Blue staining and immunohistochemistry (Caspase-3 and Nestin markers). In addition, morphometric findings were recorded for the brain and hippocampus (weight, volume, length, width).
Demyelination increased the time and distance index and decreased the residence time in the target quarter in the water maze test (p < .001). It also increases the neuromuscular and modified neurological severity score (p < .01). Demyelination increases caspase-3 (p < .05) expression and decreases Nestin expression (p < .001), which are directly related to the extent of damage.
This study showed an interaction between hippocampal structural and functional networks in explaining spatial learning and memory in the early stages of MS.
多发性硬化症（MS）是最常见的自身免疫性疾病。疾病发作时，大脑和脊髓组织会逐渐损耗。多项研究表明，大脑脑室增大，胼胝体面积减少，脑宽变窄。这种疾病的其他重要症状是认知、学习和记忆障碍。
本研究旨在比较两性脱髓鞘模型的形态计量学、组织学和功能变化。
在这项实验研究中，雄性和雌性 Wistar 大鼠被分为四组进行研究。通过向脑室区域注射溴化乙锭诱导脱髓鞘。使用 Morris 水迷宫（MWM）分别对空间记忆、运动和协调的脱髓鞘慢性影响进行测试，临床和平衡梁测试分别对其进行测试。使用卢索夫快速蓝染色和免疫组织化学（Caspase-3 和 Nestin 标志物）评估髓鞘降解、细胞死亡和神经发生。此外，还记录了大脑和海马体（重量、体积、长度、宽度）的形态计量学发现。
脱髓鞘增加了水迷宫测试中的时间和距离指数，并减少了目标象限中的停留时间（p<0.001）。它还增加了神经肌肉和改良神经严重程度评分（p<0.01）。脱髓鞘增加了 Caspase-3 的表达（p<0.05），降低了 Nestin 的表达（p<0.001），这与损伤程度直接相关。
本研究表明，海马体结构和功能网络之间存在相互作用，可以解释多发性硬化症早期的空间学习和记忆。
