Niessen Heiko G, Angenstein Frank, Vielhaber Stefan, Frisch Christian, Kudin Alexei, Elger Christian E, Heinze Hans-Jochen, Scheich Henning, Kunz Wolfram S
Department of Neurology II, Otto-von-Guericke University Magdeburg, Leipziger Strasse 44, 39120 Magdeburg, Germany.
Epilepsia. 2005 Jul;46(7):1021-6. doi: 10.1111/j.1528-1167.2005.60704.x.
After pilocarpine-induced epilepsy in rats, volumetric magnetic resonance imaging (MRI) reveals significant morphologic changes in functionally relevant structures of the brain. To relate structural changes to functional alteration, we studied the correlation of regional brain atrophy (e.g., of the hippocampus) with lesion-induced learning deficits in the Morris water maze.
MRI experiments were performed on an MR scanner at 4.7 Tesla. For volumetric analysis, various cerebral structures were segmented in horizontal and coronal T(2)-weighted MR images. Before the MRI investigations, animals were trained for 10 days in a Morris water maze.
Volumetric MRI revealed a significant loss in hippocampal size in both the dorsal and ventral parts, correlated with an increase in ventricular size. Furthermore, significant losses were found in the relative size of thalamus, putamen, cortex, and the combined areas of perirhinal, entorhinal, and piriform cortices adjacent to the hippocampus. A significant correlation of learning performance in the Morris water maze with the relative hippocampal area and not with other areas tested was observed in pilocarpine-treated animals.
The data provide a quantitative analysis of functionally relevant structural alterations in rats with chronic epilepsy. Water maze performance of pilocarpine-treated animals correlates with the degree of hippocampal but not with the degree of cortical damage, demonstrating the potential of this method for the investigation of cognitive impairments in relation to cerebral changes. In addition, the data point to an important role of even the residual hippocampus in memory formation.
在大鼠经毛果芸香碱诱发癫痫后，容积磁共振成像（MRI）显示大脑功能相关结构出现显著形态学变化。为了将结构变化与功能改变联系起来，我们研究了区域脑萎缩（如海马体）与莫里斯水迷宫中损伤诱导的学习缺陷之间的相关性。
在4.7特斯拉的磁共振扫描仪上进行MRI实验。为了进行容积分析，在水平和冠状面T2加权磁共振图像中对各种脑结构进行分割。在进行MRI检查之前，动物在莫里斯水迷宫中训练10天。
容积MRI显示背侧和腹侧海马体大小均显著减小，与脑室大小增加相关。此外，丘脑、壳核、皮质以及海马体相邻的嗅周皮质、内嗅皮质和梨状皮质的联合区域的相对大小也显著减小。在毛果芸香碱处理的动物中，观察到莫里斯水迷宫中的学习表现与相对海马体面积显著相关，而与其他测试区域无关。
这些数据提供了慢性癫痫大鼠功能相关结构改变的定量分析。毛果芸香碱处理动物的水迷宫表现与海马体损伤程度相关，而与皮质损伤程度无关，证明了该方法在研究与脑变化相关的认知障碍方面的潜力。此外，数据表明即使是残余的海马体在记忆形成中也起着重要作用。
