Analysis of the mechanism of neuronal regeneration by using multi-nuclei magnetic resonance methods with molecular imaging of brain function

本研究建立了多核磁共振分子成像技术用于神经元功能和再生的研究：（1）神经元激活的锰增强磁共振成像（MEMRI），它是基于神经元激活过程中Mn ~（2+）与Ca ~（2+）共同进入神经元的理论;该方法能清楚地显示大鼠感觉区神经元的活动以及嗅格罗夫层、视辐射层和皮层神经元纤维的结构。实验性脑缺血后恢复期，MEMRI显示缺血核心区周围出现GFAP阳性星形胶质细胞的增强区，提示反应性星形胶质细胞增生。(2)脑内抗原抗体反应的磁共振成像技术：大分子与磁共振敏感材料（Fe、Gd）的结合在体外可获得成像，但该方法难以应用于体内研究。(3)我们利用2D-JPRESS和2D-COSY方法在临床MRI扫描仪上开发了2D-MRS方法。2D-MRS方法敏感地检测脑代谢物。多核磁共振成像技术可以无创地检测脑功能和神经元再生。

We have developed multi-nuclear magnetic resonance method with molecular imaging for the analysis of neuronal function and regeneration as followings ; (1) Neuronal activation imaging by using manganese-enhanced MRI (MEMRI) which is based on the theory that Mn2+ can enter into neuronal cell in conjunction with Ca2+ during the neuronal activation; This method could clearly demonstrate the neuronal activation of the sensory area in rat and the structure of neuronal fibers in rat olfactory grove, optic radiation and cortical layers. During the recovery period after experimental ischemia, the enhanced area by MEMRI corresponded to the GFAP-positive astroglia were observed in the peripheral region of the ischemic core, indicating the reactive astrogliosis. (2) Magnetic resonance technique which can visualize antigen-antibody reaction in the brain: The imaging of macromolecule combined with magnetic resonance sensitive materials (Fe, Gd) could be obtained in vitro, but it was difficult to apply this method to in vivo study. (3) We have developed 2D-MRS method on the clinical MRI scanner by using 2D-JPRESS and 2D-COSY methods. Brain metabolites were detected sensitively by 2D-MRS method. The multi-nuclear MR methods are useful to examine the brain function and neuronal regeneration non-invasively.