Delfs J R, Saroff D M, Nishida Y, Friend J, Geula C
Laboratory for Neurodegenerative and Aging Research, New England Deaconess Hospital, Boston, MA, USA.
J Neural Transm (Vienna). 1997;104(1):31-51. doi: 10.1007/BF01271292.
Neurotoxic effects of excitatory amino acid (EAA) receptor agonist N-methyl-D-aspartic acid (NMDA) and its antagonists on ventral horn cholinergic neurons were studied in organotypic rollertube cultures of spinal cord (OTC-SCs) using biochemical assays of choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) activity, and AChE histochemistry. NMDA exposure decreased ChAT and AChE activity by 83% and 66%, respectively. Cultures treated with NMDA also showed a marked loss of AChE staining in both dorsal and ventral horns and a significant, dose-dependent decrease in the number of ventral horn AChE-positive neurons (VHANs). NMDA treatment primarily resulted in the loss of small VHANs (< 300 microns2). VHANs with a size and distribution typical of alpha-motoneurons were relatively well preserved. The effects of NMDA on OTC-SCs appeared to be independent of the age of the cultures. The NMDA antagonist DL-AP5 completely prevented the NMDA-induced loss of ChAT activity, but only attenuated the effect of NMDA on ChE activity. The antagonists DL-AP5, D-AP5 and MK-801, used alone, caused significant loss and/or shrinkage of VHANs. These effects appeared to be distinct from the NMDA mediated toxicity. The results indicate that NMDA and its antagonists exert powerful toxic effects on ventral horn cholinergic neurons. The large cholinergic alpha-motoneurons, however, appear to be relatively immune to these toxic effects.
利用胆碱乙酰转移酶（ChAT）和乙酰胆碱酯酶（AChE）活性的生化检测以及AChE组织化学方法，在脊髓器官型滚管培养物（OTC-SCs）中研究了兴奋性氨基酸（EAA）受体激动剂N-甲基-D-天冬氨酸（NMDA）及其拮抗剂对腹角胆碱能神经元的神经毒性作用。NMDA暴露分别使ChAT和AChE活性降低了83%和66%。用NMDA处理的培养物在背角和腹角均显示出AChE染色明显缺失，并且腹角AChE阳性神经元（VHANs）数量显著且呈剂量依赖性减少。NMDA处理主要导致小的VHANs（< 300平方微米）丢失。具有α运动神经元典型大小和分布的VHANs相对保存完好。NMDA对OTC-SCs的作用似乎与培养物的年龄无关。NMDA拮抗剂DL-AP5完全阻止了NMDA诱导的ChAT活性丧失，但仅减弱了NMDA对ChE活性的影响。单独使用拮抗剂DL-AP5、D-AP5和MK-801会导致VHANs显著丢失和/或萎缩。这些作用似乎与NMDA介导的毒性不同。结果表明，NMDA及其拮抗剂对腹角胆碱能神经元具有强大的毒性作用。然而，大的胆碱能α运动神经元似乎对这些毒性作用相对免疫。
