Nag S, Tang F
Department of Physiology, The University of Hong Kong, China.
Neurosci Lett. 1998 Aug 14;252(2):83-6. doi: 10.1016/s0304-3940(98)00545-x.
Impairment of the basal forebrain cholinergic system is an important change in the brains of Alzheimer's disease patients. Various neurotoxins have been used to achieve this in animal models. In this study the effects of chemical lesions by ibotenic acid (IBO), a glutamate analogue and by 192 IgG-saporin, a highly specific immunotoxin against cholinergic neurons, were investigated. The toxins were delivered stereotaxically into the brains of young Sprague-Dawley rats which were later sacrificed by decapitation. Choline acetyltransferase (ChAT) activity was measured by radioenzymatic assay and substance P (SP), neuropeptide Y (NPY) and somatostatin (SOM) levels by radioimmunoassay. Decreased ChAT and SOM levels were observed in the cortex and the hippocampus in both experiments. Cortical SP levels were increased after IBO lesions but were unaffected after 192 IgG-saporin lesions. NPY levels remained unchanged in both experiments. The results indicate that there were specific changes in neuropeptide contents in the cortex and hippocampus in response to cholinergic damage in the rat brain.
基底前脑胆碱能系统受损是阿尔茨海默病患者大脑的一个重要变化。在动物模型中，已使用各种神经毒素来实现这一点。在本研究中，研究了谷氨酸类似物鹅膏蕈氨酸（IBO）和针对胆碱能神经元的高度特异性免疫毒素192 IgG-皂草素造成化学损伤的影响。将毒素通过立体定位注射到年轻的Sprague-Dawley大鼠脑中，随后通过断头处死大鼠。通过放射酶法测定胆碱乙酰转移酶（ChAT）活性，通过放射免疫法测定P物质（SP）、神经肽Y（NPY）和生长抑素（SOM）水平。在两个实验中，均观察到皮质和海马中ChAT和SOM水平降低。IBO损伤后皮质SP水平升高，但192 IgG-皂草素损伤后不受影响。在两个实验中NPY水平均保持不变。结果表明，大鼠脑内胆碱能损伤后，皮质和海马中的神经肽含量发生了特定变化。
