Pisharodi M, Nauta H J
Appl Neurophysiol. 1985;48(1-6):226-33. doi: 10.1159/000101132.
It has been shown that N-methylaspartate (NMA), kainic acid (KA), and quisqualic acid (QA) can produce preferential neuronal damage in various parts of the striatum, hippocampus, and thalamus with relative sparing of axons in transit. Thus far, the evidence that axons in transit escape destruction has been based largely on histological observations. To test the functional integrity of axons in passage, we made unilateral lesions with these agents in the cervical spinal cord of rats and compared the subsequent functional deficits with those seen after spinal cord hemisections. Observations were made in 14 rats. In each case, a laminectomy at the C6-C7 level was performed under general anesthesia. Animals receiving microinjections of KA, QA, or NMA showed motor and sensory deficits only in the ipsilateral forepaw and remained able to use the hindpaws normally. By contrast, animals undergoing spinal cord hemisection developed obvious motor deficits in the ipsilateral hindpaw in addition to the deficits in the forepaw. Histological observations of the spinal cords confirmed an extensive gray matter destruction with relative preservation of the long tracts in animals injected with KA, QA, and NMA. In addition, it was noted that spinal cord neurons appear relatively less sensitive to KA and more sensitive to QA than neurons in the thalamus, striatum, or hippocampus. The possible application of these findings for the production of dorsal root entry zone lesions will be discussed.
已表明，N-甲基-D-天冬氨酸（NMA）、 kainic 酸（KA）和quisqualic 酸（QA）可在纹状体、海马体和丘脑的各个部位产生优先的神经元损伤，而正在传导的轴突相对幸免。到目前为止，正在传导的轴突逃避破坏的证据主要基于组织学观察。为了测试正在通过的轴突的功能完整性，我们用这些药剂在大鼠颈脊髓中制造单侧损伤，并将随后的功能缺陷与脊髓半切术后所见的缺陷进行比较。对14只大鼠进行了观察。在每种情况下，在全身麻醉下在C6-C7水平进行椎板切除术。接受KA、QA或NMA微量注射的动物仅在同侧前爪出现运动和感觉缺陷，并且仍然能够正常使用后爪。相比之下，接受脊髓半切术的动物除了前爪缺陷外，同侧后爪还出现明显的运动缺陷。对脊髓的组织学观察证实，在注射KA、QA和NMA的动物中，灰质有广泛破坏，而长束相对保留。此外，还注意到脊髓神经元似乎比丘脑、纹状体或海马体中的神经元对KA相对不敏感，对QA更敏感。将讨论这些发现用于产生背根进入区损伤的可能应用。
