异位神经元Ectopic Neuron · 神经 · 神经系统 · NTP ntp-0379
诊断要点：在 NTP 研究中，神经元异位应当被诊断，并在可能时注明具体亚部位。不需要进行严重程度分级。
病变描述
神经发育不良（neural dysplasia）描述了多种发育异常，其中神经元位置异常（异位和错位）常常是其中的一个组成部分。尽管在一般毒性研究中，神经元异位很少被认为是与处理相关的效应，但世代研究的出现使得识别此类神经发育畸形成为必要。严重的神经元异位可能源于胚胎受到辐射暴露。Figure 1 展示了神经发育异常的一种形式，在本例中为偶然发现。注意坐骨神经（sciatic nerve）中的异位神经元（箭头）。这些神经元可能来源于神经节，错误地位于坐骨神经的神经干内。注意明显的胞质尼氏体（Nissl substance，即粗面内质网的聚集）和细胞核的偏心定位。后者常与影响细胞骨架完整性的轻微神经元损伤相关，从而影响细胞核的位置。神经元异位更常见于小脑（cerebellum），其中浦肯野细胞（Purkinje cell）可能位于颗粒细胞层（granule cell layer）或其他部位。然而，这些应与颗粒细胞层的高尔基中间神经元（Golgi interneuron）相区分，后者常被误认为移位的浦肯野细胞。在啮齿类动物中，此类神经元异位与临床神经学发现之间尚无相关性，尽管不能排除这种可能性。
诊断与分级建议（NTP 共识）
在 NTP 研究中，神经元异位应当被诊断，并在可能时注明具体亚部位。不需要进行严重程度分级。
图谱
英文原文
展开 NTP 官方英文描述与建议
Comment：
Neural dysplasia describes a wide variety of developmental abnormalities, of which abnormal positioning of neurons (heterotopia and ectopia) is frequently a component. Although neuronal ectopia is seldom recognized as a treatment-related effect in general toxicity studies, the advent of generational studies necessitates the recognition of such malformations of neural development. Substantial neuronal ectopias may result from radiation exposure to embryos. Figure 1 represents a form of abnormal neural development, an incidental finding in this case. Note the ectopic neurons (arrow) in the sciatic nerve. The neurons, probably of ganglionic origin, are misplaced in the body of the sciatic nerve. Note the prominent cytoplasmic Nissl substance (aggregations of rough endoplasmic reticulum) and eccentric positioning of the nuclei. The latter are often associated with minor neuronal insult that affects cytoskeletal integrity, thus influencing the position of the nucleus. Neuronal ectopia is more commonly found in the cerebellum, where Purkinje cells may be located in the granule cell layer or other sites. These, however, should be distinguished from Golgi interneurons of the granular cell layer, which are commonly mistaken for displaced Purkinje cells. There has been no correlation between such neuronal ectopias and clinical neurologic findings in rodents, although it is not possible to rule out that prospect.
Recommendation：
Neuronal ectopia should be diagnosed and the subsite area included when possible in NTP studies. Severity grading is not required.
来源与引用
原始条目：https://ntp.niehs.nih.gov/atlas/nnl/nervous-system/nerve/EctopicNeuron
图谱总目录：NTP Nonneoplastic Lesion Atlas。 内容属美国联邦政府作品（公有领域），可引用；引用时请标注来源。
建议引用格式：NTP Nonneoplastic Lesion Atlas. Ectopic Neuron (nerve). LabSmart 中文版：
https://www.labsmart.cn/ntp/nerve-ectopic-neuron.html
中文图谱总页（可展开对照全部 595 条）：https://www.labsmart.cn/ntp-atlas.html#nerve-ectopic-neuron