大鼠Calbindin-D28K样阳性脊髓投射神经元亚群分布方式

The Subpopulation and Distribution Patterns of Calbindin-D28K Like Immunoreative Rubrospinal Neurons in Rats

目的 研究大鼠红核 脊髓投射神经元Calbindin D2 8K样免疫反应 (CaBP LI)表现形式及其分布特点。方法 采用霍乱毒素B亚单位结合胶体金 (CB Au)逆行标认神经元复合免疫细胞化学反应的非荧光双标方法。结果 红核 脊髓投射神经元表现为两种亚型 :一种为CaBP LI阴性神经元 ;另一种为CaBP LI阳性神经元。两种神经元在红核具有特殊的分布方式 ,头侧水平CB Au标认的红核 脊髓投射神经元均呈CaBP LI阴性 ,向尾侧CaBP LI阳性神经元数目逐渐增多。脑室注射L型钙离子通道激动剂BayK86 4 4仅引起CaBP LI免疫反应强度增加 ,并未改变两种神经元的分布方式 ,头侧CB Au标认的红核 脊髓投射神经元仍表现CaBP LI阴性。结论 大鼠红核 脊髓投射神经元的CaBP LI阳性和CaBP LI阴性两种亚型及其分布特点说明 ,这些神经元的性质并非均一 ,并可能与红核 脊髓投射神经元对钙超载具有不同的耐受性有关。

Objective The distribution pattern and subpopulation of calbindin D28k like immunoreactive (CaBP LI) rubrospinal neurons of red nucleus was analysed in 30 Wistar rats. Method Non fluorescent double staining technique was used to retrogradely identify the neurons immunocytochemically. Results The rubrospinal neurons were retrogradely identified by cholera toxin subuint B coulpled with colloidal gold (CB Au,prepared by our laboratory).No CaBP LI positive neurons identified by CB Au was present in the rostral level of the red nucleus.The weakly or strongly stained CaBP LI/CB Au double labelled cells gradually increased caudalward.In the middle rostrocaudal third of the red nucleus,the double labelled neurons mainly occupied the ventromedial portions of the red nucleus.Injection of Bay K8644 (an L Ca 2+ channel agonist) in lateral ventricle induced immunoreactive intensity and did not change the distribution pattern of CaBP LI positive rubrospinal neurons.Rubrospinal neurons in the rostral portion still showed CaBP LI negative. Conclusion The characteristics of CaBP LI positive rubrospinal neurons in the red nucleus showed that these neurons was not homogeneous. Rubrospinal neurons had their subpopulation in term of CaBP like immunoreactivity (from strongly posotive to negative) and special distribution features.