小鼠前庭神经核内N-甲基-D-天冬氨酸受体定位和发育

Localization of NMDA receptors in the vestibular nucleus of adult mouse and during postnatal development

目的探讨N-甲基-D-天冬氨酸(N-methyl-D- aspartate,NMDA)受体亚基NMDAR1和NMDAR2A/B在小鼠前庭神经核的细胞学定位和生后发育特征。方法免疫组织化学染色方法检测谷氨酸受体在小鼠前庭神经核的细胞学定位和生后发育特征。结果NMDAR1和NMDAR2A/B免疫反应产物丰富的分布在前庭神经上核、外侧核及部分下核、内侧核,主要定位于神经元胞体、树突和轴突样纤维终末上。生后早期的NMDAR1和NMDAR2A/B表达具有明显的动态变化,生后7天(P7)的表达微弱,随后逐渐上调,至P21达高峰,然后维持此水平。结论NMDAR1和NMDAR2A/B是构成前庭神经元功能性NMDA受体的重要亚基,NMDA受体可能参与小鼠出生后神经元成熟调控过程。

OBJECTIVE To investigate the cellular localization and developmental patterns of NMDA receptor subunits （NMDAR1 and NMDAR2A/B） in the vestibular nucleus of mouse during postnatal stages. METHODS Immunohistochemical staining method was used to determine NMDA receptor expression in the vestibular nucleus of mouse. RESULTS NMDAR1- or-NMDAR2A/B immunoreactivity was abundantly observed in the superior and lateral vestibular nucleus, and also found in inferior, medial vestibular nucleus. The immunopositive products were localized mainly in the neuronal somata, dendrites and axon terminals.Dynamic changes of NMDA receptor expression occurred in early postnatal stages. NMDA receptor subunits expressed weakly at postnatal 7 days （PT）, increased at P14, reached maximum level at P21, and then remained this level until adult. CONCLUSION Neuronal function NMDA receptors are composed of NMDAR1 and NMDAR2A in vestibular nucleus. NMDA receptors may be involved in neuron maturation and plasticity during postnatal development.