大鼠脑内GnRH神经元生后发育的免疫组织化学研究

IMMUNOHISTOCHEMICAL STUDY OF POSTNATAL DEVELOPMENT OF GNRH NEURONS IN THE RAT BRAIN

应用ABC免疫组化染色方法和图像分析仪,对生后不同时间大鼠脑内的GnRH神经元的形态学进行了定量研究。所用实验动物的GnRH神经元的分布相似。生后1～7天,GnRH神经元胞体小,突起短,染色淡,多为平滑型。其数目在1天时与成年无显著差别,7天时则显著减少。生后14天GnRH神经元胞体增大,数目恢复,染色加深,与成年水平相近。正中隆起的GnRH纤维和终末在生后逐渐增多,至14天也达成年水平。结果提示,大鼠GnRH神经元在出生后早期即已决定,生后第二周是GnRH神经元发育的关键时期,而GnRH神经元系统的功能建立则早于其形态成熟。

The morphology of the GnRH neurons in the rat brain during postnatal development was studied quantitatively using the ABC immunostaining method and an image analyser. The pattern of distribution of the GnRH neurons in different ages animals used was similar. GnRH cells of rats aged 1-7 days were small in size with short processes, pale-stained, and smooth in outline The number of GnRH cells in 1 day rats was not significantly different from that of adult, but a significant decrease in the GnRH cell number appeared in 7 day rats. In postnatal day 14, Gn-RH neurons reached adult level in cell body size, number and staining intensity. The GnRH fibers and terminals in the median eminence were gradually increased and reached adult level up to 14 postnatal days. These results suggested that the number of GnRH neurons is determined shortly after birth; the second postnatal week is the critical period for the development of GnRH neuronal morphology; and the establishment of function of the GnRH neuronal system may be earlier than its morphological maturation.