Bohn M C, Lauder J M
Dev Neurosci. 1980;3(2):81-9. doi: 10.1159/000112380.
The development of the cerebellar cortex was studied by quantitative light microscopic methods in rats treated with hydrocortisone on postnatal days 7-18. This treatment resulted in a decreased number of cells in the external granular layer (EGL) and an early disappearance of the EGL. In the adult cerebellum of these neonatally treated animals, the total number of granule cells in lobule VIII was decreased by 41% and that of molecular layer microneurons by 28%. Autoradiographic determinations of the 'birthdays' (time of origin) of cerebellar microneurons showed that the peaks of cell formation in the internal granular and molecular layers occurred at earlier ages than in controls. In the granule cell population, this observation was the result of both decreased cell proliferation during the treatment and premature cessation of division in granule cell precursors in the EGL. The morphological effects of 'late' hydrocortisone treatment on the cerebellum observed in this study are compared with those of 'early' hydrocortisone treatment on days 1-4 and those of thyroid hormone from previous studies. It is suggested that endogenous levels of both thyroid and glucocorticoid hormones during the neonatal period may influence the rate of neurogenesis in the postnatal rat cerebellum.
采用定量光学显微镜方法，研究了在出生后第7至18天接受氢化可的松治疗的大鼠小脑皮质的发育情况。这种治疗导致外颗粒层（EGL）中的细胞数量减少，且EGL提前消失。在这些新生期接受治疗的动物的成年小脑中，小叶VIII中的颗粒细胞总数减少了41%，分子层微神经元数量减少了28%。对小脑微神经元“生日”（起源时间）的放射自显影测定表明，内颗粒层和分子层中细胞形成的峰值出现在比对照组更早的年龄。在颗粒细胞群体中，这一观察结果是治疗期间细胞增殖减少以及EGL中颗粒细胞前体过早停止分裂的共同结果。本研究中观察到的“晚期”氢化可的松治疗对小脑的形态学影响，与先前研究中“早期”（出生后第1至4天）氢化可的松治疗以及甲状腺激素治疗的影响进行了比较。研究表明，新生期甲状腺激素和糖皮质激素的内源性水平可能会影响出生后大鼠小脑的神经发生速率。
