Madeira M D, Paula-Barbosa M, Cadete-Leite A, Tavares M A
Department of Anatomy, Oporto Medical School, Alameda Hernâni Monteiro, Porto, Portugal.
J Hirnforsch. 1988;29(5):587-94.
Regardless the enormous amount of morphometric data related to the influence of thyroid hormones deficiency on the cerebellar cortex histogenesis, it remains controversial whether, in fully developed hypothyroid rats, the number of granule cells is actually altered. In order to get a quantitative unbiased view of its number at the end of the neurogenic period, we studied, using recently described stereological techniques, the granular layer of groups of 30 days old rats rendered hypothyroid from the day of birth. The results were compared with age- and sex-matched controls, as sex dimorphic differences were previously described for cerebellar granule cells. The granule cell packing density was increased independently of changes of their nuclear diameters. Its numerical density was similar in hypothyroid and controls, although a significant decrease in their total number was depicted as a consequence of the volumetric reduction of the granular layer in the hypothyroid groups. When male and female control groups were compared, the number of granule cells was found to be significantly smaller in females. This sex dimorphic difference was not detected between male and female hypothyroid groups, which suggests that, to be manifested, the presence of thyroid hormones is a necessary condition.
尽管有大量关于甲状腺激素缺乏对小脑皮质组织发生影响的形态学数据，但在完全发育的甲状腺功能减退大鼠中，颗粒细胞数量是否实际发生改变仍存在争议。为了在神经发生期结束时对其数量有一个定量的、无偏差的认识，我们使用最近描述的体视学技术，研究了自出生之日起就甲状腺功能减退的30日龄大鼠组的颗粒层。将结果与年龄和性别匹配的对照组进行比较，因为之前已描述小脑颗粒细胞存在性别二态性差异。颗粒细胞堆积密度增加，与它们核直径的变化无关。甲状腺功能减退组和对照组的颗粒细胞数密度相似，尽管由于甲状腺功能减退组颗粒层体积减小，其总数显著减少。当比较雄性和雌性对照组时，发现雌性的颗粒细胞数量明显较少。在雄性和雌性甲状腺功能减退组之间未检测到这种性别二态性差异，这表明甲状腺激素的存在是这种差异得以显现的必要条件。
