Formation of excess sublobules in the cerebellum of hypothyroid rats
Formation of excess sublobules in the cerebellum of hypothyroid rats
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DOI：
10.1016/j.aanat.2011.12.005
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发表时间：
2012-01-01
影响因子：
2.2
通讯作者：
Uehara, Masato
中科院分区：
文献类型：
--
作者：
Hosaka, Yoshinao Z.;Neki, Yoshihiko;Uehara, Masato
小脑叶在甲状腺功能减退大鼠中的数量可能增加（Lauder等人，1974; Hasebe等人，2008年a）。在这项研究中，我们的目的是确认多余的小叶的形成，并确定是否多余的小叶始终形成在甲状腺功能减退大鼠的保守位置。我们用内颗粒层的分叉模式代替小脑裂分隔的叶状模式来研究甲状腺功能减退大鼠小脑皮质的复杂性。甲状腺功能减退大鼠小脑的基本叶状模式是完整的，但小叶III至IX经常表现出小叶数量的增加。多余的小叶主要分布在叶部和裂隙的沿着浅部。换句话说，多余的小叶不是位于随机的位置，而是位于特定的位置。第V ~ IX小叶内颗粒层面积明显大于对照组。从内颗粒层面积的增加可以推断，内颗粒细胞的数量比正常大鼠增加。在我们的研究中，小脑内小叶过多的区域与中间到晚期形成的内部颗粒层的区域相关（Altman，1969）。我们的观察结果符合这样的观点，即过量的小叶是由外部颗粒层形成的，显示出长期的细胞增殖，甲状腺功能减退主要对内部颗粒层发育的中期至晚期产生不利影响。(c)2012 Elsevier GmbH. All rights reserved.
Cerebellar folia may increase in number in hypothyroid rats (Lauder et al., 1974; Hasebe et al., 2008a). In this study, we aimed to confirm the formation of an excess sublobule and to determine whether excess sublobules are consistently formed in conserved positions in hypothyroid rats. Instead of the foliation pattern partitioned by cerebellar fissures, we employed the bifurcation pattern of the internal granular layer for investigation of complexity of the cerebellar cortex in hypothyroid rats. The basic foliation pattern of the cerebellum was intact in hypothyroid rats, but lobules III to IX frequently showed an increase in the number of sublobules. The excess sublobules were mainly found in the folia and along the shallow region of the fissure. In other words, the excess sublobules were not located in random locations but rather in specific locations. The area in the internal granular layer of lobules V to IX was significantly larger than that in control rats. From the increased area of the internal granular layer it may be inferred that internal granular cells increase in number than those in normal rats. In our study, regions within the cerebellum that show an excess of sublobules correlate with regions that show an intermediate to late-forming internal granular layer (Altman, 1969). Our observations fit with the view that excess sublobules are formed by the external granular layer showing prolonged cell proliferation and hypothyroidism predominantly has an adverse impact on the intermediate to late phases in development of the internal granular layer. (c) 2012 Elsevier GmbH. All rights reserved.