Rami A, Rabié A, Patel A J
Neuroscience. 1986 Dec;19(4):1207-16. doi: 10.1016/0306-4522(86)90134-x.
A quantitative autoradiographic histological study was carried out to examine mechanisms underlying the reduction in the rates of growth and of cell acquisition, including that of granule cells, in the dentate gyrus of hypothyroid rats. Thyroid deficiency in early life had no effect on the replication of intrinsic cells present in the polymorph and granular layers. The pyknotic index was also normal in the "proliferative zone", polymorph layer and granule cell layer, indicating that thyroid hormone had no effect on the survival of replicating, migrating or maturing granule cells. By contrast, the arrival of migrating cells from the "proliferative zone" to the granular layer was severely retarded in thyroid deficiency. This deficit was rapidly restored after a physiological dose of thyroxine given to hypothyroid rats. The present findings are consistent with our previous proposal that the role of thyroid hormone in the formation and/or the maintenance of nerve cells is related to changes in either cell migration or maturation, rather than to alterations in the replication of germinal cells.
进行了一项定量放射自显影组织学研究，以探讨甲状腺功能减退大鼠齿状回中生长速率和细胞获取速率降低的潜在机制，包括颗粒细胞的生长速率和获取速率。幼年时期甲状腺功能减退对多形层和颗粒层中固有细胞的复制没有影响。在“增殖区”、多形层和颗粒细胞层中，固缩指数也正常，这表明甲状腺激素对正在复制、迁移或成熟的颗粒细胞的存活没有影响。相比之下，在甲状腺功能减退时，从“增殖区”迁移至颗粒层的细胞的到达受到严重阻碍。给甲状腺功能减退的大鼠给予生理剂量的甲状腺素后，这一缺陷迅速恢复。目前的研究结果与我们之前的观点一致，即甲状腺激素在神经细胞形成和/或维持中的作用与细胞迁移或成熟的变化有关，而不是与生发细胞的复制改变有关。
