Benjamin S, Cambray-Deakin M A, Burgoyne R D
Physiological Laboratory, University of Liverpool, U.K.
Neuroscience. 1988 Dec;27(3):931-9. doi: 10.1016/0306-4522(88)90196-0.
The microtubule-associated proteins 1A, 1B and 2 are present at high levels in Purkinje cell dendrites of normal adult rat cerebellum but show characteristic changes in localization during cerebellar development that allow examination of the effects of hypothyroidism on the development of both Purkinje cells and granule cells. Neonatal rats were made hypothyroid by treatment with propylthiouracil from the day of birth (post-natal day 0, P0). The expression of the microtubule-associated proteins 1A, 1B and 2 in the cerebellum of hypothyroid animals was examined using immunocytochemical techniques and compared to the normal developmental pattern in control animals. The normal developmental decrease in microtubule-associated protein 1A and 1B levels in parallel fibres was delayed in the cerebellum of hypothyroid animals and these proteins persisted in parallel fibres until after P20. Microtubule-associated protein 1B but not 1A was still present in parallel fibres in less mature folia at P30 in hypothyroid rats suggesting that the expression of these two microtubule-associated proteins is regulated separately. In the molecular layer staining with anti-microtubule-associated protein 2 was enriched in Purkinje cell dendrites in normal and hypothyroid cerebella and the stained Purkinje cell dendrites in hypothyroid cerebellum demonstrated a typical deformed morphology at P15. The results show that the restricted subcellular localization of these microtubule-associated proteins is maintained in the cerebellum of hypothyroid rats but the developmental changes in their expression are delayed.
微管相关蛋白1A、1B和2在正常成年大鼠小脑的浦肯野细胞树突中含量很高，但在小脑发育过程中其定位会发生特征性变化，这使得研究甲状腺功能减退对浦肯野细胞和颗粒细胞发育的影响成为可能。新生大鼠自出生日（出生后第0天，P0）起用丙硫氧嘧啶处理，使其甲状腺功能减退。采用免疫细胞化学技术检测甲状腺功能减退动物小脑中微管相关蛋白1A、1B和2的表达，并与对照动物的正常发育模式进行比较。甲状腺功能减退动物小脑中平行纤维中微管相关蛋白1A和1B水平正常的发育性降低被延迟，这些蛋白在平行纤维中持续存在至P20之后。在P30时，甲状腺功能减退大鼠较不成熟小叶的平行纤维中仍存在微管相关蛋白1B而不存在1A，这表明这两种微管相关蛋白的表达是分别调控的。在分子层，抗微管相关蛋白2染色在正常和甲状腺功能减退的小脑中均在浦肯野细胞树突中富集，甲状腺功能减退小脑在P15时染色的浦肯野细胞树突呈现典型的畸形形态。结果表明，这些微管相关蛋白在甲状腺功能减退大鼠小脑中维持了受限的亚细胞定位，但其表达的发育变化被延迟。
