Ipiña S L, Ruiz-Marcos A, Escobar del Rey F, Morreale de Escobar G
Departamento de Matemática Aplicada, Facultad de Ciencias Biológicas, Universidad Complutense, Madrid, Spain.
Brain Res. 1987 Dec 15;465(1-2):219-29. doi: 10.1016/0165-3806(87)90243-4.
The changes produced on the whole dendritic morphology of layer III cortical pyramidal neurons by neonatal hypothyroidism, induced in rats by thyroidectomy at 10 days of age (T), as well as those changes related to ageing, have been studied in rats at 40 and 80 days of age. For these purposes, the dendritic structure of these neurons was defined by a set of 10 variables whose measurements were analyzed using multivariate methods. The effect of tyroxine (T4) substitution therapies applied to T rats between 12-40 and 30-80 days of age has been further investigated with the same mathematical methodology. The results obtained from the analyses performed show that hypothyroidism affects both the apical tuft and the basal dendritic arborization of these neurons. The observed damage was similar: a decrease of the total length of the dendritic segments of the apical tuft and the basal arborization. This change, however, was detected in these two different subregions with a different timing. These results seem to reinforce our findings concerning the selective effect of T on different sites of these neurons. On the other hand, 3 morphological changes have been revealed regarding the development of the pyramidal neuron studied: (1) the total length of the apical tuft dendritic segments increases from 40 to 80 days of age; (2) the total length of the basal dendritic segments decreases from 40 to 80 days of age; and (3) the perimeter of the cell body decreases from 40 to 80 days of age. Finally, the results obtained did not allow us to detect any recovery of the damage induced by T, as a consequence of the T4 substitution therapies applied.
研究了新生期甲状腺功能减退对大鼠III层皮质锥体神经元整体树突形态的影响，这种甲状腺功能减退是通过在10日龄时进行甲状腺切除术（T）诱导产生的，同时还研究了与衰老相关的变化，研究对象为40日龄和80日龄的大鼠。为此，通过一组10个变量定义了这些神经元的树突结构，并使用多变量方法对其测量值进行分析。使用相同的数学方法进一步研究了在12 - 40日龄和30 - 80日龄之间对T大鼠应用甲状腺素（T4）替代疗法的效果。分析结果表明，甲状腺功能减退会影响这些神经元的顶端簇和基底树突分支。观察到的损伤相似：顶端簇和基底分支的树突段总长度均减少。然而，这一变化在这两个不同的亚区域中检测到的时间不同。这些结果似乎强化了我们关于T对这些神经元不同部位的选择性作用的发现。另一方面，关于所研究的锥体神经元的发育揭示了3种形态学变化：（1）顶端簇树突段的总长度从40日龄增加到80日龄；（2）基底树突段的总长度从40日龄减少到80日龄；（3）细胞体周长从40日龄减少到80日龄。最后，所获得的结果不允许我们检测到由于应用T4替代疗法而导致的T诱导损伤的任何恢复情况。
