Rúa C, Trejo J L, Machín C, Arahuetes R M
Dpto. Biología Celular, Fac. CC. Biológicas, Univ. Complutense, Madrid, Spain.
J Hirnforsch. 1995;36(4):473-83.
Optic and electron microscopic analysis were performed on the hippocampus of fetuses of 20 days gestation, from pregnant rats bilaterally adrenalectomized on day 1 of gestation (ADX) and control (C), in an attempt to determine the incidence of maternal glucocorticoids on morphological parameters in fetal development. In addition, we studied 20 day old fetuses from pregnant rats betamethasone-injected on days 15, 16 and 17 (BET), and adrenalectomized on day 1 and betamethasone-injected on days 15, 16 and 17 (ADX + BET). The adrenalectomy led to a decreased total cell number and a marked depletion of the dentate gyrus of the hippocampus, and also to widespread indifferentiation, both in the pyramidal cell layer of the Ammon's horn and the dentate gyrus, as well as a decreased cell number in CA3 stratum pyramidale. No differences in cell number were found in CA1. So, the ADX effect is in relation to the neurogenic gradient. The main effect of the exogenous glucocorticoid treatment was increased maturation in relation to the control group. Betamethasone injection in adrenalectomized animals prevented the lower degree of maturation of the adrenalectomized group but not the impaired cell number. These results show that glucocorticoids participate in prenatal hippocampus in control mechanisms of cellular division and in maturation.
对妊娠20天胎儿的海马体进行光学和电子显微镜分析，这些胎儿来自于在妊娠第1天进行双侧肾上腺切除术的孕鼠（ADX）和对照组（C），旨在确定母体糖皮质激素对胎儿发育形态学参数的影响发生率。此外，我们研究了来自于在第15、16和17天注射倍他米松的孕鼠的20日龄胎儿（BET），以及在第1天进行肾上腺切除术并在第15、16和17天注射倍他米松的胎儿（ADX + BET）。肾上腺切除术导致海马体齿状回的总细胞数减少和明显的细胞耗竭，并且在海马角的锥体细胞层和齿状回中都出现广泛的未分化，以及CA3锥体层中的细胞数减少。在CA1中未发现细胞数的差异。因此，ADX效应与神经发生梯度有关。外源性糖皮质激素治疗的主要作用是相对于对照组而言成熟度增加。在肾上腺切除的动物中注射倍他米松可防止肾上腺切除组较低程度的成熟，但不能防止细胞数受损。这些结果表明，糖皮质激素参与产前海马体中细胞分裂的控制机制和成熟过程。
