Conejo N M, González-Pardo H, Cimadevilla J M, Argüelles J A, Díaz F, Vallejo-Seco G, Arias J L
Laboratory of Psychobiology, Faculty of Psychology, University of Oviedo, Spain.
J Neurosci Res. 2005 Feb 15;79(4):488-94. doi: 10.1002/jnr.20372.
It is known that expression of glial fibrillary acidic protein (GFAP) as an astrocyte-specific marker can be regulated by levels of circulating gonadal steroids during postnatal development. In addition, astrocytes play an important role in the physiology of the hippocampus, a brain region considered sexually dimorphic at the neuronal level in rodents. To evaluate the contribution of glial cells to gender-related differences in the hippocampus, we estimated the number of GFAP-immunoreactive (GFAP-IR) astrocytes in the hippocampus (CA1 and CA3 areas, dorsal and ventral regions) of male and female rats aged 30 days. Groups of 30-day-old masculinized females (TP-females; injected with testosterone propionate at birth) and feminized males (FLU-males, castrated and treated with flutamide, an androgen receptor antagonist) were included to assess the effects of gonadal hormones on these hippocampal astrocytes. Using the optical fractionator method, the total number of GFAP-IR cells found in CA1 and CA3 areas was significantly higher in males compared to that in age-matched females. This numerical pattern was reversed in TP-females and FLU-males in both hippocampal areas. In addition, more GFAP-IR cells were found in dorsal hippocampus than in the ventral region in the CA1 area from all experimental groups, whereas this result was found in the CA3 area from males and TP-females. Our results suggest an essential contribution of gonadal hormones to gender differences found in the astrocyte population of the rat hippocampus during development.
众所周知，作为星形胶质细胞特异性标志物的胶质纤维酸性蛋白（GFAP）的表达在出生后发育过程中可受循环性腺类固醇水平的调节。此外，星形胶质细胞在海马体的生理学中发挥着重要作用，海马体是啮齿动物在神经元水平上具有性别二态性的脑区。为了评估胶质细胞对海马体中与性别相关差异的贡献，我们估计了30日龄雄性和雌性大鼠海马体（CA1和CA3区域、背侧和腹侧区域）中GFAP免疫反应性（GFAP-IR）星形胶质细胞的数量。纳入了30日龄的雄性化雌性大鼠（TP-雌性；出生时注射丙酸睾酮）和雌性化雄性大鼠（FLU-雄性，阉割并用雄激素受体拮抗剂氟他胺治疗）组，以评估性腺激素对这些海马星形胶质细胞的影响。使用光学分选法，发现CA1和CA3区域中GFAP-IR细胞的总数在雄性中显著高于年龄匹配的雌性。在两个海马区域的TP-雌性和FLU-雄性中，这种数量模式发生了逆转。此外，在所有实验组的CA1区域中，背侧海马体中发现的GFAP-IR细胞比腹侧区域更多，而在雄性和TP-雌性的CA3区域中也发现了这一结果。我们的结果表明，性腺激素对大鼠海马体发育过程中星形胶质细胞群体中发现的性别差异有重要贡献。
