Lucion A B, Charchat H, Pereira G A, Rasia-Filho A A
Department of Physiology, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
Physiol Behav. 1996 Dec;60(6):1419-23. doi: 10.1016/s0031-9384(96)00246-6.
Behavioral sex differences have been linked to the presence of testosterone secretion during a critical perinatal period. The present experiment tested whether or not castration at different ages (early postnatal period and adulthood) would alter performance in the plus maze, a behavioral test of anxiety. Intact adult male rats (n = 17) were compared to intact adult females (n = 17); adult castrated males (n = 7) to sham-operated adult male rats (n = 9); and newborn castrated males (n = 7) to sham-operated male offspring (n = 8). When adult, the subjects were left on an elevated plus maze for 5 min. Females made a higher percentage of entries onto the open arms and showed a greater number of scans over the edge of an open arm than males. There were no differences in the percentage of arm entries or time spent on the open arms when adult castrated males were compared to sham-operated rats. On the other hand, newborn castrated males showed a significantly higher number of open arm entries and spent a greater percentage of time on the open arms than sham-operated offspring. The results demonstrate that the absence of male gonadal hormones during the perinatal period decreases anxiety, as assessed in the elevated plus maze, leading to a behavioral pattern that resembles that of females. These data provide evidence for the organizational role of gonadal hormones in the development of behavioral inhibitory systems.
行为性别差异与围产期关键时期睾酮分泌的存在有关。本实验测试了在不同年龄（出生后早期和成年期）进行去势是否会改变高架十字迷宫中的表现，高架十字迷宫是一种焦虑行为测试。将完整的成年雄性大鼠（n = 17）与完整的成年雌性大鼠（n = 17）进行比较；成年去势雄性大鼠（n = 7）与假手术成年雄性大鼠（n = 9）进行比较；新生去势雄性大鼠（n = 7）与假手术雄性后代（n = 8）进行比较。成年后，将实验对象置于高架十字迷宫中5分钟。雌性大鼠进入开放臂的百分比更高，并且在开放臂边缘的扫视次数比雄性大鼠更多。当将成年去势雄性大鼠与假手术大鼠进行比较时，进入臂的百分比或在开放臂上花费的时间没有差异。另一方面，新生去势雄性大鼠的开放臂进入次数明显更多，并且在开放臂上花费的时间百分比比假手术后代更高。结果表明，围产期缺乏雄性性腺激素会降低焦虑，如在高架十字迷宫中所评估的那样，导致一种类似于雌性的行为模式。这些数据为性腺激素在行为抑制系统发育中的组织作用提供了证据。
