Takahashi L K, Baker E W, Kalin N H
Department of Psychiatry, University of Wisconsin Medical School, Madison 53792.
Physiol Behav. 1990 Feb;47(2):357-64. doi: 10.1016/0031-9384(90)90154-v.
Effects of prenatal stress on stress-induced behavioral and hormonal responses were investigated in preweanling rats at two ages. Prenatal stress treatments involved the application of uncontrollable electric shocks to pregnant rats every other day throughout gestation. Offspring of undisturbed rats in home cages served as controls. When male pups were 14 and 21 days old, ultrasonic vocalizations and freezing were recorded in 10-min tests involving isolation, and isolation with the application of electric foot shocks at either 0.5- or 2.0-mA intensity. Immediately before and after each test, tail-flick latencies were measured in order to assess alterations in stress-induced analgesia. Stress-induced secretion of ACTH was measured in plasma obtained after the second tail-flick test. Results indicated that 14-day-old prenatally stressed pups emitted significantly fewer ultrasonic vocalizations and exhibited significantly lower percent increases in tail-flick latencies than control pups. Plasma ACTH, however, was significantly elevated in prenatally stressed rats, suggesting that exposure to different tests was a stress-inducing event. At 21 days of age, prenatally stressed rats no longer differed significantly from control males in the exhibition of ultrasonic vocalizations, defensive freezing, and tail-flick latencies. Plasma ACTH content, however, was significantly lower in prenatally stressed than control males after exposure to the isolation with 2.0-mA shock test. The involvement of motivational, maturational, and mediational factors is examined in order to account for these age-dependent and stressor-dependent differences in behavioral and hormonal responses occurring between prenatally stressed and control pups.
在两个年龄段的断奶前大鼠中研究了产前应激对压力诱导的行为和激素反应的影响。产前应激处理包括在整个妊娠期每隔一天对怀孕大鼠施加不可控电击。在家笼中未受干扰的大鼠的后代作为对照。当雄性幼崽14天和21天大时，在涉及隔离以及分别以0.5毫安或2.0毫安强度施加足部电击的隔离的10分钟测试中记录超声发声和僵住行为。在每次测试之前和之后立即测量甩尾潜伏期，以评估压力诱导的镇痛作用的变化。在第二次甩尾测试后获得的血浆中测量压力诱导的促肾上腺皮质激素（ACTH）分泌。结果表明，产前应激的14天大的幼崽发出的超声发声明显较少，并且与对照幼崽相比，甩尾潜伏期的百分比增加明显较低。然而，产前应激大鼠的血浆ACTH显著升高，表明暴露于不同测试是一个应激诱导事件。在21日龄时，产前应激大鼠在超声发声、防御性僵住和甩尾潜伏期的表现上与对照雄性不再有显著差异。然而，在暴露于2.0毫安电击隔离测试后，产前应激大鼠的血浆ACTH含量显著低于对照雄性。研究了动机、成熟和中介因素的参与情况，以解释产前应激和对照幼崽之间在行为和激素反应中出现的这些年龄依赖性和应激源依赖性差异。
