Rosenfeld P, Wetmore J B, Levine S
Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, CA 94305.
Physiol Behav. 1992 Oct;52(4):787-91. doi: 10.1016/0031-9384(92)90415-x.
Previous data indicate that the infant rat shows a marked increase in adrenocortical responsiveness to stress immediately following prolonged maternal separation. In Experiment 1 we studied the immediate effects of repeated maternal deprivation. Our results indicate that the increase in basal as well as stress-induced corticosterone levels is a direct function of the length of the deprivation period immediately preceding testing, and is not cumulative. In Experiment 2 we examined the long-term consequences of maternal deprivation on adrenal responsivity. Four days following a single 24-h period of maternal deprivation, pups remained hyperresponsive to stress, although their basal levels of corticosterone had returned to control values. Shorter periods of deprivation (which did result in increased responsivity immediately following deprivation) did not have persistent effects. Our data suggest: 1) short periods of deprivation do not have a cumulative effect, and 2) there is a critical length of deprivation beyond which persistent changes in adrenocortical responsivity ensue.
先前的数据表明，在长时间母婴分离后，幼鼠对压力的肾上腺皮质反应性会立即显著增加。在实验1中，我们研究了反复母婴剥夺的即时效应。我们的结果表明，基础皮质酮水平以及应激诱导的皮质酮水平的增加是紧接测试前剥夺期长度的直接函数，并非累积性的。在实验2中，我们研究了母婴剥夺对肾上腺反应性的长期影响。在单次24小时母婴剥夺期后的四天，幼崽对压力仍保持高反应性，尽管它们的基础皮质酮水平已恢复到对照值。较短的剥夺期（在剥夺后确实导致反应性增加）没有持续影响。我们的数据表明：1）短时间的剥夺没有累积效应；2）存在一个关键的剥夺时长，超过这个时长，肾上腺皮质反应性就会发生持续性变化。
