Gilles E E, Schultz L, Baram T Z
Department of Neurology, University of Southern California, USA.
Pediatr Neurol. 1996 Sep;15(2):114-9. doi: 10.1016/0887-8994(96)00153-1.
Neuroendocrine correlates of chronic stress in human infants have not been established. The goal of the present study was to create an animal model of continuous chronic stress using the immature rat to measure basal plasma corticosterone, and secretion of plasma corticosterone in response to an acute stress. This was achieved by modulation of the cage environment for rat pups and their mothers. During postnatal days 2-9, pups were maintained in three groups: (1) handled, (2) not handled and with ample bedding; and (3) not handled with limited bedding. On postnatal day 9, some pups from each group were subjected to acute cold-separation stress and were killed 90, 240, or 360 min later along with unstressed controls. The group not handled and with limited bedding manifested increased plasma corticosterone output even without cold exposure and a sustained increase of plasma corticosterone after cold-separation stress. Plasma corticosterone interanimal variability was increased and body weight was decreased in these pups, typical of a state of chronic stress. The first model of continuous stress in infant rats in which upregulation of hypothalamic-pituitary-adrenal axis is achieved without maternal separation is presented. This paradigm may more closely approximate the human situation of chronically stressed, neglected infants.
人类婴儿慢性应激的神经内分泌关联尚未明确。本研究的目的是利用未成熟大鼠创建一种持续慢性应激的动物模型，以测量基础血浆皮质酮以及急性应激反应时血浆皮质酮的分泌情况。这是通过调节幼鼠及其母鼠的饲养环境来实现的。在出生后第2至9天，幼鼠被分为三组：（1）接受抚摸；（2）未接受抚摸且有充足垫料；（3）未接受抚摸且垫料有限。在出生后第9天，每组中的一些幼鼠遭受急性冷分离应激，并在90、240或360分钟后与未受应激的对照组一起处死。未接受抚摸且垫料有限的组即使在没有冷暴露的情况下也表现出血浆皮质酮产量增加，并且在冷分离应激后血浆皮质酮持续升高。这些幼鼠的血浆皮质酮个体间变异性增加，体重下降，这是慢性应激状态的典型表现。本文提出了一种在未进行母鼠分离的情况下实现下丘脑 - 垂体 - 肾上腺轴上调的幼鼠持续应激的首个模型。这种模式可能更接近长期处于应激状态、被忽视的人类婴儿的情况。
