Early Emergence of Adult-Like Fear Renewal in the Developing Rat After Chronic Corticosterone Treatment of the Dam or the Pups
Early Emergence of Adult-Like Fear Renewal in the Developing Rat After Chronic Corticosterone Treatment of the Dam or the Pups
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DOI：
10.1037/bne0000009
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发表时间：
2014-10-01
影响因子：
1.9
通讯作者：
Richardson, Rick
中科院分区：
文献类型：
--
作者：
Callaghan, Bridget L.;Richardson, Rick
早期的逆境增加了几乎所有精神健康障碍的风险。尽管存在可控制的动物模型来探索早期逆境的心理生物学，但实证研究主要集中在成人的结果上。在目前的研究中，我们研究了早期暴露于应激激素皮质酮（CORT）如何影响幼鼠恐惧消退的成熟。幼鼠和成年啮齿动物表现出易复发的灭绝学习（即，它们表现出已消失的恐惧的更新和恢复），而在典型的饲养条件下，幼鼠的灭绝系统似乎具有抗复发性（即，灭绝导致条件恐惧的永久减少）。在目前的研究中，我们测试了这样一个假设，即长期暴露于CORT的幼鼠，无论是间接（通过母体饮用水）还是直接（通过渗透泵插入），都会导致幼鼠早期过渡到成年样灭绝系统（即更新效应的证据）。尽管两种暴露方法之间存在一些差异，但数据显示，通过任何一种方法暴露于CORT的婴儿都表现出成人样灭绝学习的过早出现（即他们表现出更新效应）。本文讨论了这些发现对情绪学习系统的典型和异常发展的理论意义，以及它们在预防和治疗精神健康障碍方面的实际应用。
Early adversity increases the risk of nearly all mental health disorders. Although tractable animal models exist to probe the psychobiology of early adversity, the empirical research has focused largely on adult outcomes. In the current studies we examined how early exposure to the stress hormone corticosterone (CORT) affects the maturation of fear extinction in infant rats. Whereas juvenile and adult rodents exhibit extinction learning that is relapse-prone (i.e., they show renewal and reinstatement of extinguished fear), under typical rearing conditions the extinction system in infant rats appears to be relapse-resistant (i.e., extinction leads to a permanent reduction in conditioned fear). In the current studies we tested the hypothesis that chronically exposing infant rats to CORT, either indirectly (through maternal drinking water) or directly (via insertion of an osmotic pump), leads to an early transition into the adult-like extinction system (i.e., evidence of the renewal effect). Although some differences were observed between the 2 methods of CORT exposure, the data showed that infants exposed to CORT via either method exhibited premature emergence of adult-like extinction learning (i.e., they exhibited the renewal effect). The theoretical implications of these findings for typical and abnormal development of emotion learning systems, as well as their practical applications in the context of prevention and treatment of mental health disorders, are discussed.