Perkeybile Allison M, Bales Karen L
Department of Psychology, University of California, Davis, Davis, CA, USA.
Department of Psychology, University of California, Davis, Davis, CA, USA.
Physiol Behav. 2015 Aug 1;147:149-56. doi: 10.1016/j.physbeh.2015.04.024. Epub 2015 Apr 15.
The early life experiences of an organism have the potential to alter its developmental trajectories. Perhaps one of the most powerful influences during this period is the parent-offspring relationship. Previous work in several mammalian species has demonstrated that parental care in early life and specifically maternal behavior can influence several adult outcomes in offspring, including affiliative and aggressive behavior, parental behavior, hypothalamic-pituitary-adrenal (HPA) functioning and risk of psychopathology. We have previously demonstrated that naturally occurring variation in the type and amount of care given to offspring in a biparental species, the prairie vole (Microtus ochrogaster), is related to social, anxiety-like, aggressive behaviors as well as HPA response to chronic and acute social stressors. Here we aim to determine the effects of early biparental care on HPA functioning and the interaction between early care and later reactivity to a forced swim test, an acute non-social stressor. Behavior during the swim test as well as several indicators of HPA activity, including plasma corticosterone (CORT), corticotropin releasing hormone immunoreactivity (CRH-ir), and vasopressin immunoreactivity (AVP-ir) were measured. Results here indicate an effect of early experience on AVP-ir but not CRH-ir or plasma CORT. There were no differences in CORT levels between high-contact (HC) and low-contact (LC) males or females for either control animals or after a swim stressor. CRH-ir was higher in the central amygdala following a swim test but was not influenced by early care. However, AVP-ir was not influenced by exposure to a swim stressor but was affected by early parental care in a sex-dependent manner. Female HC offspring had increased AVP-ir in the SON while HC male offspring had decreased AVP-ir in the PVN compared to their LC counterparts. The differential response of CRH and AVP to early experience and later stress, and the lack of an interaction between early care rearing and later adult stress, suggest an independence in response of some components of the HPA system. In addition, these findings expand our understanding of the relationship between naturally occurring variation in early biparental care and sexual dimorphisms in adult outcomes.
生物体的早期生活经历有可能改变其发育轨迹。在此期间，也许最强大的影响之一是亲子关系。此前在多个哺乳动物物种中的研究表明，早期生活中的父母照料，特别是母性行为，可以影响后代的多种成年后的表现，包括亲和与攻击行为、亲代行为、下丘脑 - 垂体 - 肾上腺（HPA）功能以及精神病理学风险。我们之前已经证明，在双亲物种草原田鼠（Microtus ochrogaster）中，给予后代的照料类型和数量的自然变异，与社交、焦虑样、攻击行为以及HPA对慢性和急性社会应激源的反应有关。在这里，我们旨在确定早期双亲照料对HPA功能的影响，以及早期照料与后期对强迫游泳测试（一种急性非社会应激源）的反应之间的相互作用。我们测量了游泳测试期间的行为以及HPA活动的几个指标，包括血浆皮质酮（CORT）、促肾上腺皮质激素释放激素免疫反应性（CRH - ir）和加压素免疫反应性（AVP - ir）。结果表明，早期经历对AVP - ir有影响，但对CRH - ir或血浆CORT没有影响。对于对照动物或游泳应激后，高接触（HC）和低接触（LC）的雄性或雌性之间的CORT水平没有差异。游泳测试后，中央杏仁核中的CRH - ir较高，但不受早期照料的影响。然而，AVP - ir不受游泳应激暴露的影响，但受到早期父母照料的性别依赖性影响。与LC后代相比，雌性HC后代在室旁核（SON）中的AVP - ir增加，而HC雄性后代在室旁核（PVN）中的AVP - ir减少。CRH和AVP对早期经历和后期应激的不同反应，以及早期照料饲养和后期成年应激之间缺乏相互作用，表明HPA系统的某些组成部分的反应具有独立性。此外，这些发现扩展了我们对早期双亲照料的自然变异与成年后结果中的性别二态性之间关系的理解。
