Grup de Recerca en Neurobiologia del Comportament-GReNeC, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona, Dr Aiguader 88, 08003 Barcelona, Spain.
Pharmacol Biochem Behav. 2012 Sep;102(3):434-41. doi: 10.1016/j.pbb.2012.06.001. Epub 2012 Jun 9.
Early-life stressful experiences are associated to alterations in behavioural responses and development of psychiatric and neurodegenerative diseases. In rodents, individual housing is considered as a stressful condition whilst enriched environment can protect against stress and its negative consequences. Neuroendocrine responses to stress can also be altered by early-life experiences and seem to contribute to behavioural alterations induced by changes in housing conditions.
To develop an improved procedure of social isolation throughout development (from pre-adolescence to adulthood) in CD1 mice and to elucidate its effects on behavioural parameters related to stress and neuroendocrine responses compared to enriched or social conditions.
CD1 male mice (PND 21) were housed in social/standard conditions, enriched conditions or isolated conditions during seven weeks. After that, different relevant behaviours were evaluated, including locomotor activity, anxiety-like and despair behaviour. Levels of plasma corticosterone were also analysed before and after a stressful event.
CD1 mice exposed to an isolated environment exhibited higher locomotion and anxiety-like responses than animals exposed to social or enriched conditions. In addition, isolated animals showed lower basal plasma corticosterone than social or enriched ones but after a stressful event the elevation of plasma corticosterone was higher, suggesting an enhanced response of the HPA axis to a novel and stressful situation.
Social interaction is an important feature to display an appropriate behavioural and neuronal development. Habituation to novel stimuli is impaired in subjects exposed to social isolation and induces increased excitability response to stressful events. Social deprivation increases the possibility of altered neuronal function and could facilitate the development of neuropsychiatric disorders in adulthood.
早期生活中的压力经历与行为反应的改变以及精神疾病和神经退行性疾病的发生有关。在啮齿动物中，单独饲养被认为是一种应激条件，而丰富的环境可以保护免受应激及其负面影响。应激的神经内分泌反应也可以被早期生活经历改变，并似乎有助于解释由饲养条件改变引起的行为改变。
在 CD1 小鼠中开发一种改进的从青春期前到成年期全程的社交隔离程序，并阐明其与丰富或社交条件相比，对与应激和神经内分泌反应相关的行为参数的影响。
CD1 雄性小鼠（PND 21）在社交/标准条件、丰富条件或隔离条件下饲养七周。之后，评估了不同相关的行为，包括运动活动、焦虑样和绝望行为。在应激事件前后还分析了血浆皮质酮水平。
暴露于隔离环境中的 CD1 小鼠表现出比暴露于社交或丰富环境中的动物更高的运动和焦虑样反应。此外，与社交或丰富环境相比，隔离动物的基础血浆皮质酮水平较低，但在应激事件后，血浆皮质酮的升高更高，这表明 HPA 轴对新的应激情况的反应增强。
社交互动是表现出适当行为和神经元发育的重要特征。暴露于社交隔离的个体对新刺激的习惯化受损，导致对应激事件的兴奋性反应增加。社会剥夺增加了神经元功能改变的可能性，并可能促进成年期神经精神疾病的发展。
