Brain-Body Center, Department of Psychiatry, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA.
Psychoneuroendocrinology. 2011 Jul;36(6):780-9. doi: 10.1016/j.psyneuen.2010.10.015. Epub 2010 Nov 20.
Previous studies have demonstrated that various type of stressors modulate messenger ribonucleic acid (mRNA) for type 1 corticotropin-releasing hormone (CRH) receptor (CRH-R1 mRNA) and type 2 CRH receptor (CRH-R2 mRNA). The purpose of this study was to explore the effect of social isolation stress of varying durations on the CRH, CRH-R1 and CRH-R2 mRNAs expression in the hypothalamus, hippocampus and pituitary of socially monogamous female and male prairie voles (Microtus ochrogaster). Isolation for 1h (single isolation) or 1h of isolation every day for 4 weeks (repeated isolation) was followed by a significant increase in plasma corticosterone levels. Single or repeated isolation increased hypothalamic CRH mRNA expression, but no changes in CRH-R1 mRNA in the hypothalamus were observed. Continuous isolation for 4 weeks (chronic isolation) showed no effect on hypothalamic CRH or CRH-R1 mRNAs in female or male animals. However, hypothalamic CRH-R2 mRNA was significantly reduced in voles exposed to chronic isolation. Single or repeated isolation, but not chronic isolation, significantly increased CRH-R1 mRNA and decreased CRH-R2 mRNA in the pituitary. Despite elevated CRH mRNA expression, CRH-R1 and CRH-R2 mRNAs were not modulated in the hippocampus following single or repeated isolation. Although, chronic isolation did not affect hippocampal CRH or CRH-R1 mRNAs, it did increase CRH-R2 mRNA expression in females and males. The results of the present study in prairie voles suggest that social isolation has receptor subtype and species-specific consequences for the modulation of gene expression for CRH and its receptors in brain and pituitary. Previous studies have revealed a female-biased increase in oxytocin in response to chronic isolation; however, we did not find a sex difference in CRH or its receptors following single, repeated or chronic social isolation, suggesting that sexually dimorphic processes beyond the CRH system, possibly involving vasopressin, might explain this difference.
先前的研究表明，各种类型的应激源会调节 1 型促肾上腺皮质激素释放激素（CRH）受体（CRH-R1 mRNA）和 2 型 CRH 受体（CRH-R2 mRNA）的信使核糖核酸（mRNA）。本研究的目的是探讨不同持续时间的社会隔离应激对社会一夫一妻制的雌性和雄性草原田鼠（Microtus ochrogaster）下丘脑、海马和垂体中 CRH、CRH-R1 和 CRH-R2 mRNA 表达的影响。单独隔离 1 小时（单次隔离）或每天隔离 1 小时，持续 4 周（重复隔离）后，血浆皮质酮水平显著升高。单次或重复隔离会增加下丘脑 CRH mRNA 的表达，但下丘脑 CRH-R1 mRNA 没有变化。连续隔离 4 周（慢性隔离）对雌性或雄性动物的下丘脑 CRH 或 CRH-R1 mRNA 没有影响。然而，慢性隔离会导致草原田鼠下丘脑 CRH-R2 mRNA 显著减少。单次或重复隔离，但不是慢性隔离，会显著增加垂体中 CRH-R1 mRNA 的表达，并降低 CRH-R2 mRNA 的表达。尽管 CRH mRNA 的表达升高，但单次或重复隔离后，海马中的 CRH-R1 和 CRH-R2 mRNA 并未发生调节。尽管慢性隔离不会影响海马中的 CRH 或 CRH-R1 mRNA，但它会增加雌性和雄性动物海马中 CRH-R2 mRNA 的表达。本研究在草原田鼠中的结果表明，社会隔离对 CRH 及其受体在脑和垂体中的基因表达的调节具有受体亚型和物种特异性的影响。先前的研究表明，慢性隔离会导致雌性动物的催产素增加，但我们没有发现单一、重复或慢性社会隔离后 CRH 或其受体存在性别差异，这表明 CRH 系统以外的性别二态过程，可能涉及加压素，可能解释了这种差异。
