دانلود مقاله ISI انگلیسی شماره 69930
ترجمه فارسی عنوان مقاله

افزایش استرس یادگیری ترس در موش سوری وابسته به نوع عوامل استرس زا است: اثر هورمون های جنسی و تخمدان

عنوان انگلیسی
Stress enhancement of fear learning in mice is dependent upon stressor type: Effects of sex and ovarian hormones
کد مقاله سال انتشار تعداد صفحات مقاله انگلیسی
69930 2010 9 صفحه PDF
منبع

Publisher : Elsevier - Science Direct (الزویر - ساینس دایرکت)

Journal : Neurobiology of Learning and Memory, Volume 94, Issue 2, September 2010, Pages 254–262

ترجمه کلمات کلیدی
استرس مزمن؛ شرطی سازی ترس پاولوفی؛ تفاوت جنسی؛ هورمون
کلمات کلیدی انگلیسی
Chronic stress; Pavlovian fear conditioning; Sex differences; Hormones
پیش نمایش مقاله
پیش نمایش مقاله  افزایش استرس یادگیری ترس در موش سوری وابسته به نوع عوامل استرس زا است: اثر هورمون های جنسی و تخمدان

چکیده انگلیسی

In three experiments, chronic stress enhancement of subsequent fear learning was investigated in C57Bl/6 mice. The first experiment focused on the influence of stressor type on subsequent Pavlovian fear learning. Male mice were subjected to 7 d of either repeated restraint stress or chronic variable stress before undergoing a fear conditioning procedure with three tone-shock trials. Subsequent tests were conducted of contextual and tone fear, through measures of the freezing response. Repeated restraint altered pre-training activity and the unconditional response to shock, but was ineffective in influencing conditional fear. Chronic variable stress significantly inflated contextual fear without altering tone fear. In a second experiment, investigating potential sex differences in the fear-enhancing effects of stress, female mice were subjected to the very same procedures. Among females, chronic variable stress selectively altered tone fear, rather than contextual fear. A final experiment investigated the potential role of ovarian hormones by subjecting female mice to either ovariectomy or sham surgery before the stress procedures. Ovariectomy had no significant effect on the ability of stress to enhance fear in females. In sum, the experiments indicate that stressor type significantly influences subsequent fear learning, that males and females are differentially sensitive to fear enhancement by stress, and that the mechanisms mediating these sex differences lie outside of the immediate influence of ovarian hormones. The findings should allow for refinement of animal models of human psychiatric disorders and for further investigations into the genetic and molecular substrates of significant gender differences in fear and anxiety.