دانلود مقاله ISI انگلیسی شماره 60838
عنوان فارسی مقاله

استرس مزمن و تفاوت های جنسی در فراخوان شرطی سازی ترس و خاموش سازی

کد مقاله سال انتشار مقاله انگلیسی ترجمه فارسی تعداد کلمات
60838 2009 10 صفحه PDF سفارش دهید محاسبه نشده
خرید مقاله
پس از پرداخت، فوراً می توانید مقاله را دانلود فرمایید.
عنوان انگلیسی
Chronic stress and sex differences on the recall of fear conditioning and extinction
منبع

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

Journal : Neurobiology of Learning and Memory, Volume 91, Issue 3, March 2009, Pages 323–332

کلمات کلیدی
فشار؛ تفاوت جنسیت؛ قشر بجلو مغز؛ شرطی سازی ترس؛ خاموش سازي
پیش نمایش مقاله
پیش نمایش مقاله استرس مزمن و تفاوت های جنسی در فراخوان شرطی سازی ترس و خاموش سازی

چکیده انگلیسی

Chronic stress effects and sex differences were examined on conditioned fear extinction. Male and female Sprague–Dawley rats were chronically stressed by restraint (6 h/d/21 d), conditioned to tone and footshock, followed by extinction after 1 h and 24 h delays. Chronic stress impaired the recall of fear extinction in males, as evidenced by high freezing to tone after the 24 h delay despite exposure to the previous 1 h delay extinction trials, and this effect was not due to ceiling effects from overtraining during conditioning. In contrast, chronic stress attenuated the recall of fear conditioning acquisition in females, regardless of exposure to the 1 h extinction exposure. Since freezing to tone was reinstated following unsignalled footshocks, the deficit in the stressed rats reflected impaired recall rather than impaired consolidation. Sex differences in fear conditioning and extinction were observed in nonstressed controls as well, with control females resisting extinction to tone. Analysis of contextual freezing showed that all groups (control, stress, male, female) increased freezing immediately after the first tone extinction trial, demonstrating contextual discrimination. These findings show that chronic stress and sex interact to influence fear conditioning, with chronic stress impairing the recall of delayed fear extinction in males to implicate the medial prefrontal cortex, disrupting the recall of the fear conditioning acquisition in females to implicate the amygdala, and nonstressed controls exhibiting sex differences in fear conditioning and extinction, which may involve the amygdala and/or corticosterone levels.

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