دانلود مقاله ISI انگلیسی شماره 144348
کد مقاله سال انتشار مقاله انگلیسی ترجمه فارسی تعداد کلمات
144348 2017 13 صفحه PDF سفارش دهید 8080 کلمه
خرید مقاله
پس از پرداخت، فوراً می توانید مقاله را دانلود فرمایید.
عنوان انگلیسی
Alpha1-adrenergic receptor blockade in the VTA modulates fear memories and stress responses
منبع

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

Journal : European Neuropsychopharmacology, Volume 27, Issue 8, August 2017, Pages 782-794

پیش نمایش مقاله
پیش نمایش مقاله

چکیده انگلیسی

Activity of the ventral tegmental area (VTA) and its terminals has been implicated in the Pavlovian associative learning of both stressful and rewarding stimuli. However, the role of the VTA noradrenergic signaling in fear responses remains unclear. We aimed to examine how alpha1-adrenergic receptor (α1-AR) signaling in the VTA affects conditioned fear. The role of α1-AR was assessed using the micro-infusions into the VTA of the selective antagonists (0.1–1 µg/0.5 µl prazosin and 1 µg/0.5 µl terazosin) in acquisition and expression of fear memory. In addition, we performed control experiments with α1-AR blockade in the mammillary bodies (MB) – a brain region with α1-AR expression adjacent to the VTA. Intra-VTA but not intra-MB α1-AR blockade prevented formation and retrieval of fear memories. Importantly, local administration of α1-AR antagonists did not influence footshock sensitivity, locomotion or anxiety-like behaviors. Similarly, α1-AR blockade in the VTA had no effects on negative affect measured as number of 22 kHz ultrasonic vocalizations during fear conditioning training. We propose that noradrenergic signaling in the VTA via α1-AR regulates formation and retrieval of fear memories but not other behavioral responses to stressful environmental stimuli. It enhances the encoding of environmental stimuli by the VTA to form and retrieve conditioned fear memories and to predict future behavioral outcomes. Our results provide novel insight into the role of the VTA α1-AR signaling in the regulation of stress responsiveness and fear memory.

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