کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6264382 1613987 2012 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Research ReportThe acute response of the amygdalar TRH system to psychogenic stressors varies dependent on the paradigm and circadian condition
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی علوم اعصاب (عمومی)
پیش نمایش صفحه اول مقاله
Research ReportThe acute response of the amygdalar TRH system to psychogenic stressors varies dependent on the paradigm and circadian condition
چکیده انگلیسی

Central administration of thyrotropin releasing hormone (TRH) reduces anxiety; amygdalar TRH expression is inversely proportional to the anxious behavior displayed in the elevated plus maze performed during the dark phase (EPM-D). To better understand the role of TRH in amygdala function, we evaluated the expression of TRH and the elements involved in its transmission in various stressful paradigms and how they associated with behavior. Wistar male rats were exposed to restraint (RES), EPM, or the open field test (OFT) and sacrificed 0-60 min afterwards; OFT, RES and EPM were performed during the light (L), and OFT during the dark phase. Restraint increased amygdalar levels of proCRH mRNA, without change in proTRH. All paradigms augmented corticosterone release, highest after OFT-L that also enhanced proCRH mRNA levels and decreased those of proTRH. OFT-D activated the TRH system. Levels of anxiety or locomotion were similar in animals tested in light or dark phases but their association with biochemical parameters differed. ProTRH expression and TRH release correlated positively with decreased anxiety in EPM-L and in OFT-D. No association with anxiety was detected in OFT-L where proCRH and proTRH expression correlated with locomotion supporting their involvement in arousal. The responses of TRH amygdalar systems appeared modulated by the extent of the stress response and by the circadian conditions. Increased proTRH expression of animals exposed to OFT-D was specifically observed in the cortical nucleus of the amygdala, area involved in processing fear stimuli; these TRH neurons may thus be part of a circuit with anxiolytic properties.

► Amygdalar TRH system responds according to the stressor type and circadian condition. ► TRHergic neurons' activity negatively correlates with anxiety in EPM in both circadian phases. ► Activation of TRHergic neurons decreases anxiety in OFT performed in the dark phase. ► TRH neurons are specifically activated in CoAa during OFT-D. ► CRH expression in amygdala is not upregulated by all psychological stressors.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Brain Research - Volume 1452, 3 May 2012, Pages 73-84
نویسندگان
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