کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5923004 1571162 2016 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Pinealectomy abolishes circadian behavior and interferes with circadian clock gene oscillations in brain and liver but not retina in a migratory songbird
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی فیزیولوژی
پیش نمایش صفحه اول مقاله
Pinealectomy abolishes circadian behavior and interferes with circadian clock gene oscillations in brain and liver but not retina in a migratory songbird
چکیده انگلیسی


- Pineal affects circadian rhythm but not development of nighttime flight, Zugunruhe.
- Pinealectomy caused decay of circadian rhythm in the 'clock' gene oscillations.
- Tissue-wise effects of pinealectomy on circadian gene oscillations were variable.
- Pineal gland interacts with the brain and liver circadian clocks in songbirds.
- Retinal clock seems to be independent of the pineal gland in migratory songbirds.

In songbirds, the pineal gland is part of the multi-oscillatory circadian timing system, with participating component oscillators in the eyes and hypothalamus. This study investigated the role of the pineal gland in development of the nighttime migratory restlessness (Zugunruhe) and generation of circadian gene oscillations in the retina, brain and liver tissues in migratory redheaded buntings (Emberiza bruniceps). Pinealectomized (pinx) and sham-operated buntings entrained to short days (8 h light: 16 h darkness, 8L:16D) were sequentially exposed for 10 days each to stimulatory long days (13L: 11D) and constant dim light (LLdim; a condition that tested circadian rhythm persistence). Whereas activity-rest pattern was monitored continuously, the mRNA expressions of clock genes (bmal1, clock, npas2, per2, cry1, rorα, reverα) were measured in the retina, hypothalamus, telencephalon, optic tectum and liver tissues at circadian times, CT, 1, 6, 13, 17 and 21 (CT 0, activity onset) on day 11 of the LLdim. The absence of the pineal gland did not affect the development of long-day induced Zugunruhe but caused decay of the circadian rhythm in Zugunruhe as well as the clock gene oscillations in the hypothalamus, but not in the retina. Further, there were variable effects of pinealectomy in the peripheral brain and liver tissue circadian gene oscillations, notably the persistence of per 2 and cry1 (optic tectum), rorα (telencephalon) and npas2 (liver) mRNA oscillations in pinx birds. We suggest the pineal gland dependence of the generation of circadian gene oscillations in the hypothalamus, not retina, and peripheral brain and liver tissues in migratory redheaded buntings.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physiology & Behavior - Volume 156, 15 March 2016, Pages 156-163
نویسندگان
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