کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
3056776 1580196 2008 13 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Serotonergic activation potentiates light resetting of the main circadian clock and alters clock gene expression in a diurnal rodent
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی عصب شناسی
پیش نمایش صفحه اول مقاله
Serotonergic activation potentiates light resetting of the main circadian clock and alters clock gene expression in a diurnal rodent
چکیده انگلیسی

The main circadian clock, localized in the suprachiasmatic nuclei (SCN) in mammals, can be synchronized by light and non-photic factors such as serotonergic cues. In nocturnal rodents, injections during the subjective day of the 5-HT1A/7 receptor agonist 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) or its positive enantiomer, induce behavioral phase-advances in correlation with decreased expression of two clock genes, Per1/2. In addition, 8-OH-DPAT and the selective serotonin reuptake inhibitor fluoxetine reduce light-induced phase-shifts during the subjective night. Beside the chronobiotic effects of serotonin, changes of serotonergic activity in humans have been involved in mood disorders, that are often associated with alterations in circadian rhythmicity. To get insights into the circadian role of serotonin in diurnal species, we investigated its modulation of the SCN in Arvicanthis ansorgei housed in constant darkness. In striking contrast to nocturnal rodents, daily serotonin content in Arvicanthis SCN peaked during daytime while the sensitivity window of its SCN to (+)8-OH-DPAT occurred essentially during the subjective night. Moreover, fluoxetine produced behavioral phase-advances at circadian time (CT) 0 and CT12. Expression of Per1/2, Rev-erbα/β and Rorα/β in the SCN was not modified after fluoxetine or (+)8-OH-DPAT injection. Furthermore, both treatments enhanced light-induced phase-advances and delays. Light responses of Per1 and Rorβ expression at CT0 and those of Per2 and Rev-erbα at CT12 were markedly altered by serotonergic activation. The present findings demonstrate that the serotonergic modulation of the SCN clock appears to differ between nocturnal species and the diurnal Arvicanthis. The potentiating effects of fluoxetine on light resetting in a diurnal rodent may be clinically relevant.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Experimental Neurology - Volume 210, Issue 2, April 2008, Pages 501–513
نویسندگان
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