Daily rhythm of tryptophan hydroxylase-2 messenger ribonucleic acid within raphe neurons is induced by corticoid daily surge and modulated by enhanced locomotor activity

被引:102
作者
Malek, Zeina S. [1 ]
Sage, Dominique [1 ]
Pevet, Paul [1 ]
Raison, Sylvie [1 ]
机构
[1] Univ Strasbourg, Inst Neurosci Cellulaires & Integrat, Dept Neurobiol Rythmes, CNRS,UMR 7168, F-67084 Strasbourg, France
关键词
D O I
10.1210/en.2007-0526
中图分类号
R5 [内科学];
学科分类号
1002 ; 100201 ;
摘要
Tryptophan hydroxylase (TPH, the rate-limiting enzyme of serotonin synthesis) protein and mRNA levels display a circadian expression in the rat dorsal and median raphe. These patterns suggest a rhythmic synthesis of serotonin under the control of the master clock of suprachiasmatic nuclei. In the present study, we examined the involvement of endocrine and behavioral output signals of the master clock upon the Tph2 mRNA levels by quantitative in situ hybridization. In the absence of adrenals, a complete suppression of Tph2 mRNA rhythm was observed in dorsal and median raphe over 24 h. The restoration of corticosterone daily variations in adrenalectomized rats induced a Tph2 mRNA rhythmic pattern de novo, indicating that Tph2 mRNA rhythm is dependent upon daily fluctuations of glucocorticoids. Enhanced voluntary locomotor activity during 6 wk increased the level of Tph2 mRNA in both raphe nuclei of control rats without concomitant increase of corticosterone plasma levels. Moreover, this long-term enhanced locomotor activity was able to restore significant variation of Tph2 mRNA in adrenalectomized rats. In conclusion, both endocrine and behavioral cues can modulate Tph2 expression in dorsal and median raphe. The corticosterone surge acts as a rhythmic cue that induces the rhythmic expression of Tph2 in the raphe neurons. On the other hand, long-term exercise modulates the expression levels of this gene. Thus, the serotonin neurons are a target for both endocrine and behavioral circadian cues, and the serotoninergic input to the suprachiasmatic nuclei might feedback and influence the functioning of the clock itself.
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页码:5165 / 5172
页数:8
相关论文
共 45 条
[41]   Changes in forebrain serotonin at the light-dark transition: Correlation with behaviour [J].
Rueter, LE ;
Jacobs, BL .
NEUROREPORT, 1996, 7 (05) :1107-1111
[42]   Influence of the corticosterone rhythm on photic entrainment of locomotor activity in rats [J].
Sage, D ;
Ganem, J ;
Guillaumond, F ;
Laforge-Anglade, G ;
François-Bellan, AM ;
Bosler, O ;
Becquet, D .
JOURNAL OF BIOLOGICAL RHYTHMS, 2004, 19 (02) :144-156
[43]   Glucocorticoid rhythms control the rhythm of expression of the clock protein, Period2, in oval nucleus of the bed nucleus of the stria terminalis and central nucleus of the amygdala in rats [J].
Segall, L. A. ;
Perrin, J. S. ;
Walker, C. -D. ;
Stewart, J. ;
Amir, S. .
NEUROSCIENCE, 2006, 140 (03) :753-757
[44]   INCREASES IN THE ACTIVITY OF TRYPTOPHAN-HYDROXYLASE FROM RAT CORTEX AND MIDBRAIN IN RESPONSE TO ACUTE OR REPEATED SOUND STRESS ARE BLOCKED BY ADRENALECTOMY AND RESTORED BY DEXAMETHASONE TREATMENT [J].
SINGH, VB ;
CORLEY, KC ;
PHAN, TH ;
BOADLEBIBER, MC .
BRAIN RESEARCH, 1990, 516 (01) :66-76
[45]   Let there be ''more'' light: enhancement of light actions on the circadian system through non-photic pathways [J].
Yannielli, P ;
Harrington, ME .
PROGRESS IN NEUROBIOLOGY, 2004, 74 (01) :59-76