Endogenous Regulation of Serotonin Release in the Hamster Suprachiasmatic Nucleus
| Autor: | Lisa A. Dinardo, Dudley Te, J. D. Glass |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Male
Serotonin medicine.medical_specialty Microdialysis Circadian clock Stimulation Motor Activity Biology Serotonergic Article Piperazines Cricetinae Internal medicine medicine Animals Autoreceptors Mesocricetus Raphe Suprachiasmatic nucleus General Neuroscience Circadian Rhythm Endocrinology Light effects on circadian rhythm Receptors Serotonin Autoreceptor Suprachiasmatic Nucleus sense organs Receptors Serotonin 5-HT1 |
| Zdroj: | The Journal of Neuroscience. 18:5045-5052 |
| ISSN: | 1529-2401 0270-6474 |
| Popis: | Serotonin (5-HT) has been strongly implicated in the regulation of the mammalian circadian clock located in the suprachiasmatic nuclei (SCN). However, little is known of the pattern of neuronal 5-HT release in the SCN or of the factors involved in regulating its release. Usingin vivomicrodialysis, we demonstrated the existence of a daily rhythm in the output of 5-HT in the SCN of freely behaving hamsters. This rhythm was characterized by a sharp increase in release from a nadir during late midday to peak levels at the light/dark transition. Output declined to basal levels throughout the remainder of the night. A similar pattern also was evident under constant darkness, with increased 5-HT output occurring at the onset of subjective night. Locomotor activity induced by exposure to a novel running wheel had a pronounced phase-dependent effect on 5-HT release in the SCN, with stimulation during the light phase and suppression during the late dark phase. Systemic application of the somatodendritic 5-HT1Aagonist BMY 7378 had a significantly greater suppressive effect on 5-HT release in the SCN during the late dark phase compared with mid light phase, indicating that a variation in raphe autoreceptor response may underlie the time-dependent effects of wheel running on 5-HT release. Collectively, these results show that the daily rhythm in output of 5-HT in the SCN is generated endogenously, and that behavioral state can strongly influence serotonergic activity in the circadian clock in a phase-dependent manner. |
| Databáze: | OpenAIRE |
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