Local administration of serotonin agonists blocks light-induced phase advances of the circadian activity rhythm in the hamster
| Autor: | M. A. Rea, Robert L. Gannon, E. T. Weber |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
0301 basic medicine
Agonist Male endocrine system medicine.medical_specialty Serotonin Light Microinjections Physiology medicine.drug_class Photoperiod Circadian clock 5 7-Dihydroxytryptamine Motor Activity Serotonergic 03 medical and health sciences 0302 clinical medicine Physiology (medical) Internal medicine Cricetinae medicine Animals Circadian rhythm 8-Hydroxy-2-(di-n-propylamino)tetralin Raphe Mesocricetus Chemistry Suprachiasmatic nucleus Circadian Rhythm Serotonin Receptor Agonists 030104 developmental biology Endocrinology nervous system Light effects on circadian rhythm Suprachiasmatic Nucleus 030217 neurology & neurosurgery Serotonin Agonist |
| Zdroj: | Journal of biological rhythms. 13(3) |
| ISSN: | 0748-7304 |
| Popis: | Circadian rhythms in mammals are synchronized to environmental light-dark cycles through a direct retinal projection to the suprachiasmatic nucleus (SCN), a circadian clock. This process is thought to be modulated by other afferents to the SCN, including a dense serotonergic projection from the midbrain raphe. Previous work from this laboratory demonstrated that a systemically administered 5-hydroxytry ptamine1A/7 (5-HT1A/7) agonist 8-hydroxy-2-(di- n-propylamino)tetralin (8-OH-DPAT) dose dependently attenuates light-induced phase shifts of the circadian activity rhythm of the Syrian hamster. In this study, we demonstrate that local injections (1-100 μM) of the 5-HT1A/7 agonists 8-OH-DPAT or 5-carboxamidotryptamine into the region of the SCN inhibit light-induced phase advances of the circadian wheel-running rhythm. In addition, the inhibitory effects of systemically administered 8-OH-DPAT were unaffected by either radiofrequency-induced lesions of the intergeniculate leaflet or 5,7-dihydroxytryptamine-induced lesions of serotonergic projections to the SCN. These findings support a modulatory role of serotonin in photic regulation of circadian phase through an action at the level of the SCN. |
| Databáze: | OpenAIRE |
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