Effects of the 5-HT1a receptor agonist 8-OH-DPAT and other non-photic stimuli on the circadian rhythm of wheel-running activity in hamsters under different constant conditions.
Our findings show that administration of the 5-HT1A receptor agonist 8-OH-DPAT (8-hydroxy-2-[di-n-propylamino] tetralin) was able to induce significant phase-advances 4 h before onset of hamster locomotor activity under constant darkness. All other non-photic treatments applied such as melatonin, dimethyl sulphoxide, Ringer, saline or enforced wheel-running failed to induce any significant phase-advances. Similar results were obtained in pinealectomized animals. In constant light (LL), all treatments produced phase-advances. These results show that: (1) LL seems to be an inappropriate constant condition to study the chronobiological effect of drugs or other non-photic stimuli; (2) the endogenous circadian pacemaker (SCN) can be affected specifically by 8-OH-DPAT.
Cutrera
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URA-CNRS 1332, Neurobiologie des Fonctions Rythmiques et Saisonnières, Université Louis Pasteur, Strasbourg, France.
Ouarour
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Pévet
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D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology*; D000818:Animals; D002940:Circadian Rhythm / Q000187:drug effects*; D006224:Cricetinae; D003624:Darkness; D008027:Light; D008297:Male; D008550:Melatonin / Q000494:pharmacology; D008647:Mesocricetus; D009043:Motor Activity / Q000187:drug effects*; D010870:Pineal Gland / Q000502:physiology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*; D013493:Suprachiasmatic Nucleus / Q000502:physiology
D017366:Serotonin Receptor Agonists; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D008550:Melatonin