Circadian and circannual rhythms in the function of central 5-HT1A receptors in laboratory rats.
In order to elucidate whether a circannual rhythm exists in the function of the central serotonin (5-HT) system, we examined the responsiveness of rats to a selective 5-HT1A agonist, 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT), at different hours of the day in different seasons. The results indicate that both a circadian rhythm and a circannual rhythm exist in the responsiveness. The phases of the circadian rhythm exhibit 1-year period variations, while those of the circannual rhythm exhibit 1-day period variations. These results will help to clarify the disparities among the reports on circadian and circannual rhythms in the phenomenon related to the central 5-HT system.
Nagayama
H
H
Department of Neuropsychiatry, Oita Medical University, Japan. nagayama@oita-med.ac.jp
Lu
J Q
JQ
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000818:Animals; D002940:Circadian Rhythm / Q000187:drug effects / Q000502:physiology*; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology*; D012621:Seasons; D017366:Serotonin Receptor Agonists / Q000494:pharmacology
D011985:Receptors, Serotonin; D017366:Serotonin Receptor Agonists; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin