This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Byku, M. Articles by Gannon, R. L. Search for Related Content PubMed PubMed Citation Articles by Byku, M. Articles by Gannon, R. L. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Medline Plus Health Information Seniors' Health Social Bookmarking                         What's this?

Effects of the 5HT1A Agonist/Antagonist BMY 7378 on Light-Induced Phase Advances in Hamster Circadian Activity Rhythms during Aging

Robert L. Gannon

Department of Biology, Dowling College, Oakdale, NY 11769, USA

The entrainment of some circadian rhythms in rodents and humans to the environmental light-dark cycle deteriorates during aging. Recent evidence suggests that the time-keeping ability of the circadian pacemaker maintains its endogenous period in both hamsters and humans. This suggests that any changes in the coupling between environmental cues and the circadian pacemaker are not due to changes in "clock speed," but rather due to a weakened coupling between the afferent systems relaying environmental information and the circadian pacemaker located in the suprachiasmatic nucleus. The suprachiasmatic nucleus receives serotonergic input from the raphe nuclei, and serotonergic 5HT_1A,7 agonists have been reported to lose their circadian phase-adjusting efficacy during aging in hamsters. In the present study, the authors report the effects of a novel serotonergic agonist BMY 7378 on light-induced phase advances during aging in the hamster. The present report demonstrates that BMY 7378 is a highly efficacious chronobiotic that more than doubles the magnitude of light-induced phase shifts in hamster wheel-running activity rhythms. Light-induced phase advances in hamster wheel-running activity of at least 6 h following a single systemic dose of BMY 7378 are routinely observed. Furthermore, BMY 7378 potentiation of phase shifts is maintained in old hamsters, suggesting that BMY 7378 has a different site of activity than previously reported 5HT_1A,7 agonists that have a diminished effect on circadian phase during aging.

Key Words: raphe • suprachiasmatic nucleus • circadian rhythms • chronobiotic • serotonin, aging

Journal of Biological Rhythms, Vol. 15, No. 4, 300-305 (2000)
DOI: 10.1177/074873000129001404


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?