Phase-resetting response to (+)8-OH-DPAT, a serotonin 1A/7 receptor agonist, in the mouse in vivo.
Several lines of evidence indicate that 5-HT neuronal systems may play a critical role for the non-photic entrainment of the rodent circadian clock. Although it is well established that (+)8-hydroxy-2-(di-n-propylamino)tetralin [(+)8-OH-DPAT], a 5-HT(1A/7) receptor agonist, causes a phase-advance of behavioral rhythm in hamsters, little is known whether this agent produces phase shifts of activity rhythm in mice. Therefore, we examined the effect of (+)8-OH-DPAT on the mouse locomotor activity rhythm. Systemic administration of this chemical at mid-subjective daytime induced a clear and dose-dependent phase advance, while there were no significant phase shifts at other times (early-subjective day, late-subjective day, or subjective night). Additionally, (+)8-OH-DPAT accelerated the re-entrainment of mouse behavioral rhythm to a 6-h advanced light-dark cycle. These results suggest that we can use mice for understanding the molecular mechanism of (+)8-OH-DPAT-induced phase shift because of availability of clock gene targeted mice.
Horikawa
Kazumasa
K
Department of Pharmacology, School of Science and Engineering, Waseda University, Higashifushimi 2-7-5, Nishitokyo-Shi, Tokyo 202-0021, Japan.
Shibata
Shigenobu
S
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology*; D000818:Animals; D001683:Biological Clocks / Q000187:drug effects*; D002940:Circadian Rhythm / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009043:Motor Activity / Q000187:drug effects; D058825:Serotonin 5-HT1 Receptor Agonists; D013997:Time Factors
D058825:Serotonin 5-HT1 Receptor Agonists; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin