title: Two distinct serotonin receptors co-mediate non-photic signals to the circadian clock.
abstract: Several lines of evidence indicate that serotonin type 7 (5-HT7) receptors play a critical role for non-photic resetting of the mammalian circadian clock; however, the contributions of other types of 5-HT receptors to non-photic entrainment are not yet clarified. The present study demonstrates that MKC-242, a selective 5-HT1A receptor agonist, can evoke a non-photic-like phase-response in hamsters in vivo. This phase-shifting response to MKC-242 was antagonized not only by the selective 5-HT1A receptor blocker WAY100635 but also by the selective 5-HT7 receptor blocker DR4004. These suggest that synchronous activation of 5-HT1A and 5-HT7 receptors mediates non-photic signals to the hamster circadian clock.
authors.affiliation: Advanced Research Center for Human Sciences, School of Human Sciences, Waseda University, Japan.
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Horikawa
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Fuji
authors.forename: Yuka
authors.initials: Y
authors.lastname: Fukazawa
authors.forename: Shigenobu
authors.initials: S
authors.lastname: Shibata
mesh_terms: D000818:Animals; D057906:Circadian Clocks / Q000235:genetics* / Q000502:physiology*; D006224:Cricetinae; D003624:Darkness; D004146:Dioxanes / Q000037:antagonists & inhibitors / Q000494:pharmacology; D004149:Dioxoles / Q000037:antagonists & inhibitors / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D008297:Male; D010879:Piperazines / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D044282:Receptor, Serotonin, 5-HT1A / Q000378:metabolism / Q000502:physiology*; D011985:Receptors, Serotonin / Q000378:metabolism / Q000502:physiology*; D058825:Serotonin 5-HT1 Receptor Agonists / Q000494:pharmacology; D058829:Serotonin 5-HT1 Receptor Antagonists / Q000494:pharmacology
chemical_list: C472242:DR-4004; D004146:Dioxanes; D004149:Dioxoles; D007211:Indoles; D010879:Piperazines; D011725:Pyridines; D011985:Receptors, Serotonin; D058825:Serotonin 5-HT1 Receptor Agonists; D058829:Serotonin 5-HT1 Receptor Antagonists; C104425:serotonin 7 receptor; D044282:Receptor, Serotonin, 5-HT1A; C090413:N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridinyl)cyclohexanecarboxamide; C096294:osemozotan