| Titre : | Control of circadian activity of birds by the interaction of melatonin with 7 alpha-hydroxypregnenolone, a newly discovered neurosteroid stimulating locomotion |
| Auteurs : | Kazuyoshi Tsutsui, Auteur ; Shogo Haraguchi, Auteur ; Kazuhiko Inoue, Auteur ; Hitomi Miyabara, Auteur ; Saori Suzuki, Auteur ; Takayoshi Ubuka, Auteur |
| Type de document : | Article |
| Dans : | Journal of Ornithology (153 AUG 2012) |
| Article en page(s) : | S235-S243 |
| Langues: | Anglais |
| Résumé : | Melatonin regulates diurnal locomotor rhythms in birds as well as in other vertebrates, but the molecular mechanism by which melatonin regulates locomotor activity is poorly understood. Here, we summarize new findings showing that 7 alpha-hydroxypregnenolone, a previously undescribed avian neurosteroid, mediates melatonin action on diurnal locomotor rhythms in birds. Recently, 7 alpha-hydroxypregnenolone was identified as a novel avian neurosteroid in Japanese quail Coturnix japonica brain. It was found that 7 alpha-hydroxypregnenolone acutely stimulates quail locomotor activity. Subsequently, it was clarified that diurnal changes in 7 alpha-hydroxypregnenolone synthesis occur in parallel with changes in locomotor activity in quail. Finally, it was demonstrated that melatonin depresses the synthesis of 7 alpha-hydroxypregnenolone, thus providing a mechanism through which the nocturnal increase in melatonin regulates diurnal changes in locomotor activity. This review highlights a novel molecular mechanism controlling circadian activity of birds by the interaction of melatonin with 7 alpha-hydroxypregnenolone, a newly discovered neurosteroid stimulating locomotion. |



