Multiphotoreceptor and multioscillator system in avian circadian organization.
Photoperiodism and circadian rhythms have been studied intensively in birds because Aves are typical seasonal breeders and diurnal animals. Light is the most important environmental factor involved in entrainment of circadian rhythms and photoperiodism. The eyes and the extraocular photoreceptors, such as the pineal organ and hypothalamus, are reported to have an important function not only for photoreception but also for circadian organization in nonmammalian vertebrates, including birds. In this report, we review the roles of the eyes, pineal organ, and deep brain as the components of the multiphotoreceptor and multioscillator system in avian circadian organization.
Oishi
T
T
Graduate School of Human Culture, Nara Women's University, Nara 630-8506, Japan. oishi@cc.nara-wu.ac.jp
Yamao
M
M
Kondo
C
C
Haida
Y
Y
Masuda
A
A
Tamotsu
S
S
D000818:Animals; D001683:Biological Clocks / Q000502:physiology*; D001717:Birds / Q000033:anatomy & histology / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology*; D007031:Hypothalamus / Q000166:cytology / Q000502:physiology; D009799:Ocular Physiological Phenomena; D017440:Photoperiod; D020419:Photoreceptor Cells, Vertebrate / Q000502:physiology*; D010870:Pineal Gland / Q000502:physiology / Q000648:ultrastructure