Identification of the suprachiasmatic nucleus in birds

T. Yoshimura, Shinobu Yasuo, Y. Suzuki, E. Makino, Y. Yokota, S. Ebihara

Research output: Contribution to journalArticle

64 Citations (Scopus)

Abstract

Circadian rhythms are generated by an internal biological clock. The suprachiasmatic nucleus (SCN) in the hypothalamus is known to be the dominant biological clock regulating circadian rhythms in mammals. In birds, two nuclei, the so-called medial SCN (mSCN) and the visual SCN (vSCN), have both been proposed to be the avian SCN. However, it remains an unsettled question which nuclei are homologous to the mammalian SCN. We have identified circadian clock genes in Japanese quail and demonstrated that these genes are expressed in known circadian oscillators, the pineal and the retina. Here, we report that these clock genes are expressed in the mSCN but not in the vSCN in Japanese quail, Java sparrow, chicken, and pigeon. In addition, mSCN lesions eliminated or disorganized circadian rhythms of locomotor activity under constant dim light, but did not eliminate entrainment under light-dark (LD) cycles in pigeon. However, the lesioned birds became completely arrhythmic even under LD after the pineal and the eye were removed. These results indicate that the mSCN is a circadian oscillator in birds.

Original languageEnglish
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Volume280
Issue number4 49-4
Publication statusPublished - 2001
Externally publishedYes

Fingerprint

Suprachiasmatic Nucleus
Birds
Circadian Rhythm
Biological Clocks
Coturnix
Columbidae
Sparrows
Genes
Light
Circadian Clocks
Photoperiod
Locomotion
Hypothalamus
Retina
Mammals
Chickens

All Science Journal Classification (ASJC) codes

  • Physiology
  • Physiology (medical)

Cite this

Identification of the suprachiasmatic nucleus in birds. / Yoshimura, T.; Yasuo, Shinobu; Suzuki, Y.; Makino, E.; Yokota, Y.; Ebihara, S.

In: American Journal of Physiology - Regulatory Integrative and Comparative Physiology, Vol. 280, No. 4 49-4, 2001.

Research output: Contribution to journalArticle

Yoshimura, T. ; Yasuo, Shinobu ; Suzuki, Y. ; Makino, E. ; Yokota, Y. ; Ebihara, S. / Identification of the suprachiasmatic nucleus in birds. In: American Journal of Physiology - Regulatory Integrative and Comparative Physiology. 2001 ; Vol. 280, No. 4 49-4.
@article{251153aeea3a48cdb194b0ae99e229b2,
title = "Identification of the suprachiasmatic nucleus in birds",
abstract = "Circadian rhythms are generated by an internal biological clock. The suprachiasmatic nucleus (SCN) in the hypothalamus is known to be the dominant biological clock regulating circadian rhythms in mammals. In birds, two nuclei, the so-called medial SCN (mSCN) and the visual SCN (vSCN), have both been proposed to be the avian SCN. However, it remains an unsettled question which nuclei are homologous to the mammalian SCN. We have identified circadian clock genes in Japanese quail and demonstrated that these genes are expressed in known circadian oscillators, the pineal and the retina. Here, we report that these clock genes are expressed in the mSCN but not in the vSCN in Japanese quail, Java sparrow, chicken, and pigeon. In addition, mSCN lesions eliminated or disorganized circadian rhythms of locomotor activity under constant dim light, but did not eliminate entrainment under light-dark (LD) cycles in pigeon. However, the lesioned birds became completely arrhythmic even under LD after the pineal and the eye were removed. These results indicate that the mSCN is a circadian oscillator in birds.",
author = "T. Yoshimura and Shinobu Yasuo and Y. Suzuki and E. Makino and Y. Yokota and S. Ebihara",
year = "2001",
language = "English",
volume = "280",
journal = "American Journal of Physiology - Heart and Circulatory Physiology",
issn = "0363-6135",
publisher = "American Physiological Society",
number = "4 49-4",

}

TY - JOUR

T1 - Identification of the suprachiasmatic nucleus in birds

AU - Yoshimura, T.

AU - Yasuo, Shinobu

AU - Suzuki, Y.

AU - Makino, E.

AU - Yokota, Y.

AU - Ebihara, S.

PY - 2001

Y1 - 2001

N2 - Circadian rhythms are generated by an internal biological clock. The suprachiasmatic nucleus (SCN) in the hypothalamus is known to be the dominant biological clock regulating circadian rhythms in mammals. In birds, two nuclei, the so-called medial SCN (mSCN) and the visual SCN (vSCN), have both been proposed to be the avian SCN. However, it remains an unsettled question which nuclei are homologous to the mammalian SCN. We have identified circadian clock genes in Japanese quail and demonstrated that these genes are expressed in known circadian oscillators, the pineal and the retina. Here, we report that these clock genes are expressed in the mSCN but not in the vSCN in Japanese quail, Java sparrow, chicken, and pigeon. In addition, mSCN lesions eliminated or disorganized circadian rhythms of locomotor activity under constant dim light, but did not eliminate entrainment under light-dark (LD) cycles in pigeon. However, the lesioned birds became completely arrhythmic even under LD after the pineal and the eye were removed. These results indicate that the mSCN is a circadian oscillator in birds.

AB - Circadian rhythms are generated by an internal biological clock. The suprachiasmatic nucleus (SCN) in the hypothalamus is known to be the dominant biological clock regulating circadian rhythms in mammals. In birds, two nuclei, the so-called medial SCN (mSCN) and the visual SCN (vSCN), have both been proposed to be the avian SCN. However, it remains an unsettled question which nuclei are homologous to the mammalian SCN. We have identified circadian clock genes in Japanese quail and demonstrated that these genes are expressed in known circadian oscillators, the pineal and the retina. Here, we report that these clock genes are expressed in the mSCN but not in the vSCN in Japanese quail, Java sparrow, chicken, and pigeon. In addition, mSCN lesions eliminated or disorganized circadian rhythms of locomotor activity under constant dim light, but did not eliminate entrainment under light-dark (LD) cycles in pigeon. However, the lesioned birds became completely arrhythmic even under LD after the pineal and the eye were removed. These results indicate that the mSCN is a circadian oscillator in birds.

UR - http://www.scopus.com/inward/record.url?scp=0035016118&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0035016118&partnerID=8YFLogxK

M3 - Article

C2 - 11247843

AN - SCOPUS:0035016118

VL - 280

JO - American Journal of Physiology - Heart and Circulatory Physiology

JF - American Journal of Physiology - Heart and Circulatory Physiology

SN - 0363-6135

IS - 4 49-4

ER -