Abstract
Somatostatin is synthesized in the suprachiasmatic nucleus (SCN), a circadian pacemaker in mammals. To explore the functional significance of somatostatin in the circadian system, we examined rhythms of rat locomotor activity and electrical firing rate of SCN neurons in the brain slice after temporal depletion of somatostatin levels in the SCN. Intraperitoneal administration of cysteamine (200 mg/kg), a somatostatin depletor, significantly reduced somatostatin level in the in vivo SCN 5 min after injection and kept low level as long as 3 to 4 days. This administration, on the other hand, induced significant phase advances of about 51 min in the subsequent free-running rhythm of locomotor activity of the rat. A marked phase advance in the circadian rhythm of firing rate in the SCN was also observed after administration of cysteamine in coronal hypothalamic slices. These persistent phase shifts after administration of a somatostatin depletor may suggest that the change of somatostatin level in the SCN have a feedback influence on the circadian pacemaker.
| Original language | English |
|---|---|
| Pages (from-to) | 677-685 |
| Number of pages | 9 |
| Journal | Journal of Comparative Physiology A |
| Volume | 175 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 1994 Dec |
| Externally published | Yes |
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Keywords
- Brain slice
- Circadian rhythm
- Cysteamine
- Somatostatin
- Suprachiasmatic nucleus
ASJC Scopus subject areas
- Behavioral Neuroscience
- Neuroscience(all)
- Physiology (medical)
- Physiology
- Animal Science and Zoology
Cite this
Phase advances of circadian rhythms in somatostatin depleted rats : effects of cysteamine on rhythms of locomotor activity and electrical discharge of the suprachiasmatic nucleus. / Fukuhara, C.; Inouye, S. I T; Aoki, K.; Hamada, T.; Shibata, Shigenobu; Watanabe, S.
In: Journal of Comparative Physiology A, Vol. 175, No. 6, 12.1994, p. 677-685.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Phase advances of circadian rhythms in somatostatin depleted rats
T2 - effects of cysteamine on rhythms of locomotor activity and electrical discharge of the suprachiasmatic nucleus
AU - Fukuhara, C.
AU - Inouye, S. I T
AU - Aoki, K.
AU - Hamada, T.
AU - Shibata, Shigenobu
AU - Watanabe, S.
PY - 1994/12
Y1 - 1994/12
N2 - Somatostatin is synthesized in the suprachiasmatic nucleus (SCN), a circadian pacemaker in mammals. To explore the functional significance of somatostatin in the circadian system, we examined rhythms of rat locomotor activity and electrical firing rate of SCN neurons in the brain slice after temporal depletion of somatostatin levels in the SCN. Intraperitoneal administration of cysteamine (200 mg/kg), a somatostatin depletor, significantly reduced somatostatin level in the in vivo SCN 5 min after injection and kept low level as long as 3 to 4 days. This administration, on the other hand, induced significant phase advances of about 51 min in the subsequent free-running rhythm of locomotor activity of the rat. A marked phase advance in the circadian rhythm of firing rate in the SCN was also observed after administration of cysteamine in coronal hypothalamic slices. These persistent phase shifts after administration of a somatostatin depletor may suggest that the change of somatostatin level in the SCN have a feedback influence on the circadian pacemaker.
AB - Somatostatin is synthesized in the suprachiasmatic nucleus (SCN), a circadian pacemaker in mammals. To explore the functional significance of somatostatin in the circadian system, we examined rhythms of rat locomotor activity and electrical firing rate of SCN neurons in the brain slice after temporal depletion of somatostatin levels in the SCN. Intraperitoneal administration of cysteamine (200 mg/kg), a somatostatin depletor, significantly reduced somatostatin level in the in vivo SCN 5 min after injection and kept low level as long as 3 to 4 days. This administration, on the other hand, induced significant phase advances of about 51 min in the subsequent free-running rhythm of locomotor activity of the rat. A marked phase advance in the circadian rhythm of firing rate in the SCN was also observed after administration of cysteamine in coronal hypothalamic slices. These persistent phase shifts after administration of a somatostatin depletor may suggest that the change of somatostatin level in the SCN have a feedback influence on the circadian pacemaker.
KW - Brain slice
KW - Circadian rhythm
KW - Cysteamine
KW - Somatostatin
KW - Suprachiasmatic nucleus
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UR - http://www.scopus.com/inward/citedby.url?scp=0028630513&partnerID=8YFLogxK
U2 - 10.1007/BF00191840
DO - 10.1007/BF00191840
M3 - Article
C2 - 7807413
AN - SCOPUS:0028630513
VL - 175
SP - 677
EP - 685
JO - Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology
JF - Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology
SN - 0340-7594
IS - 6
ER -