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Ontogeny of Circadian Rhythms and Synchrony in the Suprachiasmatic Nucleus
- Source :
- The Journal of neuroscience : the official journal of the Society for Neuroscience, vol 38, iss 6, Carmona-Alcocer, V; Abel, JH; Sun, TC; Petzold, LR; III, DFJ; Simms, CL; et al.(2018). Ontogeny of Circadian Rhythms and Synchrony in the Suprachiasmatic Nucleus. JOURNAL OF NEUROSCIENCE, 38(6), 1326-1334. doi: 10.1523/JNEUROSCI.2006-17.2017. UC Santa Barbara: Retrieved from: http://www.escholarship.org/uc/item/2f27r9gh
- Publication Year :
- 2017
- Publisher :
- Society for Neuroscience, 2017.
-
Abstract
- In mammals, the suprachiasmatic nucleus (SCN) of the hypothalamus coordinates daily rhythms including sleep–wake, hormone release, and gene expression. The cells of the SCN must synchronize to each other to drive these circadian rhythms in the rest of the body. The ontogeny of circadian cycling and intercellular coupling in the SCN remains poorly understood. Recentin vitrostudies have recorded circadian rhythms from the whole embryonic SCN. Here, we tracked the onset and precision of rhythms in PERIOD2 (PER2), a clock protein, within the SCN isolated from embryonic and postnatal mice of undetermined sex. We found that a few SCN cells developed circadian periodicity in PER2 by 14.5 d after mating (E14.5) with no evidence for daily cycling on E13.5. On E15.5, the fraction of competent oscillators increased dramatically corresponding with stabilization of their circadian periods. The cells of the SCN harvested at E15.5 expressed sustained, synchronous daily rhythms. By postnatal day 2 (P2), SCN oscillators displayed the daily, dorsal-ventral phase wave in clock gene expression typical of the adult SCN. Strikingly, vasoactive intestinal polypeptide (VIP), a neuropeptide critical for synchrony in the adult SCN, and its receptor, VPAC2R, reached detectable levels after birth and after the onset of circadian synchrony. Antagonists of GABA or VIP signaling or action potentials did not disrupt circadian synchrony in the E15.5 SCN. We conclude that endogenous daily rhythms in the fetal SCN begin with few noisy oscillators on E14.5, followed by widespread oscillations that rapidly synchronize on E15.5 by an unknown mechanism.SIGNIFICANCE STATEMENTWe recorded the onset of PER2 circadian oscillations during embryonic development in the mouse SCN. When isolated at E13.5, the anlagen of the SCN expresses high, arrhythmic PER2. In contrast, a few cells show noisy circadian rhythms in the isolated E14.5 SCN and most show reliable, self-sustained, synchronized rhythms in the E15.5 SCN. Strikingly, this synchrony at E15.5 appears before expression of VIP or its receptor and persists in the presence of blockers of VIP, GABA or neuronal firing. Finally, the dorsal-ventral phase wave of PER2 typical of the adult SCN appears ∼P2, indicating that multiple signals may mediate circadian synchrony during the ontogeny of the SCN.
- Subjects :
- Male
0301 basic medicine
Aging
endocrine system
animal structures
Endogeny
Biology
Inbred C57BL
Type II
Medical and Health Sciences
GABA Antagonists
Mice
03 medical and health sciences
0302 clinical medicine
Pregnancy
Receptors
clock genes
Animals
Circadian rhythm
Research Articles
Neurons
Neurology & Neurosurgery
Suprachiasmatic nucleus
General Neuroscience
Psychology and Cognitive Sciences
Neurosciences
Period Circadian Proteins
Bacterial circadian rhythms
Circadian Rhythm
Mice, Inbred C57BL
VIP
PER2
CLOCK
030104 developmental biology
ontogeny
nervous system
Light effects on circadian rhythm
Hypothalamus
Receptors, Vasoactive Intestinal Peptide, Type II
Suprachiasmatic Nucleus
Female
sense organs
Sleep Research
Neuroscience
hormones, hormone substitutes, and hormone antagonists
030217 neurology & neurosurgery
Vasoactive Intestinal Peptide
Subjects
Details
- ISSN :
- 15292401 and 02706474
- Volume :
- 38
- Database :
- OpenAIRE
- Journal :
- The Journal of Neuroscience
- Accession number :
- edsair.doi.dedup.....2ace321cf219bd79deb6ce966f0346f5