Developmental appearance of light-dark entrainment in the rat

Duncan, Marilyn J.; Banister, Mark; Reppert, Steven M.

doi:10.1016/0006-8993(86)90544-5

Cited by 75 publications

(56 citation statements)

References 17 publications

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“…The completion of these VIP efferents may start transmission of SCN oscillation, and the multiple synaptic relay will convey these rhythms to the behavioral and hormonal centers. However, contrary to these rhythms, a pineal sympathetic rhythm was present by P4 (Moore, 1991), and a pineal enzyme N-acetyltransferase rhythm occurred from P4 to P7 (Duncan et al, 1986). This suggests that the SCN output pathway controlling the melatonin rhythm is different from those of other behavioral and corticosterone controlling systems.…”

Section: Two Vip Neuronal Hypotheses and The Conversion Of The Endogecontrasting

confidence: 38%

Development of Vasoactive Intestinal Peptide mRNA Rhythm in the Rat Suprachiasmatic Nucleus

1997

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Development of the daily rhythm of vasoactive intestinal peptide (VIP) mRNA in the rat suprachiasmatic nucleus (SCN), a main locus of circadian oscillation, was investigated by in situ hybridization. The phenotypic expression of VIP neurons occurred in two developmental stages in the ventrolateral portion of the SCN (VLSCN): the first was found before birth in the rostral part, and the second occurred in the main part between postnatal day (P) 10 and P20. The latter period coincided with the time that the massive VIP-efferent fibers project to the subparaventricular zone. In the adult and P20, the VIP mRNA signals of the SCN showed a clear diurnal rhythm with a trough in the light phase and a peak in the dark phase under light/dark (LD) conditions, but under constant dark (DD) conditions, no VIP mRNA fluctuations were observed. At P10, however, it was found that SCN VIP mRNA showed a peak at the transition from night to day and a trough at early dark period in LD conditions, in sharp contrast to the night peak in the adult rhythm. In DD conditions, a light-phase peak and a dark-phase trough were also observed at P10, contrasting the arrhythmic feature at adult stage. The present findings suggest that daily VIP rhythm was first generated in the early developed clock-controlled rostral SCN neurons, and later regulated by light-dependent main VLSCN neurons.

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Section: Two Vip Neuronal Hypotheses and The Conversion Of The Endogecontrasting

confidence: 38%

Development of Vasoactive Intestinal Peptide mRNA Rhythm in the Rat Suprachiasmatic Nucleus

1997

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“…Even should ipRGCs not support image-forming vision, these photosensitive cells could regulate sleep/wake cycles and other well-known photo entrainable physiological processes. In support of this idea, light has been shown to control biological clock genes in premature primate infants (42), modulate heart rates in neonatal rat pups (43), and entrain pineal N-acetyltransferase rhythms in rat pups as young as P6 (44). In blind adult human patients lacking functional rod and cone function, blue light, by presumably activating melanopsin cells, was able to reset patients' circadian clocks and increase alertness (7) and exacerbate the intensity of migraine headaches (6).…”

Section: Discussionmentioning

confidence: 94%

Melanopsin-dependent light avoidance in neonatal mice

Johnson¹,

Wu²,

Donovan³

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

126

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Melanopsin-expressing, intrinsically photosensitive retinal ganglion cells (ipRGCs) form a light-sensitive system separate from rods and cones. Direct light stimulation of ipRGCs can regulate many nonimageforming visual functions such as photoentrainment of circadian rhythms and pupil responses, and can intensify migraine headache in adults. In mice, ipRGCs are light responsive as early as the day of birth. In contrast, their eyelids do not open until 12-13 d after birth (P12-13), and light signaling from rods and cones does not begin until approximately P10. No physiological or behavioral function is established for ipRGCs in neonates before the onset of rod and cone signaling. Here we report that mouse pups as young as P6 will completely turn away from a light. Light-induced responses of ipRGCs could be readily recorded in retinas of pups younger than P9, and we found no evidence for rod-and cone-mediated visual signaling to the RGCs of these younger mice. These results confirm that negative phototaxis is evident before the onset of rod-and cone-mediated visual signaling, and well before the onset of image-forming vision. Negative phototaxis was absent in mice lacking melanopsin. We conclude that light activation of melanopsin ipRGCs is necessary and sufficient for negative phototaxis. These results strongly suggest that light activation of ipRGCs may regulate physiological functions such as sleep/wake cycles in preterm and neonatal infants.

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“…In rats, retinamediated photic responsiveness is not present at birth, but develops by the end of the first postnatal week (40,41). In contrast, in sheep the retina innervate the SCN by midgestation (43).…”

Section: Discussionmentioning

confidence: 99%

Newborn primate infants are entrained by low intensity lighting

Rivkees

Hofman

Fortman

1997

Proc. Natl. Acad. Sci. U.S.A.

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At the present time we do not know when the circadian timing system of human infants becomes responsive to light. Because of human study limitations, it is not currently possible to address this issue in clinical studies. Therefore, to provide insights into when the circadian system of humans becomes responsive to light, baboons were studied. We first assessed if the biological clock located in suprachiasmatic nuclei (SCN) is responsive to light at birth. When term newborn infants were exposed to bright light at night (5000 lux), SCN metabolic activity and c-fos mRNA expression increased, indicating the presence of photic responsiveness. When photic entrainment of developing rhythmicity was examined in infants, low intensity (200 lux) cycled lighting was sufficient to entrain circadian phase. However, low intensity lighting was not sufficient to induce changes in SCN metabolic activity or c-fos mRNA expression. Phase-response studies indicated that light exposure (200 lux) before the onset of activity most effectively shifted circadian phase. These data provide direct evidence that the SCN are responsive to visually mediated light information in a primate at birth. Further consideration of lighting conditions that infants are exposed to is therefore warranted.

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Developmental appearance of light-dark entrainment in the rat

Cited by 75 publications

References 17 publications

Development of Vasoactive Intestinal Peptide mRNA Rhythm in the Rat Suprachiasmatic Nucleus

Development of Vasoactive Intestinal Peptide mRNA Rhythm in the Rat Suprachiasmatic Nucleus

Melanopsin-dependent light avoidance in neonatal mice

Newborn primate infants are entrained by low intensity lighting

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