Suprachiasmatic nucleus
نویسنده
چکیده
So what’s the fuss? In mammals, it is the site of an endogenous pacemaker that regulates 24 hour, circadian rhythmicity, synchronizing the phases and periods of a host of behavioral, physiological, and hormonal rhythms to the environmental light–dark cycle. The SCN also appears to function as a seasonal clock underlying the measurement of daylength. The SCN was first implicated as a master clock in 1972, independently by Robert Moore and Victor Eichler and Fred Stephan and Irving Zucker.
منابع مشابه
Spatial and temporal variation of passer Per2 gene expression in two distinct cell groups of the suprachiasmatic hypothalamus in the house sparrow (Passer domesticus).
In mammals, the major pacemaker controlling circadian rhythmicity is located in the hypothalamic suprachiasmatic nuclei. Although there is evidence for the presence of a hypothalamic circadian oscillator in birds from lesioning studies, neuroanatomical, neurochemical and functional investigations have failed to identify its exact location. Two cell groups in the avian hypothalamus have been sho...
متن کاملVasopressin immunoreactivity, but not vasoactive intestinal polypeptide, correlates with expression of circadian rhythmicity in the suprachiasmatic nucleus of voles.
In common voles (Microtus arvalis), natural variation in locomotor behavior can be exploited to study the mechanism of pacemaker control over circadian timing of behavior. Here we studied daily patterns in numbers of neuropeptide immunoreactive suprachiasmatic nucleus neurons in rhythmic, weakly rhythmic, and non-rhythmic voles. Circadian rhythmic voles showed circadian variation in numbers of ...
متن کاملVasopressin-deficient suprachiasmatic nucleus grafts re-instate circadian rhythmicity in suprachiasmatic nucleus-lesioned arrhythmic rats.
It was investigated whether grafts of the suprachiasmatic nucleus could re-instate circadian rhythmicity in the absence of its endogenous vasopressin production and whether the restored rhythm would have the long period length of the donor. Grafts of 17-days-old vasopressin-deficient homozygous Brattleboro rat fetuses, homotopically placed in arrhythmic suprachiasmatic nucleus-lesioned Wistar r...
متن کاملCalbindin-D(28K) cells selectively contact intra-SCN neurons.
Calbindin-D(28K)-immunoreactive cells are tightly packed within a discrete region of the caudal aspect of the suprachiasmatic nuclei of hamsters. These cells receive direct retinal input and are Fos-positive in response to a light pulse. Knowledge of their afferent and efferent connections is necessary to understand suprachiasmatic nucleus organization. The first aim of the present study is to ...
متن کاملANP presence in the hypothalamic suprachiasmatic nucleus of developing rat.
In previous research, we studied both the oxytocin and vasopressin ontogeny in the hypothalamic supraoptic and paraventricular nuclei, and the ANP-ontogeny in the hypothalamic supraoptic nucleus. In this paper we evaluate the ANP-ontogeny in the rat hypothalamic suprachiasmatic nucleus; infact the suprachiasmatic nucleus it is known to synthesize vasopressin, a peptidic hormone involved in the ...
متن کاملDistribution of NADPH-diaphorase staining and light-induced Fos expression in the rat suprachiasmatic nucleus region supports a role for nitric oxide in the circadian system.
Nitric oxide serves as a messenger molecule in some neuronal systems that use glutamate as a transmitter and it has been shown that glutamate mediates the transmission of photic signals by retinal ganglion cell axons terminating in the hypothalamic suprachiasmatic nucleus, site of the circadian pacemaker in rodents. Recent experiments have demonstrated that pharmacological treatments which bloc...
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ورودعنوان ژورنال:
- Current Biology
دوره 12 شماره
صفحات -
تاریخ انتشار 2002