Towards a molecular biology of the suprachiasmatic nucleus: photic and temporal regulation of c-fosgene expression

Schwartz, William J.; Aronin, Neil; Takeuchi, Junichi; Bennett, Michele R.; Peters, Robin V.

doi:10.1016/1044-5765(95)90017-9

Cited by 62 publications

(27 citation statements)

References 41 publications

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“…25 After a light pulse as short as five minutes, Fos peaks in the suprachiasmatic nucleus after one to two hours and disappears within six hours. 26 C-Fos induction is more effective when a novel stimulus is applied, or when the animal is stimulated after a period of sensory deprivation. For instance, c-fos mRNA levels in cerebral cortex, septum, and hippocampus are increased after acute restraint stress but are lower than in controls after repeated stress.…”

Section: Temporal Pattern Of Inductionmentioning

confidence: 99%

On the Functional Significance of c-fos Induction During the Sleep-waking Cycle

Cirelli

Tononi

2000

Sleep

130

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Abstract:A striking finding in recent years has been that the transition from sleep to waking is accompanied in many brain regions by a widespread activation of c-fos and other immediate-early genes (IEGs). IEGs are induced by various electrical or chemical signals to which neural cells are exposed and their protein products act as transcription factors to regulate the expression of other genes. After a few hours of sleep, the expression of these transcription factors in the brain is absent or restricted to very few cells. However, after a few hours of spontaneous waking or sleep deprivation, the expression of c-fos and other IEGs is high in cerebral cortex, hypothalamus, septum, and several thalamic and brainstem nuclei. While cells expressing c-fos during waking are widely distributed, they represent only a subset of all neurons in any given area. These observations raise several questions: Why is c-fos expressed during waking and not during sleep? Is waking always accompanied by c-fos induction? Which subset of cells express c-fos during waking and why only a subset? Once c-fos has been induced, what are the functional consequences of its activation? In this review, we summarize our current understanding of the meaning of c-fos activation in the brain in relation to the sleep-waking cycle and suggest that c-fos induction in the cerebral cortex during waking might be related to the occurrence of plastic phenomena.

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Section: Temporal Pattern Of Inductionmentioning

confidence: 99%

On the Functional Significance of c-fos Induction During the Sleep-waking Cycle

Cirelli

Tononi

2000

Sleep

130

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“…The vl-SCN exhibits a rhythm of sensitivity to light [6]. Norepinephrine released at night from sympathetic nerve endings in the pineal gland stimulates adrenergic recaptors and the cAMP pathway; the resulting induction and activation of pineal NAT activity leads to high nighttime melatonin levels [7].…”

Section: Introductionmentioning

confidence: 99%

The Influence of Gonadectomy on Anxiolytic and Antidepressant Effects of Melatonin in Male and Female Wistar Rats: A Possible Implication of Sex Hormones

Zahra¹,

Lagbouri²,

Mesfioui³

et al. 2012

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The main objective of this study was to analyze the effects of sex, ovariectomy (Ovx) and orchidectomy (Orx) on antidepressant and anxiolytic effect of melatonin in forced swimming test, open field test and elevated plus maze test. Initially, 4 mg/kg of melatonin was daily administered, at 4:00 pm, to intact male and female rats during 8 weeks. Our results have shown that the effect of chronic injection of Mel is sex dependent in the three behaviors tests. Females rats have responded better than males in behavior test study after administration of melatonin, this difference between the sexes may be related to the action of sex hormones (androgens and estrogens) on behavior in males as well as in females. Secondly, to determine the possible interaction between Melatonin and steroid hormones, Ovx/sham female received Mel at dose of 4 mg/kg alone or NaCl (0.9%) alone, and Orx/sham male received Mel at dose of 4 mg/kg alone or NaCl (0.9%) alone daily and during 8 weeks of treatment at 4:00 pm. All animals were tested in the open-field test, elevated plus maze test for anxiety behavior study, and forced swimming test for depression behavior study. Results revealed that Mel exerts an anxiolytic and antidepressant effects in the orchidectomized males and in intact females, confirming that the suppression of androgens by orchidectomy improved anxiolytic and antidepressant effects of melatonin in males. However in females, the suppression of estrogen by ovariectomy masked the antidepressant and anxiolytic effects of melatonin. Our results confirmed that the antidepressant and anxiolytic effects of melatonin are linked to sex hormones.

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“…Neurobiological changes of the SCN that have been associated with circadian rhythm disruptions in aged animals have included a reduction in the number of cells and the volume of the SCN (Brock 1991;Swaab et al 1985), a decrease in total and rhythmic expression of mRNA for vasoactive intestinal polypeptide in the SCN (Kawakami et al 1997;Krajnak et al 1998), and attenuated c-Fos expression induced by light (Cai et al 1997;Guido et al 1999b;Schwartz et al 1995;Schwartz et al 2000;Takahshi 1993). Although these findings do not discount other possible age-related changes outside the SCN, they do suggest that some changes within the SCN itself could be involved in the circadian rhythm disruptions observed in aged individuals.…”

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confidence: 99%

“…In the mouse, the two divisions are referred to as "core" and "shell" (Abrahamson and Moore 2001;Moore 1995;Moore 1996). The core, which receives direct retinal inputs, shows cell activity that is primarily light-induced (Cai et al 1997;Guido et al 1999b;Schwartz et al 1995;Schwartz et al 2000;Takashi 1993). This cell activity follows the behavioral pattern of the animal's phase responses to light pulses, suggesting that cells of the core are involved in entrainment to the environmental light-dark cycle (Aronin and Schwartz 1991;Colwell and Foster 1992;Schwartz et al 2000).…”

mentioning

confidence: 99%

Age-related disruptions of circadian rhythm and memory in the senescence-accelerated mouse (SAMP8)

Pang

Miller

Fortress

et al. 2006

AGE

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Common complaints of the elderly involve impaired cognitive abilities, such as loss of memory and inability to attend. Although much research has been devoted to these cognitive impairments, other factors such as disrupted sleep patterns and increased daytime drowsiness may contribute indirectly to impaired cognitive abilities. Disrupted sleep-wake cycles may be the result of age-related changes to the internal (circadian) clock. In this article, we review recent research on aging and circadian rhythms with a focus on the senescence-accelerated mouse (SAM) as a model of aging. We explore some of the neurobiological mechanisms that appear to be responsible for our aging clock, and consider implications of this work for age-related changes in cognition.Key words aging . C-Fos . circadian rhythms . mouse . running wheel . SAMP8 . suprachiasmatic nucleus Cognitive impairments are well-known complaints of the elderly. Despite their obvious clinical importance, many questions remain unanswered. One important issue concerns whether cognitive impairments are due to direct alterations in the cognitive function, or to other difficulties that may in turn result in cognitive deficits. For example, the elderly often report poor night-time sleep quality, daytime sleepiness, lack of energy, and difficulty adjusting to a time shift (increased "jet lag"). Could these effects contribute to cognitive impairments?Although a confluence of factors may lead to poor sleep quality, etc., it is likely that one general culprit is aging of the internal (circadian) clock that regulates these behaviors (Munch et al. 2005;Turek et al. 1995;Weitzman et al. 1982). Moreover, evidence suggests that our internal clock may also mediate cognitive functioning (Antoniadis et al. 2000;Brock 1991, Stone 1989van Gool 1986;van Someren et al. 1993a). In this article, we review recent research on aging and circadian rhythms, with a focus on the senescence-accelerated mouse line. We explore some of the neurobiological mechanisms that appear to be responsible for our aging clock, and consider implications of this work for the study of age-related changes in cognition.Circadian rhythms are predictable and regularly occurring daily changes in behavior and physiological states. The term circadian, literally meaning "around a day," has its origins in two Latin words: Circa (around) and dies (day). Two defining characteristics AGE (2006) of circadian rhythms are their continued persistence in the absence of external cues in the environment and their ability to be entrained (synchronized) by environmental cues. With respect to the former property, it is the endogenous (self-sustaining) nature of circadian rhythms that engenders an internal clock. With respect to the latter property, the major external cue that serves to synchronize the circadian rhythms of humans and other mammals is light, but almost any periodic event can act as a Zeitgeber ("time-giver").Research on the biological basis of circadian rhythms in humans and other mammals implicates the s...

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Towards a molecular biology of the suprachiasmatic nucleus: photic and temporal regulation of c-fosgene expression

Cited by 62 publications

References 41 publications

On the Functional Significance of c-fos Induction During the Sleep-waking Cycle

On the Functional Significance of c-fos Induction During the Sleep-waking Cycle

The Influence of Gonadectomy on Anxiolytic and Antidepressant Effects of Melatonin in Male and Female Wistar Rats: A Possible Implication of Sex Hormones

Age-related disruptions of circadian rhythm and memory in the senescence-accelerated mouse (SAMP8)

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