Sleep circadian rhythms

Melatonin secretion is synchronized to the light/dark (LD) cycle, with a nocturnal maximum (in young humans, about 200 pg/ml plasma) and low diurnal baseline levels (about 10 pg/ml plasma). Studies have supported the value of the exogenous administration of melatonin in circadian rhythm sleep disorders, insomnia, cancer, neurodegenerative diseases, disorders of the immune function, and oxidative damage (Karasek et al. 2002 Pandi-Perumal et al. 2005, 2006 Srinivasan et al. 2005a,b, 2006 Hardeland et al. 2006). 

Zisapel, N. (2001). Circadian rhythm sleep disorders pathophysiology and potential approaches to management. CNS Drugs 15, 311-28. 

Breathing-related sleep disorder Circadian rhythm sleep disorder Delayed sleep phase type Jet lag type Shift work type Unspecified type... 

To mimic melatonin action and increase the half-life is the goal of melatonin receptor agonists, which are the more recent addition to the insomnia therapeutic armamentarium. These compounds, in addition to use for insomnia, may have potential application in the synchronization of disturbed circadian rhythms, sleep disturbances in the elderly, seasonal depression and jet lag, to name a few. Furthermore, studies have shown that melatonin receptor agonists do not induce any of the hypothermic, hypotensive or bradycardic effects caused by melatonin in humans [27,28]. 

G. S. Richardson and H. V. Malin, Circadian rhythm sleep disorders Pathophysiology and treatment. J. Clin. Neurophysiol. 13, 17-31 (1996). 

C. The sleep disturbance does not occur exclusively during the course of narcolepsy, breathing-related sleep disorder, circadian rhythm sleep disorder, or a parasomnia. 

The diagnosis is not made if hypersomnia occurs only during the course of a circadian-rhythm sleep disorder. 

Mood Related Disturbances of Circadian Rhythms.Sleep-Wake Cycles and HPA Axis 207... 

Circadian rhythm sleep disorders jet lag insomnia experienced by shift workers and delayed sleep phase syndrome (sometimes seen in students who are enjoying their first experiences outside the family environment and who go to bed too late). This is something that should be discussed with the present client. 

The sleep-wake cycle is under the circadian control of oscillators and can be disrupted by misalignment between an individual s biological clock and external demands on the sleep cycle. Circadian rhythm sleep disorders usually present with either insomnia or hypersomnia, depending on the individual s performance requirements. Two commonly occurring circadian rhythm sleep disorders are jet lag and shift work sleep problems. 

Causes of excessive daytime sleepiness are numerous and include Intrinsic sleep disorders, such as obstructive sleep apnea/hypopnea syndrome and narcolepsy circadian rhythm sleep disorders, such as jet lag and sleep disorders associated with neuropsychiatric conditions, such as anxiety and depression (42). In many Instances, excessive daytime sleepiness is treated by addressing the underlying cause however, the specific etiology of narcolepsy Is unknown. Narcolepsy also can be characterized by brief periods of muscle paralysis (cataplexy). 

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