Sleep factors, endogenous

A fundamental question concerns the neurochemical mechanisms that regulate the activity of POA sleep-active neurons. Currently, this problem has been approached through studies of putative sleep factors , endogenous... 

These studies are consistent with the concept of POA control of homeostasis, but are not definitive. A definitive study demonstrating the necessity of the POA for homeostatic control of sleep using the lesion method would be difficult to interpret since baseline sleep would be greatly diminished. Instead, recent studies have examined the role of the POA in response to endogenous sleep factors thought to underlie sleep homeostasis. 

Other sedative-hypnotics (valnoctamide, propofol, plant extracts, endogenous sleep factors, melatonin)... 

Sleep Studies. As early as 1907, Legendre and Pieron discovered the existence of endogenous sleep factors (21). Injection of blood serum from sleep-deprived dogs could induce sleep in dogs who were not deprived of sleep. The search for endogenous sleep factors is still continuing. 

In the 1920s and 1930s, Kleitman studied the effects of sleep deprivation (22) and concluded that the build-up of endogenous sleep factors did not exceed certain limits, and humans became as impaired as they would get after approximately 2.5 days of wakefulness. 

Garcia-Garcia, F and Drucker-Colin, R (1999) Endogenous and exogenous factors on sleep-wake cycle regulation. Prog. Neurobiol. 58 297-314. 

Within the European Union there are no restrictions regarding these additives. However, primary fatty-acid amides have been shown to have hormone-like activity, e.g., oleamide (c -9,10-octadecenoamide) is an endogenous bioregulator that acts like a sleep-inducing factor (Cravatt et al., 1995 Bezuglov et al., 1998). 

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