Sleep-wake cycle, serotonin

Portas, CM, Bjorvatn, B and Ursin, R (2000) Serotonin and the sleep-wake cycle special emphasis on microdialysis studies. Prog. Neurobiol. 60 13-35. 

Iwakiri, H., Matsuyama, K. Mori, S. (1993). Extracellular levels of serotonin in the medial pontine reticular formation in relation to sleep-wake cycle in cats a microdialysis study. Neurosci. Res. 18, 157-70. 

Koella has reviewed the evidence implicating the involvement of serotonin in the sleep-wake cycle but the involvement of specific serotonin receptor subtypes in sleep mechanisms is unclear. Experimental evidence suggests that 5-HTia agonists delay the onset of REM sleep while 5-HT2 antagonists suppress REM and have variable effects on non-REM sleep. 

F]Setoperone Serotonin 5-HT2a receptors Sleep-wake cycle... 

Melatonin (fig. 10) is a hormone produced from serotonin in the pineal gland, which is embedded within the brain. It is released into the brain and general blood circulation and is involved in the regulation of the sleep-wake cycle and other circadian biological clock processes. 

The permissive serotonin hypothesis proposes that serotonin (5-hydroxytryptamine or 5-HT) plays a critical role in modulating brain activity (e.g., stabilization of the catecholamine system and inhibition of dopamine [DA] release), and is low in both mania and depression. L-tryptophan or 5-HT deficiency and changes in the light-dark cycle may result in reduced melatonin secretion from the pineal gland that disrupts the sleep-wake cycle, alters circadian rhythms, and causes seasonal affective changes. ... 

Serotonin is an important neurotransmitter involved in many human physiologic systems. Sleep-wake cycles, sensitivity to pain, blood... 

Nature Melatonin is a serotonin derivative produced mainly in the pineal gland. It is thought to regulate sleep-wake cycles, and its release coincides with darkness (9 pm to... 

Further in Figure 5.3, we find melatonin, which has a structure similar to serotonin. In fact, serotonin is converted to melatonin, and the two amines control our sleep-wake cycle (thus forming an inner clock, called a circadian clock). The jet lag that most of us experience after long flights is a result of disruption of this cycle. 

Devise a synthesis of melatonin, the mammalian hormone involved in regulating the sleep-wake cycle, from the neurotransmitter serotonin, alcohols, and any needed organic and inorganic reagents. 

Melatonin is /V-acetyl-5-methoxytryptamine (Figure 16-2), a simple methoxylated and /V-acetylated product of serotonin found in the pineal gland. It is produced and released primarily at night and has long been suspected of playing a role in diurnal cycles of animals and the sleep-wake behavior of humans. 

Melatonin, a hormone secreted by the pineal gland that regulates circadian rhythms, including wake-sleep cycles, is biosynthesized by a process in which the first step is an enzyme-catalyzed transfer of the acetyl group from sulfur of acetyl coenzyme A to the —NH2 group of serotonin. 

---