Ventrolateral preoptic area

Figure 2.4 Flip-flop switch model of wake and slow wave sleep active systems. Mutually inhibitory connections exist between GABAergic/Galaninergic slow wave sleep active neurons in the ventrolateral preoptic area (VLPO) of the anterior hypothalamus and aminergic neurons in the hypothalamus (histamine (HA) neurons in the tuberomammillary nucleus (TMN)) and brainstem (serotonin (5-HT) neurons in the dorsal raphe (DR) and noradrenaline (NA) neurons in the locus coeruleus (LC)). Orexinergic neurons in the perifornical hypothalamus (PFH) stabilize the waking state via excitation of the waking side of the flip-flop switch (aminergic neurons).

Saint-Mleux, B., Eggermann, E., Bisetti, A et al. (2004). Nicotinic enhancement of the noradrenergic inhibition of sleep-promoting neurons in the ventrolateral preoptic area. J. Neurosci. 24, 63-7. 

Saper, C. B., Sherin, J. E. Elmquist, J. K. (1997). Role of the ventrolateral preoptic area in sleep induction. In Sleep and Sleep Disorders From Molecule to Behavior, ed. O. Hayaishi S. Inoue, pp. 281-94. Tokyo Academic Press. 

Figure 10.2 The suprachiasmatic nuclei (SCN) and other possible diencephalic targets for melatonin in sleep regulation. See text for details. VLPO, ventrolateral preoptic area DMH, dorsomedial hypothalamus LHA, lateral hypothalamic area.

Morairty, S., Rainnie, D., McCarley, R. Greene, R. (2004). Disinhibition of ventrolateral preoptic area sleep-active neurons by adenosine a new mechanism for sleep promotion. Neuroscience 123 (2), 451-7. 

An unanswered question about adenosine is how this inhibitory neurotransmitter activates the ventrolateral preoptic area of the hypothalamus (VLPO), which contains a population of sleep-active neurons and is hypothesized to be... 

Ekimova I. V., Pastukhov I. (2005). [GABA-ergic mechanisms of the ventrolateral preoptic area of the hypothalamus in regulation of sleep and wakefulness and temperature homeostasis in pigeon Columba livia]. Zh. Evol. Biokhim. Fiziol. 41, 356-63. 

Ventrolateral and medial preoptic area (GABA and galanin)... 

Sleep-active neurons have been identified in the ventrolateral and medial preoptic areas. These neurons exhibit increased discharge during SWS and REMS rather than W. Sleep-active neurons colocalize GABA and are excited by adenosine and prostaglandin D2 (McGinty Szymusiak, 2001) (Table 9.3). 

Immunohistochemical and electrophysiological studies of the hypothalamic preoptic area (POA), which plays a major role in sleep promotion, have identified a subset of sleep-active ventrolateral POA (VLPO) neurons (Sherin et al. 1996 Szymusiak et al. 1998). A tightly clustered group of VLPO neurons appears to promote non-REM sleep, by suppression of the histaminergic arousal system, which... 

Figure 12.3 Sections of rat brain at 0.2 mm anterior to bregma (B + 0.2), and 0.3 and 0.8 mm posterior (B - 0.3, B - 0.8), showing areas relevant to adenosine influences on sleep induction. HDB, horizontal diagonal band MCPO, magnocellular preoptic nucleus VLPO, ventrolateral preoptic nucleus ac, anterior commissure ox, optic chiasm.

VLH ventrolateral hypothalamic nucleus 22-24, 82-83, 93 VLL ventral nucleus of the lateral lemniscus 50-53, 83-85, 90-98 VLPAG ventrolateral periaqueductal gray 50-54, 81 VLPO ventrolateral preoptic nucleus 19-21, 82 VLTg ventrolateral tegmental area 52-53, 82-83, 91-93 VM ventromedial thalamic nucleus 26-35, 81-83, 98-102 VMH ventromedial hypothalamic nucleus 80-81, 90-92 VMHA ventromedial hypothalamic nucleus, anterior part 28 VMHC ventromedial hypothalamic nucleus, central part 29-34 VMHDM ventromedial hypothalamic nucleus, dorsomedial part 29-... 

In the preoptic area we followed Simerly (1995) and Simerly et al. (1984) except for the identification of the ventromedial and ventrolateral preoptic nuclei, for which we followed Elmquist etal. (1996) and Sherin etal. (1996). 

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