Preoptic area activity

Phytoestrogens have also been shown to have behavioural effects in rodents including increases in sexual activity (Patisaul et al, 2001) and a reversal of sex-specific behaviours (Lund et al, 2001 Flynn et al, 2000). In rodents, the sexually dimorphic nucleus of the preoptic area (SDN-POA) is located in the hypothalamic region of the brain. This area of the brain controls... 

Methippara, M., Alam, Md. N., Szymusiak, R McGinty, D. (2003). Preoptic area warming inhibits wake-active neurons in the perifornical lateral hypothalamus. 

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).

Cornil C. A., Balthazart J., Motte P., Massotte L., Seutin V. (2002). Dopamine activates noradrenergic receptors in the preoptic area. J. Neurosci. 22(21), 9320-30. 

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... 

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... 

Fos-like immunoreactivity in the MPOA and lateral preoptic area (LPOA) is associated with maternal behavior in both virgin female rats exposed to pups and lactating postpartum females (Numan and Numan, 1992). The observed induction of fos activity in the POA is likely partially due to the receipt of olfactory and ventral tactile and suckling-related sensory stimulation from pups. The POA also receives suckling-related sensory data related to lactation. However, because maternal behavior occurs in females who have been thelectomized (nipple removal) or olfactory bul-bectomized, a population of POA output cells exists that is essential for the performance of maternal duties in the absence of the usual sensory inputs (Numan, 1994). 

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