Medial preoptic area of the

The medial preoptic area of the hypothalamus is thought to be that portion of the brain responsible for integrating external stimuli. Here dopamine exerts aproerectogenic effect, whereas, 2-adrenergic stimulation causes the penis to become and/or remain flaccid. After moving down the spinal cord, nerve impulses travel to the penis by efferent peripheral nerves, including inhibitory sympathetic... 

Gorski RA, Gordon JH, Shryne, JE, Southam AM (1978) Evidence for a morphological sex difference within the medial preoptic area of the rat brain. Brain Res 148 333-346. 

Ferraro, L., Antonelh, T., TanganeUr, S. et al. (1999). The vigilance promoting drug modafinil increases extracellular glutamate levels in the medial preoptic area and the posterior hypothalamus of the conscious rat prevention by local GABAA receptor blockade. Neuropsychopharmacology 20, 346-56. 

On do J, Mansky T, Wuttke W (1982) In vivo GABA release from the medial preoptic area of diestrous and ovariectomized rats. Exp Brain Res 4669-4672... 

By contrast, the accessory olfactory system is thought to be involved in the detection of odors that influence a variety of reproductive and aggressive behaviors (Keverne 1999). Sensory neurons are located in the vomeronasal organ (VNO) and detect pheromones which gain access to the VNO by a pumping mechanism (Meredith and O Connell, 1979). VNO neurons send projections to the accessory olfactory bulb (AOB). Mitral cells of the AOB project in turn to the medial nucleus of the amygdala olfactory information is then dispatched to several hypothalamic regions such as the bed nucleus of the stria terminalis, the medial preoptic area and the ventromedial hypothalamus (Scalia and Winans 1975). 

Scorticati et al., 2003, 2004), and increases in adreno-corticotropin hormone (ACTH) and corticosterone release in rats (Weidenfeld et al., 1994 Manzanares et al., 1999). Cannabinoids such as THC and anandamide bind to dense populations of caimabinoid CBi receptors in the brain and, notably, the hypothalamus (Herkenham et al., 1991). Autoradiography studies have demonstrated the presence of CBj receptors in several hypothalamic nuclei involved in neuroendocrine modulation, including the medial preoptic area and the paraventricular nuclei (PVN), predominant sites of GnRH and CRH neuronal cell bodies, respectively (Femandez-Ruiz et al., 1997). 

Hines, M., Davis, F. C., Coquelin, A., Goy, R. W., and Gorski, R. A., 1985, Sexually dimorphic regions in the medial preoptic area and the bed nucleus of the stria terminalis of the guinea pig brain A description and an investigation of their relationship to gonadal steroids in adulthood, J. Neurosci. 5 41 -47. 

Table 7.1 Major dopaminergic modulatory systems of the brain. Abbreviations MPO, medial preoptic area.

Azuma, S., Kodama, T., Honda, K. Inoue, S. (1996). State-dependent changes of extracellular glutamate in the medial preoptic area in freely behaving rats. Neurosci. Lett. 214, 179-82. 

Figure 11.2 Increases in wakefulness after intracerebroventricular (ICV) or intrahypothalamic administration of ghrelin, neuropeptide Y (NPY), and orexin-A in the first hour of the light period in rats. LH, lateral hypothalamus MPA, medial preoptic area PVN, paraventricular nucleus asterisks denote significant differences from baseline. Orexin data are extracted from Vogel et at, J. Neuroscience Methods, 2002, 118 89-96.

Mendelson W. (2000). Sleep-inducing effects of adenosine microinjections into the medial preoptic area are blocked by flumazenil. Brain Res. 852, 479-82. 

Baum, M. J. and Everitt, B. J. (1992) Increased expression of c-fos in the medial preoptic area after mating in male rats role of afferent inputs from the medial amygdala and midbrain central tegmental field. Neuroscience 50, 627-646. 

Di Chiara G, North RA. (1992). Neurobiology of opiate abuse. Trends Pharmacol Sci. 13(5) 185-93. Diez-Guerra FJ, Augood S, Emson PC, Dyer RG. (1987). Opioid peptides inhibit the release of noradrenaline from slices of rat medial preoptic area. Exp Brain Res. 66(2) 378-84. 

A neural circuit composed of several regions of the prefrontal cortex, amygdala, hippocampus, medial preoptic area, hypothalamus, anterior cingulate cortex, insular cortex, ventral striatum, and other interconnected structures has been implicated in emotion regiflation including the associated affective... 

Angiotensin II produces changes in body hydration and thirst by a direct action in the central nervous system. The administration of angiotensin II into the septal, anterior hypothalamic, and medial preoptic areas stimulates drinking behavior in several species. Part of the volume response also may be caused by the antinatriuretic and antidiuretic effects of angiotensin II. 

What is known about the neural circuitry for mammalian maternal behavior has been delineated using animal models, predominantly the rat. The medial preoptic area (MPOA) of the hypothalamus is important in reproductive function—i.e., in sexual behavior, gonadotrophin secretion, and the expression of normal maternal behavior (Numan, 1974). Maternal behaviors... 

Kendrick, K.M., Keverne, E.B., Hinton, M.R., and Goode J.A. (1992) Oxytocin, amino acid and monoamine release in the region of the medial preoptic area and bed nucleus of the stria terminalis of the sheep during parturition and suckling. Brain Res 569 199-209. 

Numan, M. and Numan, M.J. (1992) Maternal behavior in female rats is associated with increased numbers of Fos containing neurons in the medial preoptic area. Soc Neurosci Abstr 18 892. 

Numan, M., Rosenblatt, J.S., and Komisaruk, B.R. (1977) Medial preoptic area and onset of maternal behavior in the rat. / Comp Physiol Psychol 91 146—164. 

The brain exerts an important modulatory influence over spinal reflex pathways that control penile function (Giuliano and Rampin, 2000). A variety of visual, auditory, olfactory, and imaginative stimuli elicit erectile responses that involve cortical, thalamic, rhinencephalic, and limbic input to the medial preoptic-anterior hypothalamic area, which acts as an integrating center. Other areas of the brain, such as the amygdaloid complex, may inhibit sexual function. 

Horvath TL, Naftolin F, Leranth C (1992a) GABAergic and catecholaminergic innervation of mediobasal hypothalamic P-endorphin cells projecting to the medial preoptic area. Neuroscience 57 391-399. 

Hull EM, Du J, Lorrain DS, Matuszewich L (1995) Extracellular dopamine in the medial preoptic area implications for sexual motivation and hormonal control of copulation. J Neurosci 75 7465-7471. 

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