Preoptic area
Preoptic area is 'PO', at left, in blue.
Preoptic area of the mouse brain
Details
Identifiers
Latinarea praeoptica
Acronym(s)POA
MeSHD011301
NeuroNames377
NeuroLex IDbirnlex_1706
TA98A14.1.08.407
TA25710
FMA62313
Anatomical terms of neuroanatomy

The preoptic area is a region of the hypothalamus. MeSH classifies it as part of the anterior hypothalamus. TA lists four nuclei in this region, (medial, median, lateral, and periventricular).

Functions

The preoptic area is responsible for thermoregulation and receives nervous stimulation from thermoreceptors in the skin, mucous membranes, and hypothalamus itself.[1]

Nuclei

Median preoptic nucleus

The median preoptic nucleus is located along the midline in a position significantly dorsal to the other three preoptic nuclei, at least in the crab-eating macaque brain. It wraps around the top (dorsal), front, and bottom (ventral) surfaces of the anterior commissure.

The median preoptic nucleus generates thirst. Drinking decreases noradrenaline release in the median preoptic nucleus.[2]

Medial preoptic nucleus

Main article: Sexually dimorphic nucleus

The medial preoptic nucleus is bounded laterally by the lateral preoptic nucleus, and medially by the preoptic periventricular nucleus. It releases gonadotropin-releasing hormone (GnRH), controls copulation in males, and is larger in males than in females.

Parental behavior

The medial preoptic area (mPOA) has been implicated in parental care in both males and females. In rats, oxytocin and vasopressin are associated with maintaining maternal care through local release in the mPOA and the adjacent bed nucleus of the stria terminalis (BNST). Oxytocin and vasopressin V1a receptor binding are increased in both the mPOA and the BNST in lactating rats when compared to controls.[3] The mPOA also has a high density of estradiol receptors that, when activated, can cause a male rat to show maternal-type behaviors.[4] Additionally, the mPOA is critical for the onset and expression of parental behavior, as evidenced by increases in the immediate early gene c-fos, in experienced rat mothers or fathers when compared to controls. Also in fathers, studies have shown that when they receive ultrasonic or pheromone cues from their mates, their c-fos expression in the mPOA further increased, suggestive that rat paternal behavior is mediated through the mPOA but activated by direct interactions with a mate.[5] Large lesions of the mPOA disrupt the onset of maternal behavior, nest-building, and pup retrieval, with the lateral projections being especially critical.[6]

Sexual behavior

The mPOA is sexually dimorphic, that is, it differs in function between males and females. In females, studies have examined the influence of the mPOA on precopulatory and appetitive behaviors. Precopulatory behaviors involve several brain areas, including the mPOA as well as the medial amygdala (MA) and BNST. Studies using female Syrian hamsters have shown that the mPOA is important for sexual odor preference. While control females will investigate male odors more than female odors, those with bilateral lesions to the mPOA (MPOA-X) will show no difference in odor preference, but vaginal scent marking and lordosis remained unaffected.[7] Appetitive behaviors of female rats – including hops, darts, and solicitations – have been linked to dopamine (DA) transmission in the mPOA. Since ascorbic acid (Vitamin C) enhances DA transmission in mesolimbic and nigrostriatal pathways, it has been shown that infusions of ascorbic acid into the mPOA increases appetitive behaviors compared to controls.[8]

In male rats, the mPOA affects the consummatory phase of sexual behavior, and possibly motivation, with lesions causing a complete loss of copulatory behaviors.[9] Conversely, electrical stimulation of this area triggers male copulatory behavior, as measured by decreases in the latency to ejaculate.[10] Furthermore, testosterone implanted into the mPOA of castrated males completely restores mating, as long as aromatase is not inhibited.[11]

Ventrolateral preoptic nucleus

The ventrolateral preoptic nucleus, or intermediate nucleus, is adjacent to the medial preoptic nucleus. It also mediates non-REM sleep onset.

Preoptic periventricular nucleus

The preoptic periventricular nucleus is located along the midline and is medial to the medial preoptic nucleus.

References

  1. ^ Martin JH (2003). Neuroanatomy: Text and Atlas. McGraw-Hill Professional.
  2. ^ Miyakubo H, Yamamoto K, Hatakenaka S, Hayashi Y, Tanaka J (October 2003). "Drinking decreases the noradrenaline release in the median preoptic area caused by hypovolemia in the rat". Behavioural Brain Research. 145 (1–2): 1–5. doi:10.1016/S0166-4328(03)00102-5. PMID 14529799. S2CID 46018164.
  3. ^ Bosch OJ, Pförtsch J, Beiderbeck DI, Landgraf R, Neumann ID (May 2010). "Maternal behaviour is associated with vasopressin release in the medial preoptic area and bed nucleus of the stria terminalis in the rat". Journal of Neuroendocrinology. 22 (5): 420–9. doi:10.1111/j.1365-2826.2010.01984.x. PMID 20163514. S2CID 5286826.
  4. ^ Rosenblatt JS, Ceus K (February 1998). "Estrogen implants in the medial preoptic area stimulate maternal behavior in male rats". Hormones and Behavior. 33 (1): 23–30. doi:10.1006/hbeh.1997.1430. PMID 9571010. S2CID 45305790.
  5. ^ Zhong J, Liang M, Akther S, Higashida C, Tsuji T, Higashida H (September 2014). "c-Fos expression in the paternal mouse brain induced by communicative interaction with maternal mates". Molecular Brain. 7 (1): 66. doi:10.1186/s13041-014-0066-x. PMC 4172782. PMID 25208928.
  6. ^ Numan M (1988). "Neural basis of maternal behavior in the rat". Psychoneuroendocrinology. 13 (1–2): 47–62. doi:10.1016/0306-4530(88)90006-6. PMID 2897700. S2CID 5928669.
  7. ^ Martinez LA, Petrulis A (April 2013). "The medial preoptic area is necessary for sexual odor preference, but not sexual solicitation, in female Syrian hamsters". Hormones and Behavior. 63 (4): 606–14. doi:10.1016/j.yhbeh.2013.02.003. PMC 3633686. PMID 23415835.
  8. ^ Graham MD, Pfaus JG (October 2013). "Infusions of ascorbic acid into the medial preoptic area facilitate appetitive sexual behavior in the female rat". Physiology & Behavior. 122 (1): 140–6. doi:10.1016/j.physbeh.2013.09.008. PMID 24064109. S2CID 9515707.
  9. ^ Paredes RG (July 2003). "Medial preoptic area/anterior hypothalamus and sexual motivation". Scandinavian Journal of Psychology. 44 (3): 203–12. doi:10.1111/1467-9450.00337. PMID 12914583.
  10. ^ Malsbury CW (December 1971). "Facilitation of male rat copulatory behavior by electrical stimulation of the medial preoptic area". Physiology & Behavior. 7 (6): 797–805. doi:10.1016/0031-9384(71)90042-4. PMID 5134017.
  11. ^ Christensen LW, Clemens LG (December 1975). "Blockade of testosterone-induced mounting behavior in the male rat with intracranial application of the aromatization inhibitor, androst-1,4,6,-triene-3,17-dione". Endocrinology. 97 (6): 1545–51. doi:10.1210/endo-97-6-1545. PMID 1204576.
Category