The periventricular nucleus is a thin sheet of small neurons located in the wall of the third
ventricle, a composite structure of the
hypothalamus
The hypothalamus (: hypothalami; ) is a small part of the vertebrate brain that contains a number of nucleus (neuroanatomy), nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrin ...
. It functions in
analgesia
Pain management is an aspect of medicine and health care involving relief of pain (pain relief, analgesia, pain control) in various dimensions, from acute and simple to chronic and challenging. Most physicians and other health professionals ...
.
It is located in the rostral, intermediate, and caudal regions of the
hypothalamus
The hypothalamus (: hypothalami; ) is a small part of the vertebrate brain that contains a number of nucleus (neuroanatomy), nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrin ...
. The rostral region aids in the production of both
somatostatin
Somatostatin, also known as growth hormone-inhibiting hormone (GHIH) or by #Nomenclature, several other names, is a peptide hormone that regulates the endocrine system and affects neurotransmission and cell proliferation via interaction with G ...
and
thyroid releasing hormone. The intermediate portion aids in production of thyroid releasing hormone,
somatostatin
Somatostatin, also known as growth hormone-inhibiting hormone (GHIH) or by #Nomenclature, several other names, is a peptide hormone that regulates the endocrine system and affects neurotransmission and cell proliferation via interaction with G ...
,
leptin
Leptin (from Ancient Greek, Greek λεπτός ''leptos'', "thin" or "light" or "small"), also known as obese protein, is a protein hormone predominantly made by adipocytes (cells of adipose tissue). Its primary role is likely to regulate long ...
,
gastrin
Gastrin is a peptide hormone that stimulates secretion of gastric acid (HCl) by the parietal cells of the stomach and aids in gastric motility. It is released by G cells in the pyloric antrum of the stomach, duodenum, and the pancreas.
...
, and
neuropeptide Y. In humans and primates it also produces
GnRH. Lastly the caudal region aids in sympathetic nervous system regulation, and is regarded as the rage center. The periventricular nucleus does not have an effective blood–brain barrier.
11β-HSD2 expression turns
cortisol
Cortisol is a steroid hormone in the glucocorticoid class of hormones and a stress hormone. When used as medication, it is known as hydrocortisone.
Cortisol is produced in many animals, mainly by the ''zona fasciculata'' of the adrenal corte ...
into
cortisone
Cortisone is a pregnene (21-carbon) steroid hormone. It is a naturally-occurring corticosteroid metabolite that is also used as a pharmaceutical prodrug. Cortisol is converted by the action of the enzyme corticosteroid 11-beta-dehydrogenase ...
.
Role in LH and GnRH release
This nucleus has been shown to affect the release of
GnRH (gonadotropin-releasing hormone) in several ways. One way is its expression of
neuropeptide Y, which has an impact on the hypothalamic pathway responsible for GnRH secretion. The periventricular nucleus has also been shown to have many neurons that express
kisspeptin, which generates a surge in
LH, which ultimately leads to the release of GnRH. In female rats, there is a greater expression of
estrogen receptor beta in the periventricular nuclear cells, which is thought to lead to different levels of LH secretion in males and females.
Role in GH release
This region has been shown to aid in the production of
somatostatin
Somatostatin, also known as growth hormone-inhibiting hormone (GHIH) or by #Nomenclature, several other names, is a peptide hormone that regulates the endocrine system and affects neurotransmission and cell proliferation via interaction with G ...
and research shows that neurons releasing somatostatin are stimulated to do so by glutamatergic innervation and then this allows them to inhibit the release of
growth hormone. There is thought to be a differential level of secretion of somatostatin between males and females by the periventricular nucleus and that is thought to be responsible for the sexual dimorphism of growth hormone secretion. It has also been suggested that leptin secretion also plays a role in the release of GH from periventricular nucleus and that this hormone interacts with both somatostatin and
growth hormone-releasing hormone (GHRH) in the GH release pathway. This is further supported by the presence of leptin receptors in neurons of the periventricular nucleus. GH may also be able to provide regulatory feedback on the periventricular nucleus by increasing
cytokine
Cytokines () are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling.
Cytokines are produced by a broad range of cells, including immune cells like macrophages, B cell, B lymphocytes, T cell, T lymphocytes ...
signaling to the hypothalamus which inhibits the GH release pathway.
See also
*
Anteroventral periventricular nucleus
References
External links
*
{{Authority control
Hypothalamus