Neuroendocrinology
2467818
211027568
2008-05-08T13:42:51Z
Sardanaphalus
427947
updating link using [[Project:AutoWikiBrowser|AWB]]
{{Cleanup|date=February 2007}}
'''Neuroendocrinology''' is the study of the interactions between the [[nervous system]] and the [[endocrine system]]. The concept arose from the recognition that the secretion of [[hormones]] from the [[pituitary gland]] was closely controlled by the brain, and especially by the [[hypothalamus]].
==Pioneers of neuroendocrinology==
[[Berta Scharrer]] (1906-1995) Co-Founder of Neuroendocrinocology.
[[Geoffrey Harris]] [http://www.dafml.unito.it/anatomy/panzica/neuroendo/articolipdf/1997Raisman.pdf] (1913-1971) is considered by many to be the "father" of neuroendocrinology. Geoffrey Harris is credited as showing that the [[anterior pituitary gland]] of [[mammals]] is regulated by factors secreted by hypothalamic [[neuron]]s into the [[hypothalamohypophysial]] [[portal circulation]]. By contrast, the hormones of the [[posterior pituitary gland]] are secreted into the [[systemic circulation]] directly from the nerve endings of hypothalamic neurons.
The first of these factors to be identified were [[thyrotropin-releasing hormone]] (TRH) and [[gonadotropin-releasing hormone]] (GnRH). TRH is a small [[peptide]] that stimulates the [[secretion]] of [[thyroid stimulating hormone]] (TSH); GnRH (also called luteinising hormone releasing hormone, LHRH) stimulates the secretion of [[luteinizing hormone]] and [[follicle stimulating hormone]] (FSH).
[[Roger Guillemin]] and [[Andrew W. Schally]] isolated these factors from the hypothalamus of sheep and pigs, and then identified their structures. Guillemin and Schally were awarded the [[Nobel Prize]] in Physiology and Medicine in 1977 for their contributions to understanding "the peptide hormone production of the brain."
In 1952, [[Andor Szentivanyi]] and Geza Filipp wrote the world's first research paper showing how neural control of immunity takes place through the hypothalamus.
http://home.cc.umanitoba.ca/~berczii/dr_szentivanyi_memorial/szentivanyi_memorial.htm
==Neuroendocrine systems of the hypothalamus==
[[Oxytocin]] and [[vasopressin]]/[[anti-diuretic hormone]], the two [[peptide hormones]] of the [[posterior pituitary gland]] (the neurohypophysis), are secreted from the nerve endings of magnocellular [[neurosecretory neurons]] into the systemic circulation. The cell bodies of these oxytocin and vasopressin neurons are in the [[paraventricular nucleus]] and [[supraoptic nucleus]] respectively, and the electrical activity of these neurons is regulated by afferent synaptic inputs from other brain regions. By contrast, the hormones of the [[anterior pituitary gland]] (the adenohypophysis) are secreted from endocrine cells that, in mammals, are not directly innervated, yet the secretion of these hormones ([[adrenocorticotrophic hormone]] (ACTH), [[luteinizing hormone]] (LH), [[follicle stimulating hormone]] (FSH), [[thyroid stimulating hormone]] (TSH), [[prolactin]] and [[growth hormone]]) remains under the control of the brain. The brain controls the anterior pituitary gland by “releasing factors” and “release-inhibiting factors”; these are blood-borne substances released by hypothalamic neurons into blood vessels at the base of the brain, at the [[median eminence]]. These vessels, the hypothalamo-hypophysial portal vessels, carry the hypothalamic factors to the adenohypophysis where they bind to specific receptors on the surface of the hormone-producing cells.
For example, the secretion of growth hormone is controlled by two neuroendocrine systems: the [[growth hormone releasing hormone]] (GHRH) neurons and the [[somatostatin]] neurons, which stimulate and inhibit GH secretion respectively. The GHRH neurones are located in the [[arcuate nucleus]] of the hypothalamus, while the somatostatin cells involved in growth hormone regulation are in the [[periventricular nucleus]]. These two neuronal systems project axons to the median eminence where they release their [[peptides]] into portal blood vessels for transport to the anterior pituitary. Growth hormone is secreted in pulses, which arise from alternating episodes of GHRH release and somatostatin release, which may reflect neuronal interactions between the GHRH and somatostatin cells, and negative feedback from growth hormone.
So why are these systems of interest to physiologists and neuroscientists? Firstly, neuroendocrine systems regulate things that matter to most of us. They control reproduction in all its aspects, from bonding to sexual behavior, they control [[spermatogenesis]] and the ovarian cycle, [[parturition]], [[lactation]] and [[maternal behaviour]]. They control the way we respond to [[Stress (medicine)|stress]] and [[infection]]. They regulate our [[metabolism]] – they influence our eating and drinking behaviour, and influence how the energy intake is utilised – i.e. how fat we get. They influence our mood. They regulate body fluid and electrolyte homeostasis, and [[blood pressure]]. In other words, these are systems of central importance to many problems that are major health concerns, as well of sometimes of intimate personal interest.
Secondly, these neurons are large; they are mini “ factories” for producing secretory products; their nerve terminal are large and organised in coherent terminal fields; their output can often be measured easily in the blood; and what these neurons do and what stimuli they respond to are readily open to hypothesis and experiment. For these reasons and more, neuroendocrine neurons are good "model systems" for studying general questions, like “how does a neurone regulate the synthesis, packaging and secretion of its product?” and “how is information encoded in electrical activity?”
==The scope of neuroendocrinology==
Today, neuroendocrinology embraces a wide range of topics that arose directly or indirectly from the core concept of neuroendocrine neurons. Neuroendocrine neurones control the [[gonads]] – and gonadal [[steroids]] in turn influence the [[brain]]; and so do [[corticosteroids]] secreted from the [[adrenal gland]] under the influence of ACTH. The study of these feedbacks became naturally the province of neuroendocrinologists. The peptides secreted by hypothalamic neuroendocrine neurons into the blood proved to be released also into the brain, and the central actions often appeared to complement the peripheral actions, so understanding these central actions also became the province of neuroendocrinologists, sometimes even when these peptides cropped up in quite different parts of the brain apparently serving functions unrelated to endocrine regulation. Neuroendocrine neurons were discovered in the [[peripheral nervous system]], regulating for instance [[digestion]]. The cells in the [[adrenal medulla]] that release [[adrenaline]] and [[noradrenaline]] proved to have properties between endocrine cells and neurons, and proved to be outstanding model systems for instance for the study of the molecular mechanisms of [[exocytosis]], and these too have become, by extension, “neuroendocrine” systems.
Neuroendocrine systems have been important to our understanding of many basic principles in [[neuroscience]] and [[physiology]] – for instance our understanding of [[stimulus-secretion coupling]]. The origins and significance of patterning in neuroendocrine secretion are still dominant themes in neuroendocrinology today.
Neuroendocrinology is also used as an integral part of understanding and treating [[neurobiological brain disorder]]s. One example is the augmentation of the treatment of mood symptoms with thyroid hormone. <ref>[http://www.currentpsychiatry.com/article_pages.asp?AID=4545/ Identifying hypothyroidism’s psychiatric presentations] (November 2006 edition of Current Psychiatry Online)</ref> Another is the finding of a [[Transthyretin]] (Thyroxine transport) problem in the cerebrospinal fluid (CSF) of some patients diagnosed with schizophrenia.<ref>[http://dx.doi.org/10.1371/journal.pmed.0030428/ Disease biomarkers in cerebrospinal fluid of patients with first-onset psychosis] PLoS Med 3(11): e428. Huang JTJ, Leweke M, Oxley D, Wang L, Harris N, et al. (2006)</ref>
==See also==
* [[Neuroendocrine]]
* [[Neurobiological brain disorder]]
==Neuro-endocrine societies==
*[http://www.isneuro.org/ The International Neuroendocrine Federation]
*[http://www.neuroendocrine.org/ The American Neuroendocrine Society]
*[http://neuroendo.org.uk/ The British Society for Neuroendocrinology]
*[http://www.tours.inra.fr/societeneuroendocrino/ La Societe de Neuroendocrinologie]
*[http://www.eneassoc.org/ The European Neuroendocrine Association]
*[http://www.nacos.com/jns/ The Japan Neuroendocrine Society]
*[http://www.sbne.org/ The Society for Behavioral Neuroendocrinology]
==Neuroendocrine Journals==
*[http://www.informaworld.com/gstr Stress{{ndash}} The International Journal on the Biology of Stress (Informa Healthcare)] An official Journal of the International Neuroendocrine Federation
*[http://www.blackwell-science.com/jne/ [[Journal of Neuroendocrinology]] (Blackwell)]
*[http://www.karger.com/ Neuroendocrinology (Karger)]
*[http://www.academicpress.com/fine/ 'Frontiers in Neuroendocrinology' (Academic Press)]
*[http://www.academicpress.com/h&b/ Hormones and Behavior (Academic Press)]
*[http://www.nel.edu/home.htm Neuroendocrinology Letters (Maghira and Maas Publications)]
==Neuroendocrine physician==
*[http://www.neuroendocrinology.org (Neuroendocrinology.org)]
==References==
{{reflist}}
{{Endocrinology}}
{{Neuroscience}}
[[Category:Neuroendocrinology]]
[[Category:Endocrinology]]
[[lt:Neuroendokrinologija]]
[[ja:神経内分泌学]]
[[pt:Neuroendocrinologia]]