Endocrine - Pineal Development: Difference between revisions

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* [http://www.ncbi.nlm.nih.gov/books/bv.fcgi?db=Books&rid=eurekah.section.22799#22800 The Action of Melatonin on Experimental in-Vivo Tumors] Eurekah Bioscience Collection -> Neuropharmacology -> Pineal Gland and Cancer-An Epigenetic Approach to the Control of Malignancy: Evaluation of the Role of Melatonin -> Effect of Melatonin on Tumor Growth  
* [http://www.ncbi.nlm.nih.gov/books/bv.fcgi?db=Books&rid=eurekah.section.22799#22800 The Action of Melatonin on Experimental in-Vivo Tumors] Eurekah Bioscience Collection -> Neuropharmacology -> Pineal Gland and Cancer-An Epigenetic Approach to the Control of Malignancy: Evaluation of the Role of Melatonin -> Effect of Melatonin on Tumor Growth  
* [http://www.ncbi.nlm.nih.gov/books/bv.fcgi?db=Books&rid=eurekah.section.22818 Potential Significance of (Patho)Physiological Changes of Melatonin for the Aetiology of Cancer] Eurekah Bioscience Collection -> Neuropharmacology -> Pineal Gland and Cancer-An Epigenetic Approach to the Control of Malignancy: Evaluation of the Role of Melatonin  
* [http://www.ncbi.nlm.nih.gov/books/bv.fcgi?db=Books&rid=eurekah.section.22818 Potential Significance of (Patho)Physiological Changes of Melatonin for the Aetiology of Cancer] Eurekah Bioscience Collection -> Neuropharmacology -> Pineal Gland and Cancer-An Epigenetic Approach to the Control of Malignancy: Evaluation of the Role of Melatonin  
* [http://www.ncbi.nlm.nih.gov/books/bv.fcgi?db=Books&rid=hstat1a.section.74608#74617 Effects of Exogenous Melatonin] AHRQ Evidence reports and summaries -> AHRQ Evidence Reports, Numbers 61 - 119 -> 108. Mel  
* [http://www.ncbi.nlm.nih.gov/books/bv.fcgi?db=Books&rid=hstat1a.section.74608#74617 Effects of Exogenous Melatonin] AHRQ Evidence reports and summaries -> AHRQ Evidence Reports, Numbers 61 - 119 -> 108. Mel


===Journals===
* [http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed&term=%22J%20Pineal%20Res%22%5Bjour%5D Journal of Pineal Research] Molecular, Biological, Physiological and Clinical Aspects of Melatonin


===Reviews===
===Reviews===

Revision as of 23:58, 25 May 2011

Introduction

Adult pineal body
Pineal gland position

The pineal gland (epiphysis cerebri) has an important role in the sleep/wake daily cycle and reproductive development. The gland is thought to evolutionarily to have been positioned as to be exposed to light, and hence remains a regulator of cyclic rhythms associated with day/night and day length. The pineal hormone (melatonin) has targets both in the nervous system and in many different peripheral tissues.

In humans, the postnatal melatonin levels in premature infants is lower and delayed, but not different when calculated from conception date. Other factors such as preeclampsia, growth restriction, and nursery lighting can cause altered rhythm development. The same study has also shown that full-term infants born at home and full-term twins born in the hospital had significantly lower metabolite excretion levels than hospital-born singleton infants at the same ages despite similar body weights. (More? Kennaway DJ, etal, 1996)

In other species, it has been shown that maternal melatonin crosses the placenta into fetal circulation and may provide photoperiodic information during fetal development that influences later postnatal circadian (daily day/night) and seasonal (day length) rhythms.


  • part of epithalmus - neurons, glia and pinealocytes
  • pinealocytes secrete melatonin - cyclic nature of activity, melatonin lowest during daylight
    • inhibit hypothalamic secretion of GnRH until puberty, pineal gland then rapidly regresses.
  • other activities - possibly gamete maturation, antioxidant effect, protect neurons?
Endocrine Links: Introduction | BGD Lecture | Science Lecture | Lecture Movie | pineal | hypothalamus‎ | pituitary | thyroid | parathyroid | thymus | pancreas | adrenal | endocrine gonad‎ | endocrine placenta | other tissues | Stage 22 | endocrine abnormalities | Hormones | Category:Endocrine
Historic Embryology - Endocrine  
1903 Islets of Langerhans | 1903 Pig Adrenal | 1904 interstitial Cells | 1908 Pancreas Different Species | 1908 Pituitary | 1908 Pituitary histology | 1911 Rathke's pouch | 1912 Suprarenal Bodies | 1914 Suprarenal Organs | 1915 Pharynx | 1916 Thyroid | 1918 Rabbit Hypophysis | 1920 Adrenal | 1935 Mammalian Hypophysis | 1926 Human Hypophysis | 1927 Adrenal | 1927 Hypophyseal fossa | 1930 Adrenal | 1932 Pineal Gland and Cysts | 1935 Hypophysis | 1935 Pineal | 1937 Pineal | 1935 Parathyroid | 1940 Adrenal | 1941 Thyroid | 1950 Thyroid Parathyroid Thymus | 1957 Adrenal

Endocrine System Development | Lecture - Endocrine Development | Lecture - Head Development | original page

Development Overview

  • Neuroectoderm - prosenecephalon then diencephalon
  • caudal roof, median diverticulum, epiphysis
  • Initially a hollow diverticulum, cell proliferation to solid, pinealocytes (neuroglia), cone-shaped gland innervated by epithalamus
    • epithalamus consists of the pineal gland and habenular nuclei

Melatonin

Melatonin molecular structure
  • Melatonin is synthesized from the amino acid tryptophan within the pinealocytes.
  • Melatonin release is stimulated by darkness and inhibited by light and is said to have neurological "chronobiotic" properties for resynchronization of sleep and circadian rhythms disturbances. In the periphery, melatonin is also involved in the regulation of several complex cycles: seasonal reproduction, body weight and energy balance.
  • The hormone melatonin acts through receptors (high affinity G protein-coupled) embedded in the cell membrane. Three different receptor subtypes have been identified in mammals: MT1 (Mel 1a) and MT2 (Mel 1b) and a putative binding site called MT3.
  • Melatonin levels can be monitored by urinary excretion of the melatonin metabolite 6-sulfatoxymelatonin (aMT.6S).

Abnormalities

  • Pineal Hypoplasia associated with retinal disease.
  • Pineal Tumours in children are associated with abnormal puberty development.

Molecular Development

DARPP-32 (Dopamine- and cAMP-regulated phosphoprotein of 32 kDa) is involved in the retinal pathway transmitting photic information that resets the circadian clock.

Histology

Adult Pineal (sheep)

Adult Histology

  • Astrocytes - small dark nuclei
  • Pinealocytes - most nuclei present, larger lighter and round nuclei surrounded by a broad rim of light cytoplasm
  • Endothelial cells - nuclei in association with the vessels and capillaries traversing the tissue.
  • Cytoplasmic processes - "stringy" appearance from both pinealocytes and astrocytes

(Modified from Blue Histology)


Links: large histology image

References


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  • Endocrine Development - All (14277) Review (4620) Free Full Text (3140)

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Cite this page: Hill, M.A. (2024, March 28) Embryology Endocrine - Pineal Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Endocrine_-_Pineal_Development

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© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G