Pinealocyte

Pinealocyte
Cross-section of pineal gland displaying pinealocytes and other cells
Details
SystemEndocrine system
LocationPineal gland
Identifiers
Latinpinealocytus,
endocrinocitus pineale
THH3.08.02.3.00002
FMA83417
Anatomical terms of microanatomy

Pinealocytes are the main cells contained in the pineal gland, located behind the third ventricle and between the two hemispheres of the brain. The primary function of the pinealocytes is the secretion of the hormone melatonin, important in the regulation of circadian rhythms.[1] In humans, the suprachiasmatic nucleus of the hypothalamus communicates the message of darkness to the pinealocytes, and as a result, controls the day and night cycle.[2] It has been suggested that pinealocytes are derived from photoreceptor cells.[3][4] Research has also shown the decline in the number of pinealocytes by way of apoptosis as the age of the organism increases.[5] There are two different types of pinealocytes, type I and type II, which have been classified based on certain properties including shape, presence or absence of infolding of the nuclear envelope, and composition of the cytoplasm.

  1. ^ Pandi-Perumal SR, Srinivasan V, Maestroni GJ, Cardinali DP, Poeggeler B, Hardeland R (July 2006). "Melatonin: Nature's most versatile biological signal?". The FEBS Journal. 273 (13): 2813–38. doi:10.1111/j.1742-4658.2006.05322.x. PMID 16817850.
  2. ^ Maronde E, Stehle JH (2007). "The mammalian pineal gland: known facts, unknown facets". Trends in Endocrinology and Metabolism. 18 (4): 142–9. doi:10.1016/j.tem.2007.03.001. PMID 17374488. S2CID 20907798.
  3. ^ Mano H, Fukada Y (2006). "A median third eye: pineal gland retraces evolution of vertebrate photoreceptive organs". Photochemistry and Photobiology. 83 (1): 11–8. doi:10.1562/2006-02-24-IR-813. PMID 16771606. S2CID 13037403.
  4. ^ Klein DC (2006). "Evolution of the vertebrate pineal gland: the AANAT hypothesis". Chronobiology International. 23 (1–2): 5–20. doi:10.1080/07420520500545839. PMID 16687276. S2CID 29845507.
  5. ^ Polyakova VO, Linkova NS, Pichugin SA (February 2011). "Changes in apoptosis and cell proliferation in human pineal gland during aging". Bulletin of Experimental Biology and Medicine. 150 (4): 468–70. doi:10.1007/s10517-011-1170-x. PMID 22268045. S2CID 19539906.