Organum subcommissurale

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The organum subcommissurale or subcommissural organ (SCO) is one of the circumventricular organs of the epithalamus and is located in the roof of the III. Ventricle at the transition to the aqueduct , below the posterior commissure ( commissura epithalamica ). The subcommissural organ is an evolutionarily old secretory structure of the neuroepithelium of chordates , which has been demonstrated in all classes of cranial animals and is similarly to be found as an infundibular organ (IO) in skull- less lancetfish . In ontogenesis , it is differentiated as one of the first brain structures and in many species, including humans, reaches its full development in the embryonic phase.

In addition to transthyretin and other soluble proteins, the specific ependymal cells of the sub -commissural organ secrete various glycoproteins into the cerebrospinal fluid , such as the high molecular weight SCO-spondin . This can aggregate as Reissner's substance , form a surface film and arrange itself in the form of strands in the liquor flow to form an approximately 50  μm thin structure, the Reissner thread (named after Ernst Reissner ). Starting from the SCO, this thread then runs through the inner liquor spaces caudally - aqueduct, IV. Ventricle and the central canal of the spinal cord up to its end in the ventriculus terminalis . It can be detected in humans up to the age of two, but no longer in adults.

The exact function of the Reissner thread is unknown. Since SCO spondin stimulates the formation of neuronal cell processes in cell culture, the subcommissural organ and its secretion products could play a role in the embryonic development of the CNS , for example in the outgrowth of neurites . In addition, its importance for CSF circulation seems to be obvious; a agenesis of the SCO is a hydrocephalus associated.

Individual evidence

  1. ^ Ragnar Olsson, Roberto Yulis, Estéban Rodríguez: The infundibular organ of the lancelet (Branchiostoma lanceolatum, Acrania):… . In: Cell and Tissue Research , 1994 Jul, Volume 277 (1), pp. 107-114; here online
  2. ↑ E. Rodríguez, S. Rodríguez, S. Hein: The subcommissural organ . In: Microsc Res Tech . Volume 15, No. 41, April 1998, pp. 98-123. doi : 10.1002 / (SICI) 1097-0029 (19980415) 41: 2 <98 :: AID-JEMT2> 3.0.CO; 2-M . PMID 9579598 .
  3. ↑ F. Nualart, S. Hein: Biosynthesis and molecular biology of the secretory proteins of the subcommissural organ . In: Microsc Res Tech . Volume 52, No. 5, March 2001, pp. 468-483. PMID 11241858 .
  4. ↑ Johannes Rohen: Functional Neuroanatomy . Schattauer, 2001, ISBN 978-3-794-52128-9 , p. 267.
  5. ↑ Gert Böhme: Textbook of the anatomy of domestic animals, Volume 4: Nervous system,… . Thieme, 2004, ISBN 978-3-830-44150-2 , p. 44.
  6. ↑ a b M. Guerra, C. González, T. Caprile, M. Jara, K. Vio, R. Muñoz, S. Rodríguez, E. Rodríguez: Understanding How the Subcommissural Organ and Other periventricular Secretory Structures Contribute via the cerebrospinal fluid to neurogenesis . In: Frontiers in Cellular Neuroscience . December 9, 2015. doi : 10.3389 / fncel.2015.00480 . PMC 4689152 (free full text).
  7. ↑ David Picketts: Neuropeptide signaling and hydrocephalus: SCO with the flow . In: J Clin Invest . 116 (7), July 2006, pp. 1828-1832. doi : 10.1172 / JCI29148 . PMC 1483144 (free full text).