Amacrine cell

from Wikipedia, the free encyclopedia
Cell types in the layers of a mammalian
retina - INL: inner granular layer, R: rods, C: cones,
H: horizontal cell, Bi: bipolar cell,
A: amacrine cell, G: ganglion cell,
GC: ganglion cell layer.
(The light comes in from below.)

Amacrine cells ( amacrine from ancient Greek ἀ- a- 'un-', μακρός macros 'large', ἴνες ines 'fibers') are neurons in the retina of vertebrates . Their cell bodies are mainly located in the inner granular layer (INL). The amacrine cells represent a very diverse class of neurons in the retina; Over 30 subtypes can be distinguished based on the morphology of their cell processes and their retinal branching patterns alone .

They interact synaptically in the inner plexiform layer (IPL) with both the axons of the bipolar cells (Bi) and the dendrites of the retinal ganglion cells (G) and thus - similar to the horizontal cells (H) - ensure lateral connections within the retina, however on a second level. Amacrine cells influence the flow of signals to the ganglion cells via the bipolar cells.

The amacrine cells got their name because it was thought that they had no axon ( Santiago Ramón y Cajal , 1894). For most of them this is actually true: on their dendrites there are both entrance and exit synapses; one axon is missing. However, some 'large field' amacrine cells have long axon-like processes that serve to transmit signals over greater distances in the retina, but do not emerge from the retina like the axons of ganglion cells.

See also

literature

  • Santiago Ramon y Cajal : The retina of the vertebrate animals. Investigations with the Golgi-Gajal's chromosilver method and Ehrlich's methylene blue coloration. JF Bergmann, Wiesbaden 1894.
  • Rolf Sauermost (Ed.): Lexicon of Biology. Volume 1: A to Arjona. Spectrum, Akademischer Verlag, Heidelberg 1999, ISBN 3-8274-0326-X .

Individual evidence

  1. ^ R. Balasubramanian, L. Gan: Development of Retinal Amacrine Cells and Their Dendritic Stratification. In: Current reports ophthalmology. Volume 2, number 3, September 2014, pp. 100-106, doi : 10.1007 / s40135-014-0048-2 , PMID 25170430 , PMC 4142557 (free full text).