Müller glia, or Müller cells, are a type of retinal , first recognized and described by Heinrich Müller.
The major role of the Müller cells is to maintain the structural and functional stability of retinal cells. This includes regulation of the extracellular environment via uptake of neurotransmitters, removal of debris, regulation of K+ levels, storage of glycogen, electrical insulation of receptors and other neurons, and mechanical support of the neural retina.
Development
Müller glia are derived developmentally from two distinct populations of cells. The Müller glia cell is the only retinal glial cell that shares a common
cell lineage with retinal neurons. A subset of Müller glia has been shown to originate from
neural crest cells.
They are shown to be critical to the development of the retina in mice, serving as promoters of retinal growth and
histogenesis, via a nonspecific
esterase-mediated mechanism.
Müller glia have also been implicated as
guidepost cells for the developing
of neurons in the chick retina.
Studies using a zebrafish model of
Usher syndrome have implicated a role for Müller glia in
synaptogenesis, the formation of
.
Neuronal support
As glial cells, Müller glia serve a secondary but important role to
. As such, they have been shown to serve as important mediators of
neurotransmitter (
acetylcholine and
GABA specifically) degradation and maintenance of a favorable retinal microenvironment in turtles.
Müller glia have also been shown to be important in the induction of the enzyme glutamine synthetase in chicken embryos,
which is an important actor in the regulation of glutamine and ammonia concentrations in the central nervous system. Müller glia have been further identified as fundamental to the transmission of light through the vertebrate retina due to their unique funnel shape, orientation within the retina and more favorable physical properties.
[
]
Role in retinal regeneration
Müller glia are currently being studied for their role in neural regeneration, a phenomenon which is not known to occur in humans.[ WebVision: Regeneration in the Visual System of Adult Mammals] Studies of the regenerative properties of Müller glia in both the zebrafish
Damage to retinal cells induces Müller cells to produce gliosis. The result of the response varies depending on the damage and the organism in which this damage occurs.[
]
See also
External links
