Betz cell

Infobox_neuron
neuron_name = Betz cell
image_neuron = GolgiStainedPyramidalCell.jpg
caption_neuron = A human neocortical pyramidal neuron such as a Betz Cell stained via Golgi technique.
location = Layer V of Cortex in primary motor cortex
function = excitatory projection neuron to spinal cord
neurotransmitter = Glutamate
morphology = Multipolar Pyramidal -- some of the longest axons in the body.
afferents = Superficial cortical layers, premotor area
efferents = Ventral horn of the spinal cord
GraySubject =
GrayPage =

Betz cells are pyramidal cell neurons located within the fifth layer of the grey matter in the primary motor cortex. They are named after Vladimir Alekseyevich Betz, who described them in his work published in 1874. Betz W. (1874) "Anatomischer Nachweis zweier Gehirncentra." Centralblatt für die medizinischen Wissenschaften. 12:578-580, 595-599.] These neurons are some of the largest in the central nervous system, sometimes reaching 100 μm in diameter. Nolte, J. "The Human Brain", 5th ed. Mosby: Missouri; 2002, p.527. ISBN 0-323-01320-1] Betz cells send their axons down to the spinal cord where in humans they synapse directly with anterior horn cells, which in turn synapse directly with their target muscles. While Betz cells have one apical dendrite typical to pyramidal neurons, they have more primary dendritic shafts, and these do not leave the soma only at basal angles but rather branch out from almost any point asymmetrically. Braak H, Braak E. (1976) "The pyramidal cells of Betz within the cingulate and precentral gigantopyramidal field in the human brain. A Golgi and pigmentarchitectonic study." Cell Tissue Res. 172(1):103-19. PMID 991201] These perisomatic and basal dendrites project into all cortical layers, but most of their horizontal arbors populate layers V and VI, some reaching down into the white matter. Meyer G. (1987) "Forms and spatial arrangement of neurons in the primary motor cortex of man." J Comp Neurol 262:402–428. PMID 3655019] According to one study, Betz cells represent about 10% of the total pyramidal cell population in layer Vb of the human primary motor cortex. Rivara CB, Sherwood CC, Bouras C, Hof PR. (2003) "Stereologic characterization and spatial distribution patterns of Betz cells in the human primary motor cortex." Anat Rec A Discov Mol Cell Evol Biol. 270(2):137-51. PMID 12524689 [http://home.gwu.edu/~sherwood/2003.Human.Betz.AR.pdf free fulltext article (PDF)] [http://www.unige.ch/cyberdocuments/theses2003/RivaraC-B/these_body.html Extended HTML version] ]

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