Betz cell

The Betz cell ( according to the anatomist Vladimir Betz, 1834-1894 ), also Betz giant pyramid, is a neuronal cell type found only in the primary motor cortex. The cell bodies ( Perikaria ) of these very large (up to 100 microns ) pyramidal cells are located in the 5th layer of the cerebral cortex. Their axons project to the spinal cord or the motor cranial nerve nuclei and can be longer than one meter. Betz cell is primarily a histological term, functionally equivalent to the name of the first motoneuron. Their number is comparatively small and it is estimated in humans to about 30,000.

Betz cells form excitatory synapses from and use glutamate as a neurotransmitter.

Construction

In the drawn figure on the right, the image section from top to bottom includes almost the entire thickness of the cerebral cortex, that is about 2.5 to 3 millimeters. One can imagine the medulla down the surface of the brain up and the border. The onion-like thickening at the center of the cell body, called the perikaryon or soma, which also houses the nucleus. The strong upward pulling extension is an apical dendrite, which is fed mainly by thalamic afferents and premotor (additions ). The thorny protuberances are postsynaptic swellings. The apical dendrite is the main input information of the cell. It is possible to detect some additional dendrite, however, remain in the layer of Perikaryons.

The axon is the only information output pulls down ( label ). It sends some perpendicular collaterals. The scale corresponds, depending on the screen resolution about forty times magnification. While maintaining this scale the axon in humans may be 500 times as long as the viewport is from the top down enough.