Satellite Cells

SATELLITE CELLS (Latin satellites - bodyguards, companions). 1. Satellite cells (syn. amphicytes, perineuronal cells, Trabantenzellen), a name given by Ramón y Cajal to special cells located in the nerve nodes of the cerebrospinal system between the capsule of the ganglion cell and its body. They usually have a flattened body with long, sometimes branching processes, but can increase in volume and become round or polyhedral, resembling epithelium. This occurs between bends of the nerve process, in the so-called glomerulus, and mainly in the terminal intervals that form around the periphery of the ganglion cell with age. Satellite cells are now considered non-neuroglial; they constitute a direct continuation of the Schwann cells that form the sheath of the nerve fiber. Satellite cells are also called glial cells that sometimes adjoin the nerve cells of the brain. It is believed that satellite cells serve to nourish nerve elements, but in addition they possess, like other glial cells, the ability to phagocytosis: they penetrate into the body of the nerve cell and destroy it, first forming pits on its surface (neurophagia; Marinesco, Levaditi, Metchnikoff). In pathological processes, for example, in inflammation, proliferation of satellite cells is often observed, which, when accompanied by degeneration of ganglion cells, leads to the formation of peculiar cell nodules in their place (for example, in rabies). 2. Satellite veins, venae satellites arteriarum, s. comites - deep veins of the extremities that accompany the homonymous artery (Hyrtl). 3. In the science of city planning, satellites are understood as a system of small satellite cities surrounding a particular large city. The development of satellite cities forms the basis of one of the city planning systems (Unwin) (see City Planning).