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A neuron, neurone, [1] or nerve cell is an excitable cell that fires electric signals called action potentials across a neural network in the nervous system.Neurons communicate with other cells via synapses, which are specialized connections that commonly use minute amounts of chemical neurotransmitters to pass the electric signal from the presynaptic neuron to the target cell through the ...
Specialization These units may differ in size, shape, and structure according to their location or functional specialization. Nucleus is key The nucleus is the trophic center for the cell. If the cell is divided only the portion containing the nucleus will survive. Nerve fibers are cell processes Nerve fibers are outgrowths of nerve cells. Cell ...
Cell-count distribution featuring cellular differentiation for three types of cells (progenitor , osteoblast , and chondrocyte ) exposed to pro-osteoblast stimulus. 1. Cellular differentiation is the process in which a stem cell changes from one type to a differentiated one. [ 2 ][ 3 ] Usually, the cell changes to a more specialized type.
Anatomical terminology. [ edit on Wikidata] In biology, the nervous system is the highly complex part of an animal that coordinates its actions and sensory information by transmitting signals to and from different parts of its body. The nervous system detects environmental changes that impact the body, then works in tandem with the endocrine ...
The postsynaptic density (PSD) is a protein dense specialization attached to the postsynaptic membrane. PSDs were originally identified by electron microscopy as an electron-dense region at the membrane of a postsynaptic neuron. The PSD is in close apposition to the presynaptic active zone and ensures that receptors are in close proximity to ...
The evolution of nervous systems dates back to the first development of nervous systems in animals (or metazoans). Neurons developed as specialized electrical signaling cells in multicellular animals, adapting the mechanism of action potentials present in motile single-celled and colonial eukaryotes. Primitive systems, like those found in ...
Neural stem cells (NSCs) are self-renewing, multipotent cells that firstly generate the radial glial progenitor cells that generate the neurons and glia of the nervous system of all animals during embryonic development. [1] Some neural progenitor stem cells persist in highly restricted regions in the adult vertebrate brain and continue to ...
Neuronal precursor cells proliferate in the ventricular zone of the developing neocortex, where the principal neural stem cell is the radial glial cell. The first postmitotic cells must leave the stem cell niche and migrate outward to form the preplate, which is destined to become Cajal–Retzius cells and subplate neurons. These cells do so by ...