Neurons (also known as neurones, nerve cells and nerve fibers) are electrically excitable cells in the nervous system that function to process and transmit information.
In vertebrate animals, neurons are the core components of the brain, spinal cord and peripheral nerves.
Neurons are typically composed of a soma, or cell body, a dendritic tree and an axon.
The majority of vertebrate neurons receive input on the cell body and dendritic tree, and transmit output via the axon, although there is great heterogeneity throughout the nervous system, as well as throughout the animal kingdom, in the size, shape and function of neurons.
For invertebrate neurons, the information flow is less well defined.
Neurons communicate via chemical and electrical synapses, in a process known as synaptic transmission.
The fundamental process underlying synaptic transmission is the action potential, a propagating electrical signal that is generated by exploiting the electrically excitable membrane of the neuron.
Neurons are highly specialized for the fast processing and transmission of cellular signals.