Neurophysiology basics - Overview

The nervous system, the most complex tissue in existence ^[92], is primarily composed of two major categories of cells ^{[52, 93]}: Neurons ^{[41, 52, 64, 94, 100]} (functional units ^{[39, 64]}) and Glial cells ^{[50, 57]}, which are support cells ^{[36, 39]}. Without the latter, neurons would be unable to function, or at the very least, would struggle to do so.

Neurons devote nearly all their energy to a single goal: the transmission of nerve impulses ^{[39, 75, 95]}. It is the glial cells that are responsible for protecting them, nourishing them, and optimizing their function.

The transmission of nerve impulses by nerve cells is due to the electrochemical properties of their plasma membrane ^[96].

Signals are transmitted from one nerve cell to another through junctions called synapses ^{[41, 52]}. A very specific type of these synapses is the one that connects a neuron to an effector cell, such as a muscle fiber; this synapse is then called a neuromuscular junction ^{[4, 40]}.

Information transfer across a synapse is mediated by chemical messengers called neurotransmitters ^{[39, 40, 41, 52]}.

The proper functioning of the CNS is so crucial that it is isolated from the rest of the body by a barrier that limits the passage of potentially harmful substances: the blood-brain barrier ^{[3, 41, 42, 70, 81]}.

Finally, the most extraordinary faculty of the nervous system is its ability to adapt and constantly modify itself according to needs. Thousands of new neural circuits are formed or strengthened every day. This faculty, known as neuroplasticity ^{[97, 98]}, opens up great perspectives for the management of many disorders, particularly those of a sensory nature.