View source for Ligand-gated ion channels

== Ligand-gated Ion Channels ==

'''Ligand-gated ion channels''' (pronunciation: /ˈlɪɡənd ˈɡeɪtɪd aɪɒn ˈtʃænəlz/), also known as '''ligand-gated ionotropic receptors''' or '''ionotropic receptors''', are a group of transmembrane ion-channel proteins which open to allow ions such as Na+, K+, Ca2+, and/or Cl− to pass through the membrane in response to the binding of a chemical messenger (i.e., a ligand), such as a neurotransmitter.

=== Etymology ===

The term "ligand-gated ion channel" is derived from the words "ligand", a molecule that binds to another (usually larger) molecule, "gate", which refers to the opening and closing mechanism of the channel, and "ion", which are atoms or molecules with a net electric charge due to the loss or gain of one or more electrons.

=== Function ===

[[Ligand-gated ion channels]] are essential for rapid synaptic signaling between cells. They convert the chemical signal of a presynaptically released neurotransmitter directly and very quickly into a postsynaptic electrical signal. Many [[neurotransmitters]] are known to activate ligand-gated ion channels, including [[acetylcholine]], [[GABA]], [[glutamate]], and [[glycine]].

=== Classification ===

Ligand-gated ion channels are classified into three superfamilies which include the [[Cys-loop receptors]], the [[ATP-gated channels]], and the [[glutamate receptors]].

=== Related Terms ===

* [[Ion Channel]]: A pore-forming protein that helps establish and control the small voltage gradient across the plasma membrane of all living cells by allowing the flow of ions down their electrochemical gradient.
* [[Neurotransmitter]]: Endogenous chemicals that enable neurotransmission.
* [[Receptor (biochemistry)]]: A protein molecule that receives chemical signals from outside a cell.
* [[Transmembrane protein]]: A type of integral membrane protein that spans the entirety of the biological membrane to which it is permanently attached.

[[Category:Neuroscience]]
[[Category:Cell biology]]
[[Category:Membrane biology]]
[[Category:Ion channels]]

{{dictionary-stub}}