Neurotransmitter receptor

A neurotransmitter receptor (also known as a neuroreceptor) is a membrane receptor protein that is activated by a neurotransmitter. A membrane protein interacts with the phospholipid bilayer that encloses the cell and a membrane receptor protein interacts with a chemical in the cells external environment, which binds to the cell. Membrane receptor proteins, in neuronal and glial cells, allow cells to communicate with one another through chemical signals.

In postsynaptic cells, neurotransmitter receptors receive signals that trigger an electrical signal, by regulating the activity of ion channels. The influx of ions through ion channels opened due to the binding of neurotransmitters to specific receptors can change the membrane potential of a neuron. This can result in a signal that runs along the axon (see action potential) and is passed along at a synapse to another neuron and possibly on to a neural network. On presynaptic cells, there can be receptor sites specific to the neurotransmitters released by that cell (see Autoreceptor), which provide feedback and mediate excessive neurotransmitter release from it.

There are two types of neurotransmitter receptors: ligand-gated receptors or ionotropic receptors and G protein-coupled receptors or metabotropic receptors. Ligand-gated receptors can be excited by neurotransmitters (ligands) like glutamate and aspartate. These receptors can also be inhibited by neurotransmitters like GABA and glycine. Conversely, G protein-coupled receptors are neither excitatory nor inhibitory. Rather, they modulate the actions of excitatory and inhibitory neurotransmitters. Most neurotransmitters receptors are G-protein coupled.

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