Ionotropic glutamate receptor

Ionotropic Glutamate Receptor

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Ionotropic glutamate receptor

The Ionotropic Glutamate Receptor (iGluR) is a type of glutamate receptor that functions as a ligand-gated ion channel. These receptors are integral membrane proteins composed of four large subunits that form a central ion channel pore.

Structure

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Structure of an ionotropic glutamate receptor

Ionotropic glutamate receptors are tetrameric assemblies of four subunits. Each subunit has an extracellular amino terminal domain, an extracellular ligand binding domain, and a transmembrane domain. The ligand binding domain is responsible for binding glutamate, while the transmembrane domain forms the ion channel.

Function

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Function of an ionotropic glutamate receptor

Ionotropic glutamate receptors are responsible for the fast excitatory synaptic transmission in the central nervous system. When glutamate binds to the receptor, the channel opens, allowing ions to flow across the cell membrane. This can result in either depolarization or hyperpolarization, depending on the type of ions that flow through the channel.

Types

There are three main types of ionotropic glutamate receptors: AMPA receptors, NMDA receptors, and kainate receptors. Each type has unique properties and roles in the nervous system.

AMPA Receptors

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AMPA receptor

AMPA receptors are responsible for the majority of fast excitatory synaptic transmission in the brain. They are permeable to sodium and potassium ions, and under certain conditions, can also be permeable to calcium ions.

NMDA Receptors

NMDA receptor

NMDA receptors are unique in that they are both ligand-gated and voltage-gated. They are permeable to sodium, potassium, and calcium ions. NMDA receptors play a crucial role in synaptic plasticity, which is the ability of synapses to strengthen or weaken over time.

Kainate Receptors

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Kainate receptor

Kainate receptors are involved in both pre- and post-synaptic transmission. They are permeable to sodium and potassium ions. Kainate receptors have been implicated in several neurological disorders, including epilepsy.

See Also

• Metabotropic glutamate receptor
• Neurotransmitter receptor
• Synaptic plasticity