ionotropic receptor
Ligand-gated ion channel that opens directly upon neurotransmitter binding.
Full Definition
Ionotropic receptors are neurotransmitter receptors that function as ligand-gated ion channels, opening directly upon neurotransmitter binding to allow specific ions to flow across the membrane. These receptors mediate fast synaptic transmission, typically producing effects within milliseconds of neurotransmitter binding. Major examples include NMDA and AMPA glutamate receptors, GABA receptors, glycine receptors, and nicotinic acetylcholine receptors. The ion selectivity of these channels determines whether they produce excitatory or inhibitory effects. Ionotropic receptors are essential for rapid neural communication and are targets for many neurological and psychiatric medications. Their fast kinetics make them crucial for precise temporal coding in neural circuits.
Usage
Usage note: Contrast with metabotropic receptors in terms of mechanism and speed.
In Context
- "The ionotropic AMPA receptor mediated the fast excitatory synaptic current." — Electrophysiology study
- "Ionotropic receptors are responsible for millisecond-timescale synaptic responses." — Neuroscience textbook