Practice question

Ligand-gated ion channels such as nicotinic acetylcholine, GABA-A, glycine and ionotropic glutamate receptors open upon neurotransmitter binding, producing rapid postsynaptic currents. Studying them requires ability to apply agonist at defined concentrations while monitoring transmembrane current. Patch-clamp in outside-out or whole-cell mode permits rapid solution exchange via perfusion systems, recording dose-dependent activation, desensitization, single-channel conductance and allosteric modulation with pharmacological precision. EEG records summed population potentials, CT images anatomy using X-rays, MRI uses proton resonance, none provide controlled ligand application and channel current resolution.