Neuronal nicotinic acetylcholine receptor (nAChR)

Neuronal nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels that respond to the neurotransmitter acetylcholine and are also targeted by the addictive drug nicotine. They play crucial roles in neuronal communication by converting neurotransmitter binding into membrane electrical depolarization. Neuronal nAChRs are pentameric proteins composed of five subunits (α2-α7, α9, α10, β2-β4) arranged symmetrically around a central water-filled pore. These subunits form various combinations, creating diverse receptor subtypes, such as α4β2 heteromeric receptors (high affinity for nicotine) and α7 homomeric receptors (main contributor to α-bungarotoxin-binding sites). α4β2 receptors can exist in different stoichiometries, contributing to functional diversity and modulation. Neuronal nAChRs mediate fast neurotransmission, function as cation-selective channels allowing passage of Na+, K+, and sometimes Ca2+. Acetylcholine binding triggers rapid channel opening and membrane depolarization, followed by desensitization. They regulate neurotransmitter release, cell excitability, neuronal integration, and contribute to synaptic plasticity, learning, memory, attention, and cognitive functions. Pathologically, they are implicated in nicotine addiction, neurodegenerative disorders (e.g., Alzheimer's), pain processing, and inflammatory conditions. Neuronal nAChRs represent important therapeutic targets for conditions like pain (e.g., α4β2 agonists like ABT-594), Alzheimer's disease, and addiction. However, therapeutic development is challenging due to side effects, highlighting the need for selective compounds. They interact with endogenous ligands (acetylcholine), exogenous substances (nicotine), toxins, and inflammatory mediators.

Other names

neuronal nAChRs

Ligand-gated ion channels that open upon binding of acetylcholine or agonists, allowing the influx of cations (Na+, K+, Ca2+) and causing membrane depolarization. Targeting typically involves agonists or modulators to enhance channel activity.