Which tissues contain nicotinic receptor subtypes?

• A. Skeletal muscle, peripheral neurons, and central neurons
• B. Only skeletal muscle
• C. Only peripheral neurons
• D. Only central neurons

Answer: (A)

Nicotinic receptors are ligand-gated ion channels found in multiple tissue types, not just one. In skeletal muscle, Nm receptors at the neuromuscular junction trigger depolarization and contraction when acetylcholine is released. In peripheral neurons, Nn receptors are located in autonomic ganglia (and adrenal medulla), mediating fast synaptic transmission in the autonomic nervous system. In the brain, central nicotinic receptors on various neurons modulate neurotransmitter release and excitability, with subtypes like those containing α4β2 or α7 subunits.

Because all three tissue categories—skeletal muscle, peripheral neurons, and central neurons—house nicotinic receptor subtypes, the best answer reflects that broad distribution.