Effect of cholinergic drugs on single mechanoreceptors (Pacinian corpuscles)

Abstract

Application of acetylcholine and nicotine to the intact Pacinian corpuscle does not induce spike activity but affects its sensitivity to mechanical stimulation: low concentrations (1 · 10⁻⁶ g/ml) increase it, high concentrations (1 · 10⁻⁴ g/ml) reduce it. This effect can be explained by the action of these substances on structures generating action potentials. Application of acetylcholine to the decapsulated Pacinian corpuscle induces spike activity. This response may perhaps be due to the action of acetylcholine on the mechanoreceptive site itself. Application of tubocurarine or hexamethonium depresses the sensitivity of the receptor to mechanical stimulation, and this may also point to a role of acetylcholine in the process of adequate excitation of the receptor.