Cholinergic sensory inputs to command neurons in edible snail.

We studied cholinergic component of visceral sensory input to defensive behavior command neurons in edible snail. Nicotinic receptor antagonist tubocurarine and muscarinic receptor antagonist atropine reversibly decreased the amplitude of the total excitatory postsynaptic potential induced by electrostimulation of the peripheral region in the mechanosensory receptor field of command neurons on the surface of internal organs. Our results indicate that acetylcholine is involved in sensory signal transduction from the visceral sac to command neurons of snail parietal ganglia. The subsynaptic membrane of visceral synaptic input contains nicotinic and muscarinic receptors.