Synaptic Transmission at Taste Buds

Abstract

PREVIOUS investigations have shown that a variety of sensory receptors can be stimulated by the application of acetylcholine¹, this sensitivity being enhanced in mechanoreceptors by the addition of 10⁻⁵ g/ml. physostigmine. Excitation by acetylcholine was blocked by tubocurarine or hexamethonium (10⁻⁷–10⁻⁵ g/ml.)², but the response of the receptor to normal mechanical stimuli was unaffected by the presence of these blocking agents^1,2, and Gray and Diamond conclude, therefore, that acetylcholine has no physiological function as an intermediary in the initiation of nerve impulses at sensory receptors¹. Landgren et al.³, applying drugs to the surface of the frog's tongue, found, however, that high concentrations of anticholinesterases initially increased the spontaneous activity in the lingual nerve and afterwards blocked taste sensitivity. Tubocurarine also reduced the response of the taste buds to gustatory stimuli and these authors suggest that acetylcholine is concerned with the initiation of impulses at chemoreceptors.