GABA immunocytochemistry reveals five morphologically different nerve cell types in the frog stomach.

GABA (gamma-aminobutyric acid) immunocytochemistry was used on whole mounts of the frog stomach muscular layer to identify the GABAergic elements of the myenteric plexus. Between the labelled nerve fibres, five morphologically different types of neurons were revealed. The same cell types were also observed in the NADH-diaphorase-labelled control preparations. The different morphologies of the GABA-immunoreactive neurons may reflect the different peptide cotransmitter contents and/or different electrophysiological properties of these neurons.