Fig. 1. Location of the cell bodies of nonspiking interneurons in the metathoracic ganglion analysed in this study. The interneurons were first characterized physiologically by intracellular recordings from their neurites and were then stained by intracellular injection of Lucifer Yellow. The ganglion is viewed ventrally and the lateral nerves innervating the left hind leg and left hind wing are numbered. All the stained interneurons affected motor neurons innervating muscles in the left hind leg. The filled circles represent the 15 interneurons that were GABA-immunopositive, and the open circles represent the two interneurons that were not GABA-immunopositive. The numbering of the cell bodies refers to the figures in which these interneurons are illustrated.