Fig. 1. Anti-GABA labeling of a subesophageal ganglion (SOG, whole-mount) that was backfilled via the salivary duct nerve (SDN) with TMR-dextran. (A) A SOG (outline indicated by gray broken lines). The nerve (indicated by gray dotted lines) is partially out of view because it leaves the plane of the optical section and was turned over the ganglion during the embedding procedure. Upon entering the ganglion, the pathways (indicated by white dotted lines) of the two thick axons diverge. One axon extends to a soma with contralateral, anterioventral position (SN1) and the other originates at a soma with ipsilateral, midventral position (SN2). (B–D) Anti-GABA labeling (green) of a SOG that was backfilled with TMR-dextran (red). The right panel shows the composite images. SN1 is labeled only with TMR-dextran (B) whereas SN2 is labeled with both TMR-dextran and anti-GABA (C). Other GABA-positive neurons contain no TMR-dextran (D). Bar A, 250 µm, bar for B,C in D, 50 µm.