Fig. 2. Anti-GABA immunocytochemistry of peripheral nerves and muscles. (A) Three GABA-immunoreactive axons (arrowheads) enter nerve 6 (N6) as it branches off the posterior pro-mesothoracic connective. (B) Branching point of mesothoracic nerve 1 (N1) as it divides into N1B (here still including N1C: N1B/C) and N1D (compare Figs 1 and 6). A sensory branch that supplies the sternum (see ventralmost label in Fig. 1) also buds off at this point. Two immunoreactive axons run from the prothoracic ganglion through N1 and into N1B to supply M59. Only the larger-diameter axon gives off a branch into N1D to supply M81 and M82. (C) GABA-immunoreactive axonal branches and terminal boutons on M59. Two immunoreactive axons supply the muscle (arrowheads). Scale bars, 35 µm (A,B); 100 µm (C).