Fig. 3. Backfills reveal anatomical details of (inhibitory) innervation in the locust prothorax. (A) Backfilling the motor nerve to M59 stains two (presumptive inhibitory, see text) motor neurons in the prothoracic ganglion, the axons of which leave the ganglion through nerve 6 (N6) (confocal image of neurobiotin fill, developed with Cy2, ganglion outline indicated). Arrowheads indicate looping primary neurites. (B) Backfilling the motor nerve to M59 also stains axonal branches and terminal boutons on M82 (Ni²⁺-backfill, silver-intensified). (C) Backfilling the motor nerve to M59 finally reveals the axons of the two (inhibitory) motor neurons shown in A as they project into the periphery through N6. Only the smaller diameter axons send a branch into N1A to innervate M60 (confocal image, as in A). Scale bars, 200 µm (A); 150 µm (B); 25 µm (C).