Figure 5

Neurons in the legs of embryos and nymphs as seen after filling circumoesophageal or cervical connectives. A The middle leg of an embryo at 70% of development (borders between leg segments indicated by stippled lines). Typically one neuron is located in the proximal tibia, a second neuron in the second tarsal segment. B A neuron in the middle leg of a fourth instar nymph located in the motor nerve (outlined by stippled line) of the proximal tibial part of the retractor unguis muscle (outlined by broken line). C and D Further examples for such proximal tibial neurons at higher magnification. Please note the bulge-like extensions of the neurons (white asterisks). E Another example where the neuron is located within the major nerve 5B₂. E1 shows this neuron and two additional fibres proceeding further distal. E2 provides z- and y-projection of the same confocal stack illustrating the location of the soma within the nerve. In the high-gain projection (E1) the neuron looks as if there is a long distal process. E3 provides a 3D stereo pair obtained at lower gain to show that this distal “process” is formed by the axon that first bypasses the soma, makes a U-turn and returns to the soma. Also in this neuron that looks more elongated than the neurons shown in B-C a bulge-like extension of the soma is discernable (white asterisk). Distal is down in all panels. Scales: 100 μm in A, 20 μm in B-D, 40 μm in E.