Figure 1

The abdomen and its mechanoreceptors.(a) The dorsal cuticle of the A compartment (cuticle types a3 to a5) contains oriented mechanosensory bristles, whereas a1, a2, a6 and the entire P compartment do not (after [8]). Anterior is up, posterior is down. (b) The four cells comprising the mature bristle are a shaft cell (brown), socket cell (yellow), a single-dendrite sensory neuron (green) and a glial-like sheath cell (red). The dendrite makes contact with the shaft at the dendritic cap [61]. As far as possible we use this colour code in the other figures.