To produce behaviour that is adaptive, local circuits in the CNS must transform mechanosensory signals from receptors on the body into changes in movement. Substantial insights into the mechanisms underlying these transformations can be obtained by analysing the local circuits of animals from which intracellular recordings can be made from identified neurones during behavior, thus allowing the complete pathways between inputs and outputs to be followed. In the locust (Schistocerca gregaria) these circuits contain both non-spiking and spiking local neurones so that it is possible to elucidate two basic issues of neuronal integration: (1) the operation of the reflex circuitry that must adjust locomotion, and (2) the integrative role of local circuits that use graded interactions in complex neuropil, perhaps even involving compartmentalized neurones.