Locomotion Modulates the Sensitivity of Mechanosensory Interneurons in Freshwater Crayfish

Summary

In freshwater crayfish resting or walking on a treadmill 12 different identified mechanosensory interneurons have been recorded intracellularly in order to investigate the influence of the state of activity of the crayfish on the responsiveness of these neurons to water stimuli directed onto the tailfan of the animal. First, the background activity of these neurons is influenced by the state of activity of the crayfish, which allows to group the neurons into three classes (no change, increase, decrease of activity while walking). Second, additional stimulation of tailfan hair receptors by water movements, results in a complex across-the-fiber-pattern within the interneuron population, which might allow the distinction between self-induced stimulation by the relative water movement produced during walking and external stimulus sources.