Neurophysiological correlates of swarming behaviour in desert locusts.

Desert locusts Schistocerca gregaria are grasshoppers that can swarm. This defining characteristic of locusts - swarm formation or 'phase change' - comes about because their behaviour, morphology and physiology change in response to environmental cues. At low population densities, locusts avoid each other and do not swarm, but as populations grow, contact between the animals causes them to begin to actively aggregate: a process called gregarisation that leads to a spiralling population growth and the formation of vast coherent and devastating swarms containing millions or billions of individuals. The remarkable behavioural alterations must come about through modifications (plasticity) of neuronal activity and synaptic properties, but surprisingly little is known about the pathways or mechanisms involved. In this project we will use a range of techniques, including in vivo electrophysiology, to examine the neurophysiological correlates of environmentally-induced behavioural plasticity in this powerful model system. How does the control of posture and locomotion differ between swarming and non-swarming locusts? How quickly do the differences arise during swarm formation? Do particular stress-related molecules ('heat shock proteins') regulate variability in limb control and/or the changes that occur during swarm formation?