Electrically Evoked Course Control in the Fly Calliphora Erythrocephala

Abstract

Neurones in the optic ganglia of free-moving and fixed Calliphora were electrically stimulated with extracellular microelectrodes. The maximum diameter of the stimulating focus was 20 μm in the antero-posterior axis. Course control and landing manoeuvres could be elicited by stimulating in the lobula plate but not in the lobula or medulla. With stimulation in the vicinity of the H neurones, yaw responses were evoked. Direction of the response was dependent on stimulation polarity. This supports the hypothesis that H neurones mediate optomotor responses. Stimulation in the posterior part of the lobula plate, close to the V neurones, elicited pitch, lift and thrust responses as well as landing reactions.