Direction-sensitive partitioning of the honeybee optomotor system

ABSTRACT. The horizontal motion-detecting system controlling optomotor head-turning behaviour in honeybees, Apis mellifera , was found to be partitioned into two separate subsystems. Each subsystem is direction-specific such that visual stimulation in the preferred direction elicited a high level of responses that correcly followed the movement, whereas stimulation in the non-preferred direction resulted in response levels comparable to or lower than those for blinded controls. The results indicate that medial eye regions are specialized for the detection of posterior-to-anterior movements and lateral regions are specialized for detecting anterior-to-posterior motion. A model suggesting possible neural correlates for this functional subdivision of the optomotor response is proposed.