The Goal: Understanding of the neuronal circuits and principles underlying the higher control of visual orientation behaviour and terrestrial locomotion. Drosophila lends itself for this analysis as there is a plethora of genetic tools at hand to experimentally modify the neuronal basis.
A Screen for Walking Mutants: 230 lines with inheritable defects in walking and orientation behaviour have been isolated in a behavioural screen. 13% of these lines show structural defects in the central complex (Figure), a highly structured neuropil interconnecting the two protocerebral brain hemispheres.
The central complex in a frontal section through the fly brain.
Role of the Protocerebral Bridge: Five mutant lines with structural protocerebral-bridge defects point to a role of this neuropil in step-length control. We currently analyze two of these genes molecularly.
Role of the Fan-Shaped Body: Several lines with fan-shaped body defects indicate a role of this neuropil in right-left bargaining.
Role of the Ellipsoid Body: Common failures in orientation behaviour are observed in lines with ellipsoid-body defects. A respective gene is studied molecularly.
For further details see:
Strauss R (2002) The central complex and the genetic dissection of locomotor behaviour. Curr. Opin. Neurosci. 12, 633-8