With his moonwalk, Michael Jackson made it look easy to glide backwards across the stage. But walking backwards (whether to look good on the dance floor or to avoid an obstacle) can be tricky – and that's just with two legs: imagine how a six-legged insect might fare.
Yet fare they do, and scientists at the Research Institute of Molecular Pathology in Austria have studied "moonwalking" drosophila flies that are shedding new light on how the brain controls backward gait.
In a paper published in Science , they describe key controls in the reverse movement. To discover them, they worked with flies that switched on specific brain activity patterns if the experimenters turned up the heat. The researchers screened thousands of flies to identify which creatures "moonwalked" backwards when the heat was on. From there, they were able to tease out how the insects' funky moves were being controlled by a pair of motor neurons: messaging cells that link the brain and muscles.
They dubbed one the "moonwalker descending neuron", and found that it seems to trigger backward walking in the flies. The other, which they called the "moonwalker ascending neuron," appears to keep them in reverse.
“This is the first identification of specific neurons that carry the command for the switch in walking direction of an insect,” says researcher Salil Bidaye. “Our findings provide a great entry point into the entire walking circuit of the fly.”
