If you're in the mood for some awful neuroscience punnery, look no further than the Michael Jackson Fly's moonwalker neurons. A recent study by Bidaye and colleagues described a set of cells in the fruit fly nervous system that are responsible for the control of backward locomotion.
The authors used genetic techniques to survey 3500 potential sets of neurons until they pinpointed the group driving the movements. Leave it to geneticists to come up with 'moonwalker descending neuron'. This is, after all, the same field that has blessed us with nominal nuggets like tribbles, swiss cheese, dumpy, and methuselah.
Deconstructing the neural circuits for complex movement has obvious applications in neuroprosthetic research. Certainly, we're getting closer to understanding how the brain can store, prepare, and generate these movements, but there's still a bit of black box at play. Keep your eye out for a forthcoming Neuron paper by Hennequin, Vogels, and Gerstner—they might just have the dynamics figured out. Thrilling stuff.
To figure out whether something similar is happening in limbed locomotion, we need a better understanding of the circuitry that controls forward walking.