Two-photon image of the neural tissue which control the front legs of the fly. Neurons express fluorescent proteins to visualize neural activity (cyan) and neural anatomy (red). Source: Pavan Ramdya, EPFL

Scientists from the EPFL Brain Mind Institute and Interfaculty Institutes of Bioengineering developed a method to record the limb control activity and neural circuits of a fruit fly. This enables researchers to understand how neuron circuits control movement in living organisms, which would lead to further development of smooth robot limb control.

The new method uses the two-photon microscopy”advanced imaging technique. The researchers observed firing of fluorescently labeled neurons which light up in the brain when actives.

Researchers focused their study on the fruit fly’s ventral nerve cord. This cord controls the movement of the legs, neck, wings and halteres, which control the fly’s orientation. The team imaged the cord while the fly is moving so as to understand how the neurons move the fly’s limbs in real time.

The study found different patterns of neurons in the ventral nerve cord. Specifically, new patterns revealed which neurons were firing when the fly was grooming and walking around, as well as navigating.

The team also created a genetic technique to access the ventral nerve cord easier. The team hopes this technique helps future studies that focus on complex limb movements.

"I am very excited about our new recording approach," said Professor Pavan Ramdya. "Combined with the powerful genetic tools available for studying the fly, I believe we can rapidly make an impact on understanding how we move our limbs and how we might build robots that move around the world just as effectively as animals."

The paper on this technique was published in Nature Communications.