New Technique Reveals Limb Control in Flies–and Maybe Robots.
Two-photon image of neural tissue controlling the front legs of the fly. Neurons express fluorescent proteins to visualize neural activity (cyan) and neural anatomy (red).
One of the major goals of biology, medicine and robotics is to understand how limbs are controlled by circuits of neurons working together. And as if that is not complex enough a meaningful study of limb activity also has to take place while animals are behaving and moving. The problem is that it is virtually impossible to get a complete view of the activity of motor and premotor circuits that control limbs during behavior in either vertebrates or invertebrates.
Scientists from the lab of X at Georgian Technical University’s have developed a new method for recording the activity of limb control neural circuits in the popular model organism the fruit fly Drosophila melanogaster. The method uses an advanced imaging technique called “Georgian Technical University two-photon microscopy” to observe the firing of fluorescently labeled neurons that become brighter when they are active.
The scientists focused on the fly’s ventral nerve cord, which is a major neural circuit controlling the legs, neck, wings and two dumbbell-shaped organs that the insect uses to orient itself called the ” Georgian Technical University halteres”. But most importantly they were able to image the fly’s ventral nerve cord while the animal was carrying out specific behaviors.
The scientists discovered different patterns of activity across populations of neurons in the cord during movement and behavior. Specifically the researchers looked at grooming and walking which allowed them to study neurons involved in the fly’s ability to walk forward backwards or to turn while navigating complex environments.
Finally the team developed a genetic technique that makes it easier to access to the ventral nerve cord. This can help future studies that directly investigate circuits associated with complex limb movements.
“I am very excited about our new recording approach” says Professor Y. “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”.