Professors from the Cullen College of Engineering have created an implantable single electrode cuff and a wireless telemetry system allowing researchers to better understand how certain neurons in locusts’ brains process sensory information.
Created by Jack Wolfe and Richard Liu—both professors in the college’s electrical and computer engineering department—the cuff is smaller and more sensitive than technology available prior. It can obtain readings from tiny nerves within the insect while the telemetry system allows readings to be transmitted wirelessly to a receiver and analyzed.
These devices are a crucial component in the research by Liu, Wolfe, UH graduate student Rui Zhong, and Fabrizio Gabbiani, professor in the department of neuroscience at Baylor College of Medicine, and his graduate student and UH alumna, Haleh Fotowat. Both are helping Gabbiani and Fotowat understand the real significance of messages the brain is generating, related to jump escape behaviors, in the locust.
“There is still a lot of controversy about how motor actions are generated,” Gabbiani, said. “The only way to solve that is to look at a system where we can really analyze, from single cell to behavior, what is happening and see what information the neurons are transmitting and how they are generating whole behaviors. Locusts allow us a look at such detailed information that would be difficult to obtain in other animals.”
Over the course of the last three years, the team has explored this idea with a nearly $400,000 grant from the National Science Foundation. Though funding is up in August, the group has applied for a renewal that will allow them to expand on the research to date. This includes the creation of a multi-electrode cuff and telemetry system allowing simultaneous recordings from multiple neurons.
Researchers have come a long way since the first year, when wires were implanted on nerves and locusts were immobilized during trials. These days, locusts are implanted with Wolfe’s electrode cuff and carry Liu’s wireless telemetry system as a backpack. The cuff is fixed to their nerve cord, which is close to the size of a human hair and near the consistency of gelatin.
The locusts, which can move freely, walk through a tunnel and onto a platform where the insects are exposed to looming stimuli on a nearby computer screen.
The battery-powered radio was engineered by Liu and Zhong and weighs only .5 grams. It is designed to transmit signals from the nerve cord wirelessly to a receiver approximately two meters away. The receiver records the spikes of the neuron as the locust prepares to jump and fly from the projected stimuli. These spikes are compared to high-speed video taken simultaneously and analyzed to determine exactly how the neurons activity correlates to the insect’s actual behavior.
“No one has ever looked at the neurons activity right at the time of such behaviors to see exactly the correlation,” Gabbiani said. “That is what we are trying to do.”
Though the project is driven by basic neuroscience, Wolfe said “every one of the technologies that has been developed has enormous potential for other applications.” This includes one day utilizing the radio backpack to allow scientists to remotely control and monitor animals’ activities.