Are you smarter than a fruit fly?
Northwestern University neuroscientists now can read the mind of a fly. They have developed a clever new tool that lights up active conversations between neurons during a behavior or sensory experience, such as smelling a banana. Mapping the pattern of individual neural connections could provide insights into the computational processes that underlie the workings of the human brain.
In a study focused on three of the fruit fly’s sensory systems, the researchers used fluorescent molecules of different colors to tag neurons in the brain to see which connections were active during a sensory experience that happened hours earlier.
Synapses are points of communication where neurons exchange information. The fluorescent labeling technique is the first to allow scientists to identify individual synapses that are active during a complex behavior, such as avoiding heat. Better yet, the fluorescent signal persists for hours after the communication event, allowing researchers to study the brain’s activity after the fact, under a microscope.
“Much of the brain’s computation happens at the level of synapses, where neurons are talking to each other,” said Marco Gallio, who led the study. “Our technique gives us a window of opportunity to see which synapses were engaged in communication during a particular behavior or sensory experience. It is a unique retrospective label.”
Gallio is an assistant professor of neurobiology in Northwestern’s Weinberg College of Arts and Sciences.
By reading the fluorescent signals, the researchers could tell if a fly had been in either heat or cold for 10 minutes an entire hour after the sensory event had happened, for example. They also could see that exposure to the scent of a banana activated neural connections in the olfactory system that were different from those activated when the fly smelled jasmine.
Fruit fly image via Shutterstock.