New technology created by neuroscientists at Northwestern University has allowed researchers to successfully read the mind of flies.
The tool causes the flies’ brains to light up when their neurons communicate about sensory experiences—like when they smell bananas. Such an advance could help provide insights into the computational processes that occur in human brains.
What does a fly think about?
In the study, which was published in Nature Communications, the researchers worked with Drosophila melanogaster, a common animal model used to study the brain and how it communicates. They modified some of the flies’ neural connections, so that when their sense of smell, their visual system, or their thermosensory system activated, the pathways would fluoresce.
This was achieved by modifying the genomes of flies with a gene from jellyfish that expresses green fluorescent protein. This glowing molecule was split in half and placed in separate parts across synapses, or the communication juncture between neurons. When the neurons became active and “talked” to each other, the two halves came together and lit up—and stayed that way for up to three hours.
The fluorescent proteins were modified to appear green, yellow, or blue to help distinguish the different sensory areas, and then the flies were exposed to sensory experiences, like heat, light, or smell. Later, using a microscope, the fluorescent tags revealed which neural connections had been active during the sensory experience.
“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, in a statement. “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.”
For example, by examining the fluorescence, the researchers were able to tell if a fly had been exposed to heat or cold for 10 minutes up to an hour after it had happened. They could also see a difference between the pathways which lit up for the scent of a banana versus the scent of jasmine.
“Our results show we can detect a specific pattern of activity between neurons in the brain, recording instantaneous exchanges between them as persistent signals that can later be visualized under a microscope,” said Gallio.
Or in other words: They can “read” what a fly has experienced by looking at their brains hours later. Pretty cool stuff, huh?
I don’t want to know what’s going on in that little insect brain after ten minutes of eating dung. Some things are better left unknown.
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Image credit: Thinkstock
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