Neuroscientists from Northwestern University have developed a new tool that can light up active communications between the neurons of a fly during behaviors or sensory experiences. Using this technology, they can observe the mapping patterns of individual neural connections, as outlined in their study, and eventually help us better understand the computational processes that occur between neurons in the human brain.
The researchers used different colored florescent molecules to tag neurons in the Drosophila melanogaster fruit fly's three sensory systems in order to observe connections that were active during previous sensory experiences. This new fluorescent labeling technique is the first of its kind to allow scientists to identify the individual synapses, which are the communication points that allow neurons to communicate, that are active during complex behaviors.
"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 press release. "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 and his team also used genetic engineering to develop the fluorescent labeling method. Starting with the gene for a green fluorescent protein found in jellyfish, they created three different colored markers that lit up when neurons were actively communicating at synapses. This technique allows them to read the markers one to three hours after a complex behavior is over under a microscope.
"Different synapses are active during different behaviors, and we can see that in the same animal with our three distinct labels," said Gallio. "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."
