New research highlights the development of HySyn, a system designed to synthetically reconnect neural circuits using neuropeptides from Hydra, a small, freshwater organism, into the model organism C. elegans.
The research, published in Nature Communications, highlights the development of HySyn, a system designed to synthetically reconnect neural circuits using neuropeptides from Hydra, a small, freshwater organism. (Neuropeptides modulate the activity of neurotransmitters to increase or decrease the strength of impulses between neurons.)
For the first time, the researchers created genetic lines of mutant C. elegans that expressed neuropeptides from the Hydra brain, creating an artificial synapse that rewired a behavioral circuit in the worm. Because none of the other synapses in the brain, besides those fitted with the hydra receptor and neuropeptide, could hear the «command,» it was like giving them a cell phone so they could communicate.
«These neuromodulatory peptides let you communicate at a distance,» said MBL Fellow Daniel Colon-Ramos of Yale University School of Medicine. «It gives you more flexibility as a researcher to manipulate neurons that are not adjacent to each other.» Colon-Ramos, senior author on the paper, was postdoctoral advisor for the paper’s first author, former MBL Grass Fellow Josh Hawk. The work and analysis was performed at the MBL and at Yale University in Colon-Ramos’s lab.
The researchers used a mutant line of C. elegans that was missing the neural connection that controlled specific behavior — the behavior that told them that they were full and needed to stop searching for food. By taking genes that encode a neuropeptide and its receptor from Hydra and putting them into the C. elegans worm, researchers were able to restore the neural circuit that controls this behavior. They created two separate genetic lines — one that contained the neuropeptide and one that contained the receptor. The offspring of the pair contained the full neural peptide pathway. But, according to Hawk, it’s just one possible pathway to focus on.
«There are hundreds of neural peptides in Hydra, each of which could be a different channel of communication,» said Hawk. «To me, that’s the most exciting thing. This should open up a whole area that no one has ever explored before.»
Hawk called this study a «proof of principle» for the HySyn tool. Unlike most organisms, Hydra don’t have a classic neurotransmitter system in the brain. Instead, they rely completely on a net of neuropeptides. Each of these Hydra neuropeptides has the opportunity for a unique line of communication. Hawk focused on a particular neuropeptide that creates a slow-building signal, like the slow-building sensation of fullness as you eat a meal. Connecting different neurons with this neuropeptide could create a slowly rising pain response or strengthen a new memory.
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Materials provided by Marine Biological Laboratory. Original written by Emily Greenhalgh. Note: Content may be edited for style and length.