Eel control? Scientists find ancient fish protein that can turn off mood disorders in the brain

SEATTLE, Wash. — It may not be “mind control” exactly, but scientists say they may have a way to control how certain neurons work in the human brain. This may sound like a slippery science to perfect and, ironically, researchers from University of Washington School of Medicine say they owe the breakthrough to an eel. Using a protein from the lamprey, scientists believe they can turn off brain circuits which play a role in various mood disorders.

Study authors say they successfully used parapinopsin to switch off certain brain neurons at the genetic level. Oddly enough, this protein has been around since prehistoric times. Lampreys are an ancient species of jawless fish which have a lot in common with the present day eel. Using parapinopsin to target specific neurons, researchers believe it’s possible to develop genetic treatments for addiction and depression.

“We found a particular protein that comes from lamprey that has been around for hundreds of millions of years. We took the gene from that protein and found we can control the way neurons talk to each other, which is how chemicals are transmitted into the brain,” explains lead corresponding author and professor of anesthesiology and pain medicine Michael Bruchas in a university release.

Bruchas adds scientists have been experimenting with light-sensitive proteins from plants and bacteria for decades. This is the first attempt to use lamprey protein to control brain circuits.

What is parapinopsin?

Researchers call this protein a “g protein coupled receptor” or GPCR. These substances developed early on during evolution and are a part of many organisms, from bacteria to humans. Study authors note there are over 850 GPCRs in mammals alone. They control a vast number of bodily functions, from heart rate, to fat storage, to pleasure and stress responses. GPCRs also interact well with the body’s “feel good” chemicals, such as dopamine and serotonin.

“Some of these GPCR pathways are highly conserved across millions of years of evolution, and that allowed us to hack into them using parapinopsin,” says lead author and assistant professor of anesthesiology Bryan Copits.

The Bruchas Lab, as well as researchers from the University of California, University of Zurich, and Washington University in St. Louis, add developing a way to suppress brain neurons has been difficult until the parapinopsin discovery.

The study reveals protein in lamprey respond to light instead of chemicals. If a Parkinson’s patient suffered a seizure, it might be possible to isolate that part of the brain with an electrode. Scientists could then dampen that region having the seizure by adjusting brain neurotransmission or inhibiting certain pathways to improve mood.

Bruchas notes researchers in Japan first discovered parapinopsin while studying different light-sensitive GPCRs across various species.

“This is a perfect rationale for why basic science is so incredibly important,” Bruchas concludes. “Because of someone’s hard work of basic biological discovery, we have a new tool for medical research.”

Study authors are planning to use the discovery of the lamprey protein to gain more knowledge on how the brain works. From there, they can identify new treatments for stress, depression, addiction, and pain.

The study appears in the journal Neuron.