ORLANDO, FLORIDA – A Florida scientist studying simple sea animals called comb jellies has found the road map to a new form of brain development that could lead to treatments for Parkinson’s, Alzheimer’s and other neurodegenerative diseases.
“There is more than one way to make a brain,” said University of Florida researcher Leonid Moroz, who led an international research team that mapped the full genetic code of the Pacific sea gooseberry and decoded gene activity of nine additional species of comb jellies.
Moroz said his research, published on Wednesday in the journal Nature, also places comb jellies on the first branch of the animal kingdom’s “tree of life,” bumping up sponges from the bottom rung of evolutionary progression, even though sponges don’t have neurons.
He said that finding should lead to a reclassification of the animal kingdom’s family tree and reshape two centuries of zoological thought.
Comb jellies are different from common jellyfish. These beautiful but little-known translucent animals are often called “aliens of the sea,” for good reason.
Moroz’s team found that comb jellies’ molecular makeup and the way they develop are radically different from all other animals, involving genes and neural transmitters.
Traditional scientific reasoning has held that simple neural networks evolved all the way up to a human level of complexity along a single path. But it now appears that comb jellies took a different route, using a neurochemical language that does not exist in other animals.
“All other animals have the same chemical language, and these guys have completely different language. It’s not only different grammar. It’s a different alphabet,” Moroz said.
Comb jellies, for example, don’t use dopamine, implicated in Parkinson’s disease, to control brain activity, or other common signaling chemicals such as serotonin.
They also can regenerate their brains in less than four days. In one experiment, a comb jelly regenerated its brain four times.
“Now we know we can construct neural systems differently,” Moroz said.
Discovering the key to regeneration, or appropriating the comb jellies’ different chemical languages, could lead to advancements in synthetic and regenerative medicine, he said.
Biologist Antonis Rokas of Vanderbilt University, who wasn’t part of the new work, said: “It’s almost like evolution has given us two different blueprints for building a structure that’s very important. If your goal is to make a nervous system, it doesn’t matter what the parts are, in some ways. You could potentially mix and match. The more parts you have, the more solutions.”