Scientists study how the brain of a fish filters out signals : NPR

The elephantnose fish is native to Africa and a darling of neuroscientists, for its specialized cerebellum-like brain. Scientists have mapped the neurons in a part of the brain that senses electrical signals in detail, and found that how it filters out electrical noise is more complex than they thought.

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Here’s another story. Scientists have figured out how fish think, in particular, how they focus. NPR’s Pien Huang reports.

PIEN HUANG, BYLINE: The elephantnose fish is native to muddy rivers in West and Central Africa. It’s the champion of electrosensing, sending and receiving electrical signals as it swims around. Here’s Nathaniel Sawtell at Columbia University’s Zuckerman Institute.

NATHANIEL SAWTELL: If you want to study basketball, you study Steph Curry. You don’t study yourself (laughter).

HUANG: And this Steph Curry of fish has to filter out its own signals so it can focus on its prey. Sawtell says they do that a lot like humans do.

SAWTELL: So it’s doing this very crisp and beautiful prediction process.

HUANG: As the fish sends out an electrical pulse, its brain forms a picture of what to expect.

SAWTELL: It subtracts that prediction from what actually comes in, and then the leftover is the unexpected new thing that the brain should care about.

HUANG: How that works on the level of neurons and electrical signals has taken years to figure out. Sawtell and his colleagues sliced up part of a fish brain to make a detailed map of how all the cells are wired together. Then they added information from probes and computer modeling to explain how the cells work together to cancel out the noise. Leonard Maler is a neuroscientist at the University of Ottawa not involved in this research.

LEONARD MALER: They worked it all out. And there’s probably, you know, only five people in the world that can follow the whole argument.

HUANG: Maler, who also works on fish brains, peer reviewed the paper for the journal Nature. He says it provides a blueprint for studying more complicated systems.

MALER: If you start off with the human brain, you’re immediately lost. So you need ideas from simpler systems.

HUANG: While fish look different from us, the neurons, signals and building blocks of our brains are quite the same.

Pien Huang, NPR News.

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