Fish Brain's Complex Noise Filtering Surprises Scientists

3:10 PM ETDeveloping

Science Desk

In Short: Scientists have discovered that the elephantnose fish's brain filters out electrical noise more intricately than previously believed, enhancing its ability to focus on prey.

The elephantnose fish, native to muddy rivers in West and Central Africa, is a key subject in this research. "The elephantnose fish is the champion of electrosensing, sending and receiving electrical signals as it swims around," explained Dr. Pien Huang, a researcher involved in the study.

As the fish sends out an electrical pulse, its brain forms a picture of what to expect. "It subtracts that prediction from what actually comes in, and then the leftover is the unexpected new thing that the brain should care about," said Dr. Sawtell, another researcher. This process helps the fish focus on its prey despite its own electrical signals.

While the nervous system of the fruit fly consists of only roughly 150,000 neurons, researchers have mapped every neuron and connection in the fly brain, discovering over 300 million synaptic connections. "Building a complete picture of the hundreds of millions of synapses in a brain as small as the fruit fly’s is a task that can’t be achieved by humans in a manageable amount of time," noted a researcher from Ars Technica.

What's still developing

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.
MALER: If you start off with the human brain, you're immediately lost.
Scientists have figured out how fish think, in particular, how they focus.
Preparation of an entire brain for imaging at the necessary resolution requires a distinct set of skills, as does interpreting what those images indicate.
The people behind the effort expect that in the long term, the effort will be worth it, as the connectome could give neurobiologists a valuable tool for understanding how the brain works.
From there, most brain activity involves neurons communicating with each other.
This communication transforms the inputs into signals the rest of the brain can interpret, routes information to relevant processing centers, and often produces some kind of output, from forming a memory to moving a muscle.

Sources

NPRlink