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Fish Brain Filters Out Electrical Noise More Complexly Than Thought
Confirmed
In Short: Scientists have discovered that the brain of the elephantnose fish, a champion of electrosensing, uses complex mechanisms to filter out its own signals, allowing it to focus on its prey.
The elephantnose fish, native to muddy rivers in West and Central Africa, is a darling of neuroscientists due to its specialized cerebellum-like brain. "If you want to study basketball, you study Steph Curry," Sawtell said, drawing a parallel to the fish's electrosensing abilities.
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," Sawtell explained.
The fish's ability to filter out its own signals is crucial for focusing on its prey. "The elephantnose fish is native to muddy rivers in West and Central Africa and is the champion of electrosensing, sending and receiving electrical signals as it swims around," said Nathaniel Sawtell.
In a separate study, researchers found that red tomatoes contain a bright pigment called lycopene, a potent antioxidant that can cross the blood-brain barrier and may help reduce neuroinflammation. However, the study's findings were based on a small and statistically underpowered imaging analysis, and the trial was unblinded, which may have affected the results.
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.
- These scans revealed tentative changes in connectivity across large-scale brain networks, although the imaging analysis was small and statistically underpowered – and based on a more lenient statistical threshold than the study's own planned correction method.
- It's also worth noting that the trial was unblinded – both participants and researchers knew who was eating tomato paste and who wasn't – so the study authors can't fully rule out that knowing which diet they were on affected people's motivation or effort on the cognitive tests.
- Lycopene concentrations increased markedly on the tomato diet, and there was a borderline increase in a brain-growth protein called BDNF.
- Conversely, when a diet was low in tomato, scientists observed reduced resting-state connectivity in dorsal attention networks.
- A separate five-week crossover trial found that a mixed-berry beverage containing tomato powder improved older adults' working memory, but not their selective attention – a discrepancy the study authors suggest may reflect practice effects from repeated exposure to the same cognitive test.