Most neurons are jacks-of-all-trades, study finds
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- Stefano Fusi at Columbia University analyzed data from the International Brain Laboratory, tracking neurons throughout the brains of more than 100 mice performing a decision-making task (looking for an image on the left or right of a screen and turning a wheel to center it).
- Researchers found that truly specialized neurons exist only in dedicated sensory cortices like the primary visual cortex, while neurons in most other brain areas responded to multiple task aspects — processing the image, deciding which side it was on, and generating the wheel-turning movement.
- Across roughly 14,000 neurons analyzed, most did not respond identically to the same stimulus; even somatomotor areas associated with planning movements responded strongly to unrelated inputs like licks and whisker movements.
- Ben Hayden at Baylor College of Medicine said the sample of 14,000 neurons without finding widespread specialization is 'a giant smack in the face' to skeptics who argue researchers just need to study more neurons.
- Having neurons that respond to the same stimulus in slightly different ways may maximize how much information the brain can process, the researchers argue, with potential contributions to memory, cognition, decision-making and perception.
- Fusi's team is now collaborating with researchers studying non-human primates and conscious epilepsy-surgery patients to test whether the mouse findings extend to people, and aims to shift neuroscience from single-neuron analysis to activity patterns across many cells.
Why it matters: After sampling roughly 14,000 neurons across 100+ mice, Fusi's team argues the field should pivot from chasing famous specialized cells (place cells, mirror neurons, 'Jennifer Aniston' cells) to studying activity patterns across many neurons — a stated priority of the researchers now extending the work to primates and human epilepsy patients.
