Israeli-German discovery could help guide future neural technologies
Baku, September 30, AZERTAC
A team of Israeli and German scientists has discovered how the brain helps small sensory neurons overcome a physical limitation that should make it difficult for them to process rapid signals, according to TPS-IL.
The study, led by researchers at the Hebrew University of Jerusalem and Germany’s Max Planck Institutes, found that these neurons are paired with unusually slow background electrical activity. The combination allows groups of neurons to detect extremely weak sensory signals with high precision.
The findings, published in the peer-reviewed journal PLOS Biology, suggest that the brain’s constant background activity is not simply noise that sensory signals must overcome. In some neural circuits, the activity may be tuned to compensate for the physical limitations of individual neurons.
The researchers examined neurons in the somatosensory cortex, a brain region involved in processing information such as touch. Some of these neurons have relatively short dendrites, the branch-like structures that receive signals from other cells. This physical structure limits their ability to encode rapidly changing signals.
The researchers found that the background activity of these small neurons fluctuated more slowly than that of larger neurons. According to the study, the slower fluctuations can compensate for the neurons’ limited ability to process rapid changes.
“We found that the brain carefully balances several different features of neurons so they can respond extremely quickly to sensory input,” the researchers said. “Even very small signals can be detected and passed on with millisecond precision.”
Computer modeling supported the experimental findings. The researchers found that the number of neurons in the network, the physical size of their dendrites and the timing of background activity appear to be closely matched.
How Neurons Compensate
Together, these features allow large groups of neurons to amplify weak incoming signals. The researchers found that the population could reliably represent an extremely small sensory input, including a single signal arriving from the thalamus, a brain structure that relays sensory information to the cortex.
The study also identified a role for potassium channels, microscopic structures that regulate electrical activity in neurons. These channels are influenced by chemical signals associated with brain states such as attention and alertness, suggesting that the brain’s ability to process sensory information may change depending on its state.
“This study helps explain how the brain stays both sensitive and efficient,” the authors said. “The brain is constantly active, yet it can still pick out the faintest sensory events almost instantly.”
The study was led by Dr. Omer Revah and Prof. Michael J. Gutnick of the Hebrew University, together with Prof. Fred Wolf and Dr. Andreas Neef of the Max Planck Institutes.
The findings do not point to an immediate medical treatment, but they provide a new framework for studying how the brain maintains precise sensory processing in different brain states. The mechanism could eventually help researchers investigate disorders involving sensory processing and abnormal brain excitability, as well as inform the design of computational or neural technologies that need to detect weak signals in noisy environments.
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