Brain cells switch between rhythms such as radio tuners

Scientists have found that a single brain cell can adjust multiple electrical rhythms simultaneously, thereby switching its emission modes, such as complex radio receivers.

This discovery challenges long-term assumptions about how neurons process information and can reshape our understanding of memory formation and spatial navigation.

Published in PLOS Computational Biology, the study focuses on CA1 pyramidal neurons in the hippocampus, which are essential for remembering your brain cells to park your car or navigate in a familiar community. These neurons emit electrical signals in two different modes: a single spike or a rapid burst, each carrying a different type of information.

Double encoding discovery

What makes this finding striking is that a single neuron can respond simultaneously to slow theta waves (3-12 Hz) and fast gamma waves (30-100 Hz) but respond in a completely different way. Researchers call this phenomenon “interlaced resonance.”

“Our model shows that a single neuron can behave like a multi-band broadcast, adjusting to different frequencies and changing its behavior accordingly,” said Rodrigo Pena, senior writer and assistant professor at Atlantic University in Florida. “This is much more flexible and much more powerful than we previously thought.”

Think of this: When listening to an AM radio in the car, you receive an FM signal at the same time – your broadcasts just handle them differently. Similarly, these brain cells use different emission modes in the same electrical trace for slow and fast pace.

Silent interval factor

Perhaps most interestingly, the study shows that neurons are more likely to emit bursts after prolonged silences—especially with quiet intervals of more than 100 milliseconds. This timing element shows that the brain uses these pauses strategically, almost like the musicians use rest to emphasize certain notes.

The team found that the probability of bursts remained consistent regardless of changes in chemistry within the neuron, mainly depending on these longer periods of silence. In contrast, a single spike pattern shows greater variability based on the internal ion current of the cell.

Internal adjustment mechanism

The researchers identified three key ionic currents, which act as internal volume control, to determine the neurons’ response to different brain rhythms: sustained sodium current, delayed rectified potassium current, and hyperpolarized activated current. By adjusting these internal conductances, neurons can transfer their preferences between theta and gamma waves.

Low levels of sustained sodium current and high levels of delayed rectified potassium current locking behaviors against the eta frequency, while the opposite combination favors a single spike during gamma oscillation. This suggests that neurons can essentially reconnect their sensitivity to different brain rhythms based on their internal electrical environment.

Real-world verification

To verify their calculation results, the team analyzed voltage imaging data from the brains of living mice. Experimental records confirm that the burst probability follows the longest quiet interval, matching their simulation predictions.

This fusion between computational models and biological reality enhances the fundamental mechanisms in which interweaving resonance represents brain function, not just theoretical curiosity.

Impact on brain health

“This ‘dual code’ ability provides new perspectives on how the brain can effectively organize and transmit information and may have broad implications for neural conditions that disrupt the rhythm of the brain,” Penner explained.

This finding may help explain dysfunction in conditions such as epilepsy, Alzheimer’s disease and schizophrenia, where brain rhythms are disrupted. If neurons lose the ability to switch flexibly between shooting modes, it may interfere with memory formation and attention.

Beyond simple shooting

Previous research has shown that theta and gamma rhythms affect the shooting of neurons as the animal is space, but scientists believe that neurons are locked into a single shooting mode. This work shows that a single unit can carry multiple layers of information simultaneously.

“The building blocks of the brain are much more dynamic than imagined at once,” Penner noted. “Neurons can follow different brain rhythms at the same time, adjusting their shooting patterns to meet current needs.”

The study shows that brain cells function not simply switch switches, rather than complex signal processors, that are able to encode complex, context-dependent information in a single electrical trajectory.

This flexibility could explain how the brain uses elegant timing mechanisms and internal tuning to wrap such a large amount of computing power into its biological hardware, thereby extracting the maximum information from the smallest of resources.

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