Biology

Weak electrical field found to carry information around the brain

Weak electrical field found to...
The research team says the electrical fields could be behind the spread of sleep and theta waves, along with epileptic seizure waves
The research team says the electrical fields could be behind the spread of sleep and theta waves, along with epileptic seizure waves
View 1 Image
The research team says the electrical fields could be behind the spread of sleep and theta waves, along with epileptic seizure waves
1/1
The research team says the electrical fields could be behind the spread of sleep and theta waves, along with epileptic seizure waves

In a development that could lead to improved understanding of memory formation and epilepsy, scientists have discovered a new way information may be traveling throughout the brain. The team has identified slow-moving brainwaves it says could be carried only by the brain's gentle electrical field, a mechanism previously thought to be incapable of spreading neural signals altogether.

"Researchers have thought that the brain's endogenous electrical fields are too weak to propagate wave transmission," says Dominique Durand, professor of biomedical engineering at Case Western Reserve University. "But it appears the brain may be using the fields to communicate without synaptic transmissions, gap junctions or diffusion."

What led Durand and her team of researchers to this conclusion was the recording of neural spikes traveling too slowly to be carried by conventional means, indicating something else was at play. They claim that the only possible explanation for the passage of information in this way was the presence of a weak electrical field.

The team tested its theory both by way of computer modeling and observing activity in the hippocampus of a mouse brain, the central region associated with memory and spatial navigation. While the electrical field was weak, with an amplitude of around 2.6 mV/mm, the team found that beginning with one cell or a group of cells, the field was able to stimulate neighboring neurons which in turn stimulated their neighboring neurons. This resulted in a spread of signals throughout the brain at a rate of around 10 cm per second.

By blocking the electrical field and also increasing the distance between the cells in the computer model, the team found they could slow down the speed of the wave. This furthered their belief that the mild electrical field is in fact behind the propagation of these type of brain signals.

"Others have been working on such phenomena for decades, but no one has ever made these connections," says Steven J. Schiff, director of the Center for Neural Engineering at Penn State University, who was not involved in the study. "The implications are that such directed fields can be used to modulate both pathological activities, such as seizures, and to interact with cognitive rhythms that help regulate a variety of processes in the brain."

The research team says that the newly unearthed mechanism could be behind the spread of neural signals such as sleep and theta waves (those associated with memory formation during sleep), along with epileptic seizure waves, all of which travel at around 1 m per second. They are now exploring what part, if any, they play in epilepsy and regular brain function. If a role is established, they will seek to uncover what information the fields are carrying and where exactly they begin.

The research was published in The Journal of Neuroscience.

Source: Case Western Reserve University/EurekAlert

4 comments
christopher
Makes sense seeing as TMS messes with autism
amazed W1
It might explain thought transfer, but the worry is how the intensity of external electrical fields compare with it. Mobile phones?? Power lines?? and what effect might these therefor have on the brain if it is sensitive to the slow moving fields?
Firehawk70
@amazed, I'm thinking that the brain wouldn't produce or be tuned to such incredibly high frequencies as the radio waves we make with most devices. There would be little evolutionary benefit. Other than the pineal gland and eyes I don't think much else responds to light range frequencies. I suppose the powerlines might be closer to a low frequency. But I wonder if it's even lower, more like 5 Hz? Taking 10cm/s and dividing by 5Hz gives a wavelength of 2cm which seems possible. Perhaps it's more like mm wavelength, so maybe 100 Hz, but I doubt it would be in the microwave range.
warren52nz
The electric field is probably "DC" ie. 0 hertz if it's moving something. A static, non-oscillating field puts a steady, one way force on an electrically charged object. An "AC" field would tug it back and forth with an average velocity of zero and it wouldn't go anywhere.