The brain is known to transmit waves here and there to ensure that the body is functioning the way it should. Scientists have already established how neural signals are spread, and this has become the basis of numerous studies.
In a new paper, however, a team of researchers from the Case Western Reserve University discovered a possible new method of communication between brain waves that are linked to memory and epilepsy: the use of weak electrical fields.
A combination of electrical and chemical signal spread is one of the factors that make communication between neurons possible. Processes such as synaptic transmission, gap junction or diffusion have been proven to perform signalling actions in the brain. In the new study, researchers wanted to show that the spread of neural signals can also be possible even without these processes.
To perform the study, scientists recorded neural spikes travelling at a speed that is too slow, the mechanisms inside the brain are not capable of circulating anymore. Despite this, information propagation still took place. The sole explanation the researchers could think of was that a weak electrical field, which they were able to detect in the process, was the main factor that made the spread of brain waves possible.
"Researchers have thought that the brain's endogenous electrical fields are too weak to propagate wave transmission," says study author and biomedical engineering professor Dominique Durand. "But it appears the brain may be using the fields to communicate without synaptic transmissions, gap junctions or diffusion."
The findings were backed up by computer modelling and testing on the hippocampi of mouse models. The hippocampus is associated with normal functions such as memory and spatial regulation, but is also linked to disorders such as epilepsy.
The electrical field, although too weak, was able to stimulate neighboring cells, which also did the same to nearby cells, and so on. The process continued throughout the brain at a speed of only 0.1 meter (0.3 foot) per second.
When the researchers blocked the electrical field and increased the gap between the neighboring cells, the brain waves' speed decreased. With this, the team confirmed that the mechanism of information spread is consistent with the electrical field.
The researchers are currently looking at the electrical fields' role in normal brain function and in epilepsy, including the information they carry and where they originate.
The study was published in The Journal of Neuroscience.