Hacker News article The brain’s electrical connections can become altered, a new study has found.
The findings may help scientists understand how the brain processes information, and may help doctors design better therapies.
The study, which was published in the Journal of Neuroscience, was led by researchers at the University of Texas Health Science Center at Houston and the University College London, and involved researchers from the University Medical Center, the University Hospitals of Munich, and the National Institute for Neurological Disorders and Stroke.
It’s the first time the brain has been shown to be altered by changing electrical circuits, researchers said.
The researchers found that a subset of neurons in the thalamus, the brain’s largest brain region, could become abnormally active, firing at abnormally high frequencies, and triggering epileptic seizures.
Researchers are currently studying the impact of this on the brain.
“The results suggest that these altered connections could lead to abnormal neuronal firing patterns and seizures,” said University of Houston bioengineering professor and lead author Mark Boulton, who is a postdoctoral fellow at UT Health’s Brain Science Institute.
“We’ve shown that there are a number of neural circuits in the brain that are affected, and these circuits are likely to be implicated in epileptic activity.”
The team also found that electrical circuits that were not involved in normal brain activity were also abnormally activated.
“We found that when a circuit is altered, the signal from the circuit can become amplified in a way that is very similar to a voltage spike,” said lead author Ralf-Peter Kranz, an associate professor of neuroscience at the Institute of Medical and Biological Engineering, and a member of the Department of Electrical Engineering and Computer Science at the university.
“When the signals are amplified in this way, it’s almost like a high-frequency sound.
It’s like the sound is coming from your ears and coming through the skull, but amplified,” Kranzer said.
“This is a very interesting result, because we know that the brain is very efficient at detecting sound.
So this finding suggests that if you alter these circuits in a specific way, they can cause problems for the brain.”
To determine if the altered brain circuits might trigger epileptic symptoms, the researchers examined brain tissue samples taken from people with epilepsy, and looked for abnormal electrical activity in a subset that was normally active.
They then looked at the electrical activity of a subset known as the basal ganglia, which controls movement, including walking and jumping.
“This is very exciting because we found that the abnormal activity could be caused by these neural circuits,” Boulson said.
“There was some evidence that the basal brain circuits were involved in the formation of seizures, but it was not clear whether they were involved with epileptic onset or whether they could cause them.”
The researchers next analyzed a sample of cells from the brain of a person who was epileptic, and found abnormal activity in these cells.
“Normally, the basal and the thalamomedial areas of the brain are connected by a tight network of neurons,” Bouton said.
But when the abnormal neural activity was observed in the basal cell group, the abnormal signal could be amplified in that part of the circuit.
“It was actually like having a waveform coming from a microphone that was amplified,” Boudreau said.
This is an example of an abnormal signal that could be a seizure trigger.
The team then studied the electrical connections of the cells in the cortex, a region of the brains that controls memory and other functions.
They found abnormal electrical patterns in cells that are normally present in the cortices.
“So these abnormal connections were present in areas that normally are not involved with memory function,” BOUTON said.
They found that abnormal activity can lead to seizures in these regions of the cortex.
“Our findings suggest that abnormal electrical connections in the cerebellum, a part of our brain that regulates muscle coordination and motor coordination, could be involved in this phenomenon,” Kraml said.