Nav: Home

Seizures follow similar path regardless of speed, says study

June 27, 2017

Of the 50 million people who suffer from epilepsy worldwide, a third fail to respond to medication. As the search for better drugs continues, researchers are still trying to make sense of how seizures start and spread.

In a new study in Cell Reports, researchers at Columbia University come a step closer by showing that the neurons of mice undergoing seizures fire off in a sequential pattern no matter how quickly the seizure propagates -- a finding that confirms seizures are not the result of neurons randomly going haywire.

"This is good news," said the study's senior author, Dr. Rafael Yuste, a neuroscientist at Columbia. "It means that local neuronal circuits matter, and that targeting the right cells may stop or even prevent some types of brain seizure."

To induce the seizures, researchers injected a tiny area of cortex in awake mice with two types of drugs--one that increases neuronal firing and another that blocks the inhibitory interneurons that control information flow between cells. Recording the seizures as they rippled outward, researchers found that cells in the mouse's brain systematically fired one after the other. Under both models, the seizure spread across the top layer of cortex in a wave-like pattern before descending into its lower layers.

Unexpectedly, they found that whether the seizure lasted 10 seconds or 30 seconds, it followed the same route, like a commuter stuck in traffic. The concept of neurons firing in a reliable pattern no matter how fast the seizure is traveling is illustrated on the cover of Cell Reports, drawn by the study's lead author, Dr. Michael Wenzel.

"The basic pattern of a string stretched between two hands stays the same whether the hands move closer together or farther away," he says. "Just as neurons maintain their relative firing patterns regardless of how slowly or quickly the seizure unfolds."

Researchers were able to get a cell-by-cell view of a seizure propagating through a mouse's brain using high-speed calcium imaging that allowed them to zoom in 100 times closer than electrode techniques used on the human brain.

It may be the first time that researchers have watched a seizure unfold at this level of detail, and their findings suggest that inhibitory neurons may be a promising area of future research, said Dr. Catherine Schevon, a neurology professor at Columbia University Medical Center who was not involved in the research.

"The role of inhibitory restraint in seizure development is an area that few have studied at micrometer scale," she said. "This could be a useful treatment target for future drug development or stem cell interneuron implants."
-end-
Other authors of the study, Reliable and Elastic Propagation of Cortical Seizures in Vivo, are Jordan Hamm and Darcy Peterka of Columbia.

Columbia University

Related Neurons Articles:

The first 3D map of the heart's neurons
An interdisciplinary research team establishes a new technological pipeline to build a 3D map of the neurons in the heart, revealing foundational insight into their role in heart attacks and other cardiac conditions.
Mapping the neurons of the rat heart in 3D
A team of researchers has developed a virtual 3D heart, digitally showcasing the heart's unique network of neurons for the first time.
How to put neurons into cages
Football-shaped microscale cages have been created using special laser technologies.
A molecule that directs neurons
A research team coordinated by the University of Trento studied a mass of brain cells, the habenula, linked to disorders like autism, schizophrenia and depression.
Shaping the social networks of neurons
Identification of a protein complex that attracts or repels nerve cells during development.
With these neurons, extinguishing fear is its own reward
The same neurons responsible for encoding reward also form new memories to suppress fearful ones, according to new research by scientists at The Picower Institute for Learning and Memory at MIT.
How do we get so many different types of neurons in our brain?
SMU (Southern Methodist University) researchers have discovered another layer of complexity in gene expression, which could help explain how we're able to have so many billions of neurons in our brain.
These neurons affect how much you do, or don't, want to eat
University of Arizona researchers have identified a network of neurons that coordinate with other brain regions to influence eating behaviors.
Mood neurons mature during adolescence
Researchers have discovered a mysterious group of neurons in the amygdala -- a key center for emotional processing in the brain -- that stay in an immature, prenatal developmental state throughout childhood.
Connecting neurons in the brain
Leuven researchers uncover new mechanisms of brain development that determine when, where and how strongly distinct brain cells interconnect.
More Neurons News and Neurons Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Processing The Pandemic
Between the pandemic and America's reckoning with racism and police brutality, many of us are anxious, angry, and depressed. This hour, TED Fellow and writer Laurel Braitman helps us process it all.
Now Playing: Science for the People

#568 Poker Face Psychology
Anyone who's seen pop culture depictions of poker might think statistics and math is the only way to get ahead. But no, there's psychology too. Author Maria Konnikova took her Ph.D. in psychology to the poker table, and turned out to be good. So good, she went pro in poker, and learned all about her own biases on the way. We're talking about her new book "The Biggest Bluff: How I Learned to Pay Attention, Master Myself, and Win".
Now Playing: Radiolab

Invisible Allies
As scientists have been scrambling to find new and better ways to treat covid-19, they've come across some unexpected allies. Invisible and primordial, these protectors have been with us all along. And they just might help us to better weather this viral storm. To kick things off, we travel through time from a homeless shelter to a military hospital, pondering the pandemic-fighting power of the sun. And then, we dive deep into the periodic table to look at how a simple element might actually be a microbe's biggest foe. This episode was reported by Simon Adler and Molly Webster, and produced by Annie McEwen and Pat Walters. Support Radiolab today at Radiolab.org/donate.