Study finds new mechanism to control information flow in the brain

March 2, 2017
Different Sst interneurons, or type of nerve cell (colored red), in the outer shell, or cerebral cortex, of the mouse brain are shown. Credit: New York University School of Medicine/AAAS

Specialized nerve cells, known as somatostatin-expressing (Sst) interneurons, in the outer part of the mammalian brain (or cerebral cortex)—play a key role in controlling how information flows in the brain when it is awake and alert. This is the finding of a study published online in Science March 2 by a team of neuroscientists at NYU Langone Medical Center and its Neuroscience Institute.

In experiments in mice, the researchers found that the activity of Sst interneurons changes when the animal goes from not moving its whiskers (in a resting state) to moving them (in an active state), a process known as whisking.

Specifically, the team discovered that the cortex contains a diverse set of Sst interneuron subtypes that reach into different layers of the cortex. Some of the subtypes turn on while others turn off during whisking. The Sst interneurons then either selectively block or encourage the flow of information in ways that the researchers believe helps the animals make informed decisions and guide their movements.

"We have long wondered how the can process and integrate separate information lines coming in from different brain structures, or from other areas of the cortex, and how it sorts out what information is relevant at any given moment," says senior study investigator Bernardo Rudy, MD, PhD. "We now know that Sst interneurons operate like a switchboard that controls the flow of these information lines," adds Rudy, a professor of neuroscience and physiology at NYU Langone.

According to Rudy, who is also the Valentino D.B. Mazzia, MD, JD, Professor of Anesthesiology in the Department of Anesthesiology, Perioperative Care, and Pain Medicine, neurons in the cortex are known to play a key role in sensory perception, memory formation, and learning. But the new study, he says, is the first to show the "switchboard" role played by Sst interneurons in the cortex.

The video will load shortly.
A mouse uses its whiskers (or whisking) to sense its surroundings. Credit: Jakob Voigts at MIT.

Because the mouse and human brains have much in common, co-lead study investigator William Muñoz, an MD-PhD student at NYU Langone, says the team's findings advance the field's understanding of how the brain processes touch, smell, hearing, sight, and taste. The results, adds Muñoz, may also speed the search for drug therapies for conditions where the senses are disrupted, including Alzheimer's, schizophrenia, and autism.

Researchers say that with its combination of active and passive brain states, the mouse's reliance on "whisking" to navigate and interpret its environment makes it an "ideal model" to study nerve cell activity during these changing brain processing modes. They point out that the whiskers in the mouse snout are its most important sensory organ, adding that mice and rats are nocturnal animals and use whisker touches to sense their surroundings and decide their movements in the dark.

Researchers say the discovery of a "family" of Sst interneurons with different patterns of activity during behavior was made possible due to the recent development of a technique that chemically tags individual neurons with a light-activating substance. The tagging method, known as channelrhodopsin-assisted patching, was developed by Muñoz and Robin Tremblay, PhD, a co-lead investigator of the study.

This technique, they say, along with a probe inserted into the mouse brain, allowed them to efficiently identify and record the activity of Sst interneurons, which are rare and are intermingled with other types of neurons.

Researchers next have plans to analyze the activities of Sst interneurons and other kinds of neurons in the cerebral cortex using their innovative method during more complex behaviors to figure out their role in the processing of sensory information in the .

Explore further: Deciphering the emergence of neuronal diversity

More information: "Layer-specific modulation of neocortical dendritic inhibition during active wakefulness," Science, science.sciencemag.org/cgi/doi … 1126/science.aag2599

Related Stories

Deciphering the emergence of neuronal diversity

January 30, 2017
The development of the cerebral cortex played a major role in the evolution of mankind. Scientists are now studying the emergence of its cellular microstructure with high resolution methods. Neuroscientists at the University ...

Interneurons find their way to the striatum

June 10, 2015
Researchers from the MRC Centre for Developmental Neurobiology (MRC CDN) at King´s College London, led by Prof. Oscar Marín, have identified the mechanisms guiding interneurons to the striatum, a major brain centre involved ...

Protein identified that can disrupt embryonic brain development and neuron migration

January 14, 2013
Interneurons – nerve cells that function as 'dimmers' – play an important role in the brain. Their formation and migration to the cerebral cortex during the embryonic stage of development is crucial to normal brain functioning. ...

On the ups and downs of the seemingly idle brain

January 20, 2015
Even in its quietest moments, the brain is never "off." Instead, while under anesthesia, during slow-wave sleep, or even amid calm wakefulness, the brain's cortex maintains a cycle of activity and quiet called "up" and "down" ...

Cortex development depends on a protein

October 2, 2012
As outlined in a study published in Developmental Cell, researchers have discovered a novel function for p27 in the control of interneuron migration in the developing cerebral cortex.

Important brain network for processing sensory perceptions elucidated

January 21, 2016
Every day, we constantly absorb information through our sensory organs, which the brain then needs to process correctly. The information initially reaches the main relay center, the thalamus, and then travels to the cerebral ...

Recommended for you

Brain activity buffers against worsening anxiety

November 17, 2017
Boosting activity in brain areas related to thinking and problem-solving may also buffer against worsening anxiety, suggests a new study by Duke University researchers.

Investigating patterns of degeneration in Alzheimer's disease

November 17, 2017
Alzheimer's disease (AD) is known to cause memory loss and cognitive decline, but other functions of the brain can remain intact. The reasons cells in some brain regions degenerate while others are protected is largely unknown. ...

Study may point to new treatment approach for ASD

November 17, 2017
Using sophisticated genome mining and gene manipulation techniques, researchers at Vanderbilt University Medical Center (VUMC) have solved a mystery that could lead to a new treatment approach for autism spectrum disorder ...

Neuroscientists find chronic stress skews decisions toward higher-risk options

November 16, 2017
Making decisions is not always easy, especially when choosing between two options that have both positive and negative elements, such as deciding between a job with a high salary but long hours, and a lower-paying job that ...

Paraplegic rats walk and regain feeling after stem cell treatment

November 16, 2017
Engineered tissue containing human stem cells has allowed paraplegic rats to walk independently and regain sensory perception. The implanted rats also show some degree of healing in their spinal cords. The research, published ...

Brain implant tested in human patients found to improve memory recall

November 15, 2017
(Medical Xpress)—A team of researchers with the University of Southern California and the Wake Forest School of Medicine has conducted experiments involving implanting electrodes into the brains of human volunteers to see ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.