Nav: Home

Quick! What's that smell? Mammal brains identify type of scent faster than once thought

November 14, 2017

It takes less than one-tenth of a second -- a fraction of the time previously thought -- for the sense of smell to distinguish between one odor and another, new experiments in mice show.

In a study to be published in the journal Nature Communications online Nov. 14, researchers at NYU School of Medicine found that odorants -- chemical particles that trigger the sense of smell -- need only reach a few signaling proteins on the inside lining of the nose for the mice to identify a familiar aroma. Just as significantly, researchers say they also found that the animals' ability to tell odors apart was the same no matter how strong the scent (regardless of odorant concentration).

"Our study lays the groundwork for a new theory about how mammals, including humans, smell: one that is more streamlined than previously thought," says senior study investigator and neurobiologist Dmitry Rinberg, PhD. His team is planning further animal experiments to look for patterns of brain cell activation linked to smell detection and interpretation that could also apply to people.

"Much like human brains only need a few musical notes to name a particular song once a memory of it is formed, our findings demonstrate that a mouse's sense of smell needs only a few nerve signals to determine the kind of scent," says Rinberg, an associate professor at NYU Langone Health and its Neuroscience Institute.

When an odorant initially docks into its olfactory receptor protein on a nerve cell in the nose, the cell sends a signal to the part of the brain that assigns the odor, identifying the smell, says Rinberg.

Key among his team's latest findings was that mice recognize a scent right after activation of the first few olfactory brain receptors, and typically within the first 100 milliseconds of inhaling any odorant.

Previous research in animals had shown that it takes as long as 600 milliseconds for almost all olfactory brain receptors involved in their sense of smell to become fully activated, says Rinberg. However, earlier experiments in mice, which inhale through the nose faster than humans and have a faster sense of smell, showed that the number of activated receptors in their brains peaks after approximately 300 milliseconds.

Earlier scientific investigations had also shown that highly concentrated scents activated more receptors. But Rinberg says that until his team's latest experiments, researchers had not yet outlined the role of concentration in the odor identification process.

For the new study, mice were trained to lick a straw to get a water reward based on whether they smelled orange- or pine-like scents.

Using light-activated fibers inserted into the mouse nose, researchers could turn on individual brain receptors or groups of receptors involved in olfaction to control and track how many receptors were available to smell at any time. The optical technique was developed at NYU Langone.

The team then tested how well the mice performed on water rewards when challenged by different concentrations of each smell, and with more or fewer receptors available for activation. Early activation of too many receptors, the researchers found, impaired odor identification, increasing the number of errors made by trained mice in getting their reward.

Researchers found that early interruptions in sensing smell, less than 50 milliseconds from inhalation, reduced odor identification scores nearly to chance. By contrast, reward scores greatly improved when the mouse sense of smell was interrupted at any point after 50 milliseconds, but these gains fell off after 100 milliseconds.
-end-
Note: Video commentary from researchers, as well as b-roll are also available at https://bcove.video/2uXr4qq

Funding support for the study was provided by National Institutes of Health grants R01 DC013797 and R01 DC014366, and a grant from the Whitehall Foundation.

Besides Rinberg, other NYU researchers involved in this study are lead study investigator Christopher Wilson, PhD; and Gabriela Serrano, BS. Additional research support was provided by Alexei Koulakov, PhD, at Cold Spring Harbor Laboratory in Cold Spring, NY.

Media Inquiries:

David March
212-404-3528
david.march@nyumc.org

NYU Langone Health / NYU School of Medicine

Related Brain Articles:

Study describes changes to structural brain networks after radiotherapy for brain tumors
Researchers compared the thickness of brain cortex in patients with brain tumors before and after radiation therapy was applied and found significant dose-dependent changes in the structural properties of cortical neural networks, at both the local and global level.
Blue Brain team discovers a multi-dimensional universe in brain networks
Using a sophisticated type of mathematics in a way that it has never been used before in neuroscience, a team from the Blue Brain Project has uncovered a universe of multi-dimensional geometrical structures and spaces within the networks of the brain.
New brain mapping tool produces higher resolution data during brain surgery
Researchers have developed a new device to map the brain during surgery and distinguish between healthy and diseased tissues.
Newborn baby brain scans will help scientists track brain development
Scientists have today published ground-breaking scans of newborn babies' brains which researchers from all over the world can download and use to study how the human brain develops.
New test may quickly identify mild traumatic brain injury with underlying brain damage
A new test using peripheral vision reaction time could lead to earlier diagnosis and more effective treatment of mild traumatic brain injury, often referred to as a concussion.
This is your brain on God: Spiritual experiences activate brain reward circuits
Religious and spiritual experiences activate the brain reward circuits in much the same way as love, sex, gambling, drugs and music, report researchers at the University of Utah School of Medicine.
Brain scientists at TU Dresden examine brain networks during short-term task learning
'Practice makes perfect' is a common saying. We all have experienced that the initially effortful implementation of novel tasks is becoming rapidly easier and more fluent after only a few repetitions.
Balancing time & space in the brain: New model holds promise for predicting brain dynamics
A team of scientists has extended the balanced network model to provide deep and testable predictions linking brain circuits to brain activity.
New view of brain development: Striking differences between adult and newborn mouse brain
Spikes in neuronal activity in young mice do not spur corresponding boosts in blood flow -- a discovery that stands in stark contrast to the adult mouse brain.
Map of teenage brain provides evidence of link between antisocial behavior and brain development
The brains of teenagers with serious antisocial behavior problems differ significantly in structure to those of their peers, providing the clearest evidence to date that their behavior stems from changes in brain development in early life, according to new research led by the University of Cambridge and the University of Southampton, in collaboration with the University of Rome Tor Vergata in Italy.

Related Brain Reading:

The Brain: The Story of You
by David Eagleman (Author)

Locked in the silence and darkness of your skull, your brain fashions the rich narratives of your reality and your identity. Join renowned neuroscientist David Eagleman for a journey into the questions at the mysterious heart of our existence. What is reality? Who are “you”? How do you make decisions? Why does your brain need other people? How is technology poised to change what it means to be human?  In the course of his investigations, Eagleman guides us through the world of extreme sports, criminal justice, facial expressions, genocide, brain surgery, gut feelings, robotics, and the... View Details


Brain Maker: The Power of Gut Microbes to Heal and Protect Your Brain–for Life
by David Perlmutter (Author), Kristin Loberg (Contributor)

The bestselling author of Grain Brain uncovers the powerful role of gut bacteria in determining your brain's destiny.

Debilitating brain disorders are on the rise-from children diagnosed with autism and ADHD to adults developing dementia at younger ages than ever before. But a medical revolution is underway that can solve this problem: Astonishing new research is revealing that the health of your brain is, to an extraordinary degree, dictated by the state of your microbiome - the vast population of organisms that live in your body and outnumber your own cells... View Details


Grain Brain: The Surprising Truth about Wheat, Carbs, and Sugar--Your Brain's Silent Killers
by David Perlmutter (Author), Kristin Loberg (Contributor)

A #1 New York Times bestseller--the devastating truth about the effects of wheat, sugar, and carbs on the brain, with a 4-week plan to achieve optimum health.

Renowned neurologist David Perlmutter, MD, blows the lid off a topic that's been buried in medical literature for far too long: carbs are destroying your brain. And not just unhealthy carbs, but even healthy ones like whole grains can cause dementia, ADHD, anxiety, chronic headaches, depression, and much more. Dr. Perlmutter explains what happens when the brain encounters common... View Details


The Human Brain Coloring Book (Coloring Concepts Series)
by Marian C. Diamond (Author), Arnold B. Scheibel (Author)

Developed by internationally renowned neurosurgeons, this unique book is designed for students of psychology and the biological sciences, and medical, dental, and nursing students. View Details


The Brain: All about Our Nervous System and More!
by Seymour Simon (Author)

The human brain is behind everything you do. From taking your first step to creating the computer, this vital organ gives humans the ability to learn and adapt to an ever-changing world. Learn all about your amazing, versatile brain with award-winning science writer Seymour Simon.

View Details


The Beautiful Brain: The Drawings of Santiago Ramon y Cajal
by Larry W. Swanson (Author), Eric Newman (Author), Alfonso Araque (Author), Janet M. Dubinsky (Author)

At the crossroads of art and science, Beautiful Brain presents Nobel Laureate Santiago Ramón y Cajal’s contributions to neuroscience through his groundbreaking artistic brain imagery.
 
Santiago Ramón y Cajal (1852–1934) was the father of modern neuroscience and an exceptional artist. He devoted his life to the anatomy of the brain, the body’s most complex and mysterious organ. His superhuman feats of visualization, based on fanatically precise techniques and countless hours at the microscope, resulted in some of the most remarkable illustrations in the... View Details


The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Brain Science
by Norman Doidge (Author)

An astonishing new science called "neuroplasticity" is overthrowing the centuries-old notion that the human brain is immutable. In this revolutionary look at the brain, psychiatrist and psychoanalyst Norman Doidge, M.D., provides an introduction to both the brilliant scientists championing neuroplasticity and the people whose lives they've transformed. From stroke patients learning to speak again to the remarkable case of a woman born with half a brain that rewired itself to work as a whole, The Brain That Changes Itself will permanently alter the way we look at our brains, human... View Details


My First Book About the Brain (Dover Children's Science Books)
by Patricia J. Wynne (Author), Donald M. Silver (Author)

Winner of a Bronze 2014 Moonbeam Children's Book Award!
Discover the workings of the body's most complex organ! How does the brain control the rest of the body? How does it enable the senses to function, regulate speech, affect balance, and influence sleep and dreams? These 25 illustrations to color explain every aspect of the brain's important jobs, from communicating with the central nervous system to retaining memories. Suitable for ages 8–12. View Details


Switch On Your Brain Workbook: The Key to Peak Happiness, Thinking, and Health
by Dr. Caroline Leaf (Author)

We all want to be more at peace, to be happier and healthier, but we often don't know how to go about it. Everything we try seems to fall short of true change. Dr. Caroline Leaf knows that we cannot change anything until we change our thinking. This follow-up to her bestselling book will help readers apply the science and wisdom of Switch On Your Brain to their daily lives so that they can detox their thinking and experience improved happiness and health.

Each of the keys in the Switch On Your Brain Workbook pairs science with Scripture, asking penetrating personal... View Details


The Brain's Way of Healing: Remarkable Discoveries and Recoveries from the Frontiers of Neuroplasticity
by Norman Doidge (Author)

NEW YORK TIMES BESTSELLER

 The New York Times–bestselling author of The Brain That Changes Itself presents astounding advances in the treatment of brain injury and illness. Now in an updated and expanded paperback edition.

Winner of the 2015 Gold Nautilus Award in Science & Cosmology 

In his groundbreaking work The Brain That Changes Itself, Norman Doidge introduced readers to neuroplasticity—the brain’s ability to change its own structure and function in response to activity and mental experience. Now his revolutionary... View Details

Best Science Podcasts 2017

We have hand picked the best science podcasts for 2017. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Simple Solutions
Sometimes, the best solutions to complex problems are simple. But simple doesn't always mean easy. This hour, TED speakers describe the innovation and hard work that goes into achieving simplicity. Guests include designer Mileha Soneji, chef Sam Kass, sleep researcher Wendy Troxel, public health advocate Myriam Sidibe, and engineer Amos Winter.
Now Playing: Science for the People

#448 Pavlov (Rebroadcast)
This week, we're learning about the life and work of a groundbreaking physiologist whose work on learning and instinct is familiar worldwide, and almost universally misunderstood. We'll spend the hour with Daniel Todes, Ph.D, Professor of History of Medicine at The Johns Hopkins University, discussing his book "Ivan Pavlov: A Russian Life in Science."