Science Current Events | Science News | Brightsurf.com
 

'Can you hear me now?' Researchers detail how neurons decide how to transmit information

March 28, 2011

PITTSBURGH-There are billions of neurons in the brain and at any given time tens of thousands of these neurons might be trying to send signals to one another. Much like a person trying to be heard by his friend across a crowded room, neurons must figure out the best way to get their message heard above the din.

Researchers from the Center for the Neural Basis of Cognition, a joint program between Carnegie Mellon University and the University of Pittsburgh, have found two ways that neurons accomplish this, establishing a fundamental mechanism by which neurons communicate. The findings have been published in an online early edition of Proceedings of the National Academy of Sciences (PNAS).

"Neurons face a universal communications conundrum. They can speak together and be heard far and wide, or they can speak individually and say more. Both are important. We wanted to find out how neurons choose between these strategies," said Nathan Urban, the Dr. Frederick A. Schwertz Distinguish Professor of Life Sciences and head of the Department of Biological Sciences at CMU.

Neurons communicate by sending out electrical impulses called action potentials or "spikes." These spikes code information much like a version of Morse code with only dots and no dashes. Groups of neurons can choose to communicate information in one of two ways: by spiking simultaneously or by spiking separately.

To find out how the brain decided which method to use to process a sensory input, the researchers looked at mitral cell neurons in the brain's olfactory bulb - the part of the brain that sorts out smells and a common model for studying global information processing. Using slice electrophysiology and computer simulations, the researchers found that the brain had a clever strategy for ensuring that the neurons' message was being heard.

Over the short time scale of a few milliseconds, the brain engaged its inhibitory circuitry to make the neurons fire in synchrony. This simultaneous, correlated firing creates a loud, but simple, signal. The effect was much like a crowd at a sporting event chanting, "Let's go team!" Over short time intervals, individual neurons produced the same short message, increasing the effectiveness with which activity was transmitted to other brain areas. The researchers say that in both human and neuronal communication alike, this collective communication works well for simple messages, but not for longer or more complex messages that contain more intricate information.

The neurons studied used longer timescales (around one second) to convey these more complex concepts. Over longer time intervals, the inhibitory circuitry generated a form of competition between neurons, so that the more strongly activated neurons silenced the activity of weakly activated neurons, enhancing the differences in their firing rates and making their activity less correlated. Each neuron was able to communicate a different piece of information about the stimulus without being drowned out by the chatter of competing neurons. It would be like being in a group where each person spoke in turn. The room would be much quieter than a sports arena and the immediate audience would be able to listen and learn much more complex information.

Researchers believe that the findings can be applied beyond the olfactory system to other neural systems, and perhaps even be used in other biological systems.

"Across biology, from genetics to ecology, systems must simultaneously complete multiple functions. The solution we found in neuroscience can be applied to other systems to try to understand how they manage competing demands," Urban said.

Carnegie Mellon University


Related Neurons Current Events and Neurons News Articles


Hunting for the brain's opioid addiction switch
New research by Steven Laviolette's research team at Western University is contributing to a better understanding of the ways opiate-class drugs modify brain circuits to drive the addiction cycle.

Improving cell transplantation after spinal cord injury: When, where and how?
Spinal cord injuries are mostly caused by trauma, often incurred in road traffic or sporting incidents, often with devastating and irreversible consequences, and unfortunately having a relatively high prevalence (250,000 patients in the USA; 80% of cases are male).

Mapping neural networks to strengthen circadian rhythms
If you've ever felt groggy the morning after traversing time zones, you can thank the temporary mismatch between your body's 24-hour circadian rhythm and your new local time.

Researchers find what could be brain's trigger for binge behavior
Rats that responded to cues for sugar with the speed and excitement of binge-eaters were less motivated for the treat when certain neurons were suppressed, researchers discovered.

'Baby talk' can help songbirds learn their tunes
Adult songbirds modify their vocalizations when singing to juveniles in the same way that humans alter their speech when talking to babies.

Ancient anti-inflammatory drug salicylic acid has cancer-fighting properties
Scientists from the Gladstone Institutes have identified a new pathway by which salicylic acid--a key compound in the nonsteroidal anti-inflammatory drugs aspirin and diflunisal--stops inflammation and cancer.

The deadly toxin acrolein has a useful biological role
Scientists from RIKEN in Japan have discovered that acrolein--a toxic substance produced in cells during times of oxidative stress--in fact may play a role in preventing the process of fibrillation, an abnormal clumping of peptides that has been associated with Alzheimer's disease and other neural diseases.

Ever-changing moods may be toxic to the brain of bipolar patients
Bipolar disorder (BD) is a severe and complex mental illness with a strong genetic component that affects 2% of the world population. The disorder is characterized by episodes of mania and depression that may alternate throughout life and usually first occur in the early 20s.

The brain clock that keeps memories ticking
Just as members of an orchestra need a conductor to stay on tempo, neurons in the brain need well-timed waves of activity to organize memories across time. In the hippocampus--the brain's memory center--temporal ordering of the neural code is important for building a mental map of where you've been, where you are, and where you are going.

Identification of the action mechanism of a protein impacting neural circuit development
Research by Dr. Shernaz Bamji, from the University of British Columbia, uncovers the mechanism of action of an enzyme called DHHC9 in the normal development and function of neural networks in the brain.
More Neurons Current Events and Neurons News Articles

The Neuron: Cell and Molecular Biology

The Neuron: Cell and Molecular Biology
by Irwin B. Levitan (Author), Leonard K. Kaczmarek (Author)


The third edition of The Neuron provides a comprehensive first course in the cell and molecular biology of nerve cells. The first part of the book covers the properties of the many ion channels that shape the way a single neuron generates varied patterns of electrical activity, as well as the molecular mechanisms that convert electrical activity into the secretion of neurotransmitter hormones at synaptic junctions between neurons. The second part covers the biochemical pathways that are linked to the action of neurotransmitters and can alter the cellular properties of neurons or sensory cells that transduce information from the outside world into the electrical code used by neurons. The final section reviews our rapidly expanding knowledge of the molecular factors that induce an...

From Neuron to Brain, Fifth Edition

From Neuron to Brain, Fifth Edition
by John G. Nicholls (Author), A. Robert Martin (Author), Paul A. Fuchs (Author), David A. Brown (Author), Mathew E. Diamond (Author), David Weisblat (Author)


The entirely rewritten Fifth Editionof From Neuron to Brain describes how nerve cells go about their business of transmitting signals, how the signals are put together, and how, out of this integration, higher functions emerge. This exciting new edition begins with the anatomy and physiology of the visual system.

Neurons, Pen, and Paper.: a collection of poetry and thoughts

Neurons, Pen, and Paper.: a collection of poetry and thoughts
by Emma Horowitz


This is the author's first published book. Written over the past 5 years, these thought-provoking pieces are meant to tantalize the imagination. Soak up the words and feel the art. Enjoy.

From Neuron to Brain: A Cellular and Molecular Approach to the Function of the Nervous System, Fourth Edition

From Neuron to Brain: A Cellular and Molecular Approach to the Function of the Nervous System, Fourth Edition
by John G. Nicholls (Author), A. Robert Martin (Author), Bruce G. Wallace (Author), Paul A. Fuchs (Author)


In the 25 years since From Neuron to Brain was first published, the authors' aim has remained constant—to describe how nerve cells go about their business of transmitting signals, how the signals are put together, and how, out of this integration, higher functions emerge. The new Fourth Edition, while maintaining this focus, has been completely reformatted and updated. The emphasis, as before, is on experiments, and on the way they are carried out. Using a narrative approach, the authors follow a line from the original inception of a new idea to an account of research being done today. The wealth of new facts, techniques, and concepts, however, presented a challenge in keeping the book to a manageable size. Inevitably, the authors have had to delete descriptions of certain classical...

I of the Vortex: From Neurons to Self

I of the Vortex: From Neurons to Self
by Rodolfo R. Llinas (Author)


In I of the Vortex, Rodolfo Llinas, a founding father of modern brain science, presents an original view of the evolution and nature of mind. According to Llinas, the "mindness state" evolved to allow predictive interactions between mobile creatures and their environment. He illustrates the early evolution of mind through a primitive animal called the "sea squirt." The mobile larval form has a brainlike ganglion that receives sensory information about the surrounding environment. As an adult, the sea squirt attaches itself to a stationary object and then digests most of its own brain. This suggests that the nervous system evolved to allow active movement in animals. To move through the environment safely, a creature must anticipate the outcome of each movement on the basis of incoming...

Did My Neurons Make Me Do It?: Philosophical and Neurobiological Perspectives on Moral Responsibility and Free Will

Did My Neurons Make Me Do It?: Philosophical and Neurobiological Perspectives on Moral Responsibility and Free Will
by Nancey Murphy (Author), Warren S. Brown (Author)


If humans are purely physical, and if it is the brain that does the work formerly assigned to the mind or soul, then how can it fail to be the case that all of our thoughts and actions are determined by the laws of neurobiology? If this is the case, then free will, moral responsibility, and, indeed, reason itself would appear to be in jeopardy. Nancey Murphy and Warren S. Brown here defend a non-reductive version of physicalism whereby humans are (sometimes) the authors of their own thoughts and actions.

Did My Neurons Make Me Do It? brings together insights from both philosophy and the cognitive neurosciences to defeat neurobiological reductionism. One resource is a "post-Cartesian" account of mind as essentially embodied and constituted by action-feedback-evaluation-action...

Neuron Galaxy

Neuron Galaxy
by Karen Littman (Author), Jay Leibold (Author), Max Weinberg (Illustrator), Christine Gralapp (Illustrator)


Neuron Galaxy is a story about a lonely little neuron that wants to connect with other neurons. The book will help children to understand the basic function of the brain and appreciate what a wonderful, amazing organ their own brain is -- one of the most remarkable things in the galaxy! Prominent neuroscientists vetted the text and have endorsed the book. The story makes a graphic connection between the stars in the sky and the cells in our brain. It leaves readers with a sense of awe and wonder for the human brain equal to our awe and wonder for the universe. “This wonderfully crafted beginner’s text on the brain, its neurons and its near magical abilities will help young readers and their parents learn about the body’s most valuable organ.” — Floyd Bloom, MD,...

The Myth of Mirror Neurons: The Real Neuroscience of Communication and Cognition

The Myth of Mirror Neurons: The Real Neuroscience of Communication and Cognition
by Gregory Hickok (Author)


An essential reconsideration of one of the most far-reaching theories in modern neuroscience and psychology. In 1992, a group of neuroscientists from Parma, Italy, reported a new class of brain cells discovered in the motor cortex of the macaque monkey. These cells, later dubbed mirror neurons, responded equally well during the monkey’s own motor actions, such as grabbing an object, and while the monkey watched someone else perform similar motor actions. Researchers speculated that the neurons allowed the monkey to understand others by simulating their actions in its own brain. Mirror neurons soon jumped species and took human neuroscience and psychology by storm. In the late 1990s theorists showed how the cells provided an elegantly simple new way to explain the evolution of language,...

From Neurons to Neighborhoods : The Science of Early Childhood Development

From Neurons to Neighborhoods : The Science of Early Childhood Development
by Committee on Integrating the Science of Early Childhood Development (Author), Youth, and Families Board on Children (Author), National Research Council (Author), Committee on Integrating the Science of Early Childhood Development (Author), Jack P. Shonkoff (Editor), Deborah A. Phillips (Editor)


How we raise young children is one of today's most highly personalized and sharply politicized issues, in part because each of us can claim some level of "expertise." The debate has intensified as discoveries about our development-in the womb and in the first months and years-have reached the popular media.

How can we use our burgeoning knowledge to assure the well-being of all young children, for their own sake as well as for the sake of our nation? Drawing from new findings, this book presents important conclusions about nature-versus-nurture, the impact of being born into a working family, the effect of politics on programs for children, the costs and benefits of intervention, and other issues.

The committee issues a series of challenges to decision makers regarding...

Neuronal Dynamics: From Single Neurons to Networks and Models of Cognition

Neuronal Dynamics: From Single Neurons to Networks and Models of Cognition
by Wulfram Gerstner (Author), Werner M. Kistler (Author), Richard Naud (Author), Liam Paninski (Author)


What happens in our brain when we make a decision? What triggers a neuron to send out a signal? What is the neural code? This textbook for advanced undergraduate and beginning graduate students provides a thorough and up-to-date introduction to the fields of computational and theoretical neuroscience. It covers classical topics, including the Hodgkin-Huxley equations and Hopfield model, as well as modern developments in the field such as Generalized Linear Models and decision theory. Concepts are introduced using clear step-by-step explanations suitable for readers with only a basic knowledge of differential equations and probabilities, and are richly illustrated by figures and worked-out examples. End-of-chapter summaries and classroom-tested exercises make the book ideal for courses or...

© 2016 BrightSurf.com