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


Parkinson's disease brain cells at risk of burnout, like an overheating motor
The death of brain cells in Parkinson's disease may be caused by a form of cellular energy crisis in neurons that require unusually high quantities of energy to carry out their job of regulating movement, researchers at the University of Montreal reported today.

Glial cells use lipids to direct neuron organization in the spinal cord
Healing spinal cord damage is an incredibly difficult problem because neurons have to be reconnected in a precise fashion, and there are still many mysteries surrounding how this occurs.

Surprised? Cholinergic neurons send broadcasts enabling us to learn from the unexpected
When a large combat unit, widely dispersed in dense jungle, goes to battle, no single soldier knows precisely how his actions are affecting the unit's success or failure.

'Brainbow' reveals surprising data about visual connections in brain
Neuroscientists know that some connections in the brain are pruned through neural development. Function gives rise to structure, according to the textbooks. But scientists at the Virginia Tech Carilion Research Institute have discovered that the textbooks might be wrong.

Cannabis use may influence cortical maturation in adolescent males
Male teens who experiment with cannabis before age 16, and have a high genetic risk for schizophrenia, show a different brain development trajectory than low risk peers who use cannabis.

Researchers reveal how a common mutation causes neurodegenerative disease
Researchers have determined how the most common gene mutation in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) disrupts normal cell function, providing insight likely to advance efforts to develop targeted therapies for these brain diseases.

Neurobiology -- tuning of timing in auditory axons
An LMU team has shown that the axons of auditory neurons in the brainstem which respond to low and high-frequency sounds differ in their morphology, and that these variations correlate with differences in the speed of signal conduction.

Promising class of new cancer drugs might cause memory loss in mice
Cancer researchers are constantly in search of more-effective and less-toxic approaches to stopping the disease, and have recently launched clinical trials testing a new class of drugs called BET inhibitors. These therapies act on a group of proteins that help regulate the expression of many genes, some of which play a role in cancer.

Brief postnatal blindness triggers long-lasting reorganization in the brain
A brief period of postnatal visual deprivation, when early in life, drives a rewiring of the brain areas involved in visual processing, even if the visual restoration is completed well before the baby reaches one year of age, researchers at the University of Trento, McMaster University, and the University of Montreal revealed today in Current Biology.

New insights in pathological mechanism that causes dysfunctional synapses
Genetic analysis of human patients has shown that mutations in genes involved in synaptic communication can drive neuropsychiatric and neurological diseases such as autism spectrum disorder and Alzheimer's disease.
More Neurons Current Events and Neurons News Articles

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.

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...

The Neuron: Cell and Molecular Biology

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


The Fourth Edition of The Neuron provides a comprehensive first course in the cell and molecular biology of nerve cells. The book begins with properties of the many newly discovered ion channels that have emerged through mapping of the genome. These channels shape the way a single neuron generates varied patterns of electrical activity. Covered next are the molecular mechanisms that convert electrical activity into the secretion of neurotransmitter hormones at synaptic junctions between neurons. The following section examines the biochemical pathways that are linked to the action of neurotransmitters and that 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...

Neurons In Action 2: Tutorials and Simulations using NEURON

Neurons In Action 2: Tutorials and Simulations using NEURON
by John W. Moore (Author), Anne E. Stuart (Author)


Neurons in Action 2 is the second version of a unique CD-ROM-based learning tool that combines hyperlinked text with NEURON simulations of laboratory experiments in neurophysiology. Version 2 features nine new tutorials introducing new channel types, single-channel simulations, and a redesigned interface. Neurons in Action s moving graphs provide insight into nerve function that is simply not possible with conventional, static text and figure presentations. Students discover how changing parameters such a neuronal geometry, ion concentrations, ion channel densities, and degree of myelination affects the generation of action potentials, synaptic potentials, and the spread or propagation of voltages within a neuron. For instructors, minimovies of NEURON simulations are provided for use in...

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 the quality of...

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...

Molecular and Cellular Physiology of Neurons, Second Edition

Molecular and Cellular Physiology of Neurons, Second Edition
by Gordon L. Fain (Author), Margery J. Fain (Illustrator), Thomas O'Dell (Illustrator)


Molecular and Cellular Physiology of Neurons, Second Edition is a comprehensive, up-to-date introduction to essential concepts of cellular neuroscience. Emphasizing experimental approaches and recent discoveries, it provides an in-depth look at the structure and function of nerve cells, from protein receptors and synapses to the biochemical processes that drive the mammalian nervous system. Starting with the basics of electrical current flow across cell membranes, Gordon Fain covers voltage gating and receptor activation in the context of channel diversity, excitatory and inhibitory synaptic transmission, neuromodulation, and sensory transduction. Emphasizing long-term processes of synaptic potentiation and depression involved in memory, consciousness, and attention, he demonstrates how...

The NEURON Book

The NEURON Book
by Nicholas T. Carnevale (Author), Michael L. Hines (Author)


Assuming no previous knowledge of computer programming or numerical methods, The NEURON Book provides practical advice on how to get the most out of the NEURON software program. Although written primarily for neuroscientists, teachers and students, readers with a background in the physical sciences or mathematics and some knowledge about brain cells and circuits, will also find it helpful. Covering details of NEURON's inner workings, and practical considerations specifying anatomical and biophysical properties to be represented in models, this book uses a problem-solving approach that includes many examples to challenge readers.

© 2015 BrightSurf.com