Virtual reality allows researchers to measure brain activity during behavior at unprecedented resolutionMay 09, 2012
Researchers have developed a new technique which allows them to measure brain activity in large populations of nerve cells at the resolution of individual cells. The technique, reported today in the journal Nature, has been developed in zebrafish to represent a simplified model of how brain regions work together to flexibly control behaviour.
Our thoughts and actions are the product of large populations of nerve cells, called neurons, working in harmony, often millions at a time. Measuring brain activity during behaviour at detailed resolution in these groups of cells has proved extremely challenging. Currently, scientists are restricted to measuring their activity in individual brain areas of, for example, moving rats, typically in less than a few hundred neurons.
Dr Misha Ahrens, a Sir Henry Wellcome Postdoctoral Fellow based at Harvard University and the University of Cambridge, worked with colleagues to develop a technique which allows neuroscientists to study as many as 2,000 neurons simultaneously, anywhere in the brain of a transparent zebrafish. Their work was funded by the Wellcome Trust and the National Institutes of Health.
Dr Ahrens and colleagues created a virtual environment for zebrafish, which allowed them to measure activity in the neurons as the fish 'moved'. In reality, the zebrafish was paralysed to allow the researchers to image its brain; the fish perceived to 'move' through the virtual environment by activating their motor neuron axons, the cells responsible for generating movement.
Zebrafish are often used as a simple organism to study genetics and characteristics of the nervous system that are conserved in humans . They are genetically modifiable, so by manipulating the fish's genetic make-up, Dr Ahrens and colleagues created a fish in which all neurons contained a particular protein that increases its fluorescence when the cells are active. The fish are transparent and so the team were able to use a laser-scanning microscope, to see activity in any neuron in the brain of the fish, and up to 2,000 neurons simultaneously.
Dr Ahrens explains: "Our behaviour is determined by thousands, possibly millions, of nerve cells working in harmony. The zebrafish performs complex behaviors, with a brain of about 100,000 neurons, almost all of which are accessible to optical recording of neural activity. Our new technique will help us examine how large networks mediate behaviour, while at the same time telling us what each individual cell is doing."
Using the technique, Dr Ahrens and colleagues asked the question: do zebrafish adapt their behaviour in response to changes in their environment? To do this, they manipulated the virtual environment to simulate the fish suddenly becoming more "muscular". This served as a simplified version of what happens when the brain needs to adapt the way it drives behavior, for example, when water temperature changes the efficacy of the muscles, or when the fish gets injured.
Dr Ahrens adds: "The paralyzed fish in the virtual world do indeed adapt their behaviour, by adjusting the amount of impulses the brain sends to the muscles. They also 'remember' this change for a while. Imaging the brain everywhere during this behaviour, we identified certain brain regions that were involved, most notably the cerebellum and related structures. This technique opens the possibility that eventually, the behaviour may be used to gain insights into human motor control and motor control deficits.
"Our own motor control is continuously recalibrating itself in a similar way to the fish's to cope with ever changing conditions of our body and environment, such as when we injure a leg, or if we're walking on a slippery floor or carrying a heavy bag. The zebrafish's behaviour is an ultra-simplified version of this and we have been able to gain some insight into how its brain structures drive behaviour. This might someday help us understand how damage to certain brain regions in humans affects the way in which the brain integrates sensory information to control body movements."
Understanding the brain is one of the Wellcome Trust's five strategic challenges.
Related Neurons Articles:
One of the big challenges in the Neuroscience field is to understand how connections and communications trigger our behavior.
In a new study published in Neuron, investigators report on a transcription factor that they have found that can help certain neurons regenerate, while simultaneously killing others.
When many individual neurons collect data, how do they reach a unanimous decision?
Individual neurons can learn not only single responses to a particular signal, but also a series of reactions at precisely timed intervals.
Putting a turbo engine into an old car gives it an entirely new life -- suddenly it can go further, faster.
Turning the theory of how the human brain perceives time on its head, a novel analysis in mice reveals that dopamine neuron activity plays a key role in judgment of time, slowing down the internal clock.
Researchers have identified a large population of previously unrecognized young neurons that migrate in the human brain during the first few months of life, contributing to the expansion of the frontal lobe, a region important for social behavior and executive function.
For decades, scientists have struggled to develop a comprehensive census of cell types in the brain.
In the brain, patterns of neural activity are perfectly balanced.
University of Alberta researchers have developed a method of connecting neurons, using ultrashort laser pulses -- a breakthrough technique that opens the door to new medical research and treatment opportunities.
Related Neurons Reading:
From Neuron to Brain
by John G. Nicholls (Author), A. Robert Martin (Author), David A. Brown (Author), Mathew E. Diamond (Author), David A. Weisblat (Author), Paul A. Fuchs (Author)
From Neuron to Brain, Fifth Edition, provides a readable, up-to-date book for use in undergraduate, graduate, and medical school courses in neuroscience. As in previous editions, the emphasis is on experiments made by electrical recordings, molecular and cellular biological techniques, and behavioral studies on the nervous system, from simple reflexes to cognitive functions. Lines of research are followed from the inception of an idea to new findings being made in laboratories and clinics today.
A major change is that this edition begins with the anatomy and physiology of the... View Details
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... View Details
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... View Details
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... View Details
From Photon to Neuron: Light, Imaging, Vision
by Philip Nelson (Author)
A richly illustrated undergraduate textbook on the physics and biology of light
Students in the physical and life sciences, and in engineering, need to know about the physics and biology of light. Recently, it has become increasingly clear that an understanding of the quantum nature of light is essential, both for the latest imaging technologies and to advance our knowledge of fundamental life processes, such as photosynthesis and human vision. From Photon to Neuron provides undergraduates with an accessible introduction to the physics of light and offers a unified view... View Details
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... View Details
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.... View Details
Mirroring People: The Science of Empathy and How We Connect with Others
by Marco Iacoboni (Author)
Includes a new Afterword by the Author
What accounts for our remarkable ability to get inside another person's head--to know what he or she is thinking and feeling? Marco Iacoboni, a leading neuroscientist, explains the groundbreaking research into mirror neurons, the "smart cells" in our brain that allow us to understand others. From imitation to morality, from political affiliations to consumer choices, mirror neurons are relevant to myriad aspects of social cognition. Mirroring People is the first book for the general reader on this revolutionary new science.View Details
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... View Details
Neurons and Networks: An Introduction to Behavioral Neuroscience, Second Edition
by John E. Dowling (Author)
Harvard University Press is proud to announce the second edition of a widely admired introductory textbook. When first published, Neurons and Networks filled the need for an introductory neuroscience text that is lucid, accessible, authoritative, logically organized, and concise. Avoiding the encyclopedic coverage that makes most neuroscience texts overwhelming, Neurons and Networks focused instead on building the solid foundation of understanding and knowledge required for further study.
The new edition retains the features that made the first edition so attractive:... View Details