The brain's GPS has a buddy systemJanuary 11, 2018
To be successful as a social animal, you need to know where you stand relative to others. Brain cells that perform precisely this function--locating the 'self' and others in space--have now been identified. In rats, the same brain area that stores the animal's own location also maps the movements of other rats. Sometimes these representations are processed jointly by the same cells, depending on a rat's goals and actions. This discovery, from Japan's RIKEN Brain Science Institute, deepens our understanding of the hippocampus and its role as the brain's positioning system.
It has been known for some time that the hippocampus maintains a mental map of space--in fact, the 2014 Nobel Prize in Physiology or Medicine was awarded precisely for this research. 'Place cells' and 'grid cells' in the hippocampus register the location of the brain's owner in its environment, but until now, little was known about how the movements of others are tracked in the brain. Researchers put this to the test by observing the activity of hippocampal neurons in one rat (the 'self') watching another rat (the 'other') go through a simple T-maze. The self's neurons registered what the other was doing and changed their responses based on the self's location and subsequent actions. This study was published on January 11 in Science, which also contains a report of similar location awareness in the brains of bats.
Hippocampal place cells light up only for certain locations in the environment, and some of these cells clearly preferred the location of the other rat. Besides activation to places, the timing of neural activity in the hippocampus is also important. A 'refresh rate' of around 8 Hz dictates how often neurons update their activity, a phenomenon called theta-cycle phase precession. Three-quarters of cells updated based on the other's location, not only the self's. "It is very interesting that the trajectories of the other, that is, the past, current, and future positions of the observed rat, are compressively represented in 100-millisecond cycles in the hippocampus," says Shigeyoshi Fujisawa, research group leader at the RIKEN Brain Science Institute.
In two versions of the maze, the self-rat had to learn to visit the same T-arm as the other or the opposite arm. The majority of neurons were 'goal-focused', signaling the location of the goal, but a small number of neurons preferred the other's location regardless of whether it was on the same side as the goal. There were also cells that fired when either the other or the self were in specific spatial locations. "These cells are not confused," says Fujisawa. "We can reconstruct the paths of the pair of rats and reliably decode the location of the self or the other from the activity of these joint place cells."
Fujisawa and colleagues propose that the hippocampus has four different kinds of spatial models, one for the locations of the self, one for that of others, another for joint locations that are tuned relative to where the self and other are, and one for 'common' locations that activate when either the self or other are there (see image). This extends the existing cognitive map theory of how the hippocampus processes spatial locations and memories. "We think the cognitive map in the hippocampus is not just for knowing where the self is located," says Fujisawa, "but also for plotting the locations of other people, animals, or objects, and to comprehend the spatial environment surrounding the self."
Danjo T, Toyoizumi T, Fujisawa S (2018) Spatial representation of self and other in the hippocampus. Science. doi: 10.1126/science.aao3898.
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
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 7 Secrets of Neuron Leadership: What Top Military Commanders, Neuroscientists, and the Ancient Greeks Teach Us about Inspiring Teams
by W. Craig Reed (Author), Gordon R. England (Foreword)
Leadership techniques backed by the world's most effective teams
The 7 Secrets of Neuron Leadership offers a diverse collection of wisdom and practical knowledge to help you build and lead your most effective team yet. Written by a former U.S. Navy diver, this book draws from the author's experiences and beyond to reveal key truths about the nature of teamwork, and expose the core of effective team leadership. You'll go back to ancient Greece to discover the nine personality types and the seven types of love that form the foundation of human interaction, and learn how... 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 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 Cognition via Computational Neuroscience (Computational Neuroscience Series)
by Michael A. Arbib (Editor), James J. Bonaiuto (Editor)
A comprehensive, integrated, and accessible textbook presenting core neuroscientific topics from a computational perspective, tracing a path from cells and circuits to behavior and cognition.
This textbook presents a wide range of subjects in neuroscience from a computational perspective. It offers a comprehensive, integrated introduction to core topics, using computational tools to trace a path from neurons and circuits to behavior and cognition. Moreover, the chapters show how computational neuroscience -- methods for modeling the causal interactions underlying neural... View Details
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... View Details
Neurons in Action 2: Tutorials and Simulations using NEURON Download
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