Science Current Events | Science News |

A brain filter for clear information transmission

September 07, 2012
Every activity in the brain involves the transfer of signals between neurons. Frequently, as many as one thousand signals rain down on a single neuron simultaneously. To ensure that precise signals are delivered, the brain possesses a sophisticated inhibitory system. Stefan Remy and colleagues at the German Center for Neurodegenerative Diseases and the University Bonn have illuminated how this system works. "The system acts like a filter, only letting the most important impulses pass," explains Remy. "This produces the targeted neuronal patterns that are indispensible for long-term memory storage."

How does this refined control system work? How can inhibitory signals produce precise output signals? This was the question investigated by Remy and his colleagues. Scientists have known for some time that this inhibitory system is crucial for the learning process. For instance, newest research has shown that this system breaks down in Alzheimer's patients. Remy and his team investigated the nerve cells of the hippocampus, a region of the brain that plays a crucial role in memory formation.

The information we learn or remember is processed in the brain through nerve impulses. Incoming signals enter the cell as excitatory signals. Here, they are processed via branched structures, known as dendrites, and are sent selectively to neighboring neurons. The dendrites in this brain region serve as efficient amplifiers for synchronous signals.

"We were able to show that in specific dendrites, the 'strong' dendrites, clustered signals are amplified very well. 'Weak' dendrites only transmit signals in certain phases," says Christina Müller, postdoctoral student in Remy's working group and the lead author of the study to appear in Neuron. Dendrites are excitable to differing degrees. 'Strong' dendrites transmit synchronous excitatory signals precisely and very reliably. They can resist any inhibition. Thus ensures specific signals, perhaps most relevant for learning and memory, are reliably transmitted. This results in defined patterns of activity that are repeated regularly, creating simultaneous excitation and a combination of specific cell groups (assemblies).

"It is assumed that this coactivation of cell assemblies is a cellular correlate for learning," says Müller. If associations are to be stored in long-term memory, certain neuronal groups must be precisely and repeatedly activated in the same order. These activity patterns are enabled by the inhibitory system. It explains why the absence of this system in Alzheimer's patients has such dramatic consequences. Without it, the storage of associations in long-term memory cannot take place.

Signals that are received via 'weak' dendrites can only be passed forward during phases of weak inhibition. They can however be transformed into 'strong' dendrites during this process. According to Remy and his colleagues, only then can these dendrites provide precise signal transmission. Scientists call this "intrinsic plasticity". "This makes sense. Because this is how neuronal networks can be coupled with each other and the coupling made permanent," explains Remy. "This is a totally new learning mechanism. Here the change does not take place at the synapse - where it's already been observed - but at the dendrite." This mechanism mostly takes place during phases of heightened activity, such as when we experience something new.

The findings of Remy and his colleagues represent an important step toward better understanding the mechanisms of learning and memory.

Original publication:
Christina Müller, Heinz Beck, Douglas Coulter & Stefan Remy. Inhibitory control of linear and supralinear dendritic excitation in CA1 pyramidal neurons. Neuron, online publiziert am 5.9.2012. doi: 10.1016/j.neuron.2012.06.025

German Center for Neurodegenerative Diseases (DZNE)

Related Long-term Memory Current Events and Long-term Memory News Articles

Drug used to treat cancer appears to sharpen memory
Can you imagine a drug that would make it easier to learn a language, sharpen your memory and help those with dementia and Alzheimer's disease by rewiring the brain and keeping neurons alive?

Apes know a good thriller when they see one
Remember the scene in the classic movie Alien, when that creepiest of creatures bursts out of John Hurt's belly as he writhes in pain?

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.

Scientists show the mammary gland 'remembers' prior pregnancy, spurring milk production
Anecdotal reports of nursing mothers have long suggested that giving milk is a lot easier in second and subsequent pregnancies, compared with a first pregnancy.

NTU scientists discover new treatment for dementia
Pushing new frontiers in dementia research, Nanyang Technological University, Singapore (NTU Singapore) scientists have found a new way to treat dementia by sending electrical impulses to specific areas of the brain to enhance the growth of new brain cells.

Neuropsychology: Power naps produce a significant improvement in memory performance
Generations of school students have gone to bed the night before a maths exam or a vocabulary test with their algebra book or vocabulary notes tucked under their pillow in the hope that the knowledge would somehow be magically transferred into their brains while they slept.

Teen cannabis users have poor long-term memory in adulthood
Teens who were heavy marijuana users - smoking it daily for about three years -- had an abnormally shaped hippocampus and performed poorly on long-term memory tasks, reports a new Northwestern Medicine study.

Scripps Florida scientists find a defect responsible for memory impairment in aging
Everyone worries about losing their memory as they grow older--memory loss remains one of the most common complaints of the elderly.

Why all-nighters don't work: How sleep and memory go hand-in-hand
Want to ace that test tomorrow? Here's a tip: Put down the coffee and hit the sack.

Family voices and stories speed coma recovery
"Can he hear me?" family members are desperate to know when a loved one with a traumatic brain injury is in a coma.
More Long-term Memory Current Events and Long-term Memory News Articles

Long-Term Memory Problems in Children and Adolescents: Assessment, Intervention, and Effective Instruction

Long-Term Memory Problems in Children and Adolescents: Assessment, Intervention, and Effective Instruction
by Milton J. Dehn (Author)

Under federal and state mandates, schools must provide effective instruction and intervention for students who struggle with academic learning. The first book of its kind for psychologists, school psychologists, and special education teachers, Long-Term Memory Problems in Children and Adolescents provides education professionals with information about the impact of long-term memory on children's learning. This book offers guidance on the assessment tools, intervention programs, and effective instruction programs for use with students experiencing long-term memory impairments. School psychologists can use this book as companion to Working Memory and Academic Learning (ISBN 978-0-470-14419-0).


by Alan Baddeley (Author), Michael W. Eysenck (Author), Michael C. Anderson (Author)

People seem to be intrigued by memory, and by its sometimes spectacular failure in (for example) people with amnesia. However, students of memory sometimes fail to retain this fascination. The reason is clear: in order to study memory we must carry out carefully-designed experiments, which can seem boring even when they are exciting science. Fortunately, we now know enough about memory to relate laboratory studies to the world beyond. In other words, our scientific knowledge of memory and how it works can help us to explain those aspects of memory that most people find of greatest interest. This book presents a thorough, accessible and appealing overview of the field, written with students in mind, by some of the world's leading researchers. It starts with a brief overview and explanation...

Home Care, Long-term Care, Memory Care Units, and Other Living Arrangements (Alzheimer's Roadmap Book 6)

Home Care, Long-term Care, Memory Care Units, and Other Living Arrangements (Alzheimer's Roadmap Book 6)
by Silver Hills Press

As individuals with Alzheimer’s disease progress to the later stages of the disease, they will become increasingly dependent on others for care. This increased need for care is often seen in the individual’s living arrangements. Most individuals with Alzheimer’s disease can live at home for some time, especially with the help of home services and home healthcare. Eventually, though, they will need 24-hour live-in care. If they don’t have a spouse or if their spouse is unable to provide the needed care, they may need to move in with a caregiver or move to an assisted living or long-term care facility. When your loved one needs advanced care, you may find that a memory care unit that specializes in caring for individuals with Alzheimer’s disease and other types of dementia is the...

The Girl in the Spider's Web: A Lisbeth Salander novel, continuing Stieg Larsson's Millennium Series

The Girl in the Spider's Web: A Lisbeth Salander novel, continuing Stieg Larsson's Millennium Series
by David Lagercrantz (Author)

Lisbeth Salander and Mikael Blomkvist return
She is the girl with the dragon tattoo—a genius hacker and uncompromising misfit. He is a crusading journalist whose championing of the truth often brings him to the brink of prosecution.

Late one night, Blomkvist receives a phone call from a source claiming to have information vital to the United States. The source has been in contact with a young female superhacker—a hacker resembling someone Blomkvist knows all too well. The implications are staggering. Blomkvist, in desperate need of a scoop for Millennium, turns to Salander for help. She, as usual, has her own agenda. The secret they are both chasing is at the center of a tangled web of spies, cybercriminals, and governments around the world, and someone is prepared...

Memory, Amnesia, Amygdala, Hippocampus, Neural Networks, Long Term Potentiation, Dissociation, Confabulation, False Memories, Traumatic Stress

Memory, Amnesia, Amygdala, Hippocampus, Neural Networks, Long Term Potentiation, Dissociation, Confabulation, False Memories, Traumatic Stress
by University Press

Memory, Amnesia, Amygdala, Hippocampus, Neural Networks, Long Term Potentiation, Dissociation, Confabulation, False Memories, Traumatic Stress

Table of Contents

Part I. The Hippocampus, Amygdala, Memory, Amnesia,
Long Term Synaptic Potentiation, and Neural Networks -6
neural networks -
neural circuits & long term potentiation -
neural networks -
synaptic growth and dendritic spine proliferation -
long term potential & memory -
short & long term memory: the anterior & posterior hippocampus -
short vs long term verbal & visual memory loss & hippocampal damage -
bilateral hippocampal destruction & amnesia -
learning and memory in the absence of the hippocampus -
the hippocampus and...

Long-Term Care: How to Plan & Pay for It

Long-Term Care: How to Plan & Pay for It
by Joseph Matthews Attorney (Author)

Finding the right long-term care often means making difficult decisions during difficult times. Whether you're planning for the future or need to make a quick decision, Long-Term Care helps you understand the alternatives to nursing facilities and shows you how to find the best care you can afford.

With Long-Term Care, you'll be able to:
evaluate long-term care insurance
arrange home care
explore options beyond nursing homes
choose a nursing facility
get the most out of Medicare, Medicaid and other benefit programs
protect your assets, and recognize and prevent elder fraud.

This completely updated edition includes an expanded discussion of Medicaid coverage, special long-term care insurance, assisted living, and long-term care. Plus,...

I don't know how long my short term memory is...: Strategies for People With Brains

I don't know how long my short term memory is...: Strategies for People With Brains
by Nancy Haller (Author)

Join the Club! Are you living with some form or degree of brain injury? Are you experiencing brain fog? Are you totally brain tired? Do you know someone who has any of these issues? You are not alone. Begin the conversation. Everyone is affected by brain issues in some phase of their life. Nancy speaks of her own brain injury resulting in “foreign accent syndrome”. Wandering through the brain fog, experiencing brain exhaustion and participating in the care of family members, she attributes the Feldenkrais Method® as a resource in her ability to cope and heal. Included are: 31 simple “30 to 60 second Moments of Awareness” designed to help you begin training your brain.

The Best American Science and Nature Writing 2015

The Best American Science and Nature Writing 2015
by Rebecca Skloot (Editor), Tim Folger (Editor)

The Best American Series
The next edition in a series praised as “undeniably exquisite” (Maria Popova), The Best American Science and Nature Writing 2015 includes work from both award-winning writers and up-and-coming voices in the field. From Brooke Jarvis on deep-ocean mining to Elizabeth Kolbert on New Zealand’s unconventional conservation strategies, this is a group that celebrates the growing diversity in science and nature writing alike. Altogether, the writers honored in this year’s volume challenge us to consider the strains facing our planet and its many species, while never losing sight of the wonders we’re working to preserve for generations to come. 
The Best American Science and Nature Writing 2015 includes
Sheri Fink, Atul Gawande, Leslie...

Essentials of Working Memory Assessment and Intervention (Essentials of Psychological Assessment)

Essentials of Working Memory Assessment and Intervention (Essentials of Psychological Assessment)
by Milton J. Dehn (Editor), Alan S. Kaufman (Editor), Nadeen L. Kaufman (Editor)

Improve academic learning outcomes with accurate working memory assessment and evidence-based interventions Essentials of Working Memory Assessment and Intervention is an accessible, practical guide to accurately and efficiently assessing working memory. This comprehensive resource explains the theories of working memory, with an emphasis on cognitive load theory, and provides step-by-step guidelines for organizing a cross-battery assessment, selecting appropriate instruments, interpreting results, and formulating individualized interventions and educational programming. In-depth case studies illustrate typical profiles found in children and adolescents with working memory deficits, and the companion CD features worksheets, testing charts, and other useful resources. Reader-friendly...

The Structure of Long-term Memory: A Connectivity Model of Semantic Processing

The Structure of Long-term Memory: A Connectivity Model of Semantic Processing
by Wolfgang Klimesch (Author)

How is information stored and retrieved from long-term memory? It is argued that any systematic attempt to answer this question should be based on a particular set of specific representational assumptions that have led to the development of a new memory theory -- the connectivity model. One of the crucial predictions of this model is that, in sharp contrast to traditional theories, the speed of processing information increases as the amount and complexity of integrated knowledge increases. In this volume, the predictions of the model are examined by analyzing the results of a variety of different experiments and by studying the outcome of the simulation program CONN1, which illustrates the representation of complex semantic structures. In the final chapter, the representational...

© 2015