Posts Tagged ‘neuroscience’

The Workings of Working Memory

Friday, January 27th, 2012

Synaptic Communication

How do we keep thoughts in our mind? It seems a simple question until we remind ourselves of the brain as a dynamic labyrinth of neurons constantly firing and receiving electrical signals. But researchers from the University of Wisconsin-Madison believe they’ve figured out how working memory holds a piece of information. The holder of a thought, they have discovered, is a molecular sensor that controls nerve cell communication keeping a message present and active even long after its delivery.

“The sensor could play a role in keeping a thought ‘on line’ until it is either lost or burned into longer-lasting forms of memory,” says the study lead Dr. Edwin Chapman, a professor at the UW School of Medicine and Public Health.

Most communication between synapses occurs instantaneously–an electrical impulse spurs calcium in the sending cell to release a burst of neurotransmitter into the receiving cell. This process takes just milliseconds to play out.

The Wisconsin scientists focused instead on a second, slower, asynchronous communication phase, in which residual levels of calcium continue to cause the release of neurotransmitters over several seconds.

“We knew that different calcium sensors controlled these two distinct phases of synaptic transmission,” says Chapman, based in the Department of Neuroscience.

The team theorized that slow transmission, with its maintenance of a communication state for a longer time period, might be the key to the retention of thoughts in working memory. They found that they were able to change the speed of slow release with higher and lower levels of a protein called Doc2 without impacting fast release.

“Doc2 took its time responding to calcium, unlike synaptotagmin, which responded immediately,” Chapman says.

The research could eventually produce practical results providing insight into conditions such as autism and schizophrenia. “Defects in release mechanisms are seen in many nerve diseases,” says Chapman.


Brain Fitness Training & Tourettes Treatment

Thursday, May 12th, 2011
brain fitness Tim Howard Tourette syndrome

Goalkeeper Tim Howard, a Tourette Sufferer

Brain fitness researchers Professor Stephen Jackson and Professor Georgina Jackson from the University of Nottingham have shown evidence, using brain imaging and behavioral techniques to study a group of children with Tourettes compared to a control group, that brain fitness training may be useful to help treat children with Tourette syndrome.

“We had previously shown, somewhat paradoxically, that children with Tourette syndrome have greater control over their motor behaviour than typically-developing children of a similar age,” said Stephen Jackson, brain fitness expert and Professor of Cognitive Neuroscience in the School of Psychology, “And we had speculated that this was due to compensatory changes in the brain that helped these children control their tics.

“This new study provides compelling evidence that this enhanced control of motor output is accompanied by structural and functional alterations within the brain. This finding suggests that non-pharmacological, ‘brain-training’, approaches may prove to be an effective treatment for Tourette syndrome.”

An inherited neurological condition affecting about one child in every hundred Tourette syndrome is associated with involuntary sounds and movements such as coughing, grunting, eye blinking and repeating of words. First showing itself at age six or seven, Tourette symptoms increase until age twelve and can continue into adulthood.

This brain fitness study is the latest in a long line of similar studies that demonstrate the brain’s ability to change and adapt when we train it.

Hippocampus Takes Control of Learning

Friday, February 18th, 2011

Each week my first grade son brings home a new set of “spelling words”. It’s often a struggle to get him to focus on word study when a Clone Wars Lego project beckons. But this week my wife, faced with a particularly thorny set of new words, hit on the idea of getting Zane to integrate them into a star wars story. Fantastic!  Twenty minutes later we had a new scene synopsis for George Lucas complete with snakes and licks and dukes, and the next day Zane scored 100% on his spelling review.

Logical, inspired, and now supported by a new research study, the idea that we learn better when we have some active engagement in the learning process makes ample sense but seems to be sadly lacking from many pedagogical strategies.

Neal Cohen, University of Illinois psychology and Beckman Institute professor led the study with postdoctoral researcher Joel Voss. “Having active control over a learning situation is very powerful and we’re beginning to understand why,” commented Cohen. “Whole swaths of the brain not only turn on, but also get functionally connected when you’re actively exploring the world.”

Brain Training Online

Focused on the hippocampus and several other integrated brain regions, Voss asked participants to memorize an array of objects and their locations on a grid, one at a time. Participants with some control were permitted to reveal the objects themselves.

“They could inspect whatever they wanted, however they wanted, in whatever order for however much time they wanted, and they were just told to memorize everything on the screen,” Voss said. The “passive” learners instead reviewed a replay of the grid movements recorded in a previous trial by an active subject.

To complete the exercise the subjects tried to replicate the layout of the objects in the grid from memory. The active and passive subjects then changed roles and performed the task again with a new set of objects.

Recording significant differences in brain activity in the active and passive learners, Cohen and Voss found that the learners with had active control remembered the object placement significantly more accurately than the passive learners.

The researchers repeated the trials with people suffering memory impairment due to hippocampal damage. Surprisingly, these learners failed didn’t benefit from actively controlling the viewing window.

“These data suggest that the hippocampus has a role not just in the formation of new memory but possibly also in the beneficial effects of volitional control on memory,” the researchers wrote.

Confirming this hypothesis, further tests with fMRI showed the highest hippocampal activity in the active subjects’ brains. These tests also showed greater engagement in several other brain structures when the subject controlled the viewing window, and greater synchronization of activity in these brain regions and the hippocampus than in the passive trials.

Activity in the dorsolateral prefrontal cortex, the cerebellum and the hippocampus was higher, and more highly coordinated, in participants who did well on spatial recall, the researchers found. Increased activity in the inferior parietal lobe, the parahippocampal cortex and the hippocampus corresponded to better performance on item recognition.

“Lo and behold,” Cohen said, “our friend the hippocampus makes a very conspicuous appearance in active learning.”

The new findings challenge previous ideas about the role of the hippocampus in learning, Voss said. It is a surprise, he said, that other brain regions that are known to be involved in planning and strategizing, for instance, “can’t do very much unless they can interact with the hippocampus.”

Rather than being a passive player in learning, the hippocampus “is more like an integral part of an airplane guidance system,” Voss said. “You have all this velocity information, you have a destination target and every millisecond it’s taking in information about where you’re headed, comparing it to where you need to go, and correcting and updating it.”

The paper:
“Hippocampal Brain-network Coordination During Volitional Exploratory Behavior Enhances Learning.”

Neuroscience, Psychiatry and Brain Health

Sunday, January 30th, 2011

This interview with Pierre Magistretti from the Brain Mind Institute covers a good deal of interesting ground, from the origins of neuroscience, the discovery of anti-depressants (by accident) and the importance of mental activity and reduced stress to brain health in seniors and infants alike.

Interview In SwissInfo

New Brain Cells, Stress, And Learned Behavior

Thursday, April 1st, 2010
Stressed Out Mouse

Stressed Out Mouse

A new study by UT Southwestern scientists (Lagace, Donovan, DeCarolis, Farnbauch, Malhotra, Berton, Nestler, Krishnan and Eisch) sheds some light on the connection between stress and neurogenesis.

Eisch and her colleagues performed two experiments related to stress.

1. They exposed mice to a socially stressful experience — confrontation with a more aggressive mouse (the mouse equivalent of a carjacking), then measured the immediate and long term impact on the generation of new brain cells.

2. They irradiated mice to eliminate neurogenesis before exposing the irradiated mice to the same kind of stressful situation.

The scientists made two important findings:

In the first experiment, the stressful situation reduced neurogenesis temporarily (for a few days), and left the mice more likely to be fearful in similar situations.

In the second experiment the irradiated mice showed less fear when exposed to similar stressful situations.

These findings indicate that neurogenesis is key to forming stress memories. This can be a healthy response, educating us on avoidance. (Common sense.) But in cases of inappropriate or chronic stress response, neurogenesis may be overactive.

New Understanding of Neurogenesis

Friday, March 26th, 2010


Not all new brain cells end up getting used. Why do some survive and become useful when others don’t? That’s the question associate professor Angelique Bordey and her team from Yale University have shed some light on with a recent study, as reported in the March 25 issue of Neuron.

Bordey’s team looked at adult neurogenesis. They found that if certain receptors (NMDA receptors) associated with the new neurons are lost, the cells are much more likely to die. (NMDA receptors are key to the transmission of information in the brain and malfunctioning of these receptors has been associated with various mental disorders and diseases.)

The study has implications for stem cell transplantation and brain health education: Bordey noted that stem cells used in transplants may need to be mature enough to possess these receptors. And the general public should be aware that drugs (e.g., PCP, or angel dust,) that prevent NMDA function, kill brain cells and adversely affect brain development.

Neurogenesis & Addiction

Sunday, February 28th, 2010

Novel research at UT Southwestern Medical Center hints at new hope in combating addiction and dependence. The researchers’ experiments indicate that stimulating an increase in neurogenesis (brain cell growth) might help prevent addiction, dependence, or relapse. This is fascinating in the context of intensive brain training with programs such as Brain Fitness Pro.

Parallel studies show that intensive working memory training stimulates neurogenesis. Further, my own experience and the anecdotal experiences of Mind Sparke customers indicates that the training helps improve impulse control, self esteem, and elevate mood.

Published in the Journal of Neuroscience, the UT team’s work is the first research to directly link addiction with neurogenesis in the hippocampus.

“More research will be needed to test this hypothesis, but treatments that increase adult neurogenesis may prevent addiction before it starts, which would be especially important for patients treated with potentially addictive medications,” said Dr. Amelia Eisch, senior study author and associate professor of psychiatry at UT Southwestern. “Additionally, treatments that increase adult neurogenesis during abstinence might prevent relapse.”

Dr. Eisch and her team radiated rats’ brains to stop neurogenesis in the hippocampus. In one experiment, rats accessed cocaine by pressing a lever. The rats with radiated brains took more cocaine than rats that did not receive radiation.

In a second experiment, after becoming accustomed to taking cocaine the team radiated the rats, stopping neurogenesis while drugs were removed. Rats with reduced neurogenesis took more time to realize that the lever would no longer dispense cocaine.

“The nonirradiated rats didn’t like the cocaine as much and learned faster to not press the formerly drug-associated lever,” Dr. Eisch said. “In the context of this experiment, decreased neurogenesis fueled the process of addiction, instead of the cocaine changing the brain.”

Dr. Eisch plans to study other drugs of abuse, using imaging technology to study addiction and hippocampal neurogenesis in humans.

“If we can create and implement therapies that prevent addiction from happening in the first place, we can improve the length and quality of life for millions of drug abusers, and all those affected by an abuser’s behavior,” she said.

See Brain Region, See Other Brain Region Run

Friday, February 26th, 2010

A novel study shows that when learning new words the part of the brain we use depends on whether the words are nouns or verbs.

“Learning nouns activates the left fusiform gyrus, while learning verbs switches on other regions (the left inferior frontal gyrus and part of the left posterior medial temporal gyrus)”, says Catalan researcher Antoni Rodríguez-Fornells, co-author of the study from the Cognition and Brain Plasticity Unit of the University of Barcelona.

He and neurologist Thomas F. Münte from the Otto-von-Guericke University in Magdeburg, in Germany, reported their findings of neural differences in acquiring new nouns and verbs in the journal Neuroimage.

By studying real time scans showing brain activation during a language learning exercise the researchers confirmed prior observations that our brains handle nouns and verbs in different ways.

The scientists inserted nonsense words into otherwise meaningful sentences, and then asked the study participants to derive the meaning of the inserted word – “Joe bought his mom a grimo of flowers for Mother’s day…” for instance, indicates that the word “grimo” means “bunch.”

“This task simulates, at an experimental level, how we acquire part of our vocabulary over the course of our lives, by discovering the meaning of new words in written contexts”, explains Rodríguez-Fornells. “This kind of vocabulary acquisition based on verbal contexts is one of the most important mechanisms for learning new words during childhood and later as adults, because we are constantly learning new terms”.

They measured responses to 80 new nouns and 80 new verbs.

“[The] results suggest that the same regions previously associated with the representation of the meaning of nouns and verbs are also associated with establishing correspondences between these meanings and new words, a process that is necessary for learning a second language”, says Rodríguez-Fornells.

Neurogenesis And Depression – Further Research

Saturday, January 30th, 2010
Brain Cell

Brain Cell

A clinical study shows that promoting neurogenesis has a positive impact on the symptoms of major clinical depression.

As we’ve noted on this blog before, the process of brain training also seems to have a positive impact on mood. Evidence builds that the connection is the stimulation of new brain cell growth…

Read more about the study…

New Brain Science Facility At UCSF

Friday, January 22nd, 2010

The University of California in San Francisco today unveils newly approved plans to build a neuroscience building on its Mission Bay campus. It will house several basic research programs seeking cures for intractable neurological disorders.

Funding approval was granted yesterday by University of California Board of Regents.

The new facility will provide a shared space for clinicians, clinician-researchers and basic scientists to accelerate advances against such disorders as Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, stroke, migraine, epilepsy, autism, mental retardation and cerebral palsy.

“This culminates a 10-year dream,” says Nobel laureate Stanley B. Prusiner, MD, director of the Institute for Neurodegenerative Diseases. “This building will bring together some of the best scientists in the world to work on these very prevalent diseases of the brain. The opportunity for major progress is tremendous.”

“UCSF Mission Bay will be one of the biggest neuroscience complexes in the world.”

“This building exemplifies UCSF’s commitment to discovery, education and patient care,” says UCSF Chancellor Sue Desmond-Hellmann, MD, MPH. “It represents my vision for UCSF. In the face of these challenging financial times, it is imperative that we maintain our strategic vision and continue our leadership role in tackling the world’s devastating diseases.”

“We have an unprecedented opportunity with this building to establish a Manhattan project-like approach for moving in on these devastating neurological disorders,” says Stephen L. Hauser, MD, chair of the Department of Neurology.

“Clinicians treating patients with neurological conditions, clinician-researchers carrying out brain imaging and drug studies in patients, scientists studying the molecular and cellular basis of diseases, and scientists studying how the brain normally functions will be able to share their expertise, brainstorm, collaborate.”

“Ultimately, we want to be able to stop disease progression, repair damage that has already occurred and prevent disease from occurring in the first place,” he says.

“In MS, we’re currently planning the first clinical study to see if it can be halted before it begins.”

And in reading the press release, here is where I started to notice the emphasis on drug interventions and the absence of mention that San Francisco is also a hub for interventions that don’t require drugs, such as brain training!

** Collaborations with Silicon Valley, the biotech industry and the pharmaceutical industry will be key to this effort, Hauser says. Equally critical, he says, will be cultivating the next generation of neuroscience investigators and inspiring careers in translational medicine. **

The world-class neuroscientists of the Keck Center, whose studies of brain function have shed light on how the human brain learns and remembers, how it sees, hears, moves the body’s limbs, and feels pain, will add another dimension to the research conducted in the building. Pioneers in the study of the brain’s “plasticity,” or capacity to change, these scientsts focus on how brain cells work together to generate behaviors. Their intent is to learn enough about these processes that the brain could be taught to repair itself in patients born with disabilities, such as autism, or afflicted with disorders such as neurodegenerative diseases or stroke.

“Our goal in moving to this building is to help our colleagues understand how the brain works when it’s functioning well and for us to discover what happens in the whole system when brain function fails at the level of molecules and cells,” says Allison J. Doupe, MD, PhD, a psychiatrist and senior neuroscientist at the Keck Center.