6.18.2013
Memory Enhancing Molecule in Mice
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Scientists have identified a key memory-enhancing molecule in mice that could pave the way for boosting cognitive functions in humans, says a study.
The same biochemical pathway the molecule acts on might one day be targeted in humans to improve memory, according to the senior author of the study, Peter Walter, professor of biochemistry and biophysics at the University of California, San Francisco, and a Howard Hughes Investigator.
The discovery of the molecule and the results of the subsequent memory tests in mice were published May 28 in eLife, an online scientific open-access journal.
In one memory test included in the study, normal mice were able to relocate a submerged platform about three times faster after receiving injections of the potent chemical than mice that received sham injections.
The mice that received the chemical also better remembered cues associated with unpleasant stimuli -- the sort of fear conditioning that could help a mouse avoid being preyed upon, reports Science Daily.
Notably, the findings suggest that despite what would seem to be the importance of having the best biochemical mechanisms to maximise the power of memory, evolution does not seem to have provided them, Walter said.
The same biochemical pathway the molecule acts on might one day be targeted in humans to improve memory, according to the senior author of the study, Peter Walter, professor of biochemistry and biophysics at the University of California, San Francisco, and a Howard Hughes Investigator.
The discovery of the molecule and the results of the subsequent memory tests in mice were published May 28 in eLife, an online scientific open-access journal.
In one memory test included in the study, normal mice were able to relocate a submerged platform about three times faster after receiving injections of the potent chemical than mice that received sham injections.
The mice that received the chemical also better remembered cues associated with unpleasant stimuli -- the sort of fear conditioning that could help a mouse avoid being preyed upon, reports Science Daily.
Notably, the findings suggest that despite what would seem to be the importance of having the best biochemical mechanisms to maximise the power of memory, evolution does not seem to have provided them, Walter said.
Labels: eLife, peter-walter, ucsf
// posted by neurofuture1:54 PM permanent link
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6.12.2013
Gamers: Better Visual Memories
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People who play a lot of video games have better visual memories than those who don't, a new study says.
"Gamers see the world differently," Duke University psychiatry professor Greg Appelbaum said. "They are able to extract more information from a visual scene."
Duke University researchers recruited 125 volunteers who were either non-gamers or intensive gamers.
Each was shown a flash of a circular arrangement of eight letters for one-tenth of a second.
Between 13 milliseconds to 2.5 seconds later, an arrow would appear on the screen pointing to a spot where a letter had been.
The participants then had to remember which letter was there.
The gamers beat the non-gamers at every time interval.
Appelbaum said that's because when someone plays a game, especially a shooter, they make "probabilistic inferences" about what they're seeing: Is that character a friend or foe? Are they moving left or right?
"They need less information to arrive at a probabilistic conclusion, and they do it faster," he said.
Labels: duke-university, greg-appelbaum, milliseconds
// posted by neurofuture12:59 PM permanent link
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6.11.2013
Alzheimer's and Low Blood Sugar in Diabetes may Trigger a Vicious Cycle
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Diabetes-associated episodes of low blood sugar may increase the risk of developing dementia, while having dementia or even milder forms of cognitive impairment may increase the risk of experiencing low blood sugar, according to a UC San Francisco scientist who led a new study published online today (June 10) in JAMA Internal Medicine.
Researchers analyzed data from 783 diabetic participants and found that hospitalization for severe hypoglycemia among the diabetic elderly in the study was associated with a doubled risk of developing dementia later. Similarly, study participants with dementia were twice as likely to experience a severe hypoglycemic event.
The study results suggest some patients risk entering a downward spiral in which hypoglycemia and cognitive impairment fuel one another, leading to worse health, said Kristine Yaffe, MD, senior author and principal investigator for the study, and a UCSF professor of psychiatry, neurology and epidemiology based at the San Francisco Veterans Affair Medical Center.
"Older patients with diabetes may be especially vulnerable to a vicious cycle in which poor diabetes management may lead to cognitive decline and then to even worse diabetes management," she said.
The researchers analyzed hospital records of patients from Memphis and Pittsburgh, ages 70 to 79 at the time of enrollment, who participated in the federally funded Health, Aging and Body Composition (Health ABC) study, begun in 1997. The UCSF results are based on an average of 12 years of follow-up study. Participants in the Health ABC study periodically underwent tests to measure cognitive function.
Nearly half of participants included in the newly published analysis were black, and the rest were white. None had dementia at the start of the study, and all either had diabetes at the beginning of the study or were diagnosed during the course of the study.
"Individuals with dementia or even those with milder forms of cognitive impairment may be less able to effectively manage complex treatment regimens for diabetes and less able to recognize the symptoms of hypoglycemia and to respond appropriately, increasing their risk of severe hypoglycemia," Yaffe said. "Physicians should take cognitive function into account in managing diabetes in elderly individuals."
Certain medications known to carry a higher risk for hypoglycemia — such as insulin secretagogues and certain sulfonylureas — may be inappropriate for older adults with dementia or who or at risk for cognitive impairment, according to Yaffe.
Previous studies in which researchers investigated hypoglycemia and cognitive function have had inconsistent findings. A strength of the current study is that individuals were tracked from baseline over a relatively long time, and the older age of participants may also have been a factor in the highly statistically significant outcome, Yaffe said.
Labels: jama-internal-medicine, kristine-yaffe, ucsf
// posted by neurofuture11:02 AM permanent link
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6.06.2013
Artwork Inspired by MRI Brain Scans Installed at Stanford Imaging Center
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Art and science meet in a new installation of clay sculptures, etchings and acrylics at the Stanford Center for Cognitive and Neurobiological Imaging.
The pieces by artist Laura Jacobson, a Stanford alumna, are inspired by MRIs of the human brain and reflect the work of the center to investigate connections between neuroscience and society.
The center, in the basement of the Department of Psychology, uses the MRI to support research that advances understanding of the brain, including decision-making, cognition, perception, child development, education and emotion.
"It's not a weird, scary place filled with chemicals," said psychology professor Brian, Wandell, who directs the center. "But it's an MRI and there is a scary quality to it."
Wandell said one of the goals of the art installation is to break down some of that fear.
"It's a place where we bring families to study brain function, why we do things, behavior. We thought having art that reflects what we see and do and our mission might make all of it more inviting," he said.
Labels: brian-wandell, laura-jacobson, stanford-center-for-Cognitive-and-Neurobiological-Imaging
// posted by neurofuture9:52 AM permanent link
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6.05.2013
Scientists Study How Meditation Helps Reduce Anxiety
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Scientists at Wake Forest Baptist Medical Center have identified the brain functions involved in how meditation reduces anxiety.
The team wrote in the journal Social Cognitive and Affective Neuroscience about how they studied 15 healthy volunteers with normal levels of everyday anxiety. They said these individuals had no previous meditation experience or anxiety disorders.
The participants took four 20-minute classes to learn a technique known as mindfulness meditation. In this form of meditation, people are taught to focus on breath and body sensations and to non-judgmentally evaluate distracting thoughts and emotions.
“Although we’ve known that meditation can reduce anxiety, we hadn’t identified the specific brain mechanisms involved in relieving anxiety in healthy individuals,” said Dr. Fadel Zeidan, Ph.D., postdoctoral research fellow in neurobiology and anatomy at Wake Forest Baptist and lead author of the study. “In this study, we were able to see which areas of the brain were activated and which were deactivated during meditation-related anxiety relief.”
The researchers found that meditation reduced anxiety ratings by as much as 39 percent in the participants.
“This showed that just a few minutes of mindfulness meditation can help reduce normal everyday anxiety,” Zeidan said.
Fadel and colleagues were also able to reveal that meditation-related anxiety relief is associated with activation of the anterior cingulate cortex and ventromedial prefrontal cortex, which are areas of the brain involved with executive-level function.
“Mindfulness is premised on sustaining attention in the present moment and controlling the way we react to daily thoughts and feelings,” Zeidan said. “Interestingly, the present findings reveal that the brain regions associated with meditation-related anxiety relief are remarkably consistent with the principles of being mindful.”
He said the results of this neuroimaging experiment complement that body of knowledge by showing the brain mechanisms associated with meditation-related anxiety relief in healthy people.
Scientists wrote in the journal Frontiers in Human Neuroscience in November 2012 about how meditation has lasting emotional benefits. They found that participating in an eight-week meditation training program could have measurable effects on how the brain functions, even when someone is not actively meditating. The team used two forms of meditation training and saw some differences in the response of the amygdala, which is the part of the brain known to be important for emotion.
Labels: fadel-zeidan, social-cognitive-and-affective-neuroscience, wake-forest-baptist
// posted by neurofuture3:09 PM permanent link
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6.04.2013
PET Shows Increased Levels of Cognitive Reserve in More Educated Individuals
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Highly educated individuals with mild cognitive impairment that later progressed to Alzheimer's disease cope better with the disease than individuals with a lower level of education in the same situation, according to research published in the June issue of The Journal of Nuclear Medicine. In the study "Metabolic Networks Underlying Cognitive Reserve in Prodromal Alzheimer Disease: A European Alzheimer Disease Consortium Project,"neural reserve and neural compensation were both shown to play a role in determining cognitive reserve, as evidenced by positron emission tomography (PET).
Cognitive reserve refers to the hypothesized capacity of an adult brain to cope with brain damage in order to maintain a relatively preserved functional level. Understanding the brain adaptation mechanisms underlying this process remains a critical question, and researchers of this study sought to investigate the metabolic basis of cognitive reserve in individuals with higher (more than 12 years) and lower (less than 12 years) levels of education who had mild cognitive impairment that progressed to Alzheimer's disease, also known as prodromal Alzheimer's disease.
"This study provides new insight into the functional mechanisms that mediate the cognitive reserve phenomenon in the early stages of Alzheimer's disease," said Silvia Morbelli, MD, lead author of the study. "A crucial role of the dorso-lateral prefrontal cortex was highlighted by demonstrating that this region is involved in a wide fronto-temporal and limbic functional network in patients with Alzheimer's disease and high education, but not in poorly educated Alzheimer's disease patients."
In the study, 64 patients with prodromal Alzheimer's disease and 90 control subjects -- coming from the brain PET project (chaired by Flavio Nobili, MD, in Genoa, Italy) of the European Alzheimer Disease Consortium -- underwentbrain 18F-FDG PET scans. Individuals were divided into a subgroup with a low level of education (42 controls and 36 prodromal Alzheimer's disease patients) and a highly educated subgroup (40 controls and 28 prodromal Alzheimer's disease patients). Brain metabolism was compared between education-matched groups of patients and controls, and then between highly and poorly educated prodromal Alzheimer's disease patients.
Higher metabolic activity was shown in the dorso-lateral prefrontal cortex for prodromal Alzheimer's disease patients. More extended and significant correlations of metabolism within the right dorso-lateral prefrontal cortex and other brain regions were found with highly educated than less educated prodromal Alzheimer's disease patients or even highly educated controls.
This result suggests that neural reserve and neural compensation are activated in highly educated prodromal Alzheimer's disease patients. Researchers concluded that evaluation of the implication of metabolic connectivity in cognitive reserve further confirms that adding a comprehensive evaluation of resting 18F-FDG PET brain distribution to standard inspection may allow a more complete comprehension of Alzheimer's disease pathophysiology and possibly may increase 18F-FDG PET diagnostic sensitivity.
"This work supports the notion that employing the brain in complex tasks and developing our own education may help in forming stronger 'defenses' against cognitive deterioration once Alzheimer knocks at our door," noted Morbelli."It's possible that, in the future, a combined approach evaluating resting metabolic connectivity and cognitive performance can be used on an individual basis to better predict cognitive decline or response to disease-modifying therapy."
Labels: flavio-nobili, pet, silvia-morbelli
// posted by neurofuture11:23 AM permanent link
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6.02.2013
Low Doses of Marijuana Component Can Help Prevent Brain Damage
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Tel Aviv University researchers have found that extremely low doses of THC - the psychoactive component of marijuana - protects the brain from long-term cognitive damage in the wake of injury from hypoxia (lack of oxygen), seizures, or toxic drugs.
Brain damage can have consequences ranging from mild cognitive deficits to severe neurological damage.
Previous studies focused on injecting high doses of THC within a very short time frame - approximately 30 minutes - before or after injury.
The current research by Prof. Yosef Sarne of Tel Aviv University's Adelson Center for the Biology of Addictive Diseases at the Sackler Faculty of Medicine demonstrates that even extremely low doses of THC - around 1,000 to 10,000 times less than that in a conventional marijuana cigarette - administered over a wide window of 1 to 7 days before or 1 to 3 days after injury can jumpstart biochemical processes which protect brain cells and preserve cognitive function over time.
This treatment, especially in light of the long time frame for administration and the low dosage, could be applicable to many cases of brain injury and be safer over time, Prof. Sarne said.
While performing experiments on the biology of cannabis, Prof. Sarne and his fellow researchers discovered that low doses of the drug had a big impact on cell signalling, preventing cell death and promoting growth factors. This finding led to a series of experiments designed to test the neuroprotective ability of THC in response to various brain injuries.
In the lab, the researchers injected mice with a single low dose of THC either before or after exposing them to brain trauma. A control group of mice sustained brain injury but did not receive the THC treatment. When the mice were examined 3 to 7 weeks after initial injury, recipients of the THC treatment performed better in behavioral tests measuring learning and memory. Additionally, biochemical studies showed heightened amounts of neuroprotective chemicals in the treatment group compared to the control group.
The use of THC can prevent long-term cognitive damage that results from brain injury, the researchers concluded.
One explanation for this effect is pre- and post-conditioning, whereby the drug causes minute damage to the brain to build resistance and trigger protective measures in the face of much more severe injury, explained Prof. Sarne.
The low dosage of THC is crucial to initiating this process without causing too much initial damage.
According to Prof. Sarne, there are several practical benefits to this treatment plan. Due to the long therapeutic time window, this treatment can be used not only to treat injury after the fact, but also to prevent injury that might occur in the future.
For example, cardiopulmonary heart-lung machines used in open heart surgery carry the risk of interrupting the blood supply to the brain, and the drug can be delivered beforehand as a preventive measure. In addition, the low dosage makes it safe for regular use in patients at constant risk of brain injury, such as epileptics or people at a high risk of heart attack.
Prof. Sarne is now working in collaboration with Prof. Edith Hochhauser of the Rabin Medical Center to test the ability of low doses of THC to prevent damage to the heart. Preliminary results indicate that they will find the same protective phenomenon in relation to cardiac ischemia, in which the heart muscle receives insufficient blood flow.
His research findings were published in the journals Behavioural Brain Research and Experimental Brain Research.
Brain damage can have consequences ranging from mild cognitive deficits to severe neurological damage.
Previous studies focused on injecting high doses of THC within a very short time frame - approximately 30 minutes - before or after injury.
The current research by Prof. Yosef Sarne of Tel Aviv University's Adelson Center for the Biology of Addictive Diseases at the Sackler Faculty of Medicine demonstrates that even extremely low doses of THC - around 1,000 to 10,000 times less than that in a conventional marijuana cigarette - administered over a wide window of 1 to 7 days before or 1 to 3 days after injury can jumpstart biochemical processes which protect brain cells and preserve cognitive function over time.
This treatment, especially in light of the long time frame for administration and the low dosage, could be applicable to many cases of brain injury and be safer over time, Prof. Sarne said.
While performing experiments on the biology of cannabis, Prof. Sarne and his fellow researchers discovered that low doses of the drug had a big impact on cell signalling, preventing cell death and promoting growth factors. This finding led to a series of experiments designed to test the neuroprotective ability of THC in response to various brain injuries.
In the lab, the researchers injected mice with a single low dose of THC either before or after exposing them to brain trauma. A control group of mice sustained brain injury but did not receive the THC treatment. When the mice were examined 3 to 7 weeks after initial injury, recipients of the THC treatment performed better in behavioral tests measuring learning and memory. Additionally, biochemical studies showed heightened amounts of neuroprotective chemicals in the treatment group compared to the control group.
The use of THC can prevent long-term cognitive damage that results from brain injury, the researchers concluded.
One explanation for this effect is pre- and post-conditioning, whereby the drug causes minute damage to the brain to build resistance and trigger protective measures in the face of much more severe injury, explained Prof. Sarne.
The low dosage of THC is crucial to initiating this process without causing too much initial damage.
According to Prof. Sarne, there are several practical benefits to this treatment plan. Due to the long therapeutic time window, this treatment can be used not only to treat injury after the fact, but also to prevent injury that might occur in the future.
For example, cardiopulmonary heart-lung machines used in open heart surgery carry the risk of interrupting the blood supply to the brain, and the drug can be delivered beforehand as a preventive measure. In addition, the low dosage makes it safe for regular use in patients at constant risk of brain injury, such as epileptics or people at a high risk of heart attack.
Prof. Sarne is now working in collaboration with Prof. Edith Hochhauser of the Rabin Medical Center to test the ability of low doses of THC to prevent damage to the heart. Preliminary results indicate that they will find the same protective phenomenon in relation to cardiac ischemia, in which the heart muscle receives insufficient blood flow.
His research findings were published in the journals Behavioural Brain Research and Experimental Brain Research.
Labels: adelson-center, tel-aviv-university, yosef-sarne
// posted by neurofuture1:15 PM permanent link
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