Sleep Mechanism Identified That Plays Role in Emotional Memory

June 12, 2013
Science Daily/University of California, Riverside
http://images.sciencedaily.com/2013/06/130612224140-large.jpg
Sleep researchers from University of California campuses in Riverside and San Diego have identified the sleep mechanism that enables the brain to consolidate emotional memory and found that a popular prescription sleep aid heightens the recollection of and response to negative memories.

Their findings have implications for individuals suffering from insomnia related to posttraumatic stress disorder (PTSD) and other anxiety disorders who are prescribed zolpidem (Ambien) to help them sleep.

Mednick and UC San Diego psychologists Erik J. Kaestner and John T. Wixted determined that a sleep feature known as sleep spindles -- bursts of brain activity that last for a second or less during a specific stage of sleep -- are important for emotional memory.

"I was surprised by the specificity of the results, that the emotional memory improvement was specifically for the negative and high-arousal memories, and the ramifications of these results for people with anxiety disorders and PTSD," Mednick said. "These are people who already have heightened memory for negative and high-arousal memories. Sleep drugs might be improving their memories for things they don't want to remember."
Science Daily/SOURCE :http://www.sciencedaily.com/releases/2013/06/130612224140.htm

How Depression Blurs Memories

October 3, 2013
Science Daily/Brigham Young University
To pinpoint why depression messes with memory, researchers took a page from Sesame Street's book.

A new Brigham Young University study concludes that this same skill fades in adults in proportion to the severity of their symptoms of depression. The more depressed someone feels, the harder it is for them to distinguish similar experiences they've had.

"There are two areas in your brain where you grow new brain cells," Kirwan said. "One is the hippocampus, which is involved in memory. It turns out that this growth is decreased in cases of depression."

Because of this study, we know a little more about what these new brain cells are for: helping us see and remember new experiences. The study appears in the journal Behavioral Brain Research.
Science Daily/SOURCE :http://www.sciencedaily.com/releases/2013/10/131003132237.htm

Can Certain Herbs Stave Off Alzheimer's Disease?

November 15, 2013
Science Daily/Saint Louis University
Enhanced extracts made from special antioxidants in spearmint and rosemary improve learning and memory, a study in an animal model at Saint Louis University found.

We found that these proprietary compounds reduce deficits caused by mild cognitive impairment, which can be a precursor to Alzheimer's disease," said Susan Farr, Ph.D., research professor geriatrics at Saint Louis University School of Medicine.

Farr added, "This probably means eating spearmint and rosemary is good for you. However, our experiments were in an animal model and I don't know how much -- or if any amount -- of these herbs people would have to consume for learning and memory to improve. In other words, I'm not suggesting that people chew more gum at this point."

She found that the higher dose rosemary extract compound was the most powerful in improving memory and learning in three tested behaviors. The lower dose rosemary extract improved memory in two of the behavioral tests, as did the compound made from spearmint extract.

Further, there were signs of reduced oxidative stress, which is considered a hallmark of age-related decline, in the part of the brain that controls learning and memory.

"Our research suggests these extracts made from herbs might have beneficial effects on altering the course of age-associated cognitive decline," Farr said. "It's worth additional study."
Science Daily/SOURCE :http://www.sciencedaily.com/releases/2013/11/131115111524.htm

Trans fat consumption linked to diminished memory in working-aged adults

November 18, 2014
Science Daily/American Heart Association
Trans fat consumption is adversely linked to memory sharpness in young to middle-aged men. Men under 45 years old who ate higher amounts of trans fats, which are found in processed foods, had significantly reduced ability to recall words. Further studies need to determine whether these effects extend to women under 45 years old.

"Trans fats were most strongly linked to worse memory, in young and middle-aged men, during their working and career-building years," said Beatrice A. Golomb, M.D., Ph.D., lead author and professor of medicine at the University of California-San Diego. "From a health standpoint, trans fat consumption has been linked to higher body weight, more aggression and heart disease. As I tell patients, while trans fats increase the shelf life of foods, they reduce the shelf life of people."

Golomb and her coauthor studied adults who had not been diagnosed with heart disease, including men age 20 or older and postmenopausal women. Participants completed a dietary questionnaire, from which the researchers estimated participants' trans fat consumption. To assess memory, researchers presented participants with a series of 104 cards showing words. Participants had to state whether each word was new or a word duplicated from a prior card.

They found:
Among men under age 45, those who ate more trans fats showed notably worse performance on the word memory test. The strength of the association remained even after taking into consideration things like age, education, ethnicity and depression.

Each additional gram a day of trans fats consumed was associated with an estimated 0.76 fewer words correctly recalled.

For those eating the highest amounts of trans fats, this translated to an estimated 11 fewer words (a more than 10 percent reduction in words remembered), compared to adults who ate the least trans fat. (The average number of words correctly recalled was 86.)

"Foods have different effects on oxidative stress and cell energy," Golomb said. In a previous study, we found chocolate, which is rich in antioxidants and positively impacts cell energy, is linked to better word memory in young to middle-aged adults. In this study, we looked at whether trans fats, which are prooxidant and linked adversely to cell energy, might show the opposite effect. And they did."
Science Daily/SOURCE :http://www.sciencedaily.com/releases/2014/11/141118105406.htm

Musicians show advantages in long-term memory

November 18, 2014
http://images.sciencedaily.com/2014/11/141118125554-large.jpg
Science Daily/University of Texas at Arlington
Psychologists have demonstrated a link between musical training and long-term memory advantages.

"Musically trained people are known to process linguistic materials a split second faster than those without training, and previous research also has shown musicians have advantages in working memory," said Park. "What we wanted to know is whether there are differences between pictorial and verbal tasks and whether any advantages extend to long-term memory. If proven, those advantages could represent an intervention option to explore for people with cognitive challenges."

The musicians, all of whom had been playing classical music for more than 15 years, outperformed non-musicians in EEG-measured neural responses on the working memory tasks. But, when long-term memory was tested, the enhanced sensitivity was only found in memory for pictures.

The study has not explored why the advantages might develop. Park said it's possible professional musicians become more adept at taking in and processing a host of pictorial cues as they navigate musical scores.

Park's abstract for the conference reports that musicians' neural responses in the mid-frontal part of the brain were 300 to 500 milliseconds faster than non musicians and responses in the parietal lobe were 400 to 800 milliseconds faster than non musicians. The parietal lobe is directly behind the frontal lobe of the brain and is important for perceptual processing, attention and memory.

"Dr. Park's research uses the latest scientific instrumentation to reveal knowledge about human cognition that was previously unreachable," said James Grover, interim dean of the UT Arlington College of Science. "It provides usable information about far-reaching advantages arts training can bring."
Science Daily/SOURCE :http://www.sciencedaily.com/releases/2014/11/141118125554.htm

Spice up your memory: Just one gram of turmeric a day could boost memory

November 18, 2014
Science Daily/Monash University
Adding just one gram of turmeric to breakfast could help improve the memory of people who are in the very early stages of diabetes and at risk of cognitive impairment.

http://images.sciencedaily.com/2014/11/141118110009-large.jpg

"We found that this modest addition to breakfast improved working memory over six hours in older people with pre-diabetes," Professor Wahlqvist said.

Turmeric is widely used in cooking, particularly in Asia. Its characteristic yellow colour is due to curcumin, which accounts for 3 to 6 per cent of turmeric and has been shown by experimental studies to reduce the risk of dementia.

"Our findings with turmeric are consistent with these observations, insofar as they appear to influence cognitive function where there is disordered energy metabolism and insulin resistance," Professor Wahlqvist said.
Science Daily/SOURCE :http://www.sciencedaily.com/releases/2014/11/141118110009.htm

Poor sleep linked to toxic buildup of Alzheimer's protein, memory loss

June 1, 2015
Science Daily/University of California - Berkeley
Sleep may be a missing piece of the Alzheimer's puzzle. The toxic protein that is the hallmark of Alzheimer's disease blocks the deepest stages of sleep, resulting in memory decline, according to new research

Scientists at the University of California, Berkeley, have found compelling evidence that poor sleep -- particularly a deficit of the deep, restorative slumber needed to hit the save button on memories -- is a channel through which the beta-amyloid protein believed to trigger Alzheimer's disease attacks the brain's long-term memory.

"Our findings reveal a new pathway through which Alzheimer's disease may cause memory decline later in life," said UC Berkeley neuroscience professor Matthew Walker, senior author of the study to be published in the journal Nature Neuroscience.

Excessive deposits of beta-amyloid are key suspects in the pathology of Alzheimer's disease, a virulent form of dementia caused by the gradual death of brain cells. An unprecedented wave of aging baby boomers is expected to make Alzheimer's disease, which has been diagnosed in more than 40 million people, one of the world's fastest-growing and most debilitating public health concerns.

The good news about the findings, Walker said, is that poor sleep is potentially treatable and can be enhanced through exercise, behavioral therapy and even electrical stimulation that amplifies brain waves during sleep, a technology that has been used successfully in young adults to increase their overnight memory.

"This discovery offers hope," he said. "Sleep could be a novel therapeutic target for fighting back against memory impairment in older adults and even those with dementia."

The study was co-led by UC Berkeley neuroscientists Bryce Mander and William Jagust, a leading expert on Alzheimer's disease. The team has received a major National Institutes of Health grant to conduct a longitudinal study to test their hypothesis that sleep is an early warning sign or biomarker of Alzheimer's disease.

While most research in this area has depended on animal subjects, this latest study has the advantage of human subjects recruited by Jagust, a professor with joint appointments at UC Berkeley's Helen Wills Neuroscience Institute, the School of Public Health and the Lawrence Berkeley National Laboratory.

"Over the past few years, the links between sleep, beta-amyloid, memory, and Alzheimer's disease have been growing stronger," Jagust said. "Our study shows that this beta-amyloid deposition may lead to a vicious cycle in which sleep is further disturbed and memory impaired."

Using a powerful combination of brain imaging and other diagnostic tools on 26 older adults who have not been diagnosed with dementia, researchers looked for the link between bad sleep, poor memory and the toxic accumulation of beta-amyloid proteins.

"The data we've collected are very suggestive that there's a causal link," said Mander, lead author of the study and a postdoctoral researcher in the Sleep and Neuroimaging Laboratory directed by Walker. "If we intervene to improve sleep, perhaps we can break that causal chain."

A buildup of beta-amyloid has been found in Alzheimer's patients and, independently, in people reporting sleep disorders. Moreover, a 2013 University of Rochester study found that the brain cells of mice would shrink during non-rapid-eye-movement (non-REM) sleep to make space for cerebrospinal fluids to wash out toxic metabolites such as beta-amyloid.

"Sleep is helping wash away toxic proteins at night, preventing them from building up and from potentially destroying brain cells," Walker said. "It's providing a power cleanse for the brain."

Specifically, the researchers looked at how the quantity of beta-amyloid in the brain's medial frontal lobe impairs deep non-REM sleep, which we need to retain and consolidate fact-based memories.

In a previous study, Mander, Jagust and Walker found that the powerful brain waves generated during non-REM sleep play a key role in transferring memories from the hippocampus -- which supports short-term storage for information -- to longer-term storage in the frontal cortex. In elderly people, deterioration of this frontal region of the brain has been linked to poor-quality sleep.

For this latest study, researchers used positron emission tomography (PET) scans to measure the accumulation of beta-amyloid in the brain; functional Magnetic Resonance Imaging (fMRI) to measure activity in the brain during memory tasks; an electroencephalographic (EEG) machine to measure brain waves during sleep; and statistical models to analyze all the data.

The research was performed on 26 older adults, between the ages of 65 and 81, who showed no existing evidence of dementia or other neurodegenerative, sleep or psychiatric disorders. First, they each received PET scans to measure levels of beta-amyloid in the brain, after which they were tasked with memorizing 120 word pairs, and then tested on how well they remembered a portion of them.

The study participants then slept for eight hours, during which EEG measured their brain waves. The following morning, their brains were scanned using fMRI as they recalled the remaining word pairs. At this point, researchers tracked activity in the hippocampus, where memories are temporarily stored before they are transferred to the prefrontal cortex.

"The more you remember following a good night of sleep, the less you depend on the hippocampus and the more you use the cortex," Walker said. "It's the equivalent of retrieving files from the safe storage site of your computer's hard drive, rather than the temporary storage of a USB stick."

Overall, the results showed that the study participants with the highest levels of beta-amyloid in the medial frontal cortex had the poorest quality of sleep and, consequently, performed worst on the memory test the following morning, with some forgetting more than half of the information they had memorized the previous day.

"The more beta-amyloid you have in certain parts of your brain, the less deep sleep you get and, consequently, the worse your memory," Walker said. "Additionally, the less deep sleep you have, the less effective you are at clearing out this bad protein. It's a vicious cycle.

"But we don't yet know which of these two factors -- the bad sleep or the bad protein -- initially begins this cycle. Which one is the finger that flicks the first domino, triggering the cascade?" Walker added.

And that's what the researchers will determine as they track a new set of older adults over the next five years.

"This is a new pathway linking Alzheimer's disease to memory loss, and it's an important one because we can do something about it," Mander said.
Science Daily/SOURCE :http://www.sciencedaily.com/releases/2015/06/150601122442.htm

How the brain consolidates memory during deep sleep

Using a computational model, study explains how hippocampus influences synaptic connections in cortex

April 14, 2016
Science Daily/University of California - Riverside
How long-term memory is formed is not well understood, and remains a central question of inquiry in neuroscience. Now researchers report they may have an answer to this question
https://images.sciencedaily.com/2016/04/160414214830_1_540x360.jpg
A UC Riverside study explains how the hippocampus influences synaptic connections in the cortex during deep sleep.
Credit: © paylessimages / Fotolia

Neuroscientists at the University of California, Riverside report in the Journal of Neuroscience that they now may have an answer to this question. Their study provides for the first time a mechanistic explanation for how deep sleep (also called slow-wave sleep) may be promoting the consolidation of recent memories.

During sleep, human and animal brains are primarily decoupled from sensory input. Nevertheless, the brain remains highly active, showing electrical activity in the form of sharp-wave ripples in the hippocampus (a small region of the brain that forms part of the limbic system) and large-amplitude slow oscillations in the cortex (the outer layer of the cerebrum), reflecting alternating periods of active and silent states of cortical neurons during deep sleep. Traces of episodic memory acquired during wakefulness and initially stored in the hippocampus are progressively transferred to the cortex as long-term memory during sleep.

Using a computational model, the UC Riverside researchers provide a link between electrical activity in the brain during deep sleep and synaptic connections between neurons. They show that patterns of slow oscillations in the cortex, which their model spontaneously generates, are influenced by the hippocampal sharp-wave ripples and that these patterns of slow oscillations determine synaptic changes in the cortex. (Change in synaptic strength is widely believed to underlie learning and memory storage in the brain.) The model shows that the synaptic changes, in turn, affect the patterns of slow oscillations, promoting a kind of reinforcement and replay of specific firing sequences of the cortical neurons -- representing a replay of specific memory.

"These patterns of slow oscillations remain even without further input from the hippocampus," said Yina Wei, a postdoctoral researcher and the first author of the research paper. "We interpret these results as a mechanistic explanation for the consolidation of specific memories during deep sleep, whereby the memory traces are formed in the cortex and become independent of the hippocampus."

Study results appear in the Journal of Neuroscience.

Wei explained that according to the biologically realistic network model the researchers used, input from the hippocampus reaches the cortex during deep sleep and influences how the slow oscillations are initiated and propagated in the cortical network.

"Input from the hippocampus -- the sharp-wave ripples -- determines the spatial and temporal pattern of these slow oscillations," she said. "By influencing the nature of these oscillations, this hippocampal input activates selective memories during deep sleep and causes a replay of specific memories. During such memory replay, the corresponding synapses are strengthened for long-term storage in the cortex. These results suggest the importance of the hippocampal sharp-wave ripple events in transferring memory information to the cortex."

Normal sleep, during which brain activity remains high, is made up of non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep. NREM and REM sleep alternate in each of the 4-5 cycles during an eight-hour sleep period. Each cycle consists of NREM sleep followed by REM sleep, and roughly lasts 90-110 minutes. NREM sleep has three stages, Stage 3 being deep sleep. Deep sleep, which makes up at least 20 percent of a person's total sleep time, occurs mostly in the first third of the night.

"In our model, even weak and spatially localized input from the hippocampus influenced the spatiotemporal pattern of slow oscillations and led to a persistent change of synaptic efficacy between neurons," Wei said. "Further, our model makes predictions that can be tested experimentally, including specific interventions to suppress or augment memory consolidation processes."
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/04/160414214830.htm

Holistic approach to mealtimes could help dementia sufferers

May 4, 2016
Science Daily/University of East Anglia
Eating together could help people with dementia avoid dehydration and malnutrition, new research shows. Researchers looked at mealtime interventions including changing the color of the plate, increasing exercise, waitress service, playing different types of music, singing, doing tai-chi, and boosting the social aspect of eating. They found that eating family-style meals with care givers, playing music, and engaging with multisensory exercise could boost nutrition, hydration and quality of life.

Findings published reveal that while no interventions were unequivocally successful, promising approaches focused on a holistic approach to mealtimes.

The team found that eating family-style meals with care givers, playing music, and engaging with multisensory exercise -- could all help boost nutrition, hydration and quality of life among people with dementia.

Lead researcher Dr Lee Hooper, from UEA's Norwich Medical School, said: "The risk of dehydration and malnutrition are high in older people, but even higher in those with dementia.

"Malnutrition is associated with poor quality of life so understanding how to help people eat and drink well is very important in supporting health and quality of life for people with dementia.

"We wanted to find out what families or carers can do to help people with dementia eat well and drink enough."

The team systematically reviewed research from around the world and assessed the effectiveness of 56 interventions which all aimed to improve, maintain, or facilitate food or drink intake among more than 2,200 people with dementia.

Interventions tested included changing the colour of the plate, increasing exercise, waitress service, playing different types of music, singing, doing tai-chi, creating a home-like eating environment, providing nutrition supplements, and boosting the social aspect of eating.

They also looked at whether better education and training for formal or informal care-givers could help, as well as behavioural interventions -- such as giving encouragement for eating.

The research team assessed whether these interventions improved hydration status and body weight, and whether the intervention helped older people to enjoy the experience of eating or drinking, and improved their quality of life.

Dr Hooper said: "We found a number of promising interventions -- including eating meals with care-givers, having family-style meals, facilitating social interaction during meals, longer mealtimes, playing soothing mealtime music, doing multisensory exercise and providing constantly accessible snacks.

"Providing education and support for formal and informal care-givers were also promising.

"But one of the problems of this research is that many of the studies we looked at were too small to draw any firm conclusions -- so no interventions should be clearly ruled in or out and more research in this area is needed.

"It is probably not just what people with dementia eat and drink that is important for their nutritional wellbeing and quality of life -- but a holistic mix of where they eat and drink, the atmosphere, physical and social support offered, the understanding of formal care-givers, and levels of physical activity enjoyed."
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/05/160504121808.htm