The brain’s ability to learn and form memories of day-to-day facts and events depends on the hippocampus, a structure deep within the brain. But is the hippocampus still maintaining the memory of, say, the commencement address at your college graduation 20 years ago? The latest evidence suggests that as memories age, the hippocampus’s participation wanes.

In a 2006 study, neuroscientist Larry R. Squire of the University of California, San Diego, and the Veterans Affairs San Diego Healthcare System studied patients who had hippocampal damage. These indi­viduals did not remember details of newsworthy events that occurred in the five to 10 years prior to their injuries, but they did recall older events.

Building on those results, Squire turned to healthy brains. His team questioned 15 people in their 50s and 60s about events in the news over the past 30 years while scanning the participants’ brains with functional MRI. To single out brain activity related to the date of the event, the researchers separately evaluated activity tied to learning and remem­bering the test questions. They also accounted for the richness of participants’ recollections of events, to make sure the degree to which someone was able to recall an event did not influence the data.

Squire’s team reported in January that activity in the hippocampus steadily declined as subjects remembered events that were up to 12 years old. With more remote memories, the structure’s activity leveled off. In contrast, areas in the frontal, temporal and parietal lobes displayed increasing activity for recalled events from those dozen years, then reached a plateau during older remembrances.

The biology behind how the brain makes and keeps memories is not fully understood, Squire notes, but it appears that, initially, a memory resides in the hippocampus and in areas the structure connects to in the neocortex, the outer part of the cerebral cortex. “A time comes when the cortical regions important to a memory are connected [to one another] heavily enough to form a stable representation,” Squire says. “Then the hippocampus isn’t needed to hold the whole thing together.”

Original article here

Myfitbrain brain games

ScienceDaily (Aug. 27, 2009) — Researchers at MIT’s Picower Institute for Learning and Memory have found that rats use a mental instant replay of their actions to help them decide what to do next, shedding new light on how animals and humans learn and remember.

“By understanding how thoughts and memories are structured, we can gain insight into how they might be disrupted in diseases and disorders of memory and thought such as Alzheimer’s and schizophrenia,” said study author Matthew A. Wilson, the Sherman Fairchild Professor of Neuroscience at the Picower Institute. “This understanding may lead to new methods of diagnosis and treatment.”

Wilson’s laboratory explores how rats form and recall memories by recording — with an unprecedented level of accuracy — the activity of single neurons in the hippocampus while the animal is performing tasks, pausing between actions and sleeping. The hippocampus is the seahorse-shaped brain region researchers believe to be critical for learning and memory.

Wilson’s previous work has shown that after the animals run a maze, their brains “replay” during sleep the sequence of events they experienced while awake. Researchers believe this process is key to sleep-reinforced memory consolidation in both animals and humans.

The latest study shows that these sequences also occur when the animals are awake and may help them decide what to do next.

Not-so-instant replay

When a rat moves through a maze, certain neurons called “place cells,” which respond to the animal’s physical environment, fire in patterns and sequences unique to different locations. By looking at the patterns of firing cells, researchers can tell which part of the maze the animal is running.

While the rat is awake but standing still in the maze, its neurons fire in the same pattern of activity that occurred while it was running. The mental replay of sequences of the animals’ experience occurs in both forward and reverse time order.

“This may be the rat equivalent of ‘thinking,’” Wilson said. “This thinking process looks very much like the reactivation of memory that we see during non-REM dream states, consisting of bursts of time-compressed memory sequences lasting a fraction of a second.

“So, thinking and dreaming may share the same memory reactivation mechanisms,” he said.

Memory’s building blocks

“This study brings together concepts related to thought, memory and dreams that all potentially arise from a unified mechanism rooted in the hippocampus,” said co-author Fabian Kloosterman, senior postdoctoral associate.

The team’s results show that long experiences, which in reality could have taken tens of seconds or minutes, are replayed in only a fraction of a second. To do this, the brain links together smaller pieces to construct the memory of the long experience.

The researchers speculated that this strategy could help different areas of the brain share information — and deal with multiple memories that may share content — in a flexible and efficient way. “These results suggest that extended replay is composed of chains of shorter subsequences, which may reflect a strategy for the storage and flexible expression of memories of prolonged experience,” Wilson said.

Moreover, by comparing the content of the replay with the rat’s physical location on the track and his actual behavior immediately before and after the replay event the researchers could tell the rat was not just thinking about his most recent experience but also about other options, such as: “What if I turned around and went back the way I came?” or “How would I get here if my starting point is at a distant location?”

This suggests that the same brain mechanisms come into play to remember the past and consider future actions, reinforcing recent work by neuroscientists outside of MIT who determined that in humans, cognitive processes related to episodic recall and evaluation of future events overlap to a high degree.

Memory formation and future planning are among the cognitive functions ravaged by diseases such as Alzheimer’s disease, schizophrenia and psychosis.

“A better understanding of how we use memories, not only to learn from past experiences but also to explore our future options, can give us insights into how the system fails under these disease conditions,” Kloosterman said.

The MIT researchers plan to further explore the link between awake replay and cognition in animals engaged in more cognitively demanding tasks such as those involving multiple choices, where the rat has to make a decision (”do I go left or right?”) based on a prior learned rule.

In addition to Wilson, the study was led jointly by Kloosterman and MIT brain and cognitive sciences graduate student Thomas J. Davidson.

This research was supported by National Institutes of Health (NIH).

Original article here.

Animal studies conducted at the National Institute on Aging Gerontology Research Center and the Johns Hopkins University School of Medicine, for example, have shown that both calorie restriction and intermittent fasting along with vitamin and mineral intake, increase resistance to disease, extend lifespan, and stimulate production of neurons from stem cells.

In addition,
fasting has been shown to enhance synaptic elasticity, possibly increasing the ability for successful re-wiring following brain injury. These benefits appear to result from a cellular stress response, similar in concept to the greater muscular regeneration that results from the stress of regular exercise.

Additional research suggests that increasing time intervals between meals might be a better choice than chronic calorie restriction, because the resultant decline in sex hormones may adversely affect both sexual and brain performance. Sex steroid hormones testosterone and estrogen are positively impacted by an abundant food supply. In other words, you might get smarter that way, but it might adversely affect your fun in the bedroom, among other drawbacks.

But if your not keen on starving yourself, there are other options. Another recent finding, stemming from the Burnham Institute for Medical Research and Iwate University in Japan, reports that the herb rosemary contains an ingredient that fights off free radical damage in the brain. The active ingredient, known as carnosic acid (CA), can protect the brain from stroke and neurodegeneration such as Alzheimer’s and from the effects of normal aging.

Although researchers are patenting more potent forms of isolated compounds in this herb, unlike most new drugs, simply using the rosemary in its natural state may be the most safe and clinically tolerated because it is known to get into the brain and has been consumed by people for over a thousand years. The herb was used in European folk medicine to help the nervous system.

Another brain booster that Bruce N. Ames, Ph.D., a professor of biochemistry and molecular biology at the University of California, Berkeley, swears by his daily 800 mg of alpha-lipoic acid and 2,000 mg of acetyl-L-carnitine, chemicals which boost the energy output of mitochondria that power our cells. Mitochondrial decay is a major factor in aging and diseases such as Alzheimer’s and diabetes. Elderly rats on these supplements had more energy and ran mazes better.

Omega-3s fatty acids DHA and EPA found in walnuts and fatty fish (such as salmon, sardines, and lake trout) are thought to help ward off Alzheimer’s disease. (In addition, they likely help prevent depression and have been shown to help prevent sudden death from heart attack).

Turmeric, typically found in curry, contains curcumin, a chemical with potent antioxidant and anti-inflammatory properties. In India, it is even used as a salve to help heal wounds. East Asians also eat it, which might explain their lower rates (compared to the United States) of Parkinson’s disease and Alzheimer’s disease, in addition to various cancers. If curry isn’t part of your favorite cuisines, you might try a daily curcumin supplement of 500 to 1,000 mg.

Physical exercise may also have beneficial effects on neuron regeneration by stimulating regeneration of brain and muscle cells via activation of stress proteins and the production of growth factors. But again, additional research suggests that not all exercise is equal. Interestingly, some researchers found that exercise considered drudgery was not beneficial in neuronal regeneration, but physical activity that was engaged in purely for fun, even if equal time was spent and equal calories were burned, resulted in neuronal regeneration.

Exercise can also help reduce stress, but any stress-reducing activity, such as meditation and lifestyle changes, can help the brain. There is some evidence that chronic stress shrinks the parts of the brain involved in learning, memory, and mood. (It also delays wound healing, promotes atherosclerosis, and increases blood pressure.)

It should go without saying that short-term cognitive and physical performance is not boosted by
fasting, due to metabolic changes including decrease in body temperature, decreased heart rate and blood pressure and decreased glucose and insulin levels, so you’re better off not planning a marathon or a demanding work session during a
fasting period.

As part of a healthy lifestyle the prescription of moderating food intake, exercising, and eating anti-oxidant rich foods is what we’ve long known will boost longevity, but it’s good to know that we can bring our brains along with us as we make it into those golden years without being the 1 in 7 who suffers from dementia. Keep your fingers crossed and eat some rosemary chicken.

Professor Elizabeth Gould received the  prestigious Benjamin Franklin from the RSA organization for her groundbreaking work on neurogenesis. Her research into the effect of environments on the neuronal composition of the brain has profound and far-reaching societal implications.

Good video on how neurogenesis works in the hippocampus and why working out your brain helps it to improve for the long run.  Also how anxiety can inhibit neurogenesis which inhibits your ability to learn.

Alzheimer’s disease (AD) is a neurodegenerative disorder that currently affects nearly 5% of people 65-year old and over 30% of those 85-year old. It is now estimated that there are 18−24 million people suffering from AD worldwide, two-thirds of whom are living in developed or developing countries, and this number is expected to reach 34 million by 2025. AD is characterized by the progressive accumulation of amyloid beta peptide (Aβ), neurofibrillary tangles (NFTs) and hyperphosphorylated microtubule-associated tau protein. Many regions involved in memory and learning processes, such as the hippocampus and frontal cortex, show neuron apoptosis several years before clinical signs appear. Today there is no cure for this devastating disease and therefore it is of great interest for researchers to find new drugs that can hinder the disease process.  Current drugs on the market improve the function of still intact neurons, but do not inhibit the ongoing degenerative process leading to neuronal cell death. Curcumin, a biologically active component of turmeric (Curcuma longa) is used as a curry spice and herbal medicine for the treatment of inflammatory conditions, cancer, AIDS and other diseases. Epidemical studies in India, where turmeric is used routinely, show that the incidence of AD between the ages of 70 and 79 years is 4.4-fold less than in the USA.  Results on mice show that a low dose of curcumin significantly suppressed the inflammation, reduced oxidative damage and plaque burden and decreased the amount of insoluble amyloid. Compared to other antioxidant drugs, such as NSAID or ibuprofen, curcumin had fewer side effects. Evidence suggests that metals are concentrated in the AD brain and curcumin is a chelator which can bind the iron and copper (but not zinc) on beta amyloid, which may be one mechanism potentially contributing to amyloid reduction. In vivo, curcumin may protect cells from the beta amyloid attack and subsequent oxidative stress-induced damage in the antioxidant pathway. The findings of a previous study prove curcumin can induce cognitive improvement by enhancing the cholinergic system and its antioxidant activity. The studies on curcumin are incomplete and there needs to be further investigation of its neuroprotective mechanism.

See the research study here

The anti-inflammatory drug indomethacin could hold promise as a treatment for Alzheimer’s disease, says a Saint Louis University doctor and researcher.

Two research studies published by William A. Banks, M.D., professor of geriatrics and pharmacological and physiological science at Saint Louis University School of Medicine, support this conclusion and offer what he calls a “one-two punch” in giving clues on how Alzheimer’s disease develops and could be treated.

His study in the July edition of the Journal of Alzheimer’s Disease supports the idea that toxic levels of amyloid beta protein, the substance scientists believe is responsible for Alzheimer’s disease, accumulate in the brain because a pump that pushes it into the blood and past the blood-brain barrier malfunctions.

The blood-brain barrier is a system of cells that regulates the exchange of substances between the brain and the blood. The blood-brain barrier transporter known as LRP is the pump that removes amyloid beta protein from the brain and into the bloodstream.

“LRP malfunctions like a stop light stuck on red, and keeps amyloid beta protein trapped in the brain,” said Banks, who also is a staff physician at Veterans Affairs Medical Center in St. Louis.

Read rest of the article here

If you are over 25, your brain is atrophying unless you are pushing it to its max.  Read this article to see several ways to keep your brain optimized.

We spend hours at the gym, eat right and go for our annual physicals and eye exams. But the most important organ in our bodies is often the most neglected, says cognitive fitness expert Rebecca Shafir.

Keeping the brain fit, she says, is critical for people’s long-term health.

“You have to use it or loose it,” Shafir, author of “The Zen of Listening,” says of the brain. “As brains age, there is atrophy just like muscles and it slows as it becomes more dormant.”

Shafir, a speech and language pathologist and neurotherapist at Harborside Counseling Services in Newburyport, provides brain fitness training for baby boomers over 50 and seniors who want to preserve and advance their cognitive skills. She also works with adolescents and adults with attention deficit disorder, head injury and stroke.

While physical activity is a good thing, Shafir says, brain exercises are important as well. By practicing a few simple exercises each day, she says people can stave off some of the effects of brain aging, improve their memory and be able to recall items more quickly and precisely.