Tag Archives: old age

Credit: Boston University.

Zapping the brain with electricity reverses memory loss in the elderly

Credit: Boston University.

Credit: Boston University.

It’s normal to perform worse on cognitive tasks or remember things poorly once you reach a certain age. But scientists claim that technology can reverse some aspects of normal aging. Using a technique called transcranial stimulation, which essentially involves zapping the brain with electricity, researchers were able to induce memory improvements in elderly participants. According to the study, the improvements rapidly restored the participants’ brains to a “youthful state”.

“Age-related changes are not unchangeable”

The new study comes from Boston University where researchers first tested 42 young and 42 older individuals (aged 60 to 76 years) on a series of memory tasks. The younger subjects performed better, as expected. Later, the participants were fitted with an electrode-covered cap which non-invasively stimulated two areas of the brain with electricity for 25 minutes. The stimulated areas were the temporal and frontotemporal cortex, which are involved in processing sensory input into derived meanings and ‘higher’ brain functions, respectively.

Schematic showing the stimulated brain regions. Credit: Boston University.

Schematic showing the stimulated brain regions. Credit: Boston University.

The electric current was fired in such a way as to sync the brain waves of the two regions. When the participants were tested again, the elderly participants who had undergone transcranial stimulation performed just as well as 20-year-olds. This effect lasted for at least 50 minutes, when the measurements were ceased. Younger adults who had lower performance scores in the tests also saw improvements following the stimulation.

“Age-related changes are not unchangeable,” lead author Robert Reinhart from Boston University told The Guardian.

“We can bring back the superior working memory function that you had when you were much younger.”

Writing in the journal Nature Neuroscience, the researchers hypothesize that the synchronization of the brain waves, called phase-amplitude coupling (PAC), improves working memory. Reinhart says that brain wave rhythms originating from different areas of the brain resemble an orchestra composed of flutes, violins, and other musical instruments. Just like when a conductor fumbles causing the music to fall out of sync, sometimes brain wave rhythm can be disrupted causing memories to lose their sharpness. The stimulation organizes the melodies within the brain.

 “It’s behaviorally relevant. Now, [people are] performing tasks differently, they’re remembering things better, they’re perceiving better, they’re learning faster. It is really extraordinary,” Reinhart said in a statement.

“It’s opening up a whole new avenue of potential research and treatment options,” he says, “and we’re super excited about it.”

More research is required to establish how long these positive effects can last, as well as any long-term side effects.

Old couple.

Humor and acceptance oust conflict and bickering in long-time marriages

Years of marriage puts bickering to rest and fosters humor and acceptance instead, new research reveals.

Old couple.

Image credits Ellen / Pixabay.

You may think all those old couples hang on through the sheer spite they’ve cultivated across decades of marriage, but you’d be very wrong. A study from the University of California, Berkeley, shows that couples in long marriages bicker less, laugh more, and embrace acceptance.

Long-time pair, don’t care

The team worked with 87 middle-aged (and older) couples, who had been married between 15 to 35 years at the date of the study. The participants — mostly in their 70s, 80s, and 90s today — are heterosexual couples from the San Francisco Bay Area. The team started tracking their relationships in 1989 and used videotape recordings of their conversations (taken over the course of 13 years) to analyze the emotional undertone of their conversation. The 15-minute-long snippets of interactions were recorded in a laboratory setting as the spouses discussed shared experiences and areas of conflict. As each couple recorded these on a nearly-early basis so the team could track emotional changes in their interactions over time.

Each spouse’s listening and speaking behavior was coded and rated — this process was based on parameters such as their facial expressions, body language, verbal content and tone of voice. “Coded” essentially means that the team labeled each emotion as an expression of anger, contempt, disgust, domineering behavior, defensiveness, fear, tension, sadness, whining, interest, affection, humor, enthusiasm, or validation.

As the couples aged, the team reports, they showed more humor and tenderness towards one another. The team also reports an increase in positive behaviors — such as humor and affection — and a decrease in negative ones — such as defensiveness and criticism.

“Our findings shed light on one of the great paradoxes of late life,” said study senior author Robert Levenson, a UC Berkeley psychology professor. “Despite experiencing the loss of friends and family, older people in stable marriages are relatively happy and experience low rates of depression and anxiety. Marriage has been good for their mental health.”

The team also found that wives are generally more emotionally expressive than their husbands and tended toward more domineering behavior and less affection. However, across all the study’s age and gender cohorts, negative behaviors decreased with age. The study is consistent with previous findings at Levenson’s Berkeley Psychophysiology lab, the team adds.

“Given the links between positive emotion and health, these findings underscore the importance of intimate relationships as people age, and the potential health benefits associated with marriage,” said co-lead author Alice Verstaen, who conducted the study as a Ph.D. student at UC Berkeley and is currently a postdoctoral fellow at the VA Puget Sound Health Care System.

Researchers further found that both middle-aged and older couples, regardless of their satisfaction with their relationship, experienced increases in overall positive emotional behaviors with age, while experiencing a decrease in overall negative emotional behaviors. I find these results quite uplifting. Instead of the slow erosion of emotion most people expect to see in a long-term marriage, the findings point to things getting better and better instead. in Verstaen’s words,

“These results provide behavioral evidence that is consistent with research suggesting that, as we age, we become more focused on the positives in our lives.”

The paper “Age-related changes in emotional behavior: Evidence from a 13-year longitudinal study of long-term married couples,” has been published in the journal Emotion.

brain

Humans as old as 79 still generate new neurons, stirring new debate

A new study seems to suggest that humans are capable of growing new neurons well into old age, contradicting previous research that found neurogenesis stops altogether after childhood.

brain

Credit: Pixabay.

The team at the Columbia University in New York carefully scrutinized the autopsied brain samples sourced from 28 individuals who had died abruptly at ages 14-79. Researchers zoomed in on the hippocampus, which is the seat of learning and memory formation in the brain, looking for newly formed neurons and the state of blood vessels.

Surprisingly, the researchers found that older people had a similar ability to make thousands of new neurons in the hippocampus, from progenitor cells (stem cells), as younger people had. The idea that both young and old humans alike produce new neurons was reinforced by the fact that the hippocampus had equivalent volumes across all ages.

To identify neurogenesis, the researchers had to look for specific clues like proteins produced by neurons at particular stages of their development. For instance, proteins like GFAP and SOX2 are released by stem cells when these turn into neurons, while proteins like Ki-67 are generated by the development of newborn neurons. Across all ages, the researchers found proteins linked with newborn neurons in the dentate gyrus, which is an area of the hippocampus where neurons are born.

The number of neural stem cells was a bit lower in people in their 70s compared to individuals in their 20s. However, the older brains still possessed thousands of these cells and the number of neurons in an intermediate to an advanced stage of development was found to be the same across all age groups.

In today’s context of an aging populace, the findings are particularly important with the threat of widespread dementia looming. The findings suggest that the elderly may retain more of their cognitive and emotional abilities longer into old age than previously thought possible.

Dots represent new nerve cells. Roughly the same number of dots exist in the hippocampus of both people in their 20s (top) and in their 70s (bottom). Credit: Columbia University.

Dots represent new nerve cells. Roughly the same number of dots exist in the hippocampus of both people in their 20s (top) and in their 70s (bottom). Credit: Columbia University.

Maura Boldrini, associate professor of neurobiology at Columbia University and lead author of the new study, cautions, however, that the newly formed neurons in old age may be less capable of forming new connections, partly due to aging blood vessels.

However, it was only last month that a study performed at the University of California in San Francisco came to the opposite conclusion. After analyzing brain samples from 59 adults and children, the researchers wrote: “we found no evidence of young neurons or the dividing progenitors of new neurons” in the hippocampi of people older than 18. They found some evidence of new neural growth in children younger than one year and some signs of this happening in children aged 7 to 13. This study, which some have called ‘sobering’, suggested that the very vast majority of the human hippocampus is generated during fetal development.

Referring to the new findings, Arturo Alvarez-Buylla, who is a researcher at the University of California in San Francisco, said that “the cells they [scientists at Columbia] call new neurons in the adult hippocampus are very different in shape and appearance from what would be considered a young neuron in other species, or what we have observed in humans in young children.”

Hopefully, more research will shed light on the matter. Neither of the two studies has the last word — but this is a good debate to be had.

Scientific reference: Cell Stem Cell, Boldrini et al.: “Human Hippocampal Neurogenesis Persists Throughout Aging” http://www.cell.com/cell-stem-cell/fulltext/S1934-5909(18)30121-8 , DOI: 10.1016/j.stem.2018.03.015.

 

 

Credit: Pixabay.

Stopping muscle atrophy at old age could be possible

Old age inevitably comes with dysfunction and deterioration of the muscle and the fat tissues. Some people over 60, however, are frailer than others. Now, researchers at Manchester Metropolitan University have found exactly how old age makes people experience muscle loss, providing hope that there might be a way to reverse the condition in the future.

Credit: Pixabay.

Credit: Pixabay.

Jamie McPhee, a Professor of musculoskeletal physiology at Manchester Metropolitan University, and his colleagues learned that muscle atrophy follows changes in the nervous system. The typical 75-year-old has 30 to 50 fewer nerves controlling their legs, for instance. Because parts of these muscles are now disconnected from the nervous system, they are functionally useless and naturally wither away.

However, there would be even more atrophied muscles were it not for an internal protection mechanism that our bodies employ. Essentially, intact nerves can branch out to connect some, but not all, of the detached muscle fibers. This mechanism is the most successful in elderly individuals that have large, healthy muscles. On the flipside, when this mechanism is not working very well, excessive muscle loss follows. In some cases, the researchers found that some very old muscles only had a few dozen nerves left, where young and healthy adults have hundreds.

Researchers first measured muscle mass in 200 men with MRI — that was the easy part. However, what proved challenging was finding the right technique that enabled the researchers to separate muscles into their constituent smaller segments, known as “motor units”. Each such unit as a single motor nerve connects hundreds of individual muscle fibers. They eventually settled for enhanced electromyography, which enabled the researchers to record the electrical activity passing through the muscle to estimate the numbers and the size of surviving nerves. The team collaborated with colleagues at the University of Waterloo, Ontario, and The University of Manchester, UK.

“Using this technique we observed that the numbers of nerves controlling leg muscles declines markedly with aging and precedes the loss of muscle mass. This was a curious finding because the loss of nerves preceded loss of muscle mass, but also because ‘wasted’ (or, sarcopenic) older muscle and ‘healthy’ older muscle had both lost very significant numbers of nerves,” McPhee told ZME Science.

“We found that the motor units of ‘healthy’ older muscles had increased in size, suggesting the surviving nerves send out new branches to reconnect parts of the muscle that are disconnected as nerves decline. However, this ‘protective’ mechanism was not so successful in the wasted older muscles, hence the muscles decreased in size,” McPhee added, who is the senior author of the new paper published in the  Journal of Physiology.

As nerve connection dies to old age, muscle begins to wither away. Credit: Piasecki et al.

As nerve connection dies to old age, muscle begins to wither away. Credit: Piasecki et al.

Now, McPhee and colleagues plan on investigating the factors that lead to successful nerve branching that rescues detached muscle fibers. “It might have something to do with lifestyle or presence of underlying diseases, we cannot yet be sure,” McPhee told me.

An estimated 10-20% of individuals over 65 suffer from sarcopenia — the degenerative loss of skeletal muscle mass quality and strength associated with aging. This condition significantly increases the risk of falling, bone fracture, disability, and hospital admission. If we could reverse even some degree of muscle loss, then millions of our elderly could live better lives.

“Our research highlights two potentially modifiable features of muscle aging: the loss of nerves per se, and the re-connection of parts of the muscle disconnected as a consequence of nerves being lost.  They may be targeted together, or separately. The former is preferable because it would keep intact all the original connections, however, the latter is a good second best if we can make it work,” McPhee said.

In the meantime, the researchers say eating healthily and staying in good shape are our best allies in the fight against the degenerative effects of old age.

“It is apparent to us that muscle mass and function will inevitably decline in older age and it is linked to deterioration of the nervous system. Until we discover the causes and develop interventions, the best thing people can do is to maintain regular physical activity and healthy eating. This will keep body mass (fat mass) at healthy low levels so that the remaining muscles are more easily able to move the body around during everyday activities,” McPhee recommends.

Shown here are two aged rats. The one in the back received a peptide treatment which destroys senescent cells while the one in the front didn't. The latter mouse is in poor health as evidenced by the missing fur. Credit: Peter de Keizer

Drug reverses aging in mice. The rodents saw increased stamina, better organ function, and restored fur

Dutch researchers from the Erasmus University Medical Center boast promising results with a new drug meant to reverse the effects of aging.Tests performed on mice suggests the drug is effective at restoring stamina, coat of fur, and even some organ function.

Shown here are two aged rats. The one in the back received a peptide treatment which destroys senescent cells while the one in the front didn't. The latter mouse is in poor health as evidenced by the missing fur. Credit: Peter de Keizer

Shown here are two aged rats. The one in the back received a peptide treatment which destroys senescent cells while the one in the front didn’t. The latter mouse is in poor health as evidenced by the missing fur. Credit: Peter de Keizer

As we age, some cells begin to change their internal structure and ability to keep homeostasis. One component of aging is the damage caused by senescent cells, which are cells which have stopped dividing but which have not destroyed themselves as they should have following programmed cell death. Senescent cells secrete abnormally large amounts of some proteins that are harmful to their neighbours, stimulating excessive growth and degrading normal tissue architecture. These cells have also been associated with cancer and release chemicals that cause inflammation.

What the drug does is it effectively flushes out senescent cells out of the body by disrupting the chemical balance within them. The team led by Dr Peter de Keizer had previously made three fail attempts but were lucky the fourth time around, they report in the journal Cell.

The drug was injected into mice which were genetically modified to age very rapidly as well as in mice that were artificially aged through chemotherapy. Their equivalent age in human years was 90 and the drug was administered three times a week for nearly a year. At the end of the experiments, the rejuvenating effect of the therapy was clear. Age-related loss of fur, poor kidney function, and frailty became reversed.There were no apparent side effects, but that doesn’t mean they’re totally absent. “Mice don’t talk,” Keizer said which is why his team is planning human trials.

The drug itself is a peptide which took nearly four years of trial and error to reach its final form. It works by blocking the ability of a protein implicated in senescence, FOXO4, to tell another protein, p53, not to cause the cell to self-destruct. By interfering with this cross-talk, the senescent cells essentially perform suicide. “Only in senescent cells does this peptide cause cell death,” Kaizer said.

Improvements showed at different times over the course of the treatment. Aged mice that presented patches of missing fur began to grow their coats back after ten days. Fitness levels started to improve after three weeks as tests showed older mice could run twice as far as their counterparts who did not receive the treatment. A month later, the old mice showed improvements in healthy kidney function.

Senescent cells have some beneficial roles in the body. Killing off too many of these cells can trigger cascading complications that can lead to tumour formation. Senescent cells also foster wound healing. With this in mind, a similar treatment meant for humans has to be very well refined else the therapy could end up doing more harm than good. So, it seems very likely that a ‘magic’ age-reversal pill bought over the counter is decades away but it’s exciting to hear about all of these developments now.

Credit: Wikimedia Commons

Grumpy old monkeys are more picky with who they call friends, just like humans

Credit: Wikimedia Commons

Credit: Wikimedia Commons

Though they’re separated by 25 million years of evolution, monkeys and humans share at least one common fact of life: both choose to have a less engaged social life at old age.

The conclusion was made by researchers at the German Primate Center in Goettingen, Germany, who followed a group of Barbary macaques at a French wildlife park. The monkeys varied from age 4 to age 29 (that’s equivalent to age 105 in humans).

During the course of several weeks, the team recorded how the monkeys interacted with objects like novel toys baited with food, how often they groomed friends or fought and how they responded to social cues like photos and haul recordings from friends or strangers.

As the monkeys aged past their childhoods and began lives as adults — essentially when they reached sexual maturity — their interest in toys waned. The pensioner monkeys, or those older than 20, had the fewest “friends” and engaged in social contact rarely, akin to how our elderly prefer to stick to themselves and the few ‘true’ friendships they have left.

It’s important to note that while the old monkeys got quite grumpy with old age, they still were very much aware of their surroundings. They responded to photos and audio recordings of other monkeys and hissed during fights. And while they groomed other monkeys far less frequently, the elderly were often groomed by younger monkeys.

Psychologists say that humans become more choosy with how they decided to spend their time once with old age. When you realize you have little time to spend, you choose to use that time more wisely. You visit the same restaurant and are less inclined to engage socially with mere acquaintances. But a monkey, we suspect, is not aware of its own mortality. Yet, the pattern of similarities between old monkeys and humans is striking.

Dr.  Julia Fischer, one of the lead authors of the study, says we might just be rationalizing an inherent biological construct. Both monkeys and humans might simply have too little energy left once they hit their golden years, and thus unable to reserve resources for new relationships. There’s also a tendency to become more risk adverse with old age, which might also explain social withdrawal.

“Our behaviors that seem very much the result of our deliberation and choice,” said Dr. Freund, “might be more similar to our primate ancestors than we might think.”

mouse age reversal

Old organ regenerated to youthful state in elderly mice using gene manipulation

mouse age reversal

Photo: guardian

The popular myth of the fountain of youth tells the story of a magical spring that restores youth to anyone who drinks from it. Scientists working with longevity research have made important strides forward in recent years, however all of these efforts concentrate on prolonging life and slowing the effects old age has on the body, not reversing them. A breakthrough by researchers at University of Edinburgh may cause a paradigm shift in regenerative medicine after an old organ in elderly mice was regenerated into a youthful state, simply by manipulating a single gene.

The thymus is a specialized organ in the immune system. The functions of the thymus are the “schooling” of T-lymphocytes (T cells), which are critical cells of the adaptive immune system, and the production and secretion of thymosins, hormones which control T-lymphocyte activities and various other aspects of the immune system.

With old age, however, the thymus becomes progressively smaller making the body more vulnerable to infections and diseases. In fact, by the age of 70 the thymus is just a tenth of the size in adolescence. So, the team at the MRC Centre for Regenerative Medicine at the University of Edinburgh thought of a way to regenerate the thymus.

Rejuvenating elderly mice

Previous research showed that a gene, called Foxn1, naturally gets shut down as the thymus ages, so the Edinburgh researchers concentrated on boosting the gene back to youthful levels. A drug that targets this protein and instructs stem cell-like cells to rebuild the organ was made and given to elderly mice. The results were striking: just by manipulating this single gene, the thymus in elderly mice increased in size and made more T-cells. It almost completely regenerated.

“Our results suggest that targeting the same pathway in humans may improve thymus function and therefore boost immunity in elderly patients, or those with a suppressed immune system. However, before we test this in humans we need to carry out more work to make sure the process can be tightly controlled,” said Clare Blackburn, Professor of Tissue Stem Cell Biology, MRC Centre for Regenerative Medicine.

It’s not clear why the thymus shrinks with age, but one theory says it’s because more energy is diverted towards reproduction once entering adolescence. As such, if human trials are to begin, there needs to be a tightly controlled setting to ensure no negative side-effects are encountered. The discovery could also offer hope to patients with DiGeorge syndrome, a genetic condition that causes the thymus to not develop properly.

“One of the key goals in regenerative medicine is harnessing the body’s own repair mechanisms and manipulating these in a controlled way to treat disease. This interesting study suggests that organ regeneration in a mammal can be directed by manipulation of a single protein, which is likely to have broad implications for other areas of regenerative biology,” said Dr Rob Buckle, Head of Regenerative Medicine, Medical Research Council.

But what about other organs? The heart, lungs, liver, maybe there’s a way to regenerate these by gene manipulation as easily as it was for the thymus. The full paper can be read here.

Also worth noting is a different path that leads to the same destination – reactivating the enzyme telomerase, which repairs damaged tissue and reverses signs of aging, as shown by studies on mice at the Dana-Farber Cancer Institute, Harvard Medical School. A synergy between the two methods may propel medicine into a new age.