Nature Knows - Natural Nootropics

Double-strand DNA breaks, which occur when the phosphate backbones of both DNA strands are hydrolyzed, are considered the most significant DNA damage and have been shown to increase the risk of cancer and other deadly diseases.

So, it’s surprising enough that previous research has shown the brain actually causes double-strand breaks (DSBs) when it is trying to create a fear-based memory. What’s even more shocking—and concerning—is the extent of these DSBs in multiple key brain regions, according to a new study by Li-Huei Tsai, professor of neuroscience at MIT and director of The Picower Institute for Learning and Memory.

In a new paper published in PLOS One , Tsai and colleagues show that while the breaks are routinely repaired, the process may become more flawed and fragile with age.

“We wanted to understand exactly how widespread and extensive this natural activity is in the brain upon memory formation because that can give us insight into how genomic instability could undermine brain health down the road,” said Tsai. “Clearly memory formation is an urgent priority for healthy brain function but these new results showing that several types of brain cells break their DNA in so many places to quickly express genes is striking.”

In the most recent study, researchers in Tsai’s lab gave mice low-power electrical zaps to the feet when they entered a box to condition a fear memory. Then, the team used several methods to assess DSBs and gene expression in the brains of said mice.

Compared with control mice, the creation of a fear memory in those who were zapped doubled the number of DSBs among neurons in the hippocampus and the prefrontal cortex, affecting more than 300 genes in each region—two brain regions known to form and store fear memories. Among the 206 affected genes common to both regions, many of the genes were associated with synapses.

“Many genes essential for neuronal function and memory formation, and significantly more of them than expected based on previous observations in cultured neurons are potentially hotspots of DSB formation,” the authors explain in the study.

Through RNA measurements, the researchers also demonstrated that an increase in DSBs correlated with increased transcription and expression of affected genes—including ones affecting synapse function—as quickly as 10 to 30 minutes after the foot shock exposure.

Surprisingly, the researchers also recorded gene expression changes in glia, or non-neuronal brain cells in the central nervous system. In glia, many of the DSBs that occurred following fear conditioning occurred at genomic sites related to the specific stress hormone glutocortocoid. Further tests revealed that directly stimulating glutocortocoid receptors could trigger the same DSBs that fear conditioning did. Moreover, blocking the receptors could prevent transcription of key genes after fear conditioning.

“The ability of glia to mount a robust transcriptional response to glutocorticoids suggest that glia may have a much larger role to play in the response to stress and its impact on the brain during learning than previously appreciated,” writes Tsai and her co-authors.

The scientists say more research will have to be done to prove that the DSBs required for forming and storing fear memories are a threat to later brain health, but their new study certainly adds evidence linking lingering DSBs with neurodegeneration and cognitive decline.

Read more at www.laboratoryequipment.com

The urgency to remember a dangerous experience requires the brain to make a series of potentially dangerous moves: Neurons and other brain cells snap open their DNA in numerous locations—more than previously realized, according to a new study—to provide quick access to genetic instructions for the mechanisms of memory storage.

The extent of these DNA double-strand breaks (DSBs) in multiple key brain regions is surprising and concerning, said study senior author Li-Huei Tsai, Picower Professor of Neuroscience at MIT and director of The Picower Institute for Learning and Memory, because while the breaks are routinely repaired, that process may become more flawed and fragile with age. Tsai’s lab has shown that lingering DSBs are associated with neurodegeneration and cognitive decline and that repair mechanisms can falter.

“We wanted to understand exactly how widespread and extensive this natural activity is in the brain upon memory formation because that can give us insight into how genomic instability could undermine brain health down the road,” said Tsai, who is also a professor in the Department of Brain and Cognitive Sciences and a leader of MIT’s Aging Brain Initiative. “Clearly memory formation is an urgent priority for healthy brain function but these new results showing that several types of brain cells break their DNA in so many places to quickly express genes is still striking.” Tracking breaks

In 2015, Tsai’s lab provided the first demonstration that neuronal activity caused DSBs and that they induced rapid gene expression. But those findings, mostly made in lab preparations of neurons, did not capture the full extent of the activity in the context of memory formation in a behaving animal and did not investigate what happened in cells other than neurons.

IIn the new study published July 1 in PLOS ONE, lead author and former graduate student Ryan Stott and co-author and former research technician Oleg Kritsky sought to investigate the full landscape of DSB activity in learning and memory. To do so, they gave mice little electrical zaps to the feet when they entered a box, to condition a fear memory of that context. They then used several methods to assess DSBs and gene expression in the brains of the mice over the next half hour, particularly among a variety of cell types in the prefrontal cortex and hippocampus, two regions essential for the formation and storage of conditioned fear memories. They also made measurements in the brains of mice who did not experience the foot shock to establish a baseline of activity for comparison.

The creation of a fear memory doubled the number of DSBs among neurons in the hippocampus and the prefrontal cortex, affecting more than 300 genes in each region. Among 206 affected genes common to both regions, the researchers then looked at what those genes do. Many were associated with the function of the connections neurons make with each other, called synapses. This makes sense because learning arises when neurons change their connections (a phenomenon called “synaptic plasticity”) and memories are formed when groups of neurons connect together into ensembles called engrams.

“Many genes essential for neuronal function and memory formation, and significantly more of them than expected based on previous observations in cultured neurons…are potentially hotspots of DSB formation,” the authors wrote in the study.

In another analysis, the researchers confirmed through measurements of RNA that the increase in DSBs indeed correlated closely with increased transcription and expression of affected genes, including ones affecting synapse function, as quickly as 10-30 minutes after the foot shock exposure.

“Overall, we find transcriptional changes are more strongly associated with [DSBs] in the brain than anticipated,” they wrote. “Previously we observed 20 gene-associated [DSB] loci following stimulation of cultured neurons, while in the hippocampus and prefrontal cortex we see more than 100-150 gene associated [DSB] loci that are transcriptionally induced.” Snapping with stress

In the analysis of gene expression, the neuroscientists looked at not only neurons but also non-neuronal brain cells, or glia, and found that they also showed changes in expression of hundreds of genes after fear conditioning. Glia called astrocytes are known to be involved in fear learning, for instance, and they showed significant DSB and gene expression changes after fear conditioning.

Among the most important functions of genes associated with fear conditioning-related DSBs in glia was the response to hormones. The researchers therefore looked to see which hormones might be particularly involved and discovered that it was glutocortocoids, which are secreted in response to stress. Sure enough, the study data showed that in glia, many of the DSBs that occurred following fear conditioning occurred at genomic sites related to glutocortocoid receptors. Further tests revealed that directly stimulating those hormone receptors could trigger the same DSBs that fear conditioning did and that blocking the receptors could prevent transcription of key genes after fear conditioning.

Tsai said the finding that glia are so deeply involved in establishing memories from fear conditioning is an important surprise of the new study.

“The ability of glia to mount a robust transcriptional response to glutocorticoids suggest that glia may have a much larger role to play in the response to stress and its impact on the brain during learning than previously appreciated,” she and her co-authors wrote. Damage and danger?

More research will have to be done to prove that the DSBs required for forming and storing fear memories are a threat to later brain health, but the new study only adds to evidence that it may be the case, the authors said.

“Overall we have identified sites of DSBs at genes important for neuronal and glial functions, suggesting that impaired DNA repair of these recurrent DNA breaks which are generated as part of brain activity could result in genomic instability that contribute to aging and disease in the brain,” they wrote.

Reference: Stott RT, Kritsky O, Tsai L-H. Profiling DNA break sites and transcriptional changes in response to contextual fear learning. PLOS ONE . 2021;16(7):e0249691. doi: 10.1371/journal.pone.0249691

This article has been republished from the following materials . Note: material may have been edited for length and content. For […]

Read more at www.technologynetworks.com

When it comes to summer produce , you can’t go wrong with eggplant. Known for its deep purple hue and a certain euphemism via emoji, the veggie is impressively versatile. Serve it on sandwiches, toss it in salads, or add it to brownies. The warm weather veggie is also packed with antioxidants and fiber, offering stellar benefits for your heart, gut, and more. Not sure if eggplant deserves a place on your plate? Read on for the health benefits of eggplant, plus ways to add eggplants to your summer menu. What Is Eggplant?

As part of the nightshade family , eggplant (aka aubergine) is genetically related to peppers, potatoes, and tomatoes. It’s native to South Asia and grows in a wide range of shapes, sizes, and colors. The most common variety in the U.S. is the globe eggplant, which is dark purple and oval, according to the University of Kentucky Center for Crop Diversification . And while eggplants are typically prepared as you would other veggies (think: steamed, grilled, fried), they’re botanically classified as fruits — berries, in fact — according to the University of Florida . (Who knew?) Eggplant Nutrition

Boasting an array of nutrients — including fiber, potassium, magnesium, iron, vitamin C, and vitamin B 12 — eggplant is quite an all-star piece of produce. Its peel is rich in anthocyanins , which are antioxidants and natural plant pigments that give the fruit’s skin its purple hue, according to a 2021 study . (BTW, anthocyanins are also responsible for red- and blue-coloring of produce, such as blueberries , red cabbage, and currants, as well as butterfly pea tea .)

Here’s the nutritional profile of one cup of boiled eggplant (~99 grams), according to the United States Department of Agriculture : 35 calories

< 1 gram protein

2 grams fat

9 grams carbohydrate

2 grams fiber

3 grams sugar

Eggplant Health Benefits

Okay, so the purple produce is packed with nutrients — but how does that translate to your health? Ahead, the lowdown on eggplant health benefits, according to registered dietitians and research. Fights Oxidative Stress

Eggplant peel is packed with anthocyanins, which, ICYDK, protect the body from oxidative stress by neutralizing free radicals (aka potentially harmful molecules), says Andrea Mathis, M.A., R.D.N., L.D., registered dietitian and founder of Beautiful Eats & Things . This is key because high levels of oxidative stress can damage cells and DNA, contributing to the development of conditions such as cancer, diabetes, or heart disease. The major anthocyanin in eggplant peel is nasunin , and while there isn’t a lot of research on it, two lab studies found that nasunin has antioxidant properties that can help quell inflammation.

Meanwhile, eggplant flesh contains antioxidants known as phenolic acids , according to an article in the South African Journal of Botany . Not only do phenolic acids find and neutralize free radicals, but they also stimulate protective antioxidant enzymes in the body, making eggplant an especially awesome antioxidant food, according to research published in Biotechnology Reports . (Another seriously antioxidant-rich ingredient? Spirulina .) Supports Brain Health

As the antioxidants in eggplant combat oxidative stress, they also protect your brain. Oxidative stress can contribute to neurodegenerative diseases such as Parkinson’s disease and Alzheimer’s disease , according to a 2019 article in the journal Molecules . Plus, “the human brain is particularly susceptible to oxidative damage,” explains Susan Greeley , M.S., R.D.N., registered dietitian and chef instructor at the Institute of Culinary Education . This is due to numerous reasons, but basically, the brain relies on many molecules to function. If a certain molecule experiences oxidative damage, it can mess with the other molecules — and their ability to interact and send signals to one another, according to an article in the journal Redox Biology .

Antioxidants, however, can shield your brain from this oxidative stress. This includes the anthocyanins in eggplant peel, which “can help boost memory and benefit overall neurological health [as well],” notes Kylie Ivanir, M.S., R.D., registered dietitian and founder of Within Nutrition . A 2019 article in the journal Antioxidants also shares that anthocyanins and phenolic acids offer neuroprotective effects. Promotes Healthy Digestion

“The fiber in eggplant is a mix of insoluble and soluble fiber,” which paves the way for a happy digestive system, explains registered dietitian Tiffany Ma , R.D.N. Insoluble fiber doesn’t combine with water (and other liquids) in the gut. This promotes the movement of food through the intestines, ultimately preventing and relieving constipation, according to the University of California San Francisco . On the other hand, soluble fiber does dissolve in H20 in the gut, creating a viscous, gel-like substance that forms stool, improves constipation (by softening dry stool ) and diarrhea (by firming up loose stool). Ah, sweet relief. (FYI — You can also fill up on both types of fiber by chowing down on cantaloupe, another summer produce .) Protects Heart Health

Ma also dubs eggplant as a heart-healthy food , due in part to its fiber, which helps support healthy blood pressure and cholesterol levels, she says. (High blood pressure and high cholesterol are major risk factors of heart disease, according to the Centers for Disease Control and Prevention .) The antioxidants in eggplants can also lend a hand, as free radicals “may be involved in the development of atherosclerosis or the buildup of plaque in the arteries [that] can lead to heart disease,” explains Ivanir. As the fruit’s antioxidants combat free radicals, they also can protect against atherosclerosis, says Greeley. What’s more, eggplant flesh contains chlorogenic acid, an antioxidant that may help lower levels of LDL (“bad”) cholesterol, says Ivanir. It can also reduce high blood pressure by increasing nitric oxide, a molecule that relaxes your blood vessels, according to a 2021 scientific review . Manages Blood Sugar

The fiber in eggplant can also stabilize blood sugar levels. “Fiber is an indigestible nutrient, which means our bodies take a while to metabolize [it],” says Ma. This slows down the digestion and absorption of carbohydrates in the […]

Read more at www.msn.com

There may have been a time when you ate whatever you wanted without few, if any, health consequences. You might remember that time well! But it’s true—nothing lasts forever.

“After 50, metabolism slows, estrogen levels drop, and certain nutrient requirements rise,” says Hillary M. Wright, MEd, RDN, LDN , co-author of The Menopause Diet Plan, A Natural Guide to Hormones, Health, and Happines s . “At this point, you’ll probably need to make wiser food choices to help head off midlife weight gain and prevent conditions that are more common with age and menopause.”

Though no food is ever completely off the menu, the trick is to get the biggest bang for your caloric buck while enjoying yourself. Here’s what to choose, and avoid, most of the time, for women over the age of 50. And for more, check out The 7 Healthiest Foods to Eat Right Now . First up, here are the best foods to eat.

Shutterstock Calorie needs decline with age, but weight gain isn’t inevitable. Salmon is a stellar source of protein, which requires more calories to digest than carbohydrates and fat and could help prevent the dreaded belly fat that is common in midlife women. The omega‑3 fats in salmon are good for your heart and brain because they reduce the risk for clogged arteries, decrease elevated triglycerides (fat) in the blood, and lower blood pressure, all of which tend to increase in women in their 50s.

Fish such as salmon may also boost your mood . Eating more fish is associated with a decreased risk of depression , which is more common in women at midlife. Salmon also harbors vitamin D , a nutrient that is key in helping to prevent osteoporosis. Three ounces of cooked sockeye salmon nutrients has nearly all the vitamin D you need for the day after age 50. Shutterstock “For their small size, nuts contain relatively high levels of calories and fat, so you may think that avoiding them will help whittle your waistline, but the opposite is more likely to be true,” Wright says.

Research has found that eating nuts actually help regulate appetite which could make weight control easier. Nuts supply plant protein, heart-healthy, unsaturated fat, potassium, fiber, and other nutrients linked to good health as you age. In fact, women who munched on 1 1/2 ounces of pistachios for 12 weeks improved the quality of their diet without affecting their weight.

When you include delicious and nutritious nuts on a regular basis, you’re doing your heart and brain a favor . Nuts are rich in arginine, an amino acid necessary for making nitric oxide, which eases blood flow to the heart and the brain by relaxing constricted blood vessels. Get the greatest benefit from nuts by swapping 1/4 cup of unsalted varieties such as peanuts, almonds, walnuts, and pistachios (shell on) for snack chips, pretzels, and sweets. Shutterstock When it comes to banishing brain fog and protecting your memory after 50, it pays to squelch oxidation and inflammation. Berries supply many different types of powerful compounds called phytonutrients that help to head off brain cell damage and improve or increase communication between cells, among other ways of supporting brain function .

Blueberries, strawberries, raspberries, and other brightly-colored orbs are juicy and delicious without any added sugar. So these fruits can easily take the place of highly-processed, calorie-packed sweets that will actually provide you with some fiber to keep you fuller for longer. Blueberries and blackberries are also a source of vitamin K, which is necessary to produce osteocalcin, a protein that supports bone strength. Some research suggests that higher intakes of vitamin K are linked to better bone health in older women.

Looking for more helpful tips? Sign up for our newsletter to get daily recipes and food news in your inbox! Shutterstock Legumes such as black beans, garbanzo beans, and pinto beans contain magnesium to help protect against heart disease , stroke , type 2 diabetes , and osteoporosis . Beans are packed with potassium, which is great news for your ticker, as it’s linked to a lower risk for cardiovascular disease. One half-cup of black beans supplies about 400 milligrams of potassium— nearly as much as a medium banana , and about 15% of the recommended daily intake .

Beneficial bacteria in your colon ferment the prebiotic fiber found in beans and produce compounds called short chain fatty acids (SCFA). SCFA help reduce the risk for colon cancer, which increases after age 50, improve the body’s absorption of calcium and magnesium to support bone health, and help to head off heart disease and type 2 diabetes . Another type of fiber in beans bulks up bowel movements and prevents constipation, which can be more common with age. Shutterstock Declining estrogen levels are likely the reason for hot flashes, which affect about 75% of women living in the U.S. for at least two years in their 40s and 50s . Soy foods contain phytoestrogens, plant-based estrogen that is similar in function to human estrogen, but with much weaker effects in the body.

“Women who eat soy every day, including those who live in Asian countries, report having fewer hot flashes and other menopausal symptoms, but there is no scientific evidence to support the link between tofu, tempeh, and edamame and hot flash frequency and intensity,” Wright says.

Still, there are plenty of reasons to include soy foods in a balanced eating plan at any stage of life. Soy is a source of complete protein, and it’s a suitable substitute for fatty and processed meats. Plus, soy is also heart-healthy. Eating 25 grams of soy protein daily , about the amount found in 1/2 cup roasted soy nuts and 1 cup unsweetened soy milk, actually reduces LDL (“bad”) cholesterol, which helps lower heart disease risk. As an added bonus, tofu that’s processed with calcium offers a significant amount bone-building calcium, and tempeh and soybeans pack fiber. Shutterstock Yogurt is a mixture of milk and live active cultures (LAC), also known as probiotics , which […]

Read more at www.eatthis.com

Parents understand that a child’s diet plays a pivotal role in their growth and development. However, they may not know that organic food could help give their children a cognitive advantage. In fact, not only is adopting an organic diet beneficial for the planet that your children are going to inherit, but doing so could be exactly why they need to enhance their brain health.

Various studies have revealed that organic food is the best source of nutrients and vitamins. That said, a recent study has indicated that organic food is the key to cognitive development in your children.

The study , published in Environmental Pollution , was completed by the Barcelona Institute for Global Health and the Pere Virgili Health Research Institute . For the study, the researchers used the data of 1 298 pairs of mothers and children, with the offspring ranging in ages 6-11 years, hailing from the UK, France, Spain, Greece, Lithuania, and Norway.

The aim of the study was to look at how factors can influence the development and maturation of the human brain. So, the team then analyzed 87 environmental factors the children were exposed to in utero. These included air pollution, traffic, noise, and chemicals. They also looked at 122 external factors that they were exposed to during childhood. The findings

The results of the study found a strong link between the consumption of organic food among school-age children and working memory and fluid intelligence – the ability to identify new information and use logic and problem-solving abilities to understand it. “Organic diets are richer than fast food diets in nutrients necessary for the brain, such as fatty acids, vitamins and antioxidants, which together may enhance cognitive function in childhood,” wrote lead author of the study Dr. Jordi Júlvez Unsurprisingly, the consumption of fast food was found to influence lower measures of fluid intelligence and working memory. Living in a crowded home and exposure to tobacco smoke was also found to affect cognitive function.

“We observed that several prenatal environmental pollutants (indoor air pollution and tobacco smoke) and lifestyle habits during childhood (diet, sleep, and family social capital) were associated with behavioral problems in children,” said Martine Vrijheid, a co-author of the study and head of ISGlobal’s Childhood and Environment program, in a statement .

That said, Dr. Júlvez does point out that societal inequalities can influence living situations, which in turn can affect diet,

“The number of people living together in a home is often an indicator of the family’s economic status, and that contexts of poverty favour less healthy lifestyles, which in turn may affect children’s cognitive test scores”. It’s a brain twister

Funny enough, the study did also have some surprising results, which included a link between pregnant women’s green exposure and lower cognitive performance in their children.

We live in trying times. As such, it would be unfair not to acknowledge that not every family can afford organic food at every meal. Rather, we recommend that your child’s intake of fruits and vegetables be higher than their intake of processed foods. They don’t have to be organic, but at least be fresh.

Additionally, there are other ways that parents can improve cognitive function in their children. These include keeping them active, stimulating their reading habits , putting on music as well as encouraging them to ask a lot of questions.

Read more at longevitylive.com

The urgency to remember a dangerous experience requires the brain to make a series of potentially dangerous moves: Neurons and other brain cells snap open their DNA in numerous locations–more than previously realized, according to a new study–to provide quick access to genetic instructions for the mechanisms of memory storage.

The extent of these DNA double-strand breaks (DSBs) in multiple key brain regions is surprising and concerning, said study senior author Li-Huei Tsai, Picower Professor of Neuroscience at MIT and director of The Picower Institute for Learning and Memory, because while the breaks are routinely repaired, that process may become more flawed and fragile with age. Tsai’s lab has shown that lingering DSBs are associated with neurodegeneration and cognitive decline and that repair mechanisms can falter.

“We wanted to understand exactly how widespread and extensive this natural activity is in the brain upon memory formation because that can give us insight into how genomic instability could undermine brain health down the road,” said Tsai, who is also a professor in the Department of Brain and Cognitive Sciences and a leader of MIT’s Aging Brain Initiative. “Clearly memory formation is an urgent priority for healthy brain function but these new results showing that several types of brain cells break their DNA in so many places to quickly express genes is still striking.” Tracking breaks

In 2015, Tsai’s lab provided the first demonstration that neuronal activity caused DSBs and that they induced rapid gene expression. But those findings, mostly made in lab preparations of neurons, did not capture the full extent of the activity in the context of memory formation in a behaving animal and did not investigate what happened in cells other than neurons.

In the new study published July 1 in PLOS ONE , lead author and former graduate student Ryan Stott and co-author and former research technician Oleg Kritsky sought to investigate the full landscape of DSB activity in learning and memory. To do so, they gave mice little electrical zaps to the feet when they entered a box, to condition a fear memory of that context. They then used several methods to assess DSBs and gene expression in the brains of the mice over the next half hour, particularly among a variety of cell types in the prefrontal cortex and hippocampus, two regions essential for the formation and storage of conditioned fear memories. They also made measurements in the brains of mice who did not experience the foot shock to establish a baseline of activity for comparison.

The creation of a fear memory doubled the number of DSBs among neurons in the hippocampus and the prefrontal cortex, affecting more than 300 genes in each region. Among 206 affected genes common to both regions, the researchers then looked at what those genes do. Many were associated with the function of the connections neurons make with each other, called synapses. This makes sense because learning arises when neurons change their connections (a phenomenon called “synaptic plasticity”) and memories are formed when groups of neurons connect together into ensembles called engrams.

“Many genes essential for neuronal function and memory formation, and significantly more of them than expected based on previous observations in cultured neurons…are potentially hotspots of DSB formation,” the authors wrote in the study.

In another analysis, the researchers confirmed through measurements of RNA that the increase in DSBs indeed correlated closely with increased transcription and expression of affected genes, including ones affecting synapse function, as quickly as 10-30 minutes after the foot shock exposure.

“Overall, we find transcriptional changes are more strongly associated with [DSBs] in the brain than anticipated,” they wrote. “Previously we observed 20 gene-associated [DSB] loci following stimulation of cultured neurons, while in the hippocampus and prefrontal cortex we see more than 100-150 gene associated [DSB] loci that are transcriptionally induced.” Snapping with stress

In the analysis of gene expression, the neuroscientists looked at not only neurons but also non-neuronal brain cells, or glia, and found that they also showed changes in expression of hundreds of genes after fear conditioning. Glia called astrocytes are known to be involved in fear learning, for instance, and they showed significant DSB and gene expression changes after fear conditioning.

Among the most important functions of genes associated with fear conditioning-related DSBs in glia was the response to hormones. The researchers therefore looked to see which hormones might be particularly involved and discovered that it was glutocortocoids, which are secreted in response to stress. Sure enough, the study data showed that in glia, many of the DSBs that occurred following fear conditioning occurred at genomic sites related to glutocortocoid receptors. Further tests revealed that directly stimulating those hormone receptors could trigger the same DSBs that fear conditioning did and that blocking the receptors could prevent transcription of key genes after fear conditioning.

Tsai said the finding that glia are so deeply involved in establishing memories from fear conditioning is an important surprise of the new study.

“The ability of glia to mount a robust transcriptional response to glutocorticoids suggest that glia may have a much larger role to play in the response to stress and its impact on the brain during learning than previously appreciated,” she and her co-authors wrote. Damage and danger?

More research will have to be done to prove that the DSBs required for forming and storing fear memories are a threat to later brain health, but the new study only adds to evidence that it may be the case, the authors said.

“Overall we have identified sites of DSBs at genes important for neuronal and glial functions, suggesting that impaired DNA repair of these recurrent DNA breaks which are generated as part of brain activity could result in genomic instability that contribute to aging and disease in the brain,” they wrote.

Read more at www.news-medical.net

Credit: Pixabay/CC0 Public Domain The urgency to remember a dangerous experience requires the brain to make a series of potentially dangerous moves: Neurons and other brain cells snap open their DNA in numerous locations—more than previously realized, according to a new study—to provide quick access to genetic instructions for the mechanisms of memory storage.

The extent of these DNA double-strand breaks (DSBs) in multiple key brain regions is surprising and concerning, said study senior author Li-Huei Tsai, Picower Professor of Neuroscience at MIT and director of The Picower Institute for Learning and Memory, because while the breaks are routinely repaired, that process may become more flawed and fragile with age. Tsai’s lab has shown that lingering DSBs are associated with neurodegeneration and cognitive decline and that repair mechanisms can falter.

“We wanted to understand exactly how widespread and extensive this natural activity is in the brain upon memory formation because that can give us insight into how genomic instability could undermine brain health down the road,” said Tsai, who is also a professor in the Department of Brain and Cognitive Sciences and a leader of MIT’s Aging Brain Initiative. “Clearly memory formation is an urgent priority for healthy brain function but these new results showing that several types of brain cells break their DNA in so many places to quickly express genes is still striking.”

Tracking breaks

In 2015, Tsai’s lab provided the first demonstration that neuronal activity caused DSBs and that they induced rapid gene expression . But those findings, mostly made in lab preparations of neurons, did not capture the full extent of the activity in the context of memory formation in a behaving animal and did not investigate what happened in cells other than neurons.

In the new study published July 1 in PLOS ONE , lead author and former graduate student Ryan Stott and co-author and former research technician Oleg Kritsky sought to investigate the full landscape of DSB activity in learning and memory. To do so, they gave mice little electrical zaps to the feet when they entered a box, to condition a fear memory of that context. They then used several methods to assess DSBs and gene expression in the brains of the mice over the next half hour, particularly among a variety of cell types in the prefrontal cortex and hippocampus, two regions essential for the formation and storage of conditioned fear memories. They also made measurements in the brains of mice who did not experience the foot shock to establish a baseline of activity for comparison.

The creation of a fear memory doubled the number of DSBs among neurons in the hippocampus and the prefrontal cortex, affecting more than 300 genes in each region. Among 206 affected genes common to both regions, the researchers then looked at what those genes do. Many were associated with the function of the connections neurons make with each other, called synapses. This makes sense because learning arises when neurons change their connections (a phenomenon called “synaptic plasticity”) and memories are formed when groups of neurons connect together into ensembles called engrams.

“Many genes essential for neuronal function and memory formation , and significantly more of them than expected based on previous observations in cultured neurons…are potentially hotspots of DSB formation,” the authors wrote in the study.

In another analysis, the researchers confirmed through measurements of RNA that the increase in DSBs indeed correlated closely with increased transcription and expression of affected genes, including ones affecting synapse function, as quickly as 10-30 minutes after the foot shock exposure.

“Overall, we find transcriptional changes are more strongly associated with [DSBs] in the brain than anticipated,” they wrote. “Previously we observed 20 gene-associated [DSB] loci following stimulation of cultured neurons, while in the hippocampus and prefrontal cortex we see more than 100-150 gene associated [DSB] loci that are transcriptionally induced.”

Snapping with stress

In the analysis of gene expression, the neuroscientists looked at not only neurons but also non-neuronal brain cells, or glia, and found that they also showed changes in expression of hundreds of genes after fear conditioning. Glia called astrocytes are known to be involved in fear learning, for instance, and they showed significant DSB and gene expression changes after fear conditioning.

Among the most important functions of genes associated with fear conditioning-related DSBs in glia was the response to hormones. The researchers therefore looked to see which hormones might be particularly involved and discovered that it was glutocortocoids, which are secreted in response to stress. Sure enough, the study data showed that in glia, many of the DSBs that occurred following fear conditioning occurred at genomic sites related to glutocortocoid receptors. Further tests revealed that directly stimulating those hormone receptors could trigger the same DSBs that fear conditioning did and that blocking the receptors could prevent transcription of key genes after fear conditioning.

Tsai said the finding that glia are so deeply involved in establishing memories from fear conditioning is an important surprise of the new study.

“The ability of glia to mount a robust transcriptional response to glutocorticoids suggest that glia may have a much larger role to play in the response to stress and its impact on the brain during learning than previously appreciated,” she and her co-authors wrote.

Damage and danger?

More research will have to be done to prove that the DSBs required for forming and storing fear memories are a threat to later brain health, but the new study only adds to evidence that it may be the case, the authors said.

“Overall we have identified sites of DSBs at genes important for neuronal and glial functions, suggesting that impaired DNA repair of these recurrent DNA breaks which are generated as part of brain activity could result in genomic instability that contribute to aging and disease in the brain,” they wrote.

Provided by Massachusetts Institute of Technology

Read more at medicalxpress.com

A bite of dark chocolate a day could not only be good for your heart, but may also improve brain function, alleviate stress, and lower the risk of stroke.

Celebrate World Chocolate day by having some! Whether happy or sad, chocolate is a delicious dark dessert that always uplifts our mood and makes us smile. It is the finest sweet treat on earth, as everyone enjoys savouring these bites of heaven. Chocolate can enhance and help create the most luxurious desserts and can also be enjoyed on its own.

The World Chocolate Day is celebrated every year on July 7, to celebrate the love of chocolate, a special day to try different lip-smacking recipes of the tasty desert, whether its candy, dessert, pastries, cakes, sauces, you name it, everything is fair game on this day.

It was first observed in the year 2009. Since chocolates come with many health benefits too, this special day is celebrated by having all types of chocolates. Health Benefits of Chocolates

Scientific studies have shown that dark chocolate is rich in antioxidants and packed with nutrients, making this bittersweet treat a superfood favourite.

2. Reduces Cholesterol

One study, published in The Journal of Nutrition, suggests that chocolate consumption might help reduce low-density lipoprotein (LDL)Trusted Source cholesterol levels, also known as “bad cholesterol.”

3. Brain function

Scientists at Harvard Medical School have suggested that drinking two cups of hot chocolate a day could help keep the brain healthy and reduce memory decline in older people.

4. Heart disease

Research has suggested that consuming chocolate could help lower the risk of developing heart disease by one-third. Higher levels of chocolate consumption could be linked to a lower risk of cardiometabolic disorders.

5. Reduces chances of Stroke

People who eat one serving of chocolate are 22 percent less likely to experience a stroke than those who did not. Also, those who had about two ounces of chocolate a week were 46 percent less likely to die from a stroke.

6. Improves athletic performance

Findings published in The Journal of the International Society of Sports Nutrition suggest that a little dark chocolate might boost oxygen availability during fitness training.

7. May Improve Mood and Symptoms of Depression

Cocoa’s positive effects on mood may be due to flavanols present in it. It can also be the conversion of tryptophan to the natural mood stabiliser serotonin, its caffeine content or simply the sensory pleasure of eating chocolate.

Read more at www.freepressjournal.in