@arezarni

Scientists could be a step closer to finding a way to reduce the impact of traumatic memories, according to a Texas A&M University study published recently in the journal Nature Neuroscience.

The report details a study by researchers from the Department of Psychological and Brain Sciences and the Institute for Neuroscience. Stephen Maren, professor of psychological and brain sciences, said the group’s findings suggest that procedures used by clinicians to indirectly reactivate traumatic memories render a window whereby those memories can be altered, or even erased completely.

In therapy, imaginal reminders are often used to safely retrieve traumatic memories of experiences. For example, Maren said a military veteran wounded by an improvised explosive device may be asked to re-experience trauma cues – like the lights and sounds of the explosion – without the negative consequences. The idea is that the fear responses can be dampened through this exposure therapy.

“The one major challenge is when you do the extinction procedures, it doesn’t erase the original trauma memory,” Maren said. “It’s always there and can bubble back up, which is what causes relapse for people who re-experience fear.”

With this in mind, the researchers hoped to answer whether they could isolate a memory and drive fear responses by reactivating it artificially – and potentially disrupt the original memory itself. Maren said their findings suggest that procedures currently used by clinicians to indirectly reactivate traumatic memories create an opportunity to change or eliminate them.

To do this, the researchers used a conditioning procedure in which a cue becomes indirectly associated with a fearful event. When the cue is presented later, it indirectly reactivates a memory of the event and increases activity in the hippocampus, a brain area important for memory.

(Image caption: In this image of a neuron nucleus, bright spots show areas of focused genetic repair. Credit: Salk Institute/Waitt Advanced Biophotonics Center)

How brain cells repair their DNA reveals “hot spots” of aging and disease

Neurons lack the ability to replicate their DNA, so they’re constantly working to repair damage to their genome. Now, a new study by Salk scientists finds that these repairs are not random, but instead focus on protecting certain genetic “hot spots” that appear to play a critical role in neural identity and function.

The findings, published in Science, give novel insights into the genetic structures involved in aging and neurodegeneration, and could point to the development of potential new therapies for diseases such Alzheimer’s, Parkinson’s and other age-related dementia disorders.

“This research shows for the first time that there are sections of genome that neurons prioritize when it comes to repair,” says Professor and Salk President Rusty Gage, the paper’s co- corresponding author. “We’re excited about the potential of these findings to change the way we view many age-related diseases of the nervous system and potentially explore DNA repair as a therapeutic approach.”

Unlike other cells, neurons generally don’t replace themselves over time, making them among the longest-living cells in the human body. Their longevity makes it even more important that they repair lesions in their DNA as they age, in order to maintain their function over the decades of a human life span. As they get older, neurons’ ability to make these genetic repairs declines, which could explain why people develop age-related neurodegenerative diseases like Alzheimer’s and Parkinson’s.

To investigate how neurons maintain genome health, the study authors developed a new technique they term Repair-seq. The team produced neurons from stem cells and fed them synthetic nucleosides—molecules that serve as building blocks for DNA. These artificial nucleosides could be found via DNA sequencing and imaged, showing where the neurons used them to make repairs to DNA that was damaged by normal cellular processes. While the scientists expected to see some prioritization, they were surprised by just how focused the neurons were on protecting certain sections of the genome.

“What we saw was incredibly sharp, well-defined regions of repair; very focused areas that were substantially higher than background levels,” says co-first and co-corresponding author Dylan Reid, a former Salk postdoctoral scholar and now a fellow at Vertex Pharmaceutics. “The proteins that sit on these ‘hot spots’ are implicated in neurodegenerative disease, and the sites are also linked to aging.”

The authors found approximately 65,000 hot spots that covered around 2 percent of the neuronal genome. They then used proteomics approaches to detect what proteins were found at these hot spots, implicating many splicing-related proteins. (These are involved in the eventual production of other proteins.) Many of these sites appeared to be quite stable when the cells were treated with DNA-damaging agents, and the most stable DNA repair hot spots were found to be strongly associated with sites where chemical tags attach (“methylation”) that are best at predicting neuronal age.

Previous research has focused on identifying the sections of DNA that suffer genetic damage, but this is the first time researchers have looked for where the genome is being heavily repaired.

“We flipped the paradigm from looking for damage to looking for repair, and that’s why we were able to find these hot spots,” Reid says. “This is really new biology that might eventually change how we understand neurons in the nervous system, and the more we understand that, the more we can look to develop therapies addressing age-related diseases.”

Türlü türlü bahaneler buluyorum sevmek, sevebilmek ve sevgiden pay alabilmek için. Bazen ise artık bulmasam da kendiliğinden oluşanla mı yetinsem diyorum. Sonraları anlıyorum bir kalbi zalim kılan bu dünyayı. Ve neden bir kalbin zalimliğe teslim olduğunu. Bazı insanların zalim olmamak için direndiğine şahitlik ediyorum. Olsalar haklı değiller demeye de cesaretim yok. Evet kalbi karayı yargılıyoruz da onu o hale getireni niye yargılamıyoruz. Dünyada yaşaman lazım fakat ne zaman ne de mekan iyiysen seni kabullenmiyor. Kötüysen uyum sağlıyorsun. Arkadan iş çeviriyorsan ancak seviliyorsun. Dünya kokuyorsan ancak göz aydınlığı olabiliyorsun. Ama yaşaman da lazım. Ya da para kazanıp eve ekmek getirmen. Ama işin içine hile karıştırmazsan aç kalıyorsun. Karıştırabiliyorsan zengin oluyorsun. Çamurdan uzak durmak istiyorsan yalnız kalıyorsun. Yalnızlığa düşmek istemiyorsan çamura bulanman gerekiyor. Saf, temiz, kendi halinde olmayı istiyorsun lakin dünya buna müsaade etmiyor. Ama yaşaman da lazım. Çünkü dünyadasın. Nasıl. Nasıl yapıyorlar. Bunca tavizle nasıl övünüyorlar. Nasıl kaybolmayı kabul edebiliyorlar. Kalbi duvar bağlamasın da ne yapsın. Çünkü yaşaması lazım. Ve dünya başka seçenek sunmuyor. Ya gel ya çekil. Ortası kaybolmaktan ibaret.

Lakin direnmeliyiz. Çünkü o beşten biri direnenlerdendi.

Don’t let the small stuff get you down

Suppose you drop your morning coffee and it splatters everywhere. Later a colleague drops by to say hello. Do you grumble a testy acknowledgment, or cheerfully greet her?

In a new study on brain activity led by University of Miami psychologists, researchers found that how a person’s brain evaluates fleeting negative stimuli—such as that dropped cup—may influence their long-term psychological well-being.

“One way to think about it is the longer your brain holds on to a negative event, or stimuli, the unhappier you report being,” said Nikki Puccetti, a Ph.D. candidate in the Department of Psychology and lead author of the study published in the Journal of Neuroscience. “Basically, we found that the persistence of a person’s brain in holding on to a negative stimulus is what predicts more negative and less positive daily emotional experiences. That in turn predicts how well they think they’re doing in their life.”

“The majority of human neuroscience research looks at how intensely the brain reacts to negative stimuli, not how long the brain holds on to a stimulus,’’ said Aaron Heller, senior author of the study and assistant professor of psychology. “We looked at the spillover—how the emotional coloring of an event spills over to other things that happen. Understanding the biological mechanisms of that is critically important to understanding the differences in brain function, daily emotions, and well-being,” he added.

For their study, the researchers set out to learn how different reactions in the brain to emotional pictures relate to momentary emotional experiences in daily life and even psychological well-being over time. They hypothesized that the amygdala, the almond-shaped structure on both sides of the cerebrum that evaluates stimuli and supports emotion and memory, played an important role.

They confirmed their suspicions by analyzing data from the Midlife in the United States (MIDUS) study, one of the richest and most unique longitudinal studies on the health and well-being of thousands of adults as they age. Initiated by the National Institute on Aging in 1995, the study continued in 2002 at the University of Wisconsin-Madison, where Heller earned his Ph.D.

With other researchers affiliated with the MIDUS project, Puccetti and Heller analyzed data from 52 MIDUS participants who had completed a questionnaire about their psychological well-being and, in a nightly phone call, reported the stressful events and positive and negative emotions they had experienced each day for about a week. The study subjects also underwent functional magnetic resonance imaging (fMRI) scans that measured and mapped their brain activity as they viewed and rated 60 positive images and 60 negative images, interspersed with 60 images of neutral facial expressions.

Connecting data from the questionnaires, the daily phone diaries, and brain snapshots from the fMRIs, the researchers determined that people whose left amygdala held on to negative stimuli for fewer seconds were more likely to report more positive and fewer negative emotions in their daily lives—which spilled over to a more enduring well-being over time.

Conversely, people whose left amygdala reacted more persistently to negative images over time reported more negative and fewer positive emotions in their daily lives.

“It may be that for individuals with greater amygdala persistence, negative moments may become amplified or prolonged by imbuing unrelated moments that follow with a negative appraisal,” the authors stated. “This brain-behavior link between left amygdala persistence and daily affect can inform our understanding of more enduring, long-term evaluations of well-being.”

And it could explain, Puccetti said, why some people might let a dropped cup of coffee ruin their day, while others wouldn’t give it another thought after cleaning the mess up. It’s also why she hopes to one day repeat the study with subjects who, unlike the MIDUS participants, are at high risk for developing depression or anxiety.

You roll yours eyes, a smile ghosting over your lips. “Why? Because I died?”

“Because you died in vain.” I correct.

You raise your eyebrows. “So did Romeo and Juliet.”

“But they died for love!” I protest.

You shake your head, evidently amused. “They died from miscommunication.”

I open my mouth to retaliate, but nothing comes out.

“The poets paint them in tragedy, weaving young love and sacrifice so beautifully that we forget the truth of what happened in the tomb.

But I’m the one who touched the sun. I didn’t go in vain, neither did I lose sight of the ground. I simply decided I’d rather fly.

Even if it was just for a minute.”

- icarus wasn’t a fool. he just knew what he wanted and was brave enough to reach for it.

Millions of people are administered general anesthesia each year in the United States alone, but it’s not always easy to tell whether they are actually unconscious.

A small proportion of those patients regain some awareness during medical procedures, but a new study of the brain activity that represents consciousness could prevent that potential trauma. It may also help both people in comas and scientists struggling to define which parts of the brain can claim to be key to the conscious mind.

“What has been shown for 100 years in an unconscious state like sleep are these slow waves of electrical activity in the brain,” says Yuri Saalmann, a University of Wisconsin–Madison psychology and neuroscience professor. “But those may not be the right signals to tap into. Under a number of conditions — with different anesthetic drugs, in people that are suffering from a coma or with brain damage or other clinical situations — there can be high-frequency activity as well.”

UW–Madison researchers recorded electrical activity in about 1,000 neurons surrounding each of 100 sites throughout the brains of a pair of monkeys at the Wisconsin National Primate Research Center during several states of consciousness: under drug-induced anesthesia, light sleep, resting wakefulness, and roused from anesthesia into a waking state through electrical stimulation of a spot deep in the brain (a procedure the researchers described in 2020).

“With data across multiple brain regions and different states of consciousness, we could put together all these signs traditionally associated with consciousness — including how fast or slow the rhythms of the brain are in different brain areas — with more computational metrics that describe how complex the signals are and how the signals in different areas interact,” says Michelle Redinbaugh, a graduate student in Saalman’s lab and co-lead author of the study, published in the journal Cell Systems.

To sift out the characteristics that best indicate whether the monkeys were conscious or unconscious, the researchers used machine learning. They handed their large pool of data over to a computer, told the computer which state of consciousness had produced each pattern of brain activity, and asked the computer which areas of the brain and patterns of electrical activity corresponded most strongly with consciousness.

The results pointed away from the frontal cortex, the part of the brain typically monitored to safely maintain general anesthesia in human patients and the part most likely to exhibit the slow waves of activity long considered typical of unconsciousness.

“In the clinic now, they may put electrodes on the patient’s forehead,” says Mohsen Afrasiabi, the other lead author of the study and an assistant scientist in Saalmann’s lab. “We propose that the back of the head is a more important place for those electrodes, because we’ve learned the back of the brain and the deep brain areas are more predictive of state of consciousness than the front.”

And while both low- and high-frequency activity can be present in unconscious states, it’s complexity that best indicates a waking mind.

“In an anesthetized or unconscious state, those probes in 100 different sites record a relatively small number of activity patterns,” says Saalmann, whose work is supported by the National Institutes of Health.

A larger — or more complex — range of patterns was associated with the monkey’s awake state.

“You need more complexity to convey more information, which is why it’s related to consciousness,” Redinbaugh says. “If you have less complexity across these important brain areas, they can’t convey very much information. You’re looking at an unconscious brain.”

More accurate measurements of patients undergoing anesthesia is one possible outcome of the new findings, and the researchers are part of a collaboration supported by the National Science Foundation working on applying the knowledge of key brain areas.

Artificial ‘brain’ reveals why we can’t always believe our eyes

A computer network closely modelled on part of the human brain is enabling new insights into the way our brains process moving images - and explains some perplexing optical illusions.

By using decades’ worth of data from human motion perception studies, researchers have trained an artificial neural network to estimate the speed and direction of image sequences.

The new system, called MotionNet, is designed to closely match the motion-processing structures inside a human brain. This has allowed the researchers to explore features of human visual processing that cannot be directly measured in the brain.

Their study, published in the Journal of Vision, uses the artificial system to describe how space and time information is combined in our brain to produce our perceptions, or misperceptions, of moving images.

The brain can be easily fooled. For instance, if there’s a black spot on the left of a screen, which fades while a black spot appears on the right, we will ‘see’ the spot moving from left to right – this is called ‘phi’ motion. But if the spot that appears on the right is white on a dark background, we ‘see’ the spot moving from right to left, in what is known as ‘reverse-phi’ motion.”

The researchers reproduced reverse-phi motion in the MotionNet system, and found that it made the same mistakes in perception as a human brain – but unlike with a human brain, they could look closely at the artificial system to see why this was happening. They found that neurons are ‘tuned’ to the direction of movement, and in MotionNet, ‘reverse-phi’ was triggering neurons tuned to the direction opposite to the actual movement.

The artificial system also revealed new information about this common illusion: the speed of reverse-phi motion is affected by how far apart the dots are, in the reverse to what would be expected. Dots ‘moving’ at a constant speed appear to move faster if spaced a short distance apart, and more slowly if spaced a longer distance apart.

“We’ve known about reverse-phi motion for a long time, but the new model generated a completely new prediction about how we experience it, which no-one has ever looked at or tested before,” said Dr Reuben Rideaux, a researcher in the University of Cambridge’s Department of Psychology and first author of the study.

Humans are reasonably good at working out the speed and direction of a moving object just by looking at it. It’s how we can catch a ball, estimate depth, or decide if it’s safe to cross the road. We do this by processing the changing patterns of light into a perception of motion – but many aspects of how this happens are still not understood.

“It’s very hard to directly measure what’s going on inside the human brain when we perceive motion - even our best medical technology can’t show us the entire system at work. With MotionNet we have complete access,” said Rideaux.

Thinking things are moving at a different speed than they really are can sometimes have catastrophic consequences. For example, people tend to underestimate how fast they are driving in foggy conditions, because dimmer scenery appears to be moving past more slowly than it really is. The researchers showed in a previous study that neurons in our brain are biased towards slow speeds, so when visibility is low they tend to guess that objects are moving more slowly than they actually are.

Revealing more about the reverse-phi illusion is just one example of the way that MotionNet is providing new insights into how we perceive motion. With confidence that the artificial system is solving visual problems in a very similar way to human brains, the researchers hope to fill in many gaps in current understanding of how this part of our brain works.

✧ 20th September 2021

There is a Pisces Full Moon happening tonight at 28°. One of my personal favourite full moons of the year (not just because I am Pisces myself) because Pisces is one of the most spiritual and psychic sign of the zodiac.

An amazing time for any spells, rituals or divination. Expect heightened psychic abilities, prothetic dreams and possibly feeling more emotional than usual.

Pisces is traditionally ruled by Jupiter and at the time of this full moon, Jupiter is trine Mercury. This brings us overall luck and optimism. Make sure to write your goals and manifestations down or speak them out-loud! 

Pisces is very connected to dreams, so I truly recommend writing down any dreams you may have and trying to decipher their deeper meanings.

(Image caption: The image shows a brain section of a mouse that has received propranolol treatment. The lesions are outlined in green. Credit: Joppe Oldenburg)

Beta blockers can repair malformed blood vessels in the brain

Propranolol, a drug that is efficacious against infantile haemangiomas (“strawberry naevi”, resembling birthmarks), can also be used to treat cerebral cavernous malformations, a condition characterised by misshapen blood vessels in the brain and elsewhere. This has been shown by researchers at Uppsala University in a new study.

“Up to now, there’s been no drug treatment for these patients, so our results may become hugely important for them,” says Peetra Magnusson of the University’s Department of Immunology, Genetics and Pathology, who headed the study.

Cerebral cavernous malformations (CCMs, also called cavernous angiomas or cavernomas) are vascular lesions on blood vessels in the brain and elsewhere, caused by genetic changes that may be hereditary or arise spontaneously. Today, an operation to remove these lesions is the only possible treatment. However, surgical interventions in the brain are highly risky. Since the vascular malformations, moreover, recur in the hereditary form of the condition, a drug treatment for CCMs is urgently required instead.

The uses of propranolol, a beta blocker, include treating cardiovascular diseases and conditions, such as high blood pressure. But it can also be used to treat a haemangioma (“strawberry naevus”), a common blood-vessel malformation in children. There are some indications that the preparation might work against CCMs as well.

The blood vessels functioned better

The new study is a collaboration involving researchers at Uppsala University, the Swedish University of Agricultural Sciences and, in Italy, IFOM - The FIRC Institute of Molecular Oncology and the Mario Negri Institute of Pharmacological Research. The researchers have been investigating how propranolol affects the emergence of vascular lesions in the form of CCMs.

“We examined mice with vascular malformations in the brain – cavernomas or CCMs, as they’re called – that corresponded to the hereditary form of the condition in humans. The mice were given propranolol in their drinking water, and we were able to see that the cavernomas were becoming fewer and smaller. The blood vessels functioned better, too, with less leaking and improved contacts between their cells,” Magnusson says.

The propranolol dose administered to the animals was equivalent to the dose used to treat diseases in humans. Using an electron microscope, the researchers were able to study in detail how the drug affected the cavernomas.

The results show that propranolol can be used to shrink and stabilise vascular lesions, and may be a potential medicine for treating CCMs.

The human brain is constantly evaluating which aspects of experiences to either remember for later, ignore, or forget. Dartmouth researchers have developed a new approach for studying these aspects of memory by creating a computer program that turns sequences of events from a video into unique geometric shapes. These shapes can then be compared to the shapes of how people recounted the events. The study provides new insight into how experiences are committed to memory and recounted to others.

The results, published in Nature Human Behaviour, were based on how viewers remembered the experience of watching an episode of Sherlock, a BBC television show.

(Image caption: Left: The shape of a Sherlock episode based on the team’s computer model in which each dot represents a scene from the episode. Right: The average shape of 17 viewers’ memories of the episode. Blue arrows indicate places where the shapes of people’s memories were similar, and gray arrows indicate where people’s shapes were different. Credit: A. Heusser et al.)

“When we represent experiences and memories as shapes, we can use the tools provided by the field of geometry to explore how we remember our experiences, and to test theories of how we think, learn, remember, and communicate,” says senior author Jeremy Manning, an assistant professor of psychological and brain sciences and director of the Contextual Dynamics Lab at Dartmouth. “When you experience something, its shape is like a fingerprint that reflects its unique meaning, and how you remember or conceptualize that experience can be turned into another shape. We can think of our memories like distorted versions of our original experiences. Through our research, we wanted to find out when and where those distortions happen (i.e. what do people get right and what do people get wrong), and examine how accurate our memories of experiences are.”

The Dartmouth research team examined a public dataset containing brain recordings from 17 people who had watched the Sherlock episode and then described what had happened in their own words. The dataset also contained detailed scene-by-scene annotations of the episode.

The team ran those annotations through their computer program to identify 32 unique topics or themes that were present in each moment of the episode. Through computer modeling, the researchers then created a “topic model” of the episode, which was comprised of 32 dimensions to reflect each thematic topic. Different moments of the episode that reflected similar themes were assigned to nearby locations in the 32-dimensional space. When these results are visualized in 2D, a connect-the-dots-like representation of successive events emerges. The shape of that representation reflects how the thematic content of the episode changes over time, and how different moments are related. The researchers used an analogous process to obtain the shapes of how each of the 17 participants recounted the events of the episode.

When the geometric shapes representing the Sherlock episode were compared to the shapes representing a participant’s recounting of it, the researchers were able to identify which aspects of the episode people tended to remember accurately, forget or distort. The coarse spatial structure of the episode’s shape reflects the major plot points and acts like a building’s scaffolding. The shape of every participant’s recounting reproduced this coarse-scale scaffolding, indicating that every participant accurately remembered the major plot points. The episode’s shape also comprises finer-scale structure, analogous to architectural embellishments and decorations, that reflected specific low-level conceptual details. Some participants accurately recounted many of those low-level details, whereas others recounted only the high-level plot points.

“One of our most intriguing findings was that, as people were watching the episode, we could use their brain activity patterns to predict the distorted shapes that their memories would take on when they recounted it later,” says Manning. “This suggests that some of the details about our ongoing experiences get distorted in our brains from the moment they are stored as new memories. Even when two people experience the same physical event, their subjective experiences of that event start to diverge from the moment their brains start to make sense of what happened and distill that event into memories.”

I think it’s a second thing to be born a realist and have heartbreaking experiences that hurt, but not in ways that aren’t foreseen.

I think the it’s a much different thing to be born an optimist and to have heartbreaking experiences that tear down your hope and alter your expectations.

I think the pessimist comes out, not much different, but with better understanding of the world and its cruel sentences.

I think the realist comes out a little different, with cosmic changes in strength and compassion.

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