Category Archives: Neuroscience

Neuroscience

Signs of Alzheimers in Blood 17 Years Before Symptoms Begin – Neuroscience News

Summary: A newly developed immuno-infrared sensor allowed researchers to discover biomarkers for Alzheimers disease in blood samples 17 years before clinical symptoms appeared. The sensory is able to detect the misfolding of amyloid beta.

Source: RUB

The dementia disorder Alzheimers disease has a symptom-free course of 15 to 20 years before the first clinical symptoms emerge. Using an immuno-infrared sensor developed in Bochum, a research team is able to identify signs of Alzheimers disease in the blood up to 17 years before the first clinical symptoms appear. The sensor detects the misfolding of the protein biomarker amyloid-beta. As the disease progresses, this misfolding causes characteristic deposits in the brain, so-called plaques.

Our goal is to determine the risk of developing Alzheimers dementia at a later stage with a simple blood test even before the toxic plaques can form in the brain, in order to ensure that a therapy can be initiated in time, says Professor Klaus Gerwert, founding director of the Centre for Protein Diagnostics (PRODI) at Ruhr-Universitt Bochum. His team cooperated for the study with a group at the German Cancer Research Centre in Heidelberg (DKFZ) headed by Professor Hermann Brenner.

The team published the results obtained with the immuno-infrared sensor in the journal Alzheimers & Dementia: The Journal of the Alzheimers Association on 19 July 2022.

This study is supported by a comparative study published in the same journal on 2 March 2022, in which the researchers used complementary single-molecule array (SIMOA) technology.

Early detection of symptom-free people with a high risk of Alzheimers disease

The researchers analysed blood plasma from participants in the ESTHER study conducted in Saarland for potential Alzheimers biomarkers. The blood samples had been taken between 2000 and 2002 and then frozen.

At that time, the test participants were between 50 and 75 years old and hadnt yet been diagnosed with Alzheimers disease. For the current study, 68 participants were selected who had been diagnosed with Alzheimers disease during the 17-year follow-up and compared with 240 control subjects without such a diagnosis.

The team headed by Klaus Gerwert and Hermann Brenner aimed to find out whether signs of Alzheimers disease could already be found in the blood samples at the beginning of the study.

The immuno-infrared sensor was able to identify the 68 test subjects who later developed Alzheimers disease with a high degree of test accuracy. For comparison, the researchers examined other biomarkers with the complementary, highly sensitive SIMOA technology specifically the P-tau181 biomarker, which is currently being proposed as a promising biomarker candidate in various studies.

Unlike in the clinical phase, however, this marker is not suitable for the early symptom-free phase of Alzheimers disease, as Klaus Gerwert summarises the results of the comparative study.

Surprisingly, we found that the concentration of glial fibre protein (GFAP) can indicate the disease up to 17 years before the clinical phase, even though it does so much less precisely than the immuno-infrared sensor.

Still, by combining amyloid-beta misfolding and GFAP concentration, the researchers were able to further increase the accuracy of the test in the symptom-free stage.

Start-up aims to bring immuno-infrared sensor to market maturity

The Bochum researchers hope that an early diagnosis based on the amyloid-beta misfolding could help to apply Alzheimers drugs at such an early stage that they have a significantly better effect for example, the drug Aduhelm, which was recently approved in the USA.

We plan to use the misfolding test to establish a screening method for older people and determine their risk of developing Alzheimers dementia, says Klaus Gerwert.

The vision of our newly founded start-up betaSENSE is that the disease can be stopped in a symptom-free stage before irreversible damage occurs.

Even though the sensor is still in the development phase, the invention has already been patented worldwide. BetaSENSE aims to bring the immuno-infrared sensor to market and have it approved as a diagnostic device so that it can be used in clinical labs.

Clinical trials with Alzheimers drugs often fail

Approved by the FDA in the USA in spring 2021, the drug Aduhelm has been shown to clear amyloid-beta plaques from the brain. However, previous studies showed it had only a minor effect on clinical symptoms such as memory loss and disorientation. Consequently, the European Medicines Agency decided in winter 2021 not to approve the drug in Europe.

Up to now, clinical trials for Alzheimers drugs have been failing by the dozen, apparently because the established plaque tests used in the trials dont flag up the disease in time, says Gerwert.

It seems that once plaques are deposited, they induce irreversible damage in the brain.

In the tests used to date, the plaques are either detected directly in the brain with the complex and expensive PET scan technology or indirectly determined in a less complex way using protein biomarker concentrations in invasively obtained cerebrospinal fluid with ELISA or mass spectrometry technology.

In contrast to established plaque diagnostics, the immuno-infrared sensor indicates the earlier misfolding of amyloid-beta, which causes the later plaque deposition.

However, it is still controversially discussed whether this misfolding is the cause of Alzheimers disease or if its just an accompanying factor, points out Gerwert.

For the therapeutic approach, this question is crucial, but it is irrelevant for the diagnosis. The misfolding indicates the onset of Alzheimers disease.

The exact timing of therapeutic intervention will become even more important in the future, predicts Lon Beyer, first author and PhD student in Klaus Gerwerts team.

The success of future drug trials will depend on the study participants being correctly characterised and not yet showing irreversible damage at study entry.

Biomarkers for Parkinsons and ALS

Misfolded proteins play a central role in many neurodegenerative diseases, such as Parkinsons disease, Huntingtons disease and amyotrophic lateral sclerosis (ALS).

As the researchers have showed, the immuno-infrared sensor can in principle also be used to detect other misfolded proteins, such as TDP-43, which is characteristic of ALS. They dont measure the concentration of a specific protein, but detect its misfolding using disease-specific antibodies.

Most importantly, this platform technology enables us to make a differential, precise biomarker-based diagnosis in the early stages of neurodegenerative diseases, in which the currently applied symptom-based diagnosis is very difficult and prone to errors, stresses Gerwert.

Author: Julia WeilerSource: RUBContact: Julia Weiler RUBImage: The image is in the public domain

Original Research: Open access.Amyloid-beta misfolding and GFAP predict risk of clinical Alzheimers disease diagnosis within 17 years by Klaus Gerwert et al. Alzheimers & Dementia

Abstract

Amyloid-beta misfolding and GFAP predict risk of clinical Alzheimers disease diagnosis within 17 years

Blood-based biomarkers for Alzheimers disease (AD) are urgently needed. Here, four plasma biomarkers were measured at baseline in a community-based cohort followed over 17 years, and the association with clinical AD risk was determined.

Amyloid beta (A) misfolding status as a structure-based biomarker as well as phosphorylated tau 181 (P-tau181), glial fibrillary acidic protein (GFAP), and neurofilament light (NfL) concentration levels were determined at baseline in heparin plasma from 68 participants who were diagnosed with AD and 240 controls without dementia diagnosis throughout follow-up.

A misfolding exhibited high disease prediction accuracy of AD diagnosis within 17 years. Among the concentration markers, GFAP showed the best performance, followed by NfL and P-tau181. The combination of A misfolding and GFAP increased the accuracy.

A misfolding and GFAP showed a strong ability to predict clinical AD risk and may be important early AD risk markers. A misfolding illustrated its potential as a prescreening tool for AD risk stratification in older adults.

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Signs of Alzheimers in Blood 17 Years Before Symptoms Begin - Neuroscience News

Neuroscience

Searching for Meaning? Try Appreciating the Small Things – Neuroscience News

Summary: Appreciating the beauty in the smaller things in everyday life can contribute to a more meaningful existence, a new study reports.

Source: Texas A&M

Appreciating the intrinsic beauty in lifes everyday moments can contribute to a more meaningful existence, according to new research.

In a paper recently published inNature Human Behavior, Joshua Hicks, a professor in the Texas A&M University Department of Psychological and Brain Sciences, says this may be a previously unaccounted for factor tied to perceptions ofmeaning.

It might not relate to whether you matter in the grand scheme of things, but weve shown people who value thelittle things, like your cup of coffee in the morning or being mindful in conversations with others, tend to have a high sense of meaning in life, he said.

Hicks studies existential psychology. Put simply, he aims to understand the big questions in life. He describes his main focus as the experience of lifestudying peoples subjective feeling that their life has meaning.

Scholars like Hicks generally agree there are three main sources of a subjectively meaningful existence: coherence, or the feeling that ones life makes sense; the possession of clear, long-term goals and sense of purpose; and existential mattering. This last factor, he says, is the belief that ones actions matter to others.

What Hicks and his co-authors argue in their latest research is that appreciating and finding value in experiences, referred to as experiential appreciation, is a fourth fundamental pathway toward finding meaning in life.

Researchers measured this factor by asking study participants how strongly they identified with statements linked to findingbeautyin life and appreciating a wide variety of experiences.

They were also asked to recall the most meaningful event of the past month, among other questions, with the goal of measuring experiential appreciation. Hicks described this series of experiments ina recent articlehe co-authored forScientific American.

In each case, the results confirmed the original theory that appreciating small moments can make for a more meaningful life.

For example, participants who were assigned to watch a sequence of picturesque nature montages scored by slowly building instrumental music from the BBC documentary Planet Earth reported greater feelings of experiential appreciation than those who watched a two-minute instructional woodworking video.

Hicks said the research began early on in the COVID-19 pandemic, when people were isolated at home and in some cases unable to pursue their goals. The question of whether people could still experience a high sense of meaning during those conditions was of great importance, he said, and remains important in the post-quarantine era.

Understanding the main components contributing to meaning in life can help researchers look for interventions for those who feel their lives lack meaning, he said.

People with certain personality types may be better at practicing mindfulness and recognizing intrinsic beauty, Hicks said, but that doesnt mean everyone cant cultivate this skill. To appreciate the small things in a fast-paced world, he said, people just need to slow down.

Meaning is all around us when we can experience the natural beauty in the world. It can be the beauty in another persons face, the food we eat or the songs we listen to, he said.

Right now, since cell phones and social media are so prevalent, I think that stuff detracts from our sense of meaning. Those things can be entertaining, but too much of it can really distract from whats real, like natural beauty.

Author: Caitlin ClarkSource: Texas A&MContact: Caitlin Clark Texas A&MImage: The image is in the public domain

Original Research: Closed access.Experiential appreciation as a pathway to meaning in life by Jinhyung Kim et al. Nature Human Behavior

Abstract

Experiential appreciation as a pathway to meaning in life

A key research program within the meaning in life (MIL) literature aims to identify the key contributors to MIL. The experience of existential mattering, purpose in life and a sense of coherence are currently posited as three primary contributors to MIL. However, it is unclear whether they encompass all information people consider when judging MIL.

Based on the ideas of classic and contemporary MIL scholars, the current research examines whether valuing ones life experiences, or experiential appreciation, constitutes another unique contributor to MIL. Across seven studies, we find support for the idea that experiential appreciation uniquely predicts subjective judgements of MIL, even after accounting for the contribution of mattering, purpose and coherence to these types of evaluations.

Overall, these findings support the hypothesis that valuing ones experiences is uniquely tied to perceptions of meaning. Implications for the incorporation of experiential appreciation as a fundamental antecedent of MIL are discussed.

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Searching for Meaning? Try Appreciating the Small Things - Neuroscience News

Neuroscience

Detection of Pitch Errors in Well-Known Songs – Neuroscience News

Summary: A songs lyrics have an effect on our ability to process musical pitch, but not necessarily due to the meaningfulness of the words.

Source: University of Montreal

Ever notice when someones singing out of key? Like when youre in a karaoke bar and your best friend belts out her favorite Adele track but woefully misses the mark? Ever wonder how you know right away shes singing flat?

Well, Michael Weiss might have an answer for you.

A postdoctoral fellow of Professor Isabelle Peretz at Universit de Montrals International Laboratory for Brain, Music, and Sound Research, Weiss set up a series of listening experiments to see how humans process musicalpitch.

Choosing well-known songs like Happy Birthday and Over the Rainbow, he wanted to know whether the presence of lyrics plays a role in detecting false notes: if there are lyrics, do we have more trouble detecting changes in pitch? If so, is it because we are processing the meaning of the words, or simply that lyrics have lots of changing syllables?

The results of Weiss study were published in May in the journalPsychology in Music. We asked him to tell us more about it, with some musical examples.

First of all, can you define what pitch is?

Pitch is apsychological phenomenonthat relates to the frequency of a sound wave, and its the basis for how we hear melodies, which are just a series of pitches. We hearlower frequenciesas lower pitches, and higher frequencies as higher pitches, but theres much more to it than that. In music, pitch is also what allows us to tell if a note is in tune relative to the other notes.

How do humans know when something is in or out of tune?

Mostly, we just know, it isnt something we consciously think about. Thats why we sometimes describe an out-of-tune note as sourits a visceral experience. We all grow up in a musical culture or more than oneand learn the rules of that music simply by listening, things like musical scales or keys (for example, C major), which are really just ways of describing our expectations.

That being said, there are different sensitivities to pitch from individual to individual, and even some individuals, those with whats called congenital amusia, who have great difficulty noticing an out-of-tune note. (You can go test yourself for amusia onour labs website.)

In your study, what did you set out to find?

We had a very narrow question: when you hear a melody sung by a voice, is it more difficult to track pitch when there are lyrics? So we created short excerpts from familiar melodies and asked a singer to perform them in three ways: (1) with lyrics, (2) without lyrics but with changing syllables, namely scat singing, as in doo bah dee bah, and (3) with unchanging syllables (la la la). In all cases it was the same pitch information.

However, lyrics add extra information for the listener to processthe meaning of the words. Scat singing, in a way, also has extra information to process, because the sounds are changing, but there is no meaning to it.

So with these conditions we can see if adding lyrics makes the task more difficult, and if so, whether its due to processing meaning or simply changing sounds.

For each experiment, you had two to three dozen student participants listen to some pop songs specially recorded by an amateur female vocalist: which ones, for example?

We chose extremely familiar songs because we wanted our listeners to have expectations about what the melody should sound like when its perfectly in tune. That way, when we mistune a note, they will notice. So we chose songs like Happy Birthday, Over the Rainbow, and Brother John.

And you concluded that some songs were more easily processed than others? The ones with fewer lyrics, or with simple repeated lyrics?

The results showed that it was more difficult to detect a mistuned note in the songs with lyrics or scat singing, compared to the songs sung simply with la la la. Importantly, we found that there wasnt much of a difference between lyric singing and scat singing. Together that means that lyrics have an effect on our ability to process musical pitch, but it isnt necessarily due to the meaningfulness of the words.

Who do you think your research will benefit?

This is research in the basic sense, meaning that it helps us understand more about the psychological phenomenon of musical pitch-processing and doesnt have an immediate use or application. That said, it might be of interest to those who sing, for example in choirs, or in music therapies. But generally my hope is that it will generate more research questions about how we process pitch. Thesinging voiceis understudied in music cognition, despite being the original instrument of our species.

And looking beyond music, could all this help us better understand how the brain works?

That is the goal of cognitive psychologyunderstanding how our brain processes information and allows us to act on it. I feel that music cognition is such an important area because we are moved by music from the earliest moments of lifein lullabies, play songs, and the like and because music is present in all societies in different forms.

Humans have had music for longer than we collectively rememberthe earliest physical musical instruments are tens of thousands of years old, and we may have been singing long before that. So, how we learn the rules ofmusic, and how we act on that information, is to me as fundamental a question as how we acquire and use language.

Author: Jeff HeinrichSource: University of MontrealContact: Jeff Heinrich University of MontrealImage: The image is in the public domain

Original Research: Closed access.Detection of pitch errors in well-known songs by Michael W Weiss et al. Psychology of Music

Abstract

Detection of pitch errors in well-known songs

We examined pitch-error detection in well-known songs sung with or without meaningful lyrics.

In Experiment 1, adults heard the initial phrase of familiar songs sung with lyrics or repeating syllables (la) and judged whether they heard an out-of-tune note. Half of the renditions had a single pitch error (50 or 100 cents); half were in tune. Listeners were poorer at pitch-error detection in songs with lyrics.

In Experiment 2, within-note pitch fluctuations in the same performances were eliminated by auto-tuning. Again, pitch-error detection was worse for renditions with lyrics (50 cents), suggesting adverse effects of semantic processing.

In Experiment 3, songs were sung with repeating syllables orscatsyllables to ascertain the role of phonetic variability. Performance was poorer for scat than for repeating syllables, indicating adverse effects of phonetic variability, but overall performance exceeded Experiment 1.

In Experiment 4, listeners evaluated songs in all styles (repeating syllables, scat, lyrics) within the same session. Performance was best with repeating syllables (50 cents) and did not differ between scat or lyric versions.

In short, tracking the pitches of highly familiar songs was impaired by the presence of words, an impairment stemming primarily from phonetic variability rather than interference from semantic processing.

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Detection of Pitch Errors in Well-Known Songs - Neuroscience News

Neuroscience

Ant Colonies Behave Like Neural Networks When Making Decisions – Neuroscience News

Summary: Researchers suggest that when in a group, ants behave in a similar fashion to networks of neurons in the brain.

Source: Rockefeller University

Temperatures are rising, and one colony of ants will soon have to make a collective decision. Each ant feels the rising heat beneath its feet but carries along as usual until, suddenly, the ants reverse course. The whole group rushes out as onea decision to evacuate has been made. It is almost as if the colony of ants has a greater, collective mind.

A newstudysuggests that indeed, ants as a group behave similar to networks of neurons in a brain.

RockefellersDaniel Kronauerand postdoctoral associate Asaf Gal developed a new experimental setup to meticulously analyze decision-making in ant colonies.

As reported in theProceedings of the National Academy of Sciences, they found that when a colony evacuates due to rising temperatures, its decision is a function of both the magnitude of the heat increase and the size of the ant group.

The findings suggest that ants combine sensory information with the parameters of their group to arrive at a group responsea process similar to neural computations giving rise to decisions.

We pioneered an approach to understand the ant colony as a cognitive-like system that perceives inputs and then translates them into behavioral outputs, says Kronauer, head of the Laboratory of Social Evolution and Behavior.

This is one of the first steps toward really understanding how insect societies engage in collective computation.

A new paradigm

At its most basic level, decision-making boils down to a series of computations meant to maximize benefits and minimize costs. For instance, in a common type of decision-making called sensory response thresholding, an animal has to detect sensory input like heat past a certain level to produce a certain costly behavior, like moving away. If the rise in temperature isnt big enough, it wont be worth it.

Kronauer and Gal wanted to investigate how this type of information processing occurs at the collective level, where group dynamics come into play. They developed a system in which they could precisely perturb an ant colony with controlled temperature increases.

To track the behavioral responses of individual ants and the entire colony, they marked each insect with different colored dots and followed their movements with a tracking camera.

As the researchers expected, colonies of a set size of 36 workers and 18 larvae dependably evacuated their nest when the temperature hit around 34 degrees Celsius. This finding makes intuitive sense, Kronauer says, because if you become too uncomfortable, you leave.

However, the researchers were surprised to find that the ants were not merely responding to temperature itself. When they increased the size of the colony from 10 to 200 individuals, the temperature necessary to trigger the decision to vacate increased. Colonies of 200 individuals, for example, held out until temperatures soared past 36 degrees.

It seems that the threshold isnt fixed. Rather, its an emergent property that changes depending on the group size, Kronauer says.

Individual ants are unaware of the size of their colony, so how can their decision depend on it? He and Gal suspect that the explanation has to do with the way pheromones, the invisible messengers that pass information between ants, scale their effect when more ants are present.

They use a mathematical model to show that such a mechanism is indeed plausible. But they do not know why larger colonies would require higher temperatures to pack up shop.

Kronauer ventures that it could simply be that the larger the colonys size, the more onerous it is to relocate, pushing up the critical temperature for which relocations happen.

In future studies, Kronauer and Gal hope to refine their theoretical model of the decision-making process in the ant colony by interfering with more parameters and seeing how the insects respond. For example, they can tamper with the level of pheromones in the ants enclosure or create genetically altered ants with different abilities to detect temperature changes.

What weve been able to do so far is to perturb the system and measure the output precisely, Kronauer says. In the long term, the idea is to reverse engineer the system to deduce its inner workings in more and more detail.

Author: Katherine FenzSource: Rockefeller UniversityContact: Katherine Fenz Rockefeller UniversityImage: The image is credited to Daniel Kronauer

Original Research: Open access.The emergence of a collective sensory response threshold in ant colonies by Daniel Kronauer et al. PNAS

Abstract

The emergence of a collective sensory response threshold in ant colonies

The sensory response threshold is a fundamental biophysical property of biological systems that underlies many physiological and computational functions, and its systematic study has played a pivotal role in uncovering the principles of biological computation.

Here, we show that ant colonies, which perform computational tasks at the group level, have emergent collective sensory response thresholds.

Colonies respond collectively to step changes in temperature and evacuate the nest during severe perturbations. This response is characterized by a group-sizedependent threshold, and the underlying dynamics are dominated by social feedback between the ants.

Using a binary network model, we demonstrate that a balance between short-range excitatory and long-range inhibitory interactions can explain the emergence of the collective response threshold and its size dependency.

Our findings illustrate how simple social dynamics allow insect colonies to integrate information about the external environment and their internal state to produce adaptive collective responses.

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Ant Colonies Behave Like Neural Networks When Making Decisions - Neuroscience News

Neuroscience

Perception Depends on Whether You Are Looking Up or Down – Neuroscience News

Summary: The intensity of perceptual bias in specific views depends upon posture and the position of your neck, a new study reveals.

Source: TUT

A research team led by Fumiaki Sato, a doctoral student at the Department of Computer Science and Engineering, Toyohashi University of Technology with the Japan Society for the Promotion of Science (JSPS) Research Fellowship for Young Scientists, and professors Shigeki Nakauchi and Tetsuto Minami discovered that the intensity of perceptual bias in specific views varies depending on the posture of the neck.

This research investigated how changes in posture have a contextual effect on visual perception. Specifically, the experiment used the Necker cube as a visual stimulus that would potentially generate two different visual perceptions.

In a virtual reality (VR) space, it placed the stimulus above and below each subject and asked them to report how it appeared in a posture that involved looking up at the stimulus and in another posture that involved looking down at it.

The experiment revealed that the visual perception of the stimulus varied depending on the viewing posture.

Details

The common belief is that whenever we see something, we perceive the image as cameras do. In fact, our visual perception is flexible, changing with circumstances and context. One well-known phenomenon is the color contrast effect, or the variation in how a specific color looks depending on the colors around it.

The mechanism behind these shifts in perception is still largely unknown and investigating it is considered significant to understanding how our visual experience is constructed.

The human visual system processes a tremendous volume of information according to a method that is based on practical experience acquired through learning. This is called the heuristic method, and it has been made clear by a study on the interpretation of ambiguous figures.

Take the Necker cube shown below for example. It is possible to perceive this cube in two different ways. Observers are more likely to recognize it as an image viewed from above than from below.

This tendency in perception is called perceptual bias. It is understood that this bias arises from the fact that humans have more experience seeing a cube from above than from below in everyday life.

It is known that the human visual system is thus susceptible to an experience-based context. However, it was unknown whether the experiential context is linked to physical posture.

To resolve this point, the research team carried out an experiment using the Necker cube mentioned above to study changes in probability of perception. Participants were asked to how the Necker cube looked when it was placed at each of five different angles, specifically 60, 30, 0, -30 and -60, in a virtual space.

The experiment was conducted not only under a vertical condition, defined as moving the neck vertically, but also under a horizontal condition, defined as moving the neck horizontally, which were provided as controlled conditions. It demonstrated that the probability of the view-from-above (VFA) interpretation is significantly higher in the state of looking vertically downwards than in the state of looking upwards.

There was no significant difference observed under the horizontal condition.

Fumiaki Sato, the lead author of the research and a third-year student in the second half of the doctoral course, explains: In daily life, there will almost certainly be differences in the frequency with which we view particular objects looking up at them or looking down at them. For example, we often see the sun, fluorescent lamps and other light sources when looking up. We rarely see them looking down.

Our question was whether the difference in visual experience depending on posture leads to a difference in visual perception, and our experiment sought to answer this. This study employed a stimulus that would possibly induce two different visual interpretations despite constant input. This means that the information received on the retina is identical under any condition.

However, the percentage of interpretations did vary depending on the posture. This suggests that the human visual system uses posture as a factor in determining the perception.

The research findings show that the human visual system flexibly modulates observers perception according to their posture.

Future Outlook

The research team has demonstrated that the human visual system flexibly modulates observers perception according to their posture. This research is expected to help develop a model for the expression of human visual perception. The experiment measured the pupil diameter, believed to reflect the cognitive factor.

Although details are not provided, the results suggest that the pupil size is closely related to the neck movement in the vertical direction.

A future research objective will therefore be to explore the mechanism behind the links between the perception, the pupil diameter and the posture.

Author: Yuko ItoSource: TUTContact: Yuko Ito TUTImage: The image is credited to TUT

Original Research: Open access.Backward and forward neck tilt affects perceptual bias when interpreting ambiguous figures by Fumiaki Sato et al. Scientific Reports

Abstract

Backward and forward neck tilt affects perceptual bias when interpreting ambiguous figures

The relationships between posture and perception have already been investigated in several studies. However, it is still unclear how perceptual bias and experiential contexts of human perception affect observers perception when posture is changed. In this study, we hypothesized that a change in the perceptual probability caused by perceptual bias also depends on posture.

In order to verify this hypothesis, we used the Necker cube with two types of appearance, from above and below, although the input is constant, and investigated the change of the probability of perceptual content. Specifically, we asked observers their perception of the appearance of the Necker cube placed at any of the five angles in the space of virtual reality. There were two patterns of neck movement, vertical and horizontal. During the experiment, pupil diameter, one of the cognitive indices, was also measured.

Results showed that during the condition of looking down vertically, the probability of the viewing-from-above perception of the Necker cube was significantly greater than during the condition of looking up. Interestingly, the pupillary results were also consistent with the probability of the perception.

These results indicate that perception was modulated by the posture of the neck and suggest that neck posture is incorporated into ecological constraints.

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Neuroscience

Childhood Loneliness Linked to Stress and Problem Drinking in Young Adults – Neuroscience News

Summary: Children who experience loneliness before the age of 12 are more likely to experience stress in early adulthood which leads to an increased risk of an unhealthy relationship with alcohol.

Source: Arizona State University

Before the pandemic, over1 in 10 childrenaged 10-12 years reported being lonely.

New research has shown that experiencing loneliness as a pre-adolescent child predicts problem drinking years later, in early adulthood.

Alcohol misuse is not the only health problem connected to loneliness. In older adults,lonelinesscontributes to poor physical health, including dementia, heart disease and stroke.

Researchers from Arizona State University examined the effects of experiencing childhood loneliness on current stress levels and drinking behaviors in young adults. Thestudywill be published inAddictive Behaviors Reports.

In young adults, childhood loneliness before age 12 was associated with perceived stress right now and affected dysregulated drinking, said Julie Patock-Peckham, assistant research professor in the ASU Department of Psychology.

Because stress affects whether people drink to excess,especially women, the research team tested whether past experiences with loneliness impacted the stress people feel today.

Over 300 college students participated in the study, completing assessments of childhood loneliness, current stress levels and drinking behaviors. Feeling lonely in the past was related to present-day stress levels and drinking behaviors.

Higher levels of loneliness before age 12 predicted more stress in early adulthood that was associated with greater alcohol use and alcohol-related problems.

The data used in this study were collected before the pandemic, and the findings suggest that we could have another public health crisis on our hands in a few years as todays children grow up, Patock-Peckham said.

We need more research into whether mitigating childhood loneliness could be a way to disrupt the pathways that lead to alcohol use disorders in adults. Combating childhood loneliness should help to reduce impaired control over drinking, especially among women.

This study was funded by the National Institute on Alcohol Abuse and Alcoholism and the Burton Family Foundation. The research team also consisted of Sophia Berbian and Kiana Guarino, undergraduate students at ASU; Tanya Gupta, a recent graduate of the psychology doctoral program; and Federico Sanabria and Frank Infurna, associate professors of psychology.

Author: Robert EwingSource: Arizona State UniversityContact: Robert Ewing Arizona State UniversityImage: The image is in the public domain

Original Research: Open access.Does loneliness before the age of twelve indirectly affect impaired control over drinking, alcohol use, and problems through perceived stress? by Julie Patock-Peckham et al. Addictive Behaviors Reports

Abstract

Does loneliness before the age of twelve indirectly affect impaired control over drinking, alcohol use, and problems through perceived stress?

Loneliness is the pain of feeling socially isolated from others (Russell et al., 1980). The Stress-Dampening Hypothesis (Marlatt, 1987; Sayette, 1993; Sher, 1987) posits that individuals drink to alleviate negative affect. To date, it has not been determined whether loneliness experienced as a child can indirectly influence at-risk patterns of alcohol use through the mediating mechanism of stress and impaired control. Impaired control over alcohol use (IC) is the difficulty adhering to ones own self-proscribed limits on drinking behaviors (Heather et al., 1993). Impaired control is an at-risk pattern of use that is particularly relevant to emerging adults.

Methods:We examined the direct and indirect relationships between childhood loneliness, stress, IC, and alcohol-related problems with a structural equation model. In a college student sample, we utilized a (k=20,000) bootstrap technique and a model indirect command in Mplus to examine potential mediational pathways. Cisgender sex was included as a covariate.

Results:Loneliness was directly linked to stress as well as to alcohol-related problems. Higher levels of loneliness were indirectly linked to both more alcohol use and alcohol-related problems through more stress and in turn, more impaired control over drinking.

Conclusions:The current study is consistent with the Stress Dampening Hypothesis (Marlatt, 1987; Sayette, 1993; Sher, 1987). Our findings suggest that therapeutic interventions combating loneliness in childhood may disrupt the stress-dampening pathway to dysregulated alcohol use in emerging adulthood.

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Childhood Loneliness Linked to Stress and Problem Drinking in Young Adults - Neuroscience News

Neuroscience

Going to the Beach? Planning a Hike? Be Prepared: Men Will Be Much Hungrier! – Neuroscience News

Summary: In males, sun exposure activates the p53 protein which signals to the body to produce the appetite-associated ghrelin hormone. In women, estrogen blocks the interaction between p53 and ghrelin, reducing the urge to eat following sun exposure.

Source: Tel Aviv University

A new study from Tel Aviv University reveals that solar exposure increases appetite in males, but not in females. Conducted on lab models, the study unravels the differences between males and females in the activation of the metabolic mechanism.

The researchers explain that in males of both animal species and humans, sun exposure activates a protein called p53, in order to repair any DNA damage in the skin that might have been caused by the exposure. The activation of p53 signals the body to produce a hormone called ghrelin, which stimulates the appetite.

In females, the hormone estrogen blocks the interaction between p53 and ghrelin, and consequently does not catalyze the urge to eat following exposure to the sun.

The groundbreaking study was led by Prof. Carmit Levy and PhD student Shivang Parikh of the Department of Human Genetics and Biochemistry at TAUs Sackler Faculty of Medicine.

It was conducted in collaboration with many researchers in Israel and worldwide, including contributors from Tel Aviv Sourasky (Ichilov), Assuta, Meir, and Sheba Medical Centers, along with Dr. Yiftach Gepner and Dr. Lior Bikovski from TAUs Sackler Faculty of Medicine, and Prof. Aron Weller of Bar-Ilan University.

The paper was published in the prestigious journalNature Metabolism.

The study was based on epidemiological data collected in a year-long survey about the eating habits of approximately 3,000 Israelis of both sexes, including self-reports from students who had spent time in the sun, combined with the results of a genetic study in a lab model.

The findings identify the skin as a primary regulator of energy and appetite (metabolism) in both lab models and humans.

The researchers explain that there is a dramatic metabolic difference between males and females, impacting both their health and their behavior. However, so far it has not been established whether the two sexes respond differently to environmental triggers such as exposures to the suns UV radiation.

Prof. Levy: We examined the differences between men and women after sun exposure and found that men eat more than women because their appetite has increased.

Our study was the first gender-dependent medical study ever conducted on UV exposure, and for the first time, the molecular connection between UV exposure and appetite was deciphered.

Gender-dependent medical studies are particularly complex, since twice the number of participants are required in order to find statistically significant differences.

Prof. Levy concludes: As humans, we have cast off our furand consequently, our skin, the largest organ in our body, is exposed to signals from the environment. The protein p53, found in the skin, repairs damage to the DNA caused by sun exposure, but it does more than that. It signals to our bodies that winter is over, and we are out in the sun, possibly in preparation for the mating season.

Our results provide an encouraging basis for more research, on both human metabolism and potential UV-based therapies for metabolic diseases and appetite disorders.

Author: Noga ShaharSource: Tel Aviv UniversityContact: Noga Shahar Tel Aviv UniversityImage: The image is in the public domain

Original Research: Open access.Food-seeking behavior is triggered by skin ultraviolet exposure in males by Carmit Levy et al. Nature Metabolism

Abstract

Food-seeking behavior is triggered by skin ultraviolet exposure in males

Sexual dimorphisms are responsible for profound metabolic differences in health and behavior. Whether males and females react differently to environmental cues, such as solar ultraviolet (UV) exposure, is unknown.

Here we show that solar exposure induces food-seeking behavior, food intake, and food-seeking behavior and food intake in men, but not in women, through epidemiological evidence of approximately 3,000 individuals throughout the year.

In mice, UVB exposure leads to increased food-seeking behavior, food intake and weight gain, with a sexual dimorphism towards males.

In both mice and human males, increased appetite is correlated with elevated levels of circulating ghrelin.

Specifically, UVB irradiation leads to p53 transcriptional activation of ghrelin in skin adipocytes, while a conditional p53-knockout in mice abolishes UVB-induced ghrelin expression and food-seeking behavior. In females, estrogen interferes with the p53chromatin interaction on the ghrelin promoter, thus blocking ghrelin and food-seeking behavior in response to UVB exposure.

These results identify the skin as a major mediator of energy homeostasis and may lead to therapeutic opportunities for sex-based treatments of endocrine-related diseases.

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Going to the Beach? Planning a Hike? Be Prepared: Men Will Be Much Hungrier! - Neuroscience News

Neuroscience

Engineered Mattress Tricks Your Body to Fall Asleep Faster – Neuroscience News

Summary: A new pillow and mattress system stimulates the body to trigger sleepy feelings by using heating and cooling sensations. Researchers say the new system helps people fall asleep faster and improves the quality of overall sleep.

Source: UT Austin

When people feel sleepy or alert, that sensation is controlled in part by the ebb and flow of a 24-hour rhythm of their body temperature.

Bioengineers at The University of Texas at Austin have developed a unique mattress and pillow system that uses heating and cooling to tell the body it is time to go to sleep.

Sleep is possible when the body temperature declines at night as part of the 24-hour rhythm. This new mattress stimulates the body to trigger the sleepy feeling, helping people fall asleep faster and improving the quality of sleep.

We facilitate the readiness to fall asleep by manipulating internal body temperature-sensitive sensors to briefly adjust the thermostat of the body so it thinks the temperature is higher than it actually is, said Shahab Haghayegh, a research fellow at Harvard Medical Schools Division of Sleep Medicine and Brigham and Womens Hospital, who helped lead the development of the mattress at UT Austin while earning a Ph.D. in biomedical engineering. Haghayegh graduated in 2020.

The skin of the neck is an important bodily thermostat for humans, and it is the primary sensor the mattress targets, with a warming pillow. The mattress is designed to simultaneously cool the central areas of the body while heating up the neck, hands and feet, thereby increasing blood flow to dissipate body heat.

The researchers published a proof-of-concept study about the unique combination warming pillow plus cooling-warming, dual-zone mattress system in theJournal of Sleep Research, looking at two versions of the mattress: one that uses water and another that uses air to manipulate the core body temperature.

They tested the mattresses with 11 subjects, asking them to go to bed two hours earlier than usual, some nights using the cooling-warming functions of the mattresses and other nights not.

The study found that the warming and the cooling-warming mattress helped them fall asleep faster approximately 58% faster compared with nights when they did not use the cooling-warming function, even in the challenging setting of an earlier bedtime.

Not only did lowering internal body temperature significantly shorten the amount of time required to fall asleep, it also resulted in significantly improved quality of sleep.

The project arose out of a larger goal in the lab of Kenneth Diller, a professor in the Cockrell School of Engineering and an expert in heat and temperature regulation for therapeutic devices, to find new ways to use thermal stimulation to help people sleep.

The researchers published astudy in 2019 that found taking a warm bathan hour or two before bed helped people fall asleep quickly and sleep better.

This project is similar but more targeted. Lowering the internal body temperature at the right circadian time sends the signal that it is time to go to sleep. Targeting the important bodily sensors in just a few areas that control heat dissipation, and thus body temperature level, made more sense than focusing on the entire body.

It is remarkable how effective gentle warming along the cervical spine is in sending a signal to the body to increase blood flow to the hands and feet to lower the core temperature and precipitate sleep onset, Diller said.

This same effect also enables the blood pressure to fall slightly overnight, with the benefit of allowing the cardiovascular system to recover from the stress of maintaining blood flow during daily activities, which is highly important for long-term health.

The team has a patent for the cooling-warming mattress and pillow technology and is seeking partnerships with mattress companies to commercialize it.

Other members of the team are Sepideh Khoshnevis and Michael Smolensky of UT Austin, Ramn Hermida of the University of Vigo in Spain, Richard Castriotta of the University of Southern California and Eva Schernhammer of Harvard University.

Author: Nat LevySource: UT AustinContact: Nat Levy UT AustinImage: The image is credited to UT Austin

Original Research: Closed access.Novel temperature-controlled sleep system to improve sleep: a proof-of-concept study by Shahab Haghayegh et al. Journal of Sleep Research

Abstract

Novel temperature-controlled sleep system to improve sleep: a proof-of-concept study

The sleepwake cycle is regulated by circadian Process C and homeostatic Process S. Selective thermal stimulation (STS) of the cervical spine region enhances glabrous skin blood flow (GSBF) and augments body heat dissipation to increase distal-to-proximal skin gradient (DPG) causing decrease of core body temperature (CBT), which can shorten sleep onset latency (SOL) and improve sleep quality.

A total of 11 young healthy/normal sleeper males challenged to go to bed (lights-off) 2h earlier than usual were subjected in a randomised order to non-consecutive treatment and control night-time sleep sessions.

The treatment night entailed activation of a dual-temperature zone mattress with a cooler centre and warmer periphery plus STS pillow that applied mild heating to the cervical spinal skin for 30min after lights-off for sleep.

During the first 30min after lights-off, GSBF (mean [standard error (SE)] =49.77[19.13]perfusion units,p=0.013) and DPG (mean [SE] =2.05[0.62]C,p=0.005) were significantly higher and CBT (mean [SE] =0.15[0.07]C,p=0.029) was significantly lower in the treatment than control night, while there was no significant difference in these variables during the 45min prior to lights-off (baseline).

Moreover, SOL was significantly reduced (mean [SE] =48.6[23.4]min,p=0.032) and subjective sleep quality significantly better (p<0.001) in the treatment than control night. In conclusion, the novel sleep facilitating system comprised of the STS pillow plus dual-temperature zone mattress induced earlier increase in GSBF and DPG and earlier decline in CBT.

This resulted in statistically significant shortened SOL and improved overall sleep quality, thereby reducing sleep pressure of Process S, even under the challenging investigative protocol requiring participants to go to sleep 2h earlier than customary.

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Engineered Mattress Tricks Your Body to Fall Asleep Faster - Neuroscience News

Neuroscience

Study Finds Widespread False Memories of Logos and Characters, Including Mr. Monopoly and Pikachu – Neuroscience News

Summary: When it comes to famous logos and characters, people often experience a Visual Mandela Effect, or consistent, confident, and widespread false memories of such famous icons.

Source: University of Chicago

If you had to describe Rich Uncle Pennybagsthe Monopoly mascotwould you mention his top hat? His mustache? How about his monocle?

The face of the famous board game has, in reality, never worn a monocle. Yet, many people confidently list the accessory when recalling his featuresan example of a phenomenon of falsevisual memories.

A forthcoming paper by University of Chicago scholars, currently available in preprint, found that people have consistent, confident, and widespreadfalse memoriesof famous iconsalso known as the Visual Mandela Effect. Co-authored by University of Chicago scholars, the paper is the first scientific study of the internet phenomenon.

Forthcoming in the journalPsychological Science, the paper adds to a growing body of evidence showing consistency in what people rememberbut by demonstrating new evidence that there is also consistency in what people misremember.

This effect is really fascinating because it reveals that there are these consistencies across people in false memories that they have for images theyve actually never seen, said Asst. Prof. Wilma Bainbridge, a neuroscientist and principal investigator at the Brain Bridge Lab in UChicagos Department of Psychology.

Motivated by reports of misremembered images online, Bainbridge and Deepasri Prasada lab manager and research assistant in the Brain Bridge Labcompiled images and their false-remembered counterpartsmostly from popular culturefrom the online discussions. Added to this mix of previously reported misremembered images were other pop culture icons and characters that the researchers made small tweaks to that would further test their theory.

The team set out to test four ideas. The first and main goal was to determine how widespread and consistent the Visual Mandela Effect was across individuals for the 40 different icons that they assembled. They also wanted to see where people were still making these errorseven if theyre very familiar and confident with their responses and with the characters.

Second, they wanted to know the underlying causes: Is it that people are just not looking at where this error is on the image? In the third experiment, they looked to quantify how common these false memory images are in the world by looking at Google Images. In the fourth experiment, they studied whether people spontaneously produce these errors: If asked to draw an image from memory, they often make the same errors.

We found that there really is a strong effect where people are reporting a false memory for an image theyve actually never seenbecause youve never seen Pikachu with a black tip on the tail, said Bainbridge, referring to a common false memory of the Pokmon character.

Whats more is that people tend to be very confident in picking this wrong image. And they also report that theyre pretty familiar with characters like Pikachuyet they still make these errors.

The researchers havent yet been able to pinpoint a single reason for why this happens, but they have eliminated a few possibilities. The visual differences arent striking across the different versions, so people arent looking at the images differently. So even if people look at the correct version of that part of the image (say, Pikachus tail), they still make this error.

They also ruled out schema theory as a universal explanation. Schema theory suggests we fill in the information thats missing based on our associations. This would explain why so many people misremember Rich Uncle Pennybags (also known as Mr. Monopoly) as having a monocle, because we associate the accessory with wealth.

But the researchers found examples where this doesnt fit. For example, people often falsely remember the Fruit of the Loom logo having a large cornucopia behind iteven though cornucopias arent very common in everyday life.

We had an alternative wrong version as well, Prasad said.

They could have picked the correct Fruit of the Loom logo, the Fruit of the Loom logo with the cornucopia, or the Fruit of the Loom logo with a plate underneath it. The fact that they chose cornucopia over plate, when plates are more frequently associated with fruit, is evidence against the idea that its just the schema theory explaining it.

One of the big questions in the Brain Bridge Lab is why people remember certain things over others. So far, the researchers have found that people tend to remember and forget the same things.

You would think that because all of us have our own individual experiences throughout our lives that wed all have these idiosyncratic differences in our memories, Bainbridge said.

But surprisingly, we find that we tend to remember the same faces and pictures as each other. This consistency in our memories is really powerful, because this means that I can know how memorable certain pictures are, I could quantify it. I could even manipulate the memorability of an image.

In finding that theres an intrinsic ability in some images to create false memories, the research suggests we may also be able to determine what creates false memories.

It also has some interesting implications in terms of logo design or how to select photographs for educational material and advertisement, because you want people to have accurate memories, Bainbridge said. You dont want them to misremember information. And that actually relates a lot to some other important topics right now, including what images are used in the media.

Author: Sarah SteimerSource: University of ChicagoContact: Sarah Steimer University of ChicagoImage: The image is credited to University of Chicago

Original Research: Closed access.The Visual Mandela Effect as evidence for shared and specific false memories across people by Wilma Bainbridge et al. Psychological Science

Abstract

The Visual Mandela Effect as evidence for shared and specific false memories across people

The Mandela Effect is an internet phenomenon describing shared and consistent false memories for specific icons in popular culture. The Visual Mandela Effect (VME) is a Mandela Effect specific to visual icons (e.g., the Monopoly Man is falsely remembered with a monocle) and has not yet been empirically quantified or tested.

In Experiment 1 (N=100), we demonstrate that certain images from popular iconography elicit consistent, specific false memories. In Experiment 2 (N=60), using eye-tracking-like methods, we find no attentional or visual differences that drive this phenomenon. There is no clear difference in the natural visual experience of these images (Experiment 3), and these VME-errors also occur spontaneously during recall (Experiment 4; N=50).

These results demonstrate that there are certain images for which people consistently make the same false memory error, despite majority of visual experience being the canonical image.

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Study Finds Widespread False Memories of Logos and Characters, Including Mr. Monopoly and Pikachu - Neuroscience News

Neuroscience

Loss of Youth Protein May Drive Aging in Eye – Neuroscience News

Summary: Age-related changes in the retina may be driven by the loss of the pigment epithelium-derived factor protein. The findings could pave the way for the development of treatment for age-related macular degeneration and other age-related vision loss disorders.

Source: NIH

Loss of the protein pigment epithelium-derived factor (PEDF), which protects retinal support cells, may drive age-related changes in the retina, according to a new study in mice from the National Eye Institute (NEI).

The retina is the light-sensitive tissue at the back of the eye, and aging-associated diseases of the retina, like age-related macular degeneration (AMD), can lead to blindness. This new finding could lead to therapies to prevent AMD and other aging conditions of the retina.

The study was published in theInternational Journal of Molecular Sciences.

People have called PEDF the youth protein, because it is abundant in young retinas, but it declines during aging, said Patricia Becerra, Ph.D., chief of NEIs Section of Protein Structure and Function and senior author of the study.

This study showed for the first time that just removing PEDF leads to a host of gene changes that mimic aging in the retina.

The retina is composed of layers ofcellsthat function together to detect and process light signals, which the brain uses to generate vision. The retinas light-sensing photoreceptors sit above theretinal pigment epithelium(RPE), a layer of support cells. The RPE nourishes photoreceptors and recycles pieces of the photoreceptor cells called outer segments, which get used up and their tips shed each time photoreceptors detect light.

If the RPE cannot provide recycled components of older outer segment tips back to photoreceptors, these cells lose their ability to make new segments, and eventually become unable to sense light. And without nutrients supplied by the RPE, photoreceptors die. In people with AMD or certain types of retinal dystrophies, senescence (aging) or death of RPE cells in the retina leads tovision loss.

Previous work from Becerras lab and others has shown that PEDF protects retinal cells, preventing both damage to the cells and abnormal growth of blood vessels in the retina. RPE cells produce and secrete the PEDF protein. The protein then binds to its receptor, PEDF-R, which is also expressed by RPE cells.

Binding by PEDF stimulates PEDF-R to break down lipid molecules, key components of the cell membranes that enclose photoreceptor outer segments and other cellular compartments. This breakdown step is a key part of the outer segment recycling process. And while researchers have known that PEDF levels drop in the retina during the aging process, it was not clear whether this loss of PEDF was causing, or merely correlated with, age-related changes in the retina.

To examine the retinal role of PEDF, Becerra and colleagues studied amouse modelthat lacks the PEDF gene (Serpin1). The researchers examined the cellular structure of the retina in the mouse model, finding that the RPE cell nuclei were enlarged, which may indicate changes in how the cells DNA is packed. The RPE cells also had turned on four genes associated with aging and cellular senescence, and levels of the PEDF receptor were significantly below normal.

Finally, unprocessed lipids and otherphotoreceptorouter segment components had accumulated in the RPE layer of the retina. Similar changes ingene expressionand defects in RPE metabolism are found in the aging retina.

One of the most striking things was this reduction in the PEDF receptor on the surface of the RPE cells in the mouse lacking the PEDF protein, said the studys lead author, Ivan Rebustini, Ph.D., a staff scientist in Becerras lab. It seems theres some sort of feedback-loop involving PEDF that maintains the levels of PEDF-R and lipid metabolism in the RPE.

While at first glance, the retinas of these PEDF-negative mice appear normal, these new findings suggest that PEDF is playing a protective role that helps the retina weather trauma and aging-related wear and tear.

We always wondered if loss of PEDF was driven by aging, or was driving aging, said Becerra. This study, especially with the clear link to altered lipid metabolism and gene expression, indicates the loss of PEDF is a driver of aging-related changes in theretina.

Author: Press OfficeSource: NIHContact: Press Office NIHImage: The image is credited to the NIH

Original Research: Open access.PEDF Deletion Induces Senescence and Defects in Phagocytosis in the RPE by Ivan T. Rebustini et al. International Journal of Molecular Sciences

Abstract

PEDF Deletion Induces Senescence and Defects in Phagocytosis in the RPE

The retinal pigment epithelium (RPE) expresses theSerpinf1gene to produce pigment epithelium-derived factor (PEDF), a retinoprotective protein that is downregulated with cell senescence, aging and retinal degenerations.

We determined the expression of senescence-associated genes in the RPE of 3-month-old mice that lack theSerpinf1gene and found thatSerpinf1deletion inducedH2axfor histone H2AX protein,Cdkn1afor p21 protein, andGlb1gene for -galactosidase. Senescence-associated -galactosidase activity increased in theSerpinf1null RPE when compared with wild-type RPE.

We evaluated the subcellular morphology of the RPE and found that ablation ofSerpinf1increased the volume of the nuclei and the nucleoli number of RPE cells, implying chromatin reorganization. Given that the RPE phagocytic function declines with aging, we assessed the expression of thePnpla2gene, which is required for the degradation of photoreceptor outer segments by the RPE.

We found that both thePnpla2gene and its protein PEDF-R declined with theSerpinf1gene ablation. Moreover, we determined the levels of phagocytosed rhodopsin and lipids in the RPE of theSerpinf1null mice. The RPE of theSerpinf1null mice accumulated rhodopsin and lipids compared to littermate controls, implying an association of PEDF deficiency with RPE phagocytosis dysfunction.

Our findings establish PEDF loss as a cause of senescence-like changes in the RPE, highlighting PEDF as both a retinoprotective and a regulatory protein of aging-like changes associated with defective degradation of the photoreceptor outer segment in the RPE.

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Loss of Youth Protein May Drive Aging in Eye - Neuroscience News