Research Your Resolution: Focus on Your Mental Health, Especially As You Age

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Jennifer Gatchel, MD, PhD

Jennifer Gatchel MD, PhD, is a geriatric psychiatrist at Massachusetts General Hospital and McLean Hospital and an investigator in the Department of Psychiatry at Mass General. She works with adults ages 60 and over to help them cope with life’s transitions. Read more about her research.


Although dementia is on the rise, it is not an inevitable part of getting older.

While the number of individuals with dementia worldwide is on the rise as populations age, data are encouraging that a fraction of dementias may be preventable and that lifestyle interventions may have the potential to modify the course of changes in memory and thinking with aging¹.

Data in healthy older adults from the Harvard Aging Brain Study showed an association between subclinical depressive symptoms and tau—a marker of neurodegenerative change—in two brain regions vulnerable in aging and dementia².

While the direction and causality of this relationship is unknown, this and other data highlight the importance of maintaining awareness of changes in your mental health, seeking help and support for symptoms of depression and anxiety, and maintaining intellectual and social engagement¹ ².

¹Livingston G, Sommerlad A, Orgeta V, et al: Dementia prevention, intervention, and care. Lancet 2017; 390:2673-2734
²Gatchel JR, Donovan NJ, Locascio JJ, et al: Depressive Symptoms and Tau Accumulation in the Inferior Temporal Lobe and Entorhinal Cortex in Cognitively Normal Older Adults: A Pilot Study. J Alzheimers Dis 2017; 59:975-985


Research Your Resolution

Do you have goals for improving your health in the New Year? This month, investigators from the Mass General Research Institute are discussing the science behind some common New Year’s resolutions, and offering tips and advice based on their research into exercise, diet, healthy aging, heart health, and much more.

Massachusetts General Hospital is home to the largest hospital-based research program in the United States, a community of more than 10,000 people working across 30 departments, centers and institutes. The Mass General Research Institute works to support, guide and promote these research initiatives.

Research Your Resolution: Boost Your Brain Health With Social Connections

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Joel Salinas, MD
Joel Salinas, MD

Joel Salinas, MD, is a behavioral neurologist, neuropsychiatrist, and social epidemiologist at the Massachusetts General Hospital Institute for Brain Health. To learn more about his research, please visit his lab website.


When we make social connections with other people, we live better and have healthier brains for longer.

This might mean re-connecting with old friends, making new friends, joining a group or a class, teaching someone something new, volunteering or offering to help others, or using technology to keep in touch, getting a pet, or simply sharing a smile.

Studying over 3,000 members of the Framingham, MA, community since 1948, and across multiple generations, we found that people who are the most socially isolated have lower blood levels of a molecule known as brain-derived neurotrophic factor (or BDNF) which is critical for keeping brain cells healthy and forming new connections between cells.

However, people who have someone available to listen to them or receive emotional support from someone else most or all of the time not only seem to have increased levels of BDNF, but they also have a lower risk of developing stroke and dementia.

There is no cure yet for many age-related brain diseases, but there is a cure for social isolation.

By addressing what we can change in our life to reduce our risk for brain disease, there may be a way to delay and eventually prevent these diseases and prolong the span of our brain health.


Research Your Resolution

Do you have goals for improving your health in the New Year? This month, investigators from the Mass General Research Institute are discussing the science behind some common New Year’s resolutions, and offering tips and advice based on their research into exercise, diet, healthy aging, heart health, and much more. See more posts in the series.

Massachusetts General Hospital is home to the largest hospital-based research program in the United States, a community of more than 10,000 people working across 30 departments, centers and institutes. The Mass General Research Institute works to support, guide and promote these research initiatives.

In Case You Missed it: Science Stories from Around the Web

We love good science stories here at the Mass General Research Institute and wanted to share a few of our favorites from other health and science websites. Enjoy!

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The best and worst analogies for CRISPR, ranked

From a knockout punch to an act of God, CRISPR technology has drawn comparisons to a vast array of things. Here is a list of 10 analogies ranked from worst to best. (STAT)


Is ‘Man Flu’ real? Men suffer more when sick, study suggests

A research team in the United Kingdom found evidence that men may have a weaker immune response to the viruses that cause the flu or common cold, and as a result, men may have a greater risk for serious symptoms.


It’s time to stop excluding people with disabilities from science

You can be a great scientist without being able to carry a 50-pound backpack out of cave, writes Gabriela Serrato Marks, a Marine Geologist at the Massachusetts Institute of Technology.


Altmetric’s Top 100 Articles of the Year

In the past year, Altmetric has tracked over 18.5 million mentions of 2.2 million research outputs. Here are the Top 100 ranked in order of their Altmetric Attention Score as of Nov. 15, 2017.


What is really driving the Altmetric’s Top 100 Articles List

“There is a data availability problem plaguing Altmetric’s annual top 100 list,” argues Kent Anderson of Scholarly Kitchen in this detailed critical breakdown of how the rankings are compiled. But Anderson also concludes that “Overall, the Top 100 list remains interesting, and perhaps data availability and other elements will improve over time.”


How loneliness affects our health

Scientists are gaining a more refined—and surprising—understanding of the effects of loneliness and isolation on health. (New York Times)


Jawdropping images reveal science is amazing

Photos are said to be worth “a thousand words.” And that’s what the Royal Society looks for when judging images for their Publishing Photography Competition, which celebrates the power of photography to communicate science.


Study: Opioids overused in migraine treatment, regardless of race

African Americans are more likely to experience debilitating migraine headaches than whites, but a new study probing the issue found no evidence of racial disparities in treatment practices. Instead, researchers from the University of Michigan report a different finding that affects everyone: opioid overuse.


Check out this video of perspiration on a human fingertip

This incredible up close video shows drops of sweat forming on the ridges of human fingertips. It was the second place winner in the video portion of the Nikon Small World Competition this year.


Neuroscience can learn a lot from Buddhism

A scientist and a monk compare notes on mediation, therapy and their effects on the brain. (Atlantic Monthly)

12 Days of Research at Mass General: Untangling the Connections Between Alzheimer’s Disease and Mental Illness

Banner 12 days of researchIn the 12 days leading up to our holiday hiatus, we are looking back on the past year and sharing some highlights in Massachusetts General Hospital research news from each month of 2017.

But before we get to the research, we want to thank you for following along with the Research Institute in 2017! We’ll be taking a short break over the holidays, but we can’t wait to continue sharing all the exciting research news and breakthroughs from Mass General in 2018!

December 2017:

Gatchel Untangles the Causes of Mood and Anxiety Symptoms and Loss of Brain Function in Aging Populations

Jennifer Gatchel studying Alzheimer's disease

Often referred to as the golden years, life after retirement can sometimes turn out to be less than sunny.

Dramatic lifestyle changes such as admittance to an assisted care facility and loss of mobility or independence can take a toll on mental health.

In fact, twenty percent of people over 55 suffer from a mental disorder, and two-thirds of nursing home residents exhibit mental and behavioral problems.

As a geriatric psychiatrist at Massachusetts General Hospital and McLean Hospital, Jennifer Gatchel MD, PhD, works with adults ages 60 and over to help them cope with life’s transitions.

For many of her patients, symptoms of mental illness are often compounded by symptoms that indicate the onset of degenerative conditions like Alzheimer’s disease.

“These are conditions I see every day in my practice that I find highly compelling,” says Gatchel. “Could psychiatric symptoms in older adults be driven in part by Alzheimer’s disease pathology and proteins impacting brain circuitry? If so, it would represent an important shift in the way we think about treating older adults presenting with these symptoms.”

Gatchel is using a combination of neuroimaging, cognitive testing, clinical assessments, and her ongoing interactions with patients to inform her research on the relationships between mood and anxiety symptoms and dementia.

She ultimately hopes to improve care and brain health for older patients and help them make the most of their golden years.

Measuring changes in brain structure and function

Gatchel uses positron-emission tomography (PET) neuroimaging to visualize amyloid and tau, the two proteins thought to be the core pathological drivers of Alzheimer’s disease, in living older adults.

By looking at amyloid and tau concurrently, both at a single time point and over time, she can follow individuals to see how the changes in their brain map onto the changes they are experiencing clinically.

To measure brain function and mental health, Gatchel asks participants and their families about observable changes in their mood, memory and performance of day-to-day activities. Participants also complete cognitive tests sensitive enough to pick up on small changes that may indicate degeneration in the brain.

Chicken or the egg scenario

In analyzing the data, Gatchel has found that the relationships between psychiatric and cognitive symptoms are very complex and akin to a chicken or the egg scenario.

“On the one hand, symptoms of depression or anxiety may be a precursor of Alzheimer’s disease, and may be among the earliest signs of the disease,” she explains.

“On the other end of the spectrum, recurrent episodes of depression may serve as risk factor for dementia. Also, older adults who have a diagnosis of Alzheimer’s disease may experience a reactive depression. It’s a complex question depending on which stage of the disease we’re looking at.”

She has unearthed some intriguing findings by looking at a cohort of older adults over the age of 60 with no reported cognitive impairments or psychiatric conditions enrolled in the Harvard Aging Brain Study, led by Drs. Reisa A. Sperling and Keith A.  Johnson.

Results thus far show that subclinical depressive symptoms in cognitively normal older adults are associated with accumulations of tau in a brain region affected in aging and early stages of Alzheimer’s disease.

She has also carried out work with a cohort of younger adults from Colombia. This research, led by Dr. Yakeel T. Quiroz, looks at individuals who may carry a mutation in a single gene that gives rise to early onset Alzheimer’s disease. Similar to the Harvard Aging Brain Study, participants in the study had no reported cognitive impairments or psychiatric conditions at study entry.

Interestingly, Gatchel has found that subclinical symptoms of anxiety are associated with amyloid buildup, rather than tau pathology in this younger cohort.

Intrigued by these results, Gatchel plans to conduct future research to further disentangle the underlying pathology of depressive and anxiety symptoms, and to determine whether this differs across a range of symptom severity and in late onset vs. early onset Alzheimer’s disease.

One next step is to recruit an additional cohort of older adults with more severe psychiatric symptoms to complement the existing participants in the Harvard Aging Brain Study.

“We may be observing only a modest relationship between depressive symptoms and tau because individuals with more severe depressive symptoms were excluded from the study at entry,” says Gatchel.

“Would we see a stronger relationship if we examined individuals who had more severe depressive symptoms? Would we still observe a relationship with tau as compared to amyloid? Also, if we follow individuals over time, do those with more significant depressive or anxiety symptoms accumulate pathology more rapidly? These are just some of the questions we hope to address in the next phase of work.”

Gatchel will also continue to look to patients and clinical research participants to help her refine her research questions.

“It’s been incredibly helpful to maintain clinical practice as a psychiatrist,” she says. “My clinical encounters and relationships with patients are critical to informing the research process, and are continually changing the way I think about designing studies.

“It’s also extremely motivating to know that something you’re doing—a research question you are trying to tackle—could impact or improve clinical practice.”

You can find the original article here

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12 Days of Research at Mass General: Modeling Alzheimer’s Disease in 3D

Banner 12 days of researchIn the 12 days leading up to our holiday hiatus, we are looking back on the past year and sharing some highlights in Massachusetts General Hospital research news from each month of 2017.

October 2017:

How a 3D Model of Alzheimer’s Disease is Providing New Hope in the Search for Treatments

Reigning in Alzheimer’s disease continues to be a challenge — more than 10 million families are affected by this degenerative neurological disease, and the number of patients dying from the disease has increased 68 percent since 2010.

In the past decade, attempts at developing drugs to slow or halt the progression of Alzheimer’s disease have been unsuccessful. The traditional path for early testing of promising therapies – mouse models – has been ineffective, and more than a dozen major clinical trials have failed.

But scientists and clinicians at Massachusetts General Hospital’s Institute for Neurodegenerative Disease (MIND) have developed an innovative new approach that could significantly improve the drug development process.  The laboratory teams of Doo Yeon Kim, PhD, an investigator in the Genetics and Aging Research Unit at MIND, and Rudy Tanzi, PhD, have found a way to grow human neural stem cells in a three-dimensional gel matrix.

This gel system allows the neural cells to grow more naturally and form into 3-D networks just like they do in the brain. It also provides a more accurate model of the signature plaques and tangles that develop around these neurons in Alzheimer’s disease.

The stem cells used in this lab model are genetically engineered to produce two proteins that are the hallmarks of Alzheimer’s disease – β-amyloid and tau. In the brains of people with Alzheimer’s, excessive accumulation of β-amyloid results in the formation of plaques in the spaces between neural cells, while tau is the main component of destructive neurofibrillary tangles within the cells.

Until Dr. Kim’s success, no single model of Alzheimer’s disease contained both amyloid plaques and neurofibrillary tangles. It usually takes a year to develop plaques in mouse models, it took only six weeks to develop both plaques and tangles in the “dish.”

Dr. Kim is now working with a consortium of labs to test thousands of FDA-approved drugs in this “Alzheimer’s in a dish” model to see if any of the drugs are effective in reducing levels of p-tau, a protein that is increased in Alzheimer’s patients.

Of the 2,400 drugs that have been tested, the team had approximately 40 promising hits that they can now investigate further.

Learn more: https://giving.massgeneral.org/fresh-alzheimers-approach-sparks-hope/

You can find the original post here.

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12 Days of Research at Mass General: Lady Gaga News Highlights Fibromyalgia Research

Banner 12 days of researchIn the 12 days leading up to our holiday hiatus, we are looking back on the past year and sharing some highlights in Massachusetts General Hospital research news from each month of 2017.

September 2017:

Lady Gaga’s Diagnosis Helps Shed Light on a Perplexing Chronic Pain Disorder

Despite her celebrity status, Lady Gaga has been remarkably honest and open about her struggles with fibromyalgia, a chronic pain disorder. The star announced her diagnosis on social media earlier this month, and just recently canceled tour dates due to disorder-related complications.

Fibromyalgia has traditionally been a challenge to diagnose and treat, because there is no test for it. Doctors make the diagnosis based on patient reported symptoms. Researchers at Mass General are hoping to change that by using imaging techniques to demonstrate brain changes in fibromyalgia patients and investigating potential causes for the disease.

What is fibromyalgia and what are the symptoms?

Fibromyalgia is a common chronic pain disorder that can be extremely debilitating. The disorder is characterized by widespread pain, accompanied with un-refreshing sleep, fatigue, memory and cognitive problems, sensitivity to temperatures, light, and sound, and headaches. It can also co-exist with other conditions including depression, anxiety and irritable bowel syndrome.

These symptoms severely impact the 5-10 million Americans living with this disorder. The pain and fatigue of fibromyalgia can make it difficult to maintain work and social obligations. Symptoms also come in waves at seemingly random intervals, which can blindside individuals.

What causes fibromyalgia?

It’s thought that disturbances in the central nervous system affect the way the brain processes pain signals, which amplifies the painful sensations that fibromyalgia patients experience. But why these disturbances occur remains a mystery.

Experts suggest that the disorder could be driven by several factors, including physical or emotional trauma, prior illness or infection, and genetics. Women are also more likely to develop fibromyalgia than are men, though researchers don’t know why.

In an effort to find answers to these questions, Marco Loggia, PhD, Associate Director of the Center for Integrative Pain NeuroImaging and a researcher in the Martinos Center for Biomedical Imaging at Massachusetts General Hospital, studies the brain mechanisms of pain in patients with fibromyalgia. His research suggests that some degree of brain inflammation may be at play, given that brain inflammation is common among chronic back pain sufferers and most fibromyalgia patients suffer from chronic back pain.

How is it treated?

There is no cure for fibromyalgia. As a result, the focus of treatment is on managing pain and improving quality of life for patients. However, patients often struggle to find the right combination of treatments to manage their condition.

Clinicians often recommend medications including pain relievers, anti-depressants, and anti-seizure drugs to reduce pain and improve sleep. Some patients also utilize therapies such as physical therapy or counseling and alternative treatments like massage therapy, yoga or acupuncture.

Is there stigma associated with fibromyalgia?

Because there are no lab tests to diagnose fibromyalgia, patients are frequently met with skepticism, even by their own primary care team. The pain they report is often dismissed as being “all in their head.”

In a recent interview with HealthDay News, Loggia said, “Many studies—and particularly those using brain imaging techniques such as functional magnetic resonance imaging—have now provided substantial support to the notion that the excessive sensitivity to pain that these patients demonstrate is genuine. I think that it is time to stop dismissing these patients.”

With celebrities like Lady Gaga raising awareness of this disease and researchers like Loggia investigating its causes and progression, could individuals suffering from fibromyalgia soon see advances in treatment and care—as well as more public understanding of this debilitating disorder?

To read more on this topic:

You can find the original post here.

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12 Days of Research at Mass General: Predicting Painful Migraine Attacks

Banner 12 days of researchIn the 12 days leading up to our holiday hiatus, we are looking back on the past year and sharing some highlights in Massachusetts General Hospital research news from each month of 2017.

August 2017:

Making Migraines Less of a Headache: Researchers Find New Way to Predict Migraine Attacks

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If you’ve ever felt the pulsating pain, nausea and blinding light sensitivity that comes with a migraine, you’re not alone. In the US, more than 37 million people get these severe headache attacks that can last for several hours at a time.

If you’ve experienced migraines, you also know that their arrival can be sudden and unpredictable. Now a team of researchers at Massachusetts General Hospital has developed a new forecasting model that has the potential to pinpoint when a migraine will strike by tracking an individual’s stress levels over time.

While more work is needed before the model is ready for clinical use, a system that reliably predicts the onset of migraines could provide much needed relief for chronic migraine sufferers.

About Migraines

Migraines are more than just a bad headache – they are an incapacitating collection of neurological symptoms that affect 18% of American women and 6% of men, according to the Migraine Research Foundation. Symptoms range from flashes of light, one-sided throbbing pain, sensitivity to light and sound, nausea and much more. Migraine attacks can be incredibly painful and debilitating, sometimes confining the sufferer to a darkened room until the symptoms subside. More than 90% of sufferers are unable to work or function normally during their migraine.

Doctors know that certain genes can make some individuals more susceptible to getting migraines, and potential migraine triggers can include stress, hormone fluctuations, lack of sleep and certain foods. However, predicting the exact cause and time of an individual migraine attack remains difficult. To make matters worse, preventative drugs that help to nip a migraine in the bud are only effective when taken at the onset of symptoms.

Developing and Testing a Forecast Model

Because perceived stress has received considerable attention for its association with the onset of headaches, a team of researchers led by Tim Houle, PhD, Associate Professor of Anesthesia, Critical Care, and Pain Medicine at Massachusetts General Hospital and Harvard Medical School, developed a forecasting model for predicting future migraine attacks based on current levels of stress and head pain.

To test out the model, the team recruited 95 participants with a history of migraines. Participants were asked to keep a daily diary recording the frequency and intensity of their stress levels and presence/absence of any head pain. Each variable was measured using a specific scale.

Of the 4,195 days of analyzed diary data, participants experienced a migraine on 1,613 of these days (38.5%).  By analyzing participants’ self reported stress levels, the research team found statistically significant evidence that stress was greater in the days leading up to a reported migraine.

What This Means for Migraine Sufferers

The results provide the first statistically significant evidence that individual headache attacks can be forecasted within an individual sufferer. However, Houle cautions that the predictive model needs to be refined before it can be of widespread clinical use, and for now should be viewed as a first step in a new venture of forecasting migraine attacks.

In the future, a reliable forecasting model could be used to improve treatment options, reduce anxiety about the unpredictability of attacks and increase an individual’s confidence in their ability to self-manage migraine attacks.

Read the full study here

You can find the original post here.

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12 Days of Research at Mass General: Why Autistic Individuals Avoid Eye Contact

Banner 12 days of researchIn the 12 days leading up to our holiday hiatus, we are looking back on the past year and sharing some highlights in Massachusetts General Hospital research news from each month of 2017.

June 2017:

More Than Meets the Eye: Researchers Find Eye Contact Causes Stress and Overactivation in the Brains of Autistic Individuals

They say that eyes are the windows to the soul, but for individuals with autism, a lack of eye contact can reveal much more. A team of investigators based at the Athinoula A. Martinos Center for Biomedical Imaging at Massachusetts General Hospital has shed light on why those with autism often avoid looking others in the eyes.

Here are five things to know about the study published in Nature Scientific Reports this month:

  1. Individuals with autism often find it difficult to look others in the eyes. Many say that maintaining eye contact is uncomfortable or stressful for them – some will even say that “it burns” – which suggests the root of this discomfort is neurological.
  2. Previous work by Nouchine Hadjikhani, MD, PhD, Director of Neurolimbic Research in the Martinos Center and corresponding author of the new study, demonstrated that the subcortical system, the part of the brain activated by eye contact and responsible for processing emotions and facial recognition, was oversensitive to direct gaze and emotional expression in autistic individuals.
  3. In her most recent study, Hadjikhani presented images of faces conveying different emotions to study subjects with and without autism and measured their brain activity via functional magnetic resonance imaging (fMRI). When both groups were able to gaze at the images freely, there was no difference in subcortical activation.
  4. When the test was changed to narrow the focus to the eyes, Hadjikhani observed overactivation of the subcortical system in participants with autism. Images of fearful faces prompted the most significant response, but happy, angry and neutral faces had an effect as well. Their results support the idea that there is an imbalance between the brain’s “excitatory” network, which reacts to stimulation, and inhibitory network, which calms it down.
  5. The findings suggest that behavioral therapies that try to force individuals with autism to make eye contact could be counterproductive. A better approach may be to slowly introduce these individuals to eye contact so they can learn strategies for managing the accompanying sensations.

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12 Days of Research at Mass General: Do Alzheimer’s Patients Suffer Silent Seizures?

Banner 12 days of researchIn the 12 days leading up to our holiday hiatus, we are looking back on the past year and sharing some highlights in Massachusetts General Hospital research news from each month of 2017.

May 2017:

Researchers Detect “Silent” Seizures in Alzheimer’s Patients

First let’s define a key word:
Hippocampus: The brain structure responsible for memory development. The hippocampus is a key part of the brain affected by Alzheimer’s disease, and also a common source of seizures in people with epilepsy.

New research from Massachusetts General Hospital suggests a potential new connection between the devastating memory loss associated with Alzheimer’s disease (AD) and “silent” seizures in the memory center of the brain.

The small study enrolled two female patients in their 60s with early AD and no known history of seizures. Because electrodes placed on the scalp are often unable to detect seizure activity deep in the brain, researchers surgically implanted electrodes on both sides of the brain through the foramen ovale (FO), a narrow opening at the base of the skull, in addition to scalp EEG. Each patient’s brain activity was monitored for 24 to 72 hours.

The FO electrodes recorded evidence of seizures in the hippocampuses of both patients, while the scalp EEG readings did not detect any abnormal electrical activity. Most notably, these seizures primarily occurred when patients were asleep, a critical time for memory consolidation.

“While it is not surprising to find dysfunction in brain networks in Alzheimer’s disease, our novel finding that networks involved in memory function can become silently epileptic could lead to opportunities to target that dysfunction with new or existing drugs to reduce symptoms or potentially alter the course of the disease,” says Andrew Cole, MD, Director of the Mass General Epilepsy Service and senior author of the Nature Medicine paper.

One patient received anti-seizure medicine as a treatment following the scan, which seemed to cut down on AD-linked symptoms such as confusion and repeating the same question. The other patient started on the medication but it had to be discontinued due to adverse effects on her mood.

A recent study led by Alice Lam, MD, PhD, also of the MGH Epilepsy Service and lead author of the current study, demonstrated a novel tool for detecting hippocampal seizures not detectible by scalp EEGs in patients with epilepsy. Cole and his team are working to refine this tool and apply it to AD.

Due to the small size of the study, further research is also needed to validate the results with a broader population.

You can find the original post here.

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12 Days of Research at Mass General: She Watches Worms While They Sleep

Banner 12 days of researchIn the 12 days leading up to our holiday hiatus, we are looking back on the past year and sharing some highlights in Massachusetts General Hospital research news from each month of 2017.

January 2017:

Postdoc Profile: Hayley Mattison, PhD

mattison-banner.jpgOn a typical day, you will find me in the lab at my microscope taking images of neurons that ‘glow’ green in the brains of the microscopic worm, Caenorhabditis elegans (C. elegans).

As a postdoctoral fellow in the laboratory of Joshua Kaplan, PhD, in the Department of Molecular Biology at Massachusetts General Hospital, I study the neurons that control sleep in the worm. (Yes, worms sleep).

Worms have four larval stages between hatching and adulthood, and they undergo a sleep-like state called lethargus prior to entering each stage.

Sleep is thought to have a role in biological processes such as growth and development in animals, including humans and worms. But what happens in the brain to allow and maintain the state of sleep is not entirely understood, which is why a simple model system like the worm is a great place to start.

Worms have a small and well-characterized nervous system consisting of only 302 neurons. The connections between these neurons have been completely mapped so learning about the circuits, or neural networks, that control behaviors is simpler than in more complex organisms.

In contrast, humans have billions of neurons and trillions of synapses. Scientists have started to map these connections, but it will take many more years of research to achieve the complete picture.

Worm genetics are also much simpler than other animals because C. elegans exist primarily as self-fertilizing hermaphrodites, meaning they produce both sperm and eggs and can reproduce independently of a mate. Therefore, new or modified DNA can be introduced into worms to alter the expression of genes in their offspring, which allows us to create new strains of worms with relative ease.

These new strains of worms can be designed to express certain proteins in individual neurons, and/or to make the neurons glow green for imaging experiments. This helps us to identify the neurons that have a role in behaviors, such as sleep.

Just like humans, worms do not interact with their environment when they are asleep, because their sensory neurons are not able to respond to external cues such as the presence of food or odors. This is because sensory neurons are being “silenced” by the action of neuropeptides in the brain that promote the sleep state.

Neuropeptides are hormone-like chemical messengers that are released by one set of neurons to affect another set of neurons. To wake the worm up, other neuropeptides are released to wake up, or “arouse,” the worm by allowing their sensory neurons to become active again. Once awake, the worms can respond to their environment and resume normal activities such as eating and mating.

The Kaplan lab is interested in identifying which neurons play a role in this process, and the mechanisms these neuropeptides employ to create the sleep and arousal states.

We have already identified a circuit of neurons associated with sleep and arousal in worms. The goal of my project is to find additional neurons that function in this circuit, and then learn how these neurons communicate to regulate these behavioral states.

As a neuroscientist, I have always been fascinated by the complexity of the nervous system and how much is still unknown about how the brain works. Understanding the nervous system of a “simple” organism such as C. elegans can help us to deconstruct basic functions of the brain in more complex organisms.

Down the road, what we discover about worm sleep could be applicable to humans and lead to therapies that promote sleep in the brain. These tiny worms have a lot to tell us about our own brains. Even in their sleep.

You can find the original article here.

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