Breaking News
January 23, 2019 - Parents’ mental health problems associated with reactive attachment disorder in children
January 23, 2019 - Graphene Flagship project studies impact of graphene and related materials on our health
January 23, 2019 - The connection between the Pope and contraceptive pills
January 23, 2019 - Prior dengue infection could protect children from symptomatic Zika
January 23, 2019 - VISTA checkpoint implicated in pancreatic cancer immunotherapy resistance
January 23, 2019 - The Tiny Camera That Could Revolutionize Cardiovascular Surgery
January 23, 2019 - Peptide isolated from soil fungi has antitumor and antibacterial properties
January 23, 2019 - TGen identifies polio-like virus as potential cause of Acute Flaccid Myelitis outbreak
January 23, 2019 - Migrants and refugees do not bring disease and are at greater health risk themselves says WHO
January 23, 2019 - Examing the effects of menopause in workplace
January 23, 2019 - Enemy number 1 – Air pollution and climate change top of WHO agenda
January 23, 2019 - Two Positive Phase III studies of Tafenoquine for the Radical Cure of Plasmodium vivax Malaria Published in The New England Journal of Medicine
January 23, 2019 - World Trade Center responders at increased risk for head and neck cancers
January 23, 2019 - Low-sugar diet leads to significant improvement in nonalcoholic fatty liver disease in boys
January 23, 2019 - Chaos in bodily regulation can optimize our immune system, finds study
January 23, 2019 - Short, text-based exercises can increase happiness for adults recovering from substance use disorders
January 23, 2019 - Body size may have greater influence on women’s lifespan than men
January 23, 2019 - Groundbreaking tool helps visualize neuronal activity with near-infrared light
January 23, 2019 - Holocaust survivors with PTSD and their offspring exhibit more unhealthy behavior patterns
January 23, 2019 - Scientists discover new genetic mutations causing inherited deaf-blindness
January 23, 2019 - UC team designs new naloxone-dispensing smart device
January 23, 2019 - Torrent Pharmaceuticals Limited Issues Voluntary Nationwide Recall of Losartan Potassium Tablets, USP and Losartan Potassium and Hydrochlorothiazide Tablets, USP
January 23, 2019 - Brain activity shows development of visual sensitivity in autism
January 23, 2019 - Two hour gap between dinner and sleep is overrated says Japanese research
January 23, 2019 - Fear and embarrassment are causing smear test numbers to plummet
January 23, 2019 - Protein-secreting device implanted in epileptic rats reduces seizures, improves cognition
January 23, 2019 - Reintroduction project recovers current wild population of green turtle in Cayman Islands
January 23, 2019 - Cancer survivors face greater financial burden related to medical bills
January 23, 2019 - PSA screening reduces prostate cancer deaths by 30%
January 23, 2019 - LSTM receives grant to help improve health of people living in informal settlements
January 23, 2019 - Hemochromatosis Mutation Linked to Other Morbidity
January 23, 2019 - Why early diagnosis of autism should lead to early intervention
January 23, 2019 - Aspirin May Lower Stroke Risk in Women with History of Preeclampsia
January 23, 2019 - Exposure to certain chemicals may be linked to decrease in blood pressure during pregnancy
January 23, 2019 - Bowel cancer on the rise among younger Australians
January 23, 2019 - Scientists have reversed memory loss in a mouse model of Alzheimer’s
January 23, 2019 - Defective molecular master switch could lead to age-related macular degeneration
January 23, 2019 - Researchers identify how concussions may contribute to seizures
January 23, 2019 - Short interval between last meal of the day and bedtime may not affect blood glucose levels
January 23, 2019 - Still Too Many Highway Deaths Tied to Speeding
January 23, 2019 - Prenatal valproate exposure linked to increased ADHD risk
January 23, 2019 - Compound identified that may help treat heart failure
January 23, 2019 - Undiagnosed Asthma in Urban Adolescents May Be Common
January 23, 2019 - Study describes metabolism of intestinal microbiota in babies for the first time
January 22, 2019 - Study links concussions to development of epilepsy
January 22, 2019 - Specialist-led hospital bereavement service may help restrain legal action after difficult deaths
January 22, 2019 - Genetic study reveals possible new routes to treating osteoarthritis
January 22, 2019 - Blood test may detect early signs of lung-transplant rejection
January 22, 2019 - Blood marker could aid in early prediction of Alzheimer’s progression
January 22, 2019 - Orthodontic treatment does not guarantee future dental health
January 22, 2019 - Rutgers researchers discover cause of bone loss in people with joint replacements
January 22, 2019 - Diversity among rural Africans extends to their gut microbiomes
January 22, 2019 - Newly developed biological system lets cells to create self-curving cornea
January 22, 2019 - VTv Therapeutics Announces Publication of Comprehensive Data in Science Translational Medicine Detailing the Discovery and Clinical Development of TTP399, including Results of Phase 2 AGATA Study
January 22, 2019 - about one in three adults with prediabetes has arthritis
January 22, 2019 - A look at how data is democratizing health care
January 22, 2019 - Alcohol-Linked Disease Overtakes Hep C As Top Reason For Liver Transplant
January 22, 2019 - Researchers identify new genes linked with age-related macular degeneration
January 22, 2019 - MPFI researchers identify synaptic logic for connections between two brain hemispheres
January 22, 2019 - New approach to reduce toxic protein production in ALS
January 22, 2019 - New study extends our knowledge of the link between miRNAs and cancer
January 22, 2019 - Asthma, eczema are not barriers to active lifestyle in teenagers
January 22, 2019 - Genetic changes may predict likelihood of relapse in breast cancer patients
January 22, 2019 - Antiepileptic drug use by people with Alzheimer’s disease linked to accumulation of hospital days
January 22, 2019 - IUPUI researcher receives $2.85 million grant to find ways to improve bone strength
January 22, 2019 - Precision medicine can help keep astronauts healthy during deep space missions
January 22, 2019 - Detecting signs of neurodegeneration earlier and more accurately
January 22, 2019 - Mouse studies challenge ‘inhibition’ theory of autism
January 22, 2019 - SSB launches BIOSTAT RM TX single-use bioreactor for producing consistent quality cellular products
January 22, 2019 - Experimental drug can positively modify key characteristic behavior in FXS patients
January 22, 2019 - Low-Income Women Lack Menstrual Hygiene Supplies
January 22, 2019 - Better mouse model built to enable precision-medicine research for Alzheimer’s
January 22, 2019 - Molecular profiling of precancerous lung lesions could lead to early detection and new treatments
January 22, 2019 - Genetic factors influence where fat is stored in our bodies
January 22, 2019 - The Psychology Behind Sticking to Your New Year’s Resolutions
January 22, 2019 - Scientists aim to find genetic causes of developmental abnormalities in the vagina and uterus
January 22, 2019 - New survey reveals scale of preventative healthcare challenge in the UK
January 22, 2019 - Looming Global Crisis Means People’s Diets Must Change: Experts
January 22, 2019 - Excessive social media use is comparable to drug addiction
January 22, 2019 - Researchers show how mechanical stress affects bone development
Neuroscientist wins NIH grant to find whether pear- or apple-shape physique is best for our brains

Neuroscientist wins NIH grant to find whether pear- or apple-shape physique is best for our brains

image_pdfDownload PDFimage_print

With the new year still ringing, many of us have fat on our minds, but Dr. Alexis M. Stranahan is more interested in what fat does to our minds.

The neuroscientist in the Department of Neuroscience and Regenerative Medicine at the Medical College of Georgia is principal investigator on a new $1.7 million grant from the National Institutes of Health that will help determine whether a pear- or apple-shape physique is best for our brains.

Like with cardiovascular disease, she suspects and has early evidence that the apple shape – characterized by fat depositing around the major organs in the abdominal cavity – is far worse for the brain. In fact, subcutaneous fat, the more diffuse fat we have under our skin, may be somewhat protective.

“We are refining our risk factors,” says Stranahan, to find which obese individuals really are at increased risk of cognitive decline and dementia.

“We need to start understanding and parsing the contributions of obesity alone because we can’t just tell everybody who has a body mass index that categorizes them as overweight that they are at risk for dementia,” Stranahan says. Because they probably are not.

So she is looking to find what signal(s) visceral and subcutaneous fat are sending, how they get into the brain and what message they deliver. “We need to break down the dichotomy between the brain and the rest of the body, because it’s not operating in isolation.”

Stranahan reported two years ago that a high-fat diet causes immune cells in our brain called microglia to start consuming the connections between our neurons, a loss that is rapidly recovered once a low-fat diet is resumed. Normally microglia protect the brain by traveling about, internalizing dead cells and extracellular debris. A high-fat diet and related obesity prompts them instead to settle down and start consuming the invaluable synapses. The year before, she reported that cognitive decline in obese and diabetic mice could be reversed with exercise or surgical removal of belly fat. Conversely, transplanting belly fat from one of the unhealthy mice to a normal mouse, prompted increased brain inflammation and cognitive decline.

Now she is taking diabetes out of the equation for a moment to look more purely at the cognitive impact of fat. She is looking at what happens when she transplants fat from an obese to a normal mouse that has a few genetic modifications so her research team can see how the visceral fat transplant is causing brain inflammation and cognitive impairment. The genetic manipulation allows her to selectively turn off genes in the microglia to see if these normally helpful cells become unwitting sensors for visceral fat.

“We think the specific receptor in microglia called interleukin 1 receptor 1, is a sensor for prominent inflammatory cytokines that get into the brain from visceral fat in obesity. We are knocking it out in microglia to see whether that receptor is involved in the cognitive impact and brain inflammation that we see in fat transplant recipients,” she says. Interleukin 1 is part ofa family of cytokines key to regulating the immune response and inflammation.

She suspects that visceral fat releases inflammatory cytokines and the microglia sense them with this receptor, which transforms microglia from their protective to destructive mode.

“Now instead of supporting the neurons, they are reaching out, they are internalizing the synapses and they are releasing factors locally in the brain that impair cognition,” Stranahan says.

Visceral fat appears particularly toxic because of location. “If you are there in the viscera, you are close up to all the gut microbiota and the gut can actually become leaky so the bacteria can start leaking out and the visceral fat right there next to it has the potential to get inflamed that way,” Stranahan says. Even in normal weight individuals, any visceral fat just tends to have more immune cells – and so reactivity – than subcutaneous fat.

When she and her research team look at subcutaneous fat, they find it’s more than just storage space, rather the immune cells in this under-the-skin and more diffuse fat do not promote inflammation, rather appear to protect the brain from an attack on the synapses and cognitive decline.

To ensure they are really focusing on the cognitive impact of obesity – without its common partner diabetes – they are doing a series of metabolic tests to ensure that the mice are not diabetic.

Stranahan sees a day when multiple factors like the levels of inflammatory markers in your blood along with your fat distribution and family history could better personalize treatment.

“Just like we have diabetes educators today, we need to have brain educators to explain to some individuals that, 20 years from now, if you want to be living on your own, you need to stop eating the way you are eating and exercise more or both,” she says.

Her studies of distinctive reactions by the two fat types should also yield some treatment targets to address the clearly negative effects of visceral adiposity. One of the factors she is studying for the brain also plays a role in obesity-related diabetes. “If we could kill two birds with one stone, that would be great,” she says.

Obesity, diabetes and cognitive decline have been associated for decades. Some of the earliest associations came from the Netherland’s prospective and ongoing Rotterdam Study, looking at the major health issues of aging led by Erasmus Medical Center. It’s also when disparities started emerging between individuals with obesity and diabetes and those with obesity alone, Stranahan says of findings published in the late 1990s.

She notes that fat under the skin rather than around your major organs, is not a panacea, particularly if a trend of poor eating and activity habits result in continued weight gain.

“Eventually that reserve that you are putting in a place that does not hurt you as much will overflow and you will have to put it in another place,” she says. In fact, in addition to the viscera, fat droplets can even start collecting in the liver, bone and muscle potentially, prompting the immune system to become hyperactive to the fat tissue that has no business in these tissues.

Chronic inflammation is one of the most well characterized features of obesity, Stranahan notes. That is one reason males, who early on tend to store fat in their viscera, also tend to get diabetes earlier in life than females.

Tagged with:

About author

Related Articles