PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

MIT researchers find that interneurons are not all created equally

Study shows that some classes of interneurons may underlie distinct brain disorders

2010-09-08
(Press-News.org) CAMBRIDGE, Mass. – A type of neuron that, when malfunctioning, has been tied to epilepsy, autism and schizophrenia is much more complex than previously thought, researchers at MIT's Picower Institute for Learning and Memory report in the Sept. 9 issue of Neuron.

The majority of brain cells are called excitatory because they ramp up the action of target cells. In contrast, inhibitory cells called interneurons put the brakes on unbridled activity to maintain order and control. Epileptic seizures, as well as symptoms of autism and schizophrenia, have been tied to dysfunctional inhibitory cells.

"Too much activity and you run the risk of uncontrolled activity, while too little leads to cognitive and behavioral deficits," said Mriganka Sur, Paul E. Newton Professor of Neuroscience, whose laboratory carried out the study. "Normal brain development and function hinges on the delicate balance between excitation and inhibition."

For a long time, interneurons, which make up only one-fifth of brain cells, were thought to be a kind of generic, homogenous shutdown agent. The MIT study points to a new view: At least some interneurons have very precise responses and form specific connections and circuits.

"If these cells are targeted in brain disorders, then these disorders must arise from precise dysfunction in specific circuits," said Sur, head of the MIT Department of Brain and Cognitive Sciences. "This study sheds light on precisely what is going on in these circuits that may be targeted for future treatments."

Inhibitory cells are diverse: researchers are only starting to discern distinct electrophysiological profiles, shapes and molecular signatures among the 20 or more known types.

But all interneurons fall into two clear subtypes: those that target the cell body, or soma, of their target cells and those that target the branchlike dendrites. The soma-targeting type expresses a protein called parvalbumin and has been linked to brain disorders and circuit development. This type of interneuron was thought to dampen activity uniformly across the cortex. "Our paper overturns this view," Sur said.

"These neurons had been thought to have only broad response features that would nonspecifically dampen their target cells. Our finding indicates that they have well-defined properties and functions," he said.

MIT graduate student Caroline Runyan and postdoctoral fellows James Schummers, Audra Van Wart and Nathan Wilson used cutting-edge techniques to examine the properties of parvalbumin-expressing inhibitory neurons.

With the help of mice genetically engineered to have just these cells fluoresce red in their visual cortex, the researchers used a sophisticated technique called two-photon imaging to identify and record the activity of these cells in living animals.

They found that parvalbumin-expressing interneurons have a range of response features. Many of these cells have precisely tuned responses. Some only respond to very specific signals and locations in space.

"These cells are components of and contributors to highly specific networks that shape the selectivity of neuronal responses," Runyan said. "They need to be defined by a combination of features, including structure, connections, gene expression profiles, electrophysiological properties and response types.

"This study supports the idea that individual cell classes may provide specific forms of inhibition and serve unique functions," she said.

INFORMATION: Source: "Response features of parvalbumin-expressing interneurons suggest precise roles for subtypes of inhibition in visual cortex" by TK TK. Neuron, 9 Sept. 2010.


ELSE PRESS RELEASES FROM THIS DATE:

Neurogenetic studies show proprietary compound reduces brain plaques linked to Alzheimer's

2010-09-08
SAN DIEGO -- In the Sept 9, 2010 issue of Neuron, Neurogenetic Pharmaceuticals, Inc. (NGP) reports proof of concept studies that show its proprietary compound, NGP 555, is effective in preventing the amyloid pathology of Alzheimer's disease (AD) in a transgenic mouse model. The study further demonstrates that following chronic treatment with the gamma secretase modulator (GSM) compound from NGP, the mice were devoid of gastrointestinal side effects, an adverse finding commonly associated with gamma secretase inhibitors (GSIs). A major pathological hallmark of Alzheimer's ...

Use of informatics, EMRs enable genetic study of vascular disease

2010-09-08
Scientific research published in the current issue of the Journal of the American Medical Informatics Association (JAMIA) reports on a study of genetic variants that influence human susceptibility to peripheral arterial disease (PAD), made possible by leveraging electronic medical records (EMRs; also called EHRs or electronic health records). A team of authors from the Mayo Clinic Divisions of Cardiovascular Diseases and Biomedical Informatics and Statistics conducted the study and concluded that EMR-based data, used across institutions in a structured way, "offer great ...

NOAA designates the eastern North Pacific basking shark a 'species of concern'

NOAA designates the eastern North Pacific basking shark a species of concern
2010-09-08
NOAA's Fisheries Service has designated the eastern North Pacific basking shark, a "species of concern" because it has suffered a dramatic decline in population despite decreasing fishing pressure. The label "species of concern" may be given to a species when there are concerns regarding the population status. The eastern Pacific basking shark is not being considered for listing pursuant to the Endangered Species Act, rather it is a species of concern because it has been over fished and its population has apparently not responded to conservation measures implemented ...

Brain cells determine obesity -- not lack of willpower: Study

2010-09-08
An international study has discovered the reason why some people who eat a high-fat diet remain slim, yet others pile on the weight. The study, led in Australia by the Monash Obesity and Diabetes Institute (MODI) at Monash University, found a high-fat diet causes brain cells to become insulated from the body preventing vital signals, which tell the body to stop eating and to burn energy, from reaching the brain efficiently. MODI director and Australian Life Scientist of the Year Professor Michael Cowley said there were two clear outcomes from the findings. 'We discovered ...

Adults demonstrate modified immune response after receiving massage, Cedars-Sinai researchers show

2010-09-08
LOS ANGELES – Sept. 7, 2010 – Researchers in Cedars-Sinai's Department of Psychiatry and Behavioral Neurosciences have reported people who undergo massage experience measureable changes in their body's immune and endocrine response. Although there have been previous, smaller studies about the health benefits of massage, the Cedars-Sinai study is widely believed to be the first systematic study of a larger group of healthy adults. The study is published online at http://www.liebertonline.com/loi/acm. It also will be published in the October printed edition of ...

Energy drinks may give young sports teams an edge, study says

2010-09-08
Consuming energy drinks during team sports could help young people perform better, a study suggests. Sports scientists found that 12-14 year olds can play for longer in team games when they drink an isotonic sports drink before and during games. Researchers at the University of Edinburgh measured the performance of 15 adolescents during exercise designed to simulate the physical demands of team games such as football, rugby and hockey. They showed for the first time that sports drinks helped the young people continue high intensity, stop-start activity for up to ...

Experts question claim that Alexander the Great's half-brother is buried at Vergina

2010-09-08
The tomb was discovered during the excavation of a large mound – the Great Tumulus – at Vergina in 1977. Along with many treasures including ceremonial military equipment, bronze utensils, silver tableware, and gold wreaths, the tomb contained two sets of skeletal remains. Those of a man were found in a gold casket in the main chamber and those of a woman in a smaller gold casket in the second chamber. Both individuals had been cremated and evidence of a wooden funerary house containing a pyre was also found near the tomb. Dr Jonathan Musgrave of the University of ...

Micro-RNA determines malignancy of lung cancer

2010-09-08
Cancer becomes life-threatening when tumor cells start leaving their primary site. They travel through the lymph and blood streams to other tissues where they grow into metastases. This transition to malignancy is associated with characteristic changes in the cancer cells. The activity of several genes is reprogrammed and, thus, the production of proteins anchoring cells to a tissue is reduced. On the other hand, the amount of surface markers which make a cancer cell mobile increases. Professor Dr. Heike Allgayer heads a Clinical Cooperation Unit of DKFZ and UMM. She ...

A nearby galactic exemplar

A nearby galactic exemplar
2010-09-08
Originally discovered from Australia by the Scottish astronomer James Dunlop early in the nineteenth century, NGC 300 is one of the closest and most prominent spiral galaxies in the southern skies and is bright enough to be seen easily in binoculars. It lies in the inconspicuous constellation of Sculptor, which has few bright stars, but is home to a collection of nearby galaxies that form the Sculptor Group [1]. Other members that have been imaged by ESO telescopes include NGC 55 (eso0914 - http://www.eso.org/public/news/eso0914/), NGC 253 (eso1025 - http://www.eso.org/public/news/eso1025/, ...

Chopping and changing in the microbial world: How mycoplasmas stay alive

2010-09-08
Mycoplasmas are responsible for a variety of important diseases, including atypical pneumonia in humans and mastitis in cows, sheep and goats, which results in loss of milk production. Mycoplasmal mastitis represents a particular problem in the dairy industry and is thus a subject of intense study. One of the most important mastitis agents in sheep and goats is Mycoplasma agalactiae, which has been under investigation by the group of Renate Rosengarten and Rohini Chopra-Dewasthaly at the Institute of Bacteriology, Mycology and Hygiene at the University of Veterinary Medicine, ...

LAST 30 PRESS RELEASES:

Long-term anticoagulation discontinuation after catheter ablation for atrial fibrillation

Fractional flow reserve–guided complete vs culprit-only revascularization in non–ST-elevation myocardial infarction and multivessel disease

Participation of women in cardiovascular trials from 2017 to 2023

Semaglutide and tirzepatide in patients with heart failure with preserved ejection fraction

Changes in biology of internal fat may be the leading cause of heart failure

Transcatheter or surgical treatment of patients with aortic stenosis at low to intermediate risk

Promising new drug for people with stubborn high blood pressure

One shot of RSV vaccine effective against hospitalization in older adults for two seasons

Bivalent RSV prefusion F protein–based vaccine for preventing cardiovascular hospitalizations in older adults

Clonal hematopoiesis and risk of new-onset myocarditis and pericarditis

Risk of myocarditis or pericarditis with high-dose vs standard-dose influenza vaccine

High-dose vs standard-dose influenza vaccine and cardiovascular outcomes in older adults

Prevalence, determinants, and time trends of cardiovascular health in the WHO African region

New study finds that, after a heart attack, women have worse prognosis when treated with beta-blockers

CNIC-led REBOOT clinical trial challenges 40-year-old standard of care for heart attack patients

Systolic blood pressure and microaxial flow pump–associated survival in infarct-related cardiogenic shock

Beta blockers, the standard treatment after a heart attack, may offer no benefit for heart attack patients and women can have worse outcomes

High Mountain Asia’s shrinking glaciers linked to monsoon changes

All DRII-ed up: How do plants recover after drought?

Research on stigma says to just ‘shake it off’

Scientists track lightning “pollution” in real time using NASA satellite

Millions of women rely on contraceptives, but new Rice study shows they may do more than just prevent pregnancy

Hot days make for icy weather, Philippine study finds

Roxana Mehran, MD, receives the most prestigious award given by the European Society of Cardiology

World's first clinical trial showing lubiprostone aids kidney function

Capturing language change through the genes

Public trust in elections increases with clear facts

Thawing permafrost raised carbon dioxide levels after the last ice age

New DNA test reveals plants’ hidden climate role

Retinitis pigmentosa mouse models reflect pathobiology of human RP59

[Press-News.org] MIT researchers find that interneurons are not all created equally
Study shows that some classes of interneurons may underlie distinct brain disorders