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

Brain waves encode information as time signals

2013-12-16
(Press-News.org) Contact information: Oliver Lehmann
oliver.lehmann@ist.ac.at
43-022-439-000-1006
Institute of Science and Technology Austria
Brain waves encode information as time signals

How information is processed and encoded in the brain is a central question in neuroscience, as it is essential for high cognitive function such as learning and memory. Theta-gamma oscillations are "brain waves" observed in the hippocampus of behaving rats, a brain region involved in learning and memory. In rodents, theta-gamma oscillations are associated with information processing during exploration and spatial navigation. However, the underlying synaptic mechanisms have so far remained unclear. In research published this week in the journal Neuron, postdoc Alejandro Pernía-Andrade and Professor Peter Jonas, both at the Institute of Science and Technology Austria (IST Austria), discovered the synaptic mechanisms underlying oscillations at the dentate gyrus (main entrance of the hippocampus). Furthermore, the researchers suggest a role for these oscillations in the coding of information by the dentate gyrus principal neurons. Thus, these findings contribute to a better understanding of how information is processed in the brain.

Brain oscillations are, in fact, rhythmic changes in voltage in the extracellular space, referred to as electrical brain signals associated with the processing of information. These electrical signals are similar to those seen in electro-encephalographic recordings (EEG) in humans. Pernía-Andrade and Jonas observed these oscillations in a brain region called the hippocampus in behaving rats, and recorded oscillations occurring in this area using extracellular probes. To understand how oscillations are generated and which synaptic events trigger these oscillations, the researchers looked at synaptic transmission in granule cells (principal cells at the main entrance of the hippocampus) from both the extracellular (oscillations) and the intracellular perspectives (synaptic currents and neuronal firing), and then correlated the two. They discovered that excitatory and inhibitory synaptic signals contributed to different frequencies of oscillations, with excitation from the entorhinal cortex generating theta oscillations and inhibition by local dentate gyrus interneurons generating gamma oscillations. Together, excitation and inhibition provide the rhythmic signals of oscillations. It has been speculated that oscillations may help the dentate gyrus to encode information by acting as reference signals in temporal coding. Pernía-Andrade and Jonas now show that granule cell neurons send signals only at specific times in the cycle of oscillations. This so-called "phase locking" is necessary if oscillations are to function as reference signals in temporal coding.

The precise, high-resolution recording from granule cells necessary for these discoveries was possible only through technological innovations by Pernía-Andrade and Jonas, as previously no equipment was available to record synaptic signals in active rats in such high resolution. They are the result of a collaboration with the Miba machine shop, IST Austria's electrical and mechanical SSU (Scientific Service Unit). Adapting commercially available equipment and custom-designing tools, Pernía-Andrade, Jonas and Todor Asenov, manager of the Miba machine shop, produced the first tools for precise biophysical analysis in active rats. This research is therefore not only a scientific advance but also represents a significant technological and conceptual progress in the quest to understand neuronal behavior under natural conditions.



INFORMATION:



ELSE PRESS RELEASES FROM THIS DATE:

Nanofriction on the tip of the microscope

2013-12-16
Nanofriction on the tip of the microscope A new research paper from SISSA published in Nature Materials Atomic force microscopes are able to reproduce spectacular images, at the scale of single atoms. This is made possible by the ...

Families urged to get to the heart of their medical histories this Christmas

2013-12-16
Families urged to get to the heart of their medical histories this Christmas Doctors are encouraging people to take advantage of Christmas gatherings with relatives to discuss family medical histories to help tackle ill-health. The call from clinical ...

Golden trap: Highly sensitive system to detect individual molecules

2013-12-16
Golden trap: Highly sensitive system to detect individual molecules Medical diagnostics is searching for substances capable of documenting early on whether a serious disease is developing or what its course will be. In many cases, the treacherous ...

Ultrafast heating of water -- This pot boils faster than you can watch it

2013-12-16
Ultrafast heating of water -- This pot boils faster than you can watch it Novel method opens new paths for experiments with heated samples of biological relevance Scientists from the Hamburg Center for Free-Electron Laser Science have devised a novel ...

New classification system to improve scheduling of emergency surgery highlighted in BJS issue

2013-12-16
New classification system to improve scheduling of emergency surgery highlighted in BJS issue Researchers in Finland have implemented a classification system for emergency operations that allows for a fair and efficient way to manage a large volume of such surgery. The system ...

A Terahertz generator with the highest signal quality

2013-12-16
A Terahertz generator with the highest signal quality This news release is available in Spanish. Terahertz waves (THz) are found on the furthest extreme of the infrared band, just before the beginning of the microwave band. "This area is possibly the last range of the electromagnetic ...

EU membership may have led to allergy increase in rural Poland

2013-12-16
EU membership may have led to allergy increase in rural Poland Poland's entry into the EU may have had the surprising consequence of increasing allergies in rural villages, according to a new study. Surveys show that the prevalence of atopy, a predisposition ...

Life's not a squeeze for pregnant women

2013-12-16
Life's not a squeeze for pregnant women Pregnant women accurately judge the space needed to accommodate their growing bodies Despite their changed body size, pregnant women are just as good as other people at judging whether they are able to fit through openings, ...

Brittle-bone babies helped by fetal stem cell grafts

2013-12-16
Brittle-bone babies helped by fetal stem cell grafts Osteogeneis imperfecta (OI) is a congenital bone disease that causes stunted growth and repeated, painful fracturing. Ultrasound scans can reveal fractures already in the fetus, and now an international team of researchers ...

Nearby failed stars may harbor planet

2013-12-16
Nearby failed stars may harbor planet Pasadena, CA— Astronomers, including Carnegie's Yuri Beletsky, took precise measurements of the closest pair of failed stars to the Sun, which suggest that the system harbors a third, planetary-mass object.The research is published as a letter ...

LAST 30 PRESS RELEASES:

Not hunters but collectors: the bone that challenges the ‘humans wiped out Australian megafauna’ theory

Discovery of new mechanism concerning plasma confinement performance

Humans evolved fastest amongst the apes

Biochar and wetter soils offer breakthrough path to slash farm emissions without cutting crop yields

New biochar-enhanced cement could lock away more carbon dioxide

Strong evidence supports skin-to-skin contact after birth as standard care

Why it’s not just about money: Who goes to the ballet, opera and symphony

Daily step counts of 4,000 or more tied to reduced risk of heart disease, mortality in older women

Number of steps taken matters more for better health in older women than the frequency

Less than half of schoolkids at risk of food anaphylaxis in England prescribed adrenaline ‘antidote’

The Lancet: Antidepressants vary widely in their physical side effects, highlighting the need for personalised prescribing, says major meta-analysis

Scientists discover clean and green way to recycle Teflon®

‘Messy’ galaxies in the early universe struggled to settle

Global supply chains benefit most from who you know

While searching for the world’s oldest ice, scientists find sediment sneaking under the Antarctic ice sheet

Contrasting risk profiles for suicide attempt and suicide

Future-focused conservation index identifies reptiles as highest conservation priority

Ideological polarization and the spread of biased or fake news on Facebook are on the rise, according to a study by the UPF

New study reveals how tiny but powerful gatekeepers guard the nucleus

Discovery of a brown dwarf orbiting a red dwarf through the synergy of ground- and space-based observatories

CPA journal wins prestigious award at high-quality development conference

Disruptive investments can build a cleaner aviation industry

Wearable optical device distinguishes blood flow signals from the brain and scalp

USC-Caltech study moves novel tool to measure brain blood flow closer to the clinic

Changes in colorectal cancer screening modalities among insured individuals

Seaweed makes for eco-friendly tissue scaffolds and reduces animal testing

New study: AI chatbots systematically violate mental health ethics standards

Smoking both cannabis and tobacco may alter brain’s ‘bliss molecule,’ study finds

The rise of longevity clinics: Promise, risk, and the future of aging

Decoding the T-cell burst: Signature genes that predict T-cell expansion in cancer immunotherapy

[Press-News.org] Brain waves encode information as time signals