The human brain consists of around a hundred million nerve cells linked together by around ten billion contact junctions called synapses. The activity of this extremely complex network is regulated through a dynamic balance between excitatory signals, which are transmitted by one type of synapse, and inhibitory counter-signals, which are transmitted by another.
An imbalance between excitatory and inhibitory activity is associated with diseases such as epilepsy, schizophrenia, and anxiety. But despite the fact that excitatory synapses are much more common than their inhibitory counterparts, the system is generally kept in a state of equilibrium. Just how the brain manages this feat is a puzzle to scientists.Scientists at Karolinska Institutet and the Brain Mind Institute in Switzerland have now discovered a mechanism that might explain how the most common type of neuron in the cerebral cortex – the pyramid cell – is prevented from becoming over-activated. Their results show that a rarer cell type that links collections of pyramid cells – called a Martinotti cell –
acts as a kind of safety device. When a Martinotti cell receives signals above a certain frequency, it responds by sending back inhibitory signals that moderate surrounding pyramid cells.
Gilad Silberberg, one of the researchers behind the study, believes that the mechanism is essential to understanding brain disorders like epilepsy.
“A characteristic feature of epilepsy is the hyperactivation of cortical pyramid cells, which is exactly what this mechanism inhibits. It is possible that epilepsy is related to a deficit of Martinotti cells or a deficiency of Martinotti activity in the brain.”
Katarina Sternudd | alfa
Satellites, airport visibility readings shed light on troops' exposure to air pollution
09.12.2016 | Veterans Affairs Research Communications
Oxygen can wake up dormant bacteria for antibiotic attacks
08.12.2016 | Penn State
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine