In our brains, groups of neurons fire up simultaneously for just milliseconds at a time, in random rhythms, similar to twinkling lightning bugs in our backyards. New research from neuroscientists at Indiana University and the University of Montreal provides a model -- a rhyme and reason -- for this random synchronization.
The findings, both of which appear in the Journal of Neuroscience this week, draw on the variability and creative nature of neurons -- no two are exactly the same, providing for a rich and ever-changing repertoire of brain activity. The findings expand scientists' understanding of brain rhythms, both reoccurring and random, and shed light on the decades-old mystery of how the brain learns temporal patterns.
"Our model is proposing a way that the brain processes temporal information and how this can vary over time" said Jean-Philippe Thivierge, a post-doctorate researcher in IU Bloomington's Department of Psychological and Brain Sciences.
A better understanding of rhythms in the brain -- how to create them or stop them -- would help researchers studying such neural diseases as epilepsy, which involves seizures or uncontrollable rhythms in the brain.
Thivierge and co-author Paul Cisek, an assistant professor at the University of Montreal, created a mathematical model for how hundreds of neurons interact after being stimulated by an electric current. They propose that the random synchronization, which occurs in large populations of neurons, results from "positive excitatory feedback originating from recurrent connections between the cells."
The synchronization involves most of the cells in the group but begins with a preferred small group of cells -- like "elite" cells -- that tend to become active just before all the others do. When enough cells in the group become active, a threshold, or "point of no return" is reached where all the cells become active and their activity spikes.
The study also demonstrates how neural activity can spike periodically or rhythmically. When researchers introduced a specific rhythm to the model, they discovered that the model could learn and repeat the rhythm. Scientists have known for 50 years that the brain could do this, but the mechanism was unknown until now. Thivierge said the mechanism is based on how the neurons come together to motivate each other to fire in a specific, periodic way, following the rhythmic stimuli.
The spontaneous neural activity modeled in this study has been detected in several regions of the brain as well as in other species. The authors conjecture that the benefits of such spontaneity come in the brain's ability to be more flexible and responsive to external events, that the random synchronization can prevent the brain from remaining "stuck" in a particular state.
"It seems like when you're in a more flexible brain state, it's easier for you to redirect your attention to new and important things," Thivierge said.
The study was supported by the Fonds Québéçois de Recherche sur la Nature et les Technologies (FQRNT), the National Science and Engineering Research Council (NSERC) and the Fonds de Recherche en Santé du Québec (FRSQ).
Thivierge can be reached at firstname.lastname@example.org or by contacting James.
"Nonperiodic Synchronization in Heterogeneous Networks of Spiking Neurons," The Journal of Neuroscience, Aug. 6, 28 (32).
Tracy James | Newswise Science News
Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration
"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...
Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.
Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
16.01.2017 | Power and Electrical Engineering
16.01.2017 | Information Technology
16.01.2017 | Power and Electrical Engineering