They investigated how nerve signals are suppressed inside the so-called entorhinal cortex. According to the researchers, this neuronal inhibition leads nerve cells to synchronize their activity. The results of this study are now published in Neuron.
A microscopic view of the entorhinal cortex. The bright spots are the bodies of neurons.
Source: DZNE/Charité – Universitätsmedizin Berlin, Beed/Schmitz
The entorhinal cortex is a link between the brain’s memory centre, the hippocampus, and the other areas of the brain. It is, however, more than an interface that only transfers nervous impulses. The entorhinal cortex also has an independent role in learning and thinking processes. This is particularly applicable for spatial navigation. “We know precious little about how this happens," says Prof. Dietmar Schmitz, a researcher at the Cluster of Excellence NeuroCure at the Charité – Universitätsmedizin Berlin and Site Speaker for the DZNE in Berlin. “This is why we are investigating in animal models how the nerve cells within the entorhinal cortex are connected with each other.“
Signals wander inside the brain as electrical impulses from nerve cell to nerve cell. In general, signals are not merely forwarded. Rather, operation of the brain critically depends on the fact that the nerve impulses in some situations are activated and in other cases suppressed. A correct balance between suppression and excitation is decisive for all brain processes. “Until now research has mainly concentrated on signal excitation within the entorhinal cortex. This is why we looked into inhibition and detected a gradient inside the entorhinal cortex,” explains Dr. Prateep Beed, lead author of the study. "This means that nerve signals are not suppressed equally. The blockage of the nerve signals is weaker in certain parts of the entorhinal cortex and stronger in others. The inhibition has, so to speak, a spatial profile.”
When the brain is busy, nerve cells often coordinate their operation. In an electroencephalogram (EEG) – a recording of the brain’s electrical activity – the synchronous rhythm of the nerve cells manifests as a periodic pattern. "It is a moot question as to how nerve cells synchronize their behavior and how they bring about such rhythms," says Beed. As he explains, it is also unclear whether these oscillations are only just a side effect or whether they trigger other phenomena. "But it has been demonstrated that neuronal oscillations accompany learning processes and even happen during sleep. They are a typical feature of the brain's activity," describes the scientist. "In our opinion, the inhibitory gradient, which we detected, plays an important role in creating the synchronous rhythm of the nerve cells and the related oscillations.”
In the case of Alzheimer’s, the entorhinal cortex is among the regions of the brain that are the first to be affected. “In recent times, studies related to this brain structure have increased. Here, already in the early stages of Alzheimer's, one finds the protein deposits that are typical of this disease,” explains Schmitz, who headed the research. “It is also known that patients affected by Alzheimer’s have a striking EEG. Our studies help us to understand how the nerve cells in the entorhinal cortex operate and how electrical activities might get interrupted in this area of the brain.”Original publication
Prateep Beed, Anja Gundlfinger et al., Neuron, DOI: 10.1016/j.neuron.2013.06.038Contact
Daniel Bayer | idw
Embryonic development: How do limbs develop from cells?
18.05.2018 | Humboldt-Universität zu Berlin
Reading histone modifications, an oncoprotein is modified in return
18.05.2018 | American Society for Biochemistry and Molecular Biology
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.
The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...
Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.
Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...
A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.
Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
18.05.2018 | Power and Electrical Engineering
18.05.2018 | Information Technology
18.05.2018 | Information Technology