Hirnscanner: In einem solchen Magnetresonanztomographen (MRT) betrachteten die Probanden mit einer Bildschirmbrille blaue und grüne Quadrate, die auftauchten und wieder verschwanden.
(c) Foto: BCAN
Neuronale Mechanismen der Einprägung negativer Erfahrungen: Passend zu tierexperimentellen Daten mit Knock-Out Mäusen zeigen gesunde Versuchspersonen mit natürlich vorkommenden Varianten des Dynorphin-Gens eine vermehrte Aktivität in der Amygdala während des Vergessens sowie eine verminderte Kopplung zwischen Amygdala und ventromedialem präfrontalen Kortex.
(c) Abbildung: Susanne Erk
Body’s own dynorphin weakens fearsWhy is it that in some people terrible events are deeply engraved in their memory, while after a while others seem to have completely put aside any anxiety related to the incident? Scientists in the fields of psychiatry, molecular psychiatry and radiology at the University of Bonn are all involved in probing this issue. “We were able to demonstrate by way of a series of experiments that dynorphin plays an important role in weakening anxiety,” says Prof. Dr. Andreas Zimmer, Director of the Institute for Molecular Psychiatry at the University of Bonn. The substance group in question is opiods which also includes, for instance, endorphins. The latter are released by the body of athletes and have an analgesic and euphoric effect. The reverse, however, is true of dynorphins: They are known for putting a damper on emotional moods.
Results are transferrable to peopleNext the researchers showed that these results can be transferred to people. “We took advantage of the fact that people exhibit natural variations of the dynorphin gene that lead to different levels of this substance being released in the brain,” reports Prof. Dr. Dr. Henrik Walter, Director of the Research Area Mind and Brain at the Psychiatric University Clinic at the Charité in Berlin, who also used to perform research in this area at the University Clinic in Bonn. A total of 33 healthy probands were divided into two groups: One with the genetically stronger dynorphin release and the other which exhibits less gene activity.
Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden
The pyrenoid is a carbon-fixing liquid droplet
22.09.2017 | Max-Planck-Institut für Biochemie
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
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22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy