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Erinnerungen beobachten | Forschende am ISTA werfen un Blick in den Hippocampus
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Erinnerungen beobachten | Forschende am ISTA werfen un Blick in den Hippocampus

This image in large format (openPR) Henry Gustav Molaison, better informed as patient “HM”, reads epilepsy. Aufgrund seiner Anfälle wurde er an einen Chirurgien überwiesen, der die Epilepsie im Schläfenlappen seines Gehirns lokalisierte, ainer Region, der sich der Hippocampus befindet.

On September 1, 1953, an HM operation was launched, within the Hippocampus, which took place, and which was followed by Epilepsie zu heilen. You have to wait for the Epilepsy Operation and the Anfälle verschwunden, doch HM entwickelte schwere Nebenwirkungen. Er litt nonunter anterograder Amnesia: Er konnte sich an alle Ereignisse vor der Operation erinnern, war aber nicht in der Lage, neue Erinnerungen zu bilden. Sein prägnanter Fall trug dazu bei, den Hippocampus mit der Gehirnfunktion et der Gedächtnisbildung in Verbindung zu bringen.

This is a well-known region of the Hippocampus in a menschlichen Gehirn region, both in general education and in räumlichen navigation. It indicates the Kurzzeitgedächtnis in Langzeitgedächtnis um und erleichtert so die Wiedergabe persönlicher Erfahrungen.

In a new study led by Olena Kim, Yuji Okamoto and Peter Jonas, Magdalena Walz Professor for Life Sciences at the Austrian Institute of Science and Technology (ISTA), an international team of Neurowissenschafter: from new details on the molecular mechanisms of the general organization aufgedeckt. Die Forschenden nahmen die sogenannte Moosfaser-Synapse (aus dem English “mossy fiber synapse”) – un wichtiger Verbindungspunkt zwischen bestimmten Nervenzellen (Neuronen) im Hippocampus – genau under die Lupe. With general-purpose methods, you have the structure, the molecules and their functions.

Das Gedächtnis-Zentrum

Verschiedense Neuronen are found in the hippocampus and as part of the general organization. Granularzellen beispielsweise are what is suitable for detailed verification information. “These granular cells are now being reported in different regions, which are verarbeiten and other fields,” said Olena Kim, ISTA-Absolventin and her postdoc at the Institut für Molekulare Biotechnologie (IMBA) of the Österreichischen Akademie der Wissenschaften (ÖAW).

This signal is emitted by the Axon der Granularzellen weitergeleitet. These tools are provided with the Moosfasern bezeichnet and an image of a contact of the pyramids – the Moosfaser-Synapse. This association of neurotransmitters (Signalmoleküle) for communication, which also applies to images and the dissemination of general information.

The characteristics of the Moosfaser-Synapsen are their high plasticization, and you can access this in terms of activity, structure and bond auf der Grundlage von Reizen ändern. This Hippocampus approach supports the Hippocampus, detailed organizational information, and two detailed instructions for follow-up.

Kim erklärt dies and eines Beispiels: “Nehmen wir an, Sie treffen gleichzeitig auf einen Panther et eine schwarze Katze. Beide haben schwarzes Fell et haben katzenartige Eigenschaften. Now you can see the Katze and the Panther unterscheiden. The Moosfaser-Synapsen play a complex roll here in terms of programming and organization of retail operations and are ideally suited for preparation and information operations.

Moosfaser-Synapsen in Nahaufnahme

If the signal is switched on by the current synapses on the molecule, it is still not clear. 2020 saw Peter Jonas, Carolina Borges-Merjane and Olena Kim create the Moosfaser-Synapsen structure to support them, in addition to a new technology called “Flash and Freeze”. This handelt is also a leistungsstarkes Werkzeug, bei dem Neuronen direct nach der Stimulation eingefroren werden.

“Damals konnten wir strukturelle Veränderungen in den Moosfaser-Synapsen mit ihrer Funktionalität in Verbindung broughten”, so Kim. “No matter how long the technologies are available and no structure of the Synapse subsidies, we also know the Veränderungen, but we also find out about the molecular structure, and we can find out about it. »

The research is interesting to focus on two proteins, which are found in each area where neurotransmitters are free. Dazu gehört beispielsweise Cav2.1, the Baustein of the Kalziumkanäle, by the Kalzium einströmt, was the Freisetzung von Neurotransmittern auslöst. But beyond Munc13, a self-actor interested in the future, the neurotransmitter is free to function.

“It’s time to get the protein out there and try to fix it,” says Kim. The above is that you have a single click on the dynamic process, and this problem is no longer active. “Deswegen wollten wir für nosere neue Studie lebendes Hirngewebe verwenden, um so die Dynamik, the natural Zusammensetzung et lokalisierung ceser Protein zu erhalten. »

A global Oberfläche

Together with their colleagues at ISTA-Kollegen, Professor Ryuichi Shigemoto and scientist Walter Kaufmann, studied the technique further: in the “Flash and Frost Fracture” technology. Granularzellen in Gehirnproben von Mäusen wurden chemisch stimuliert, um den der Gedächtnisbildung zu aktivieren. Anschließend wurde das Hirngewebe sofort eingefroren et in 2wei Hälften geteilt. The inside of the cutting board page contains the Freiliegende Oberfläche des Gewebes dar – a 3D print of the Gewebes to create this Moment – ​​with integrated proteins and molecules.

Cav2.1 and Munc13 are labeled and can then be located with an electron microscope. The images, possible sessions and Monday-high have arrived, but the details are interesting: Next Stimulation ordnen sich beide Proteine ​​​​neu an und rücken näher zusammen.

After carrying out tests, the installation is carried out with the functionality of the Moosfaser-Synapse zusammenhängt. Peter Jonas expresses himself quickly: “The activity is within the reach of two companies. Erstens nimmt die Zahl der Vesikel in der Nähe der Membran zu. Twice it is a new version of Cav2.1 and Munc13 in Nanobereich, which allows the synapses to be more efficient and präziser. Beide Veränderungen könnten zur Gedächtnisbildung beitragen“.

Die Studie wirft Licht auf die Beziehung zwischen Struktur et Funktion an einer Schlüsselsynapse im Hippocampus. Unsere Erinnerungen rufen often lebhafte Bilder hervor. We invite you to use the molecular signal, which is not applied to general information. Previous studies are not a given Grundstein.

Draft proposal:

This project was developed with the European Research Council and the European Union’s Horizon 2020 research and innovation programs (ERC 692692 for PJ) and the Scientific Research Fund (Z312-B27 697 Wittgenstein Prize for PJ ; W1205-B09 and P362). 32 -B for PJ; I6166-B for RS) included.

Level information:

A complex project and that of basic neurological sciences, immunology or genetics better oriented towards knowledge, is the insatz of levels in unique research. There are other methods, such as an in-silico model, which may be alternative models. Die Tiere werden gemäß der strengen in Österreich geltenden gesetzlichen Richtlinien aufgezogen, gehalten and behandelt. All experimental activities are carried out by the Federal Ministry of Photography, Science and Research.

Original publication:
O. Kim, Y. Okamoto, WA Kaufmann, N. Brose, R. Shigemoto, and P. Jonas. 2024. cAMP-PKA-mediated presynaptic potentiation induces reconfiguration of synaptic vesicle pools and channel-vesicle coupling at hippocampal mossy fiber knobs. PLOS biology. DOÏ: