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ePaper created 2014-07-24, 14:56:51 | version 1.32.01
36 ence more macroscopic potentials quasi in vivo. The model input was based on own patch-clamp data of nanoparticle cell interactions. After successfully being able to model neural fields originating from Hodgkin-Huxley type neurons, another object was to close the loop between field potentials and its generators: we investigated how the neural field potentials influence the spike generation in neu- rons that are physically located within these fields, if this feedback causes relevant changes in the un- derlying neuronal signaling within the circuit, and if this is strong enough to cause observable chan- ges in the generated field potentials themselves. Due to our patch-clamp data, the linear model is also able to forecast the depth that nanoparticles, brought in contact with a few cells in the network, have on neural field potentials. We found the emerging field potentials of a basic two-dimensi- onal, two-layer model to be extensively diversified after assuming feedback to pyramidal neurons. The field potentials have strong effects on the action potential generation of neurons that are exposed to those fields. Applying this developed model to simulate the effects nanoparticles affecting cells in small scale have on field potentials of much hig- her scale, we found that nanoparticles in thalamic tissue may cause distortions in cortical field po- tentials. This linear model may subserve as basic approach to estimate the spatiotemporal dynamics of cortical field potentials on a very small cortical patch that may be electrophysiologically mea- surable. Such models are important for a further understanding of possible benefits and risks of the exposure of neuronal structures to NPs, thus being relevant for nanotoxicology. Zielsetzung Aufgabe des Programmbereichs ist die Erstellung von Mo- dellen und Simulationen. Zukünftig sollen auch verstärkt eigene Forschungsprojekte betrieben werden. Im Jahr 2013 wurden zwei Forschungsprojekte in enger Verzahnung mit anderen Gruppen bearbeitet: Die Studie NeuroNano untersucht den Einfluss beschichte- ter Silber-Nanopartikel (NP)-induzierter Diversifikationen einzelner Zellen über die Antwort neuronaler Systeme bis hin zu makroskopischen Effekten elektrophysiologisch messbarer Feldpotenziale von Kortexneuronen. Das Projekt TriboBrain befasst sich mit der Identifizierung und Analyse hirnelektrischer Antwortpotentiale, welche im Zuge tribologischer Experimente zwischen dem menschli- chen Finger und unterschiedlichsten Materialien gewonnen werden. Mission The Program Division is supposed to prepare models and perform simulations. In the future, the division will increa- singly perform its own research projects. Current Research NeuroNano (with Program Division Nano Cell Interactions) The purpose of the present modeling study was to develop a computational multiscale model that links the neuronal acti- vity of a single neuron in the high-resolution domain of the well-established Hodgkin-Huxley model across a circuitry of such neurons up to neural field potentials generated by those neurons. Such models allow to investigate how small changes, e.g. synaptic coupling, channel activation, etc., in- duced by pharmaceutical agents or nanoparticles may influ- Modellierung/Simulation / Modelling/Simulation N.N. Gruppenberichte / Group Reports // querschnittsFeld / Cross linking activities