Acoplamento efático em modelo neuronal híbrido

Abstract

There is growing interest in the impact of electrical fields generated in the brain. Transmembrane ionic currents originate electric fields in the extracellular space and are capable of affecting nearby neurons, a phenomenon called ephatic communication. In the present work, the Quadratic Integrate-and-Fire model was adapted to include the ephatic coupling behavior and its results were compared to the empirical results. Therefore, the analysis tools were divided according to the neuronal activity regime. For the subthreshold regime, circular statistics were used to describe the phase differences between the stimulus signal and the modeled membrane response; In the suprathreshold regime, the Population Vector and Spike Field Coherence were used to estimate phase preferences and the coupling intensity between the stimulus and the spikes of the model. The subthreshold phase difference was sensitive to the characteristic membrane response time, as well as the frequency of the stimulus given to the model. On the other hand, the intensity of the coupling between spikes and stimulus was sensitive to the intensity of noise added to the stimulus signal and also to the stimulus frequency. The preferential phase of spikes are sensitive, according to the model, only to the stimulus frequency. Such results are consistent with the results observed in empirical experiments on ephatic neuronal coupling. It was observed that the Quadratic Integrate-e-Fire model with ephatic coupling is able to successfully model this neuronal communication. Thus, the model makes it possible to pursue further studies on the physiological importance of ephatic coupling in the brain, including significant implications for our understanding of brain processing for neuroscience.