DEAN · Dynamical Entropies in Assemblies of Neurons

Final Activity Report Summary - DEAN (Dynamical Entropies in Assemblies of Neurons)

This project applied techniques borrowed from physics and nonlinear dynamics to the analysis of neuronal dynamics. In order to capture the mechanisms underlying storing and processing of information in the brain, the present studies focused on the investigation of the response of single neurons subjected to erratic as well as regular inputs. The research activity has been directed along two parallel directions, one involving numerical studies of realistic neuronal models, the other devoted to the nonlinear analysis of time series obtained via dynamic clamp of stellate cells of the enthorinal cortex. The investigation of the responses of neuronal models subjected to excitatory and inhibitory stochastic post-synaptic stimuli revealed for the first time that the presence of a certain level of correlation among the inputs could lead to a maximal degree of regularity in the neuronal response. The analysis of the experimental data led to the development of a new indicator, called the inter-spike interval (ISI) distance, to quantify synchronisation and information transfer between two or more spike trains. This tool was parameter free, time-scale independent and easy to visualise. Moreover, comparison with existing approaches revealed that the ISI distance performed as well as the best time-scale-optimised measure based on spike timing. It should be stressed out that the present research project allowed for establishing a fruitful collaboration between scientific institutions located in Europe and the USA, in particular between the Institute of complex systems of the national research council in Florence, Italy and the institute for nonlinear science, University of California San Diego, in La Jolla, California, USA.

Data: CORDIS, © European Union