Objectif Recent neurophysiological experiments have revealed the existence of nonrandom connectivity patterns in the cortex of rats. These patterns consist of certain connectivity structures that appear more often than one would expect if neurons were randomly connected. An example of such departure from randomness is the prevalence of pairs of neurons reciprocally connected. Another example is the overrepresentation of certain connectivity patterns involving three or more neurons connected through strong synapses. It is currently unknown how these nontrivial connectivity patterns arise, and what function they serve. The goal of this project is to study, using analytical and numerical techniques, the emergence of these connectivity patterns, and to elucidate the possible function of nonrandom circuits. We will explore the hypothesis that these patterns naturally result from the interplay between the ongoing cortical activity and the synaptic modifications induced by correlated neuronal activity. In particular, we will determine the conditions necessary for the formation of the nonrandom structures observed in experiments, studying how the rule governing synaptic changes and the input statistics determine the emergent connectivity structure. In a second stage, we will investigate the impact of nonrandom connectivities in the dynamics of cortical circuits, emphasizing the consequences for the stability of self-sustained activity patterns (attractors). Finally, we will concentrate on the distribution of synaptic weights seen in experiments, consisting in a large fraction of silent synapses coexisting with a small fraction of functional synapses whose weights are log-normally distributed. Using analytical tools developed in statistical physics, we will compute the distribution of synaptic weights that maximizes the number of attractors sustained by the cortical circuit, and we will assess whether the distribution measured in the cortex agrees with the optimal distribution. Programme(s) FP7-PEOPLE - Specific programme "People" implementing the Seventh Framework Programme of the European Community for research, technological development and demonstration activities (2007 to 2013) Thème(s) FP7-PEOPLE-2011-IEF - Marie-Curie Action: "Intra-European fellowships for career development" Appel à propositions FP7-PEOPLE-2011-IEF Voir d’autres projets de cet appel Régime de financement MC-IEF - Intra-European Fellowships (IEF) Coordinateur INSTITUT NATIONAL DE LA SANTE ET DE LA RECHERCHE MEDICALE Contribution de l’UE € 193 594,80 Adresse RUE DE TOLBIAC 101 75654 Paris France Voir sur la carte Région Ile-de-France Ile-de-France Paris Type d’activité Research Organisations Contact administratif Laurie Louis-Joseph (Ms.) Liens Contacter l’organisation Opens in new window Site web Opens in new window Coût total Aucune donnée Participants (1) Trier par ordre alphabétique Trier par contribution de l’UE Tout développer Tout réduire CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS Participation terminée France Contribution de l’UE Aucune donnée Adresse RUE MICHEL ANGE 3 75794 Paris Voir sur la carte Région Ile-de-France Ile-de-France Paris Type d’activité Research Organisations Contact administratif Chiara Chelini (Ms.) Liens Contacter l’organisation Opens in new window Site web Opens in new window Coût total Aucune donnée