Connectivity motifs

…information can be challenging, as connectivity and activity continuously influence each other. Activity-dependent synaptic plasticity shapes and refines this intricate relationship. Connectivity motifs, small subnetworks of a few neurons, have been found to play a key role in linking circuit structure to the dynamical properties of neural activity, such as covariability and dimensionality. Significant progress has been made in measuring precise neural connectivity; multipatch experiments and recent connectomic studies have quantified thr

…physiology datasets have uncovered connectivity patterns that deviate significantly from independent connection models. Simultaneously, studies of task-trained recurrent networks have emphasize

Understanding the fine-scale connectivity structure of neural networks is key to deciphering their behaviour. Motifs in network connectivity are instrumental in relating circuit structure to dynamical properties of neural activity, such as covariability and dimensionality [1]. Experiments have made significant progress in measuring precise neural connectivity: multi-patch experiments, as well as more recent studies in connectomics, have found that certain types of three-neuron (triplet) connectivity motifs are over- or underrepresented relative to chance (Fig.1A, [2,3]). However, it is still u

Understanding how connectivity structure shapes network dynamics is paramount in the field of neuroscience. Theoretical investigations of multi-population neuronal networks often consider statistically homogeneous populations and incorporate either only the population-averaged mean or i.i.d. fluctuations in synaptic couplings. A newly released synaptic physiology dataset highlighted the strong presence of motifs – specific connectivity patterns between pairs and triplets of neurons–beyond the scope of mean connectivity[1] However, it is a priori not clear which of the experimentally identifie

The connectivity between neurons plays a major role in the dynamics and function of all neural systems. Here, we investigate the joint effects of two previously reported connectivity motifs, partial symmetry and self-coupling, on the dynamics of recurrent neural networks (RNNs). Both motifs can be thought of as statistical deviations from i.i.d. connectivity. In particular, we define self-coupling as the values of diagonal entries and partial symmetry as the correlations across the diagonals of coupling matrices. We calculate the full Lyapunov spectrum to characterize the stability of perturba

GABAergic interneurons play crucial roles in the regulation of neural activity in the cerebral cortex. In this Dual Lecture, Prof Oscar Marín and Prof Beatriz Rico will discuss several aspects of the formation of inhibitory circuits in the mammalian cerebral cortex. Prof. Marín will provide an overview of the mechanisms regulating the generation of the remarkable diversity of GABAergic interneurons and their ultimate numbers. Prof. Rico will describe the molecular logic through which specific pyramidal cell-interneuron circuits are established in the cerebral cortex, and how alterations in s

GABAergic interneurons play crucial roles in the regulation of neural activity in the cerebral cortex. In this Dual Lecture, Prof Oscar Marín and Prof Beatriz Rico will discuss several aspects of the formation of inhibitory circuits in the mammalian cerebral cortex. Prof. Marín will provide an overview of the mechanisms regulating the generation of the remarkable diversity of GABAergic interneurons and their ultimate numbers. Prof. Rico will describe the molecular logic through which specific pyramidal cell-interneuron circuits are established in the cerebral cortex, and how alterations in som

…mechanisms responsible for the precise connectivity of specific neural circuits remain largely unknown. Previous work has shown that the assembly of cortical circuits requires specific functions of molecular signalling complexes at different classes of synapses. In this talk, I will describe the molecular logic through which specific pyramidal cell-interneuron circuits are established in the cerebral cortex of the mouse, and how alterations in some of these connectivity motifs might be liked to