PROJECT TITLE :

Hierarchy of Neural Organization in the Embryonic Spinal Cord: Granger-Causality Graph Analysis of In Vivo Calcium Imaging Data

ABSTRACT:

The recent development of genetically encoded calcium indicators enables monitoring in vivo the activity of neuronal populations. Most analysis of those calcium transients relies on linear regression analysis based mostly on the sensory stimulus applied or the behavior observed. To estimate the fundamental properties of the functional neural circuitry, we have a tendency to propose a network approach to calcium imaging recorded at single cell resolution. Differently from previous analysis based on cross-correlation, we have a tendency to used Granger-causality estimates to infer information propagation between the activities of different neurons. The ensuing practical network was then modeled as a directed graph and characterised in terms of connectivity and node centralities. We tend to applied our approach to calcium transients recorded at low frequency (four Hz) in ventral neurons of the zebrafish spinal wire at the embryonic stage when spontaneous coiling of the tail occurs. Our analysis on population calcium imaging data revealed a robust ipsilateral connectivity and a characteristic hierarchical organization of the network hubs that supported established propagation of activity from rostral to caudal spinal twine. Our methodology could be used for detecting useful defects in neuronal circuitry throughout development and pathological conditions.