Spontaneous activity in neuronal networks with dictated connectivity

Abstract

We studied spontaneous activity in rat neuronal cultures and compared two configurations, namely homogeneous and patterned. In the former, neurons grew over a plain glass substrate and therefore could develop isotropically. In the latter, neurons grew on a substrate shaped with topographical obstacles, which dictated the connectivity of the neurons and broke the isotropy of the system. Activity in all networks was recorded using fluorescence calcium imaging. By analyzing and comparing their activity patterns, we have found that activity in patterned cultures is markedly different, with richer spatiotemporal activity fronts and slower propagation speeds.