Evaluation of in vitro neuronal networks for the study ofspontaneous activity

Abstract

In the absence of external stimuli, the nervous system exhibits a spontaneous electrical activity whose functions are not fully understood, and that represents the background noise of brain operations.Spontaneous activity has been proven to arise not only in vivo, but in in vitro neuronal networks as well,following some stereotypical patterns that reproduce the time course of development of the mammalian nervous system. This review provides an overview of in vitro models for the study of spontaneous network activity, discussing their ability to reproduce in vivo - like dynamics and the main findings obtained with each particular model. While explanted brain slices are able to reproduce the neuronal oscillations typically observed in anaesthetized animals, dissociated cultures allow the use of patient-derived neurons and limit the number of animals used for sample preparation. Moreover, dissociated neurons can be cultured on three-dimensional (3D) substrates that mimic the extra-cellular matrix of the brain. Depending on the material used, 3D substrates are able to increase neuronal connectivity and synaptic strength.