Perturbational Complexity Index (PCI) protocol in the mouse (in vivo) and ferret (in vitro) (v1)

The spatiotemporal complexity of the activity expressed by the cerebral cortex is a highly revealing feature of the underlying network’s state. Quantifying cortical complexity can be achieved by perturbing the system and investigating the causal interactions that follow. Here, by means of two different projects, we aimed to assess cortical complexity differences across brain states, anesthesia levels, and stimulus location using in vitro and in vivo experiments, ultimately contributing to a better understanding of the underlying network dynamics and their modulation. Firstly, we explore the differences in cortical complexity between the effect of the ventral posteromedial thalamic nucleus (VPM) stimulation and the motor (M1/M2) cortex. Secondly, we explore the role of inhibition in cortical complexity using in vitro experiments. We investigate the influence of GABAergic inhibition, mediated by GABA_A or GABA_B receptors, on cortical complexity, departing from a desynchronized state that mimics wakefulness.