Sleep/wake changes in perturbational complexity in rats and mice

Matias Lorenzo Cavelli; Rong Mao; Graham Findlay; Kort Driessen; Tom Bugnon; Giulio Tononi; Chiara Cirelli

doi:10.1016/j.isci.2023.106186

Sleep/wake changes in perturbational complexity in rats and mice

iScience. 2023 Feb 13;26(3):106186. doi: 10.1016/j.isci.2023.106186. eCollection 2023 Mar 17.

Authors

Matias Lorenzo Cavelli^{1

2}, Rong Mao^{1

3}, Graham Findlay^{1

3}, Kort Driessen^{1

3}, Tom Bugnon¹, Giulio Tononi¹, Chiara Cirelli¹

Affiliations

¹ Department of Psychiatry, University of Wisconsin-Madison, Madison, WI 53719, USA.
² Departamento de Fisiología de Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay.
³ Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI 53719, USA.

Abstract

In humans, the level of consciousness is assessed by quantifying the spatiotemporal complexity of cortical responses using Perturbational Complexity Index (PCI) and related PCI^st (st, state transitions). Here we validate PCI^st in freely moving rats and mice by showing that it is lower in NREM sleep and slow wave anesthesia than in wake or REM sleep, as in humans. We then show that (1) low PCI^st is associated with the occurrence of an OFF period of neuronal silence; (2) stimulation of deep, but not superficial, cortical layers leads to reliable PCI^st changes across sleep/wake and anesthesia; (3) consistent PCI^st changes are independent of which single area is being stimulated or recorded, except for recordings in mouse prefrontal cortex. These experiments show that PCI^st can reliably measure vigilance states in unresponsive animals and support the hypothesis that it is low when an OFF period disrupts causal interactions in cortical networks.

Keywords: Biological sciences; Natural sciences; Neuroscience.