--- res: bibo_abstract: - Origin and functions of intermittent transitions among sleep stages, including brief awakenings and arousals, constitute a challenge to the current homeostatic framework for sleep regulation, focusing on factors modulating sleep over large time scales. Here we propose that the complex micro-architecture characterizing sleep on scales of seconds and minutes results from intrinsic non-equilibrium critical dynamics. We investigate θ- and δ-wave dynamics in control rats and in rats where the sleep-promoting ventrolateral preoptic nucleus (VLPO) is lesioned (male Sprague-Dawley rats). We demonstrate that bursts in θ and δ cortical rhythms exhibit complex temporal organization, with long-range correlations and robust duality of power-law (θ-bursts, active phase) and exponential-like (δ-bursts, quiescent phase) duration distributions, features typical of non-equilibrium systems self-organizing at criticality. We show that such non-equilibrium behavior relates to anti-correlated coupling between θ- and δ-bursts, persists across a range of time scales, and is independent of the dominant physiologic state; indications of a basic principle in sleep regulation. Further, we find that VLPO lesions lead to a modulation of cortical dynamics resulting in altered dynamical parameters of θ- and δ-bursts and significant reduction in θ–δ coupling. Our empirical findings and model simulations demonstrate that θ–δ coupling is essential for the emerging non-equilibrium critical dynamics observed across the sleep–wake cycle, and indicate that VLPO neurons may have dual role for both sleep and arousal/brief wake activation. The uncovered critical behavior in sleep- and wake-related cortical rhythms indicates a mechanism essential for the micro-architecture of spontaneous sleep-stage and arousal transitions within a novel, non-homeostatic paradigm of sleep regulation.@eng bibo_authorlist: - foaf_Person: foaf_givenName: Fabrizio foaf_name: Lombardi, Fabrizio foaf_surname: Lombardi foaf_workInfoHomepage: http://www.librecat.org/personId=A057D288-3E88-11E9-986D-0CF4E5697425 orcid: 0000-0003-2623-5249 - foaf_Person: foaf_givenName: Manuel foaf_name: Gómez-Extremera, Manuel foaf_surname: Gómez-Extremera - foaf_Person: foaf_givenName: Pedro foaf_name: Bernaola-Galván, Pedro foaf_surname: Bernaola-Galván - foaf_Person: foaf_givenName: Ramalingam foaf_name: Vetrivelan, Ramalingam foaf_surname: Vetrivelan - foaf_Person: foaf_givenName: Clifford B. foaf_name: Saper, Clifford B. foaf_surname: Saper - foaf_Person: foaf_givenName: Thomas E. foaf_name: Scammell, Thomas E. foaf_surname: Scammell - foaf_Person: foaf_givenName: Plamen Ch. foaf_name: Ivanov, Plamen Ch. foaf_surname: Ivanov bibo_doi: 10.1523/jneurosci.1278-19.2019 bibo_issue: '1' bibo_volume: 40 dct_date: 2020^xs_gYear dct_identifier: - UT:000505167600016 dct_isPartOf: - http://id.crossref.org/issn/0270-6474 - http://id.crossref.org/issn/1529-2401 dct_language: eng dct_publisher: Society for Neuroscience@ dct_title: Critical dynamics and coupling in bursts of cortical rhythms indicate non-homeostatic mechanism for sleep-stage transitions and dual role of VLPO neurons in both sleep and wake@ fabio_hasPubmedId: '31694962' ...