title: Critical role for resource constraints in neural models.
abstract: Criticality has emerged as a leading dynamical candidate for healthy and pathological neuronal activity. At the heart of criticality in neural systems is the need for parameters to be tuned to specific values or for the existence of self-organizing mechanisms. Existing models lack precise physiological descriptions for how the brain maintains its tuning near a critical point. In this paper we argue that a key ingredient missing from the field is a formulation of reciprocal coupling between neural activity and metabolic resources. We propose that the constraint of optimizing the balance between energy use and activity plays a major role in tuning brain states to lie near criticality. Important recent findings aligned with our viewpoint have emerged from analyses of disorders that involve severe metabolic disturbances and alter scale-free properties of brain dynamics, including burst suppression. Moreover, we argue that average shapes of neuronal avalanches are a signature of scale-free activity that offers sharper insights into underlying mechanisms than afforded by traditional analyses of avalanche statistics.
authors.affiliation: Systems Neuroscience Group, QIMR Berghofer Medical Research Institute Brisbane, QLD, Australia.
authors.forename: James A
authors.initials: JA
authors.lastname: Roberts
authors.affiliation: Systems Neuroscience Group, QIMR Berghofer Medical Research Institute Brisbane, QLD, Australia ; Faculty of Health Sciences, School of Medicine, University of Queensland Brisbane, QLD, Australia.
authors.forename: Kartik K
authors.initials: KK
authors.lastname: Iyer
authors.affiliation: Department Clinical Neurophysiology, Children's Hospital, Helsinki University Central Hospital, University of Helsinki Helsinki, Finland.
authors.forename: Sampsa
authors.initials: S
authors.lastname: Vanhatalo
authors.affiliation: Systems Neuroscience Group, QIMR Berghofer Medical Research Institute Brisbane, QLD, Australia ; Royal Brisbane and Women's Hospital Herston, QLD, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Breakspear
keywords: burst suppression; criticality; mathematical models; metabolic resources; scale-free dynamics