title: A canonical circuit for generating phase-amplitude coupling.
abstract: 'Phase amplitude coupling' (PAC) in oscillatory neural activity describes a phenomenon whereby the amplitude of higher frequency activity is modulated by the phase of lower frequency activity. Such coupled oscillatory activity--also referred to as 'cross-frequency coupling' or 'nested rhythms'--has been shown to occur in a number of brain regions and at behaviorally relevant time points during cognitive tasks; this suggests functional relevance, but the circuit mechanisms of PAC generation remain unclear. In this paper we present a model of a canonical circuit for generating PAC activity, showing how interconnected excitatory and inhibitory neural populations can be periodically shifted in to and out of oscillatory firing patterns by afferent drive, hence generating higher frequency oscillations phase-locked to a lower frequency, oscillating input signal. Since many brain regions contain mutually connected excitatory-inhibitory populations receiving oscillatory input, the simplicity of the mechanism generating PAC in such networks may explain the ubiquity of PAC across diverse neural systems and behaviors. Analytic treatment of this circuit as a nonlinear dynamical system demonstrates how connection strengths and inputs to the populations can be varied in order to change the extent and nature of PAC activity, importantly which phase of the lower frequency rhythm the higher frequency activity is locked to. Consequently, this model can inform attempts to associate distinct types of PAC with different network topologies and physiologies in real data.
authors.affiliation: Bristol Centre for Complexity Sciences (B.C.C.S.), University of Bristol, Queen's Building, Bristol, United Kingdom; Department of Psychology, Center for Memory and Brain, Boston University, Boston, MA, United States of America.
authors.forename: Angela C E
authors.initials: AC
authors.lastname: Onslow
authors.affiliation: School of Physiology and Pharmacology, University of Bristol, Medical Sciences Building, Bristol, United Kingdom.
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Jones
authors.affiliation: Department of Computer Science, University of Bristol, Merchant Venturers Building, Bristol, United Kingdom; Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom; Medical Research Council Anatomical Neuropharmacology Unit, Department of Pharmacology, University of Oxford, Oxford, United Kingdom.
authors.forename: Rafal
authors.initials: R
authors.lastname: Bogacz
mesh_terms: D000200:Action Potentials / Q000502:physiology; D001921:Brain; D058256:Brain Waves / Q000502:physiology*; D006801:Humans; D008959:Models, Neurological; D009415:Nerve Net / Q000166:cytology / Q000502:physiology*; D009433:Neural Inhibition / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D017711:Nonlinear Dynamics