Periodicity, mixed-mode oscillations, and quasiperiodicity in a rhythm-generating neural network.
We studied patterns of oscillatory neural activity in the network that generates respiratory rhythm in mammals. When isolated in vitro, this network spontaneously generates an inspiratory-related motor rhythm, with stable amplitude from cycle to cycle. We show that progressively elevating neuronal excitability in vitro causes periodic modulation of this inspiratory rhythm, evoking (in order): mixed-mode oscillations, quasiperiodicity, and ultimately disorganized aperiodic activity. Thus, the respiratory network oscillator follows a well defined sequence of behavioral states characterized by dynamical systems theory, which includes discrete stages of periodic and quasiperiodic amplitude modulation and progresses (according to theory) to aperiodic chaos-like behavior. We also observed periodic, mixed-mode periodic, and quasiperiodic breathing patterns in neonatal rodents and human infants in vivo, suggesting that breathing patterns generated by the intact nervous system reflect deterministic neural activity patterns in the underlying rhythm-generating network.
Del Negro
Christopher A
CA
Cellular and Systems Neurobiology Section, Laboratory of Neural Control, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
Wilson
Christopher G
CG
Butera
Robert J
RJ
Rigatto
Henrique
H
Smith
Jeffrey C
JC
D000818:Animals; D000831:Animals, Newborn; D001933:Brain Stem / Q000502:physiology; D004576:Electromyography; D066298:In Vitro Techniques; D001239:Inhalation / Q000502:physiology; D008526:Medulla Oblongata / Q000502:physiology*; D008959:Models, Neurological; D009415:Nerve Net / Q000502:physiology*; D009482:Neurophysiology; D010507:Periodicity; D051381:Rats; D015656:Respiratory Mechanics / Q000502:physiology; D014628:Vagotomy