Neural dynamics during anoxia and the "wave of death"

• Published in: PloS one Vol. 6; no. 7; p. e22127
• Main Authors: Zandt, Bas-Jan, ten Haken, Bennie, van Dijk, J Gert, van Putten, Michel J A M
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 13.07.2011; Public Library of Science (PLoS)
• Subjects: Analysis; Animal experimentation; Animals; Anoxia; Apoptosis; Biology; Brain; Brain - physiology; Brain - physiopathology; Computational neuroscience; Depolarization; EEG; Electroencephalography; Experiments; Homeostasis; Humans; Hypoxia; Hypoxia - physiopathology; Ischemia; Medical imaging; Medicine; Membrane potential; Models, Neurological; Models, Theoretical; Neurons; Neurons - metabolism; Neurons - physiology; Neurosciences; Oscillations; Physics; Physiological aspects; Potassium; Potassium Channels; Potassium channels (voltage-gated); Potential oscillations; Rats; Rodents; Sodium; Sodium Channels; Netherlands
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0022127

Recent experiments in rats have shown the occurrence of a high amplitude slow brain wave in the EEG approximately 1 minute after decapitation, with a duration of 5-15 s (van Rijn et al, PLoS One 6, e16514, 2011) that was presumed to signify the death of brain neurons. We present a computational model of a single neuron and its intra- and extracellular ion concentrations, which shows the physiological mechanism for this observation. The wave is caused by membrane potential oscillations, that occur after the cessation of activity of the sodium-potassium pumps has lead to an excess of extracellular potassium. These oscillations can be described by the Hodgkin-Huxley equations for the sodium and potassium channels, and result in a sudden change in mean membrane voltage. In combination with a high-pass filter, this sudden depolarization leads to a wave in the EEG. We discuss that this process is not necessarily irreversible.