"Mild traumatic injury can modify the key sodium (Na+) current underlying the excitability of neurons. It causes the activation and inactivation properties of this current to become shifted to more negative trans-membrane voltages. This so-called coupled left shift (CLS) leads to a chronic influx of Na+ into the cell that eventually causes spontaneous or “ectopic” firing along the axon, even in the absence of stimuli. The bifurcations underlying this enhanced excitability have been worked out in full ionic models of this effect. Here, we present computational evidence that increased temperature T can exacerbate this pathological state. Conversely, and perhaps of clinical relevance, mild cooling is shown to move the naturally quiescent cell further away from the threshold of ectopic behavior. ..."
Model Type: Axon
Currents: I K; I Na,t; I Sodium; Na/K pump
Model Concept(s): Bifurcation; Temperature
Simulation Environment: NEURON
Implementer(s): Barlow, Benjamin Stephen [BBarlow at uottawa.ca]
Barlow BM, Joos B, Trinh AK, Longtin A. (2018). Cooling reverses pathological bifurcations to spontaneous firing caused by mild traumatic injury. Chaos (Woodbury, N.Y.). 28 [PubMed]