Details

Autor(en) / Beteiligte

• Crotty, Patrick
• Levy, William B.

Titel

Effects of Na + channel inactivation kinetics on metabolic energy costs of action potentials

Ist Teil von

• Neurocomputing (Amsterdam), 2007-06, Vol.70 (10), p.1652-1656

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2007

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• We investigate whether the inactivation properties of Na + channels in squid giant axons show evidence of having been optimized by evolution so as to reduce the energy expenditure associated with propagating action potentials. Using Hodgkin–Huxley-type models of the squid giant axon and varying the voltage dependence and overall scaling of the Na + inactivation rate, we find that faster inactivation rates correspond to less costly and more energy-efficient action potentials. However, and in contrast to the case when the ionic conductances and axon diameters are varied, the metabolic energy consumption does not have a minimum when restricted to an isovelocity curve in the phase space associated with these inactivation parameters. This failure-to-optimize encourages other hypotheses about the evolution and functionality of inactivation, such as its effects on information rates.