Optimum ion channel properties in the squid giant axon.
Evolutionary pressures are presumed to act so as to maximize the efficiency of biological systems. However, the utility of that premise is marred by the difficulties in defining and evaluating both the efficiency of systems and the character of the available variation space. Following Hodgkin and Adrian, we examine the character of voltage gated ion channels in the nonmyelinated giant axons of the squid and find that both the channel densities and channel transition rates have values that nearly optimize signal sensitivity as well as signal velocity.
Adair
Robert K
RK
Department of Physics, Yale University, New Haven, Connecticut 06520-8121, USA.
D000200:Action Potentials / Q000502:physiology*; D001369:Axons / Q000502:physiology*; D003198:Computer Simulation; D008564:Membrane Potentials / Q000502:physiology*; D008959:Models, Neurological; D009431:Neural Conduction / Q000502:physiology*; D015221:Potassium Channels / Q000502:physiology*; D015222:Sodium Channels / Q000502:physiology*
D015221:Potassium Channels; D015222:Sodium Channels