Periaxonal ion regulation in the squid
Pichon, Y.; Abbott, N.J.; Brown, E.R.; Inoue, I.; Revest, P.A. (1995). Periaxonal ion regulation in the squid, in: Abbott, N.J. et al. (Ed.) Cephalopod neurobiology: neuroscience studies in squid, octopus and cuttlefish. pp. 229-251
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| Authors | | Top |
- Pichon, Y.
- Abbott, N.J.
- Brown, E.R.
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| Abstract |
In the majority of animal groups, axons release K+ and take up Na+ during action potential production, with a tendency for an accumulation of K+ and depletion of Na+ in the narrow extracellular spaces adjacent to the axon. Homeostatic mechanisms are present to reduce the severity of these changes, and so limit their undesirable effects on neuronal function. This chapter reviews studies in squid giant axons, to show that under normal physiological conditions the Schwann cell sheath around the axon has powerful mechanisms for regulating the [K+] in the periaxonal space, using a combination of passive diffusion (particularly via the transcellular glial tubular system and across its membranes) and carrier-mediated transport. The significance of this regulation for the normal function of the giant axon system in swimming and escape responses is discussed. |
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