A New Framework for Assessment of Potassium‐Buffering Mechanisms

A new concept, that of "buffer capacity," is defined for potassium-buffering mechanisms in neural tissue. Buffer capacities for different mechanisms can be added and compared, thus simplifying quantitative assessment of diffusion, cytoplasmic uptake, and spatial buffering under varied conditions. The characteristic frequency components for potassium disturbances due to neural events are identified. The effect of buffering by a reservoir of fluid at a tissue surface is analyzed, together with its intrinsic limitations. The role of retinal Muller cells in spatial buffering is considered quantitatively: both buffering to the tissue surface and buffering sideways through cell-to-cell connections.

[1]  D. Attwell,et al.  Is the potassium channel distribution in glial cells optimal for spatial buffering of potassium? , 1985, Biophysical journal.

[2]  E. Newman,et al.  Control of extracellular potassium levels by retinal glial cell K+ siphoning. , 1984, Science.

[3]  E. Newman,et al.  Regional specialization of retinal glial cell membrane , 1984, Nature.

[4]  C. Nicholson,et al.  Changes of extracellular potassium activity induced by electric current through brain tissue in the rat. , 1983, The Journal of physiology.

[5]  A. Gardner-Medwin A study of the mechanisms by which potassium moves through brain tissue in the rat. , 1983, The Journal of physiology.

[6]  A. Gardner-Medwin,et al.  Analysis of potassium dynamics in mammalian brain tissue. , 1983, The Journal of physiology.

[7]  C. Nicholson,et al.  Ion diffusion modified by tortuosity and volume fraction in the extracellular microenvironment of the rat cerebellum. , 1981, The Journal of physiology.

[8]  A R Gardner-Medwin,et al.  Possible roles of vertebrate neuroglia in potassium dynamics, spreading depression and migraine. , 1981, The Journal of experimental biology.

[9]  W. H. Miller,et al.  Müller cell function during spreading depression in frog retina. , 1976, Proceedings of the National Academy of Sciences of the United States of America.

[10]  S. W. Kuffler,et al.  Effect of nerve impulses on the membrane potential of glial cells in the central nervous system of amphibia. , 1966, Journal of neurophysiology.

[11]  E. Conway,et al.  Potassium accumulation in muscle and associated changes 1 , 1941 .

[12]  E J Conway,et al.  Potassium accumulation in muscle and associated changes. , 1941, The Journal of physiology.