I'm interested to know how much activity-dependent variation in conduction
velocity is exhibited by individual axons in the human nervous system
(particularly in the CNS).
There were a couple of papers published in the 80s (below) suggesting that
activity dependent modulation of conduction velocity occurs in the normal
brain. I have been unable to find reference a similar effect in standard
texts. Is this a well established property of nerve cells or has this
research since been discredited?
If this effect has been noted, could velocity variation noticeably affect
reaction times during adaptation?
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References:
Aston-Jones, G., Segal, M., & Bloom, F. E. (1980). Brain aminergic axons
exhibit marked variability in conduction velocity. Brain Res, 195, 215-222.
George, S. A., Mastronarde, D. N., & Dubin, M. W. (1984). Prior activity
influences the velocity of impulses in frog and cat optic nerve fibers.
Brain Res, 304, 121-126.
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Paul Davidson
Bioengineer
Christchurch Hospital
New Zealand