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The Body Electric
mendously exaggerated and lead to spastic paralysis of the muscles. The
interesting difference is in the duration of shock. In young salamanders
and goldfish it lasts only a few minutes, but it may endure for over a
week in old ones. In mammals it takes even longer to wear off—as long
as six months in humans.
We made some electrical measurements on salamander and frog spines
in our lab. The injured area turned out to be strongly positive during
spinal shock, even though all direct-current flow ceased in the entire
cord and in the peripheral nerves arising from the part below the
trauma. Then, as the shock resolved, a steadily increasing negative po-
tential appeared, its size reflecting the amount of outgrowth by epen-
dyma and nerve fibers. We found that we'd only rediscovered these
potentials, however. G. N. Sorokhtin and Y. B. Temper had made the
same measurements at the Khabarovsk Medical Institute twenty years
before. The patterns of shock and polarity both correlated, not only with
the cell activity, but with the end result of regenerative success or
failure. A few minutes of shock and a correspondingly short period of
positivity led to full repair of the cord. Longer delays produced in-
complete regeneration, and, when the shock and positive potential per-
sisted for five to eight days or longer, the salamander became completely
SPINAL SHOCK AND AGE INHIBIT CORD REGROWTH