The Missing Chapter
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prick of a needle. In each case, I found that the frontal negative poten-
tial of the head became less negative, often reaching zero, as the client
attained deep trance. The reading changed in the same direction as in
anesthesia, only not as far. Then, when the suggestion for pain control
was given, the arm potential reversed just as it had in response to pro-
caine. Conversely, when a control subject was asked in normal waking
consciousness to concentrate forcefully on one arm, its sensitivity to pain
increased, and the hand potential became more negative. We found we
could use this difference to determine whether a person was really hyp-
notized or just cooperating.
Some doubters (including myself, I'm afraid) had believed hypno-
analgesia was merely a state in which the patient still felt the pain but
didn't respond to it, but these experiments proved it was a real blockage
of pain perception. It seems that the brain can shut off pain by altering the
direct-current potentials in the rest of the body "at will." There's every
reason to suppose that pain control through biofeedback or yoga likewise
works by using an innate circuit for attenuating the pain signal, which
releases a shot of the body's own pain-killers. When the signal is appro-
priately modulated, it releases endorphins (internally produced opiates),
as shown by experiments in which an injection of the opiate-antagonist
naloxone negates the anesthesia of acupuncture. I predict that research
on this system will eventually let us learn to control pain, healing, and
growth with our minds alone, substantially reducing the need for physi-
cians.
Direct evidence for the perineural DC system has been accumulating
gradually for several decades. Electric currents were detected in the glial
cells of rat brains as long ago as 1958, and good (though long-ignored)
measurements of direct currents in the frog's brain go back to the work
of Ralph Gerard and Benjamin Libet in the early 1940s. Electron micro-
scope work has shown that the cytoplasm of all Schwann cells is linked
together through holes in the adjacent membranes, forming a syncytium
that could provide the uninterrupted pathway needed by the current.
The other perineural cells—the ependyma and glia—are probably con-
nected in the same way, for syncytial links have recently been found in
the glia of the leech, whose nervous system is much studied because of
its unusually large cells. Recent use of selective radiation to isolate
Schwann cells has shown that they, and not the neuron fibers, supply the
nerve stimulus essential to regeneration.
The invention of a better magnetometer has yielded definitive proof
that's
now
widely acknowledged.
Any
electric current automatically
generates a magnetic field around itself. Hence, as the perineural current