Cord Dorsum Potentials Evoked by Electroacupuncture Applied to the Hind Limbs of Rats
Abstract
The longitudinal distribution of the cord dorsum potentials (CDPs) produced by electroacupuncture (EA) stimulation at acupuncture points (APs) located on the hind limbs of
rats was analyzed in this study. Single electrical pulses (0.05 ms, 1 Hz) applied to the
bladder (BL) and the gallbladder (GB) APs produced CDPs on several spinal segments
and were composed of the following four components: an afferent volley, two negative
components (N1 and N2), and one positive component (P wave). The larger evoked CDPs
differed in their rostrocaudal distributions depending on the stimulated AP site, with
those evoked by GB32e33 (at L3) and GB36e37 (at L4) being more caudal than those
generated by BL58e59 (at L5) and BL37e38 (at L6). The CDPs produced by stimulating
nonacupoints (NAPs) showed similar components and rostrocaudal distributions that
were smaller in amplitude than those evoked by stimulating APs. The CDPs produced
by stimulating NAPs located on a meridian acupuncture area were similar in amplitude
and longitudinal distribution to those produced by stimulating APs.