Analgesia by low-frequency nerve stimulation mediated by low-threshold afferents in XXXX .

@entity1 @entity1931 @entity910 @entity1510 @entity158 @entity35
Several authors claim that analgesia by low-frequency peripheral nerve stimulation (transcutaneously or through inserted needles) depends on the activation of small-diameter A delta afferents. In the present study, a marked increase in @entity158 threshold assessed by the squeak threshold test (vocalization to electric shocks delivered to the tail) was obtained by 2 Hz sciatic or radial nerve low-intensity stimulation, using single pulses. Conduction velocities of the activated nerve fibers ranged between 33.6 and 46.4 m/sec, which is consistent with activation of large afferent A fibers. This analgesic effect was reversed by @entity1510 (3 mg/kg i.v.). Thus, low-threshold afferents may contribute to the analgesic effect in addition to the previously reported high-threshold induced effect. High-intensity stimulation (5-6 times the threshold for visible @entity910 ), activating small-diameter afferents (A delta fibers) resulted in a decrease in @entity158 threshold. @entity1931 also resulted from low-intensity stimulation using trains of pulses. The analgesic or @entity1931 effects were correlated with the animal's behavior during stimulation. Analgesia was obtained in calm @entity35 , who went to sleep regularly. When the @entity35 showed signs of being distressed, @entity1931 resulted. These findings may explain the occasional failure to obtain reduction in @entity158 in anxious @entity1 @entity1 by peripheral stimulation.
