WHICH AFFERENTS INDUCE AND TRANSMIT DORSAL-ROOT REFLEX IN RATS

The dorsal root reflex (DRR) in single fibers, recorded in the severed L5 dorsal root central stump, initiated spontaneously or by electric stimulation (St) of sciatic nerve, was studied in anesthetized rats. T he excitation of group II afferents were the major inputs to induce DR Rs which were transmitted mainly in fibers with conduction velocity be low 20 m/s, and its central delay was 3-5 ms. The firing frequency of both spontaneous and evoked DRRs were increased two to four times afte r spinalization (T13). These results suggested that the DRR may play a n important role in the modulation of sensory afferent inputs regulate d by supraspinal structures. (C) 1998 Elsevier Science Ireland Ltd.