Possibility of different effects of primary afferent depolarization on spinal reflexes

The development of intensive depolarization of terminals through stimulation of the afferent nerve or dorsal root of sufficient strength causes the appearance of antidromic discharges recordable as a dorsal-root reflex. The discharges were shown to spread simultaneously in the dorso-ventral direction, with consequent facilitation of spinal reflexes. The results suggest the possible existence of two types of effect of presynaptic depolarization on spinal afferent pathways.