[The possibility of different effects of primary afferent depolarization on spinal reflexes]

Intensive depolarization of central primary afferent terminals evoked by strong stimulation of afferent nerves or dorsal root produces recurrent discharges which may be recorded as antidromic dorsal root reflexes. It is shown that the discharges are simultaneously propagating in the dorso-ventral direction and thus produce facilitation of spinal reflexes. The obtained results allow suggesting the existence of two types of influences of the primary afferent depolarization on the reflex transmission to the spinal cord.