[Effect 4-aminopyridine on the recovery of segmental reflexes after sectioning of the sciatic nerve in the rat].

L5 ventral root reflex discharges evoked by dorsal root stimulation were studied 3-4 weeks after transection of sciatic nerve in rats; only polysynaptic transmission was found on the side of operation. Injection of 4-aminopyridine (500-600 mg/kg, intraperitoneally) resulted in facilitation of reflex discharges on the intact side and in reappearance of intensive monosynaptic component in such discharges on the affected side. It is concluded that 4-aminopyridine recovers monosynaptic transmission between primary afferents and chromatolysed motoneurons because of increased transmitter liberation.