title: Spinal expansion of saphenous afferents after sciatic nerve constriction in rats.
abstract: In rats with chronic constriction of one sciatic nerve, neurone pair responses to saphenous electrical stimulation were simultaneously recorded in sciatic (L5-6) and in saphenous (L2) spinal areas. In 16 rats with thermal hyperalgesia, 43 pairs of neurons were recorded, 4 and 14 days after constriction, on both sides of the spinal cord. On the side ipsilateral to nerve constriction, stimulation of the saphenous evoked excitatory responses in 90% of neurones recorded in the L5-L6 sciatic area, regardless of the post-constriction time. No responses were evoked by saphenous stimulation of the L5-L6 contralateral spinal cord neurones. The possibility that pre-existing connections are unmasked after nerve injury and impinge on sensitized neurones, contributing to abnormal pain sensations such as, for instance, extraterritorial pain, is discussed.
authors: Istituto di Neuroscienze e Bioimmagini CNR, Milano, Italy.
authors: M L
authors: ML
authors: Sotgiu
authors: G
authors: G
authors: Biella
mesh_terms: D000818:Animals; D003251:Constriction, Pathologic / Q000503:physiopathology; D004558:Electric Stimulation; D004594:Electrophysiology; D006930:Hyperalgesia / Q000503:physiopathology; D008297:Male; D009475:Neurons, Afferent / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000293:injuries / Q000503:physiopathology*; D013116:Spinal Cord / Q000503:physiopathology*; D009435:Synaptic Transmission / Q000502:physiology