Discharge characteristics of heat-sensitive C-fibers innervating the dorsal site of the hindpaw recorded in an in vitro skin-nerve preparation from gp130fl/fl
mice upon a heat-ramp stimulus. (A) Left panel; the discharge pattern of gp130fl/fl C-fibers is changed upon stimulation with 5 ng/ml OSM, the amount of discharges recorded is increased and has shifted to lower temperatures. The mean cumulative discharge rates in heat-sensitive C-fibers from gp130fl/fl were significantly higher after perfusion with 5 ng/ml OSM (filled squares, n = 8) compared with rate of discharge before OSM application (open squares, n = 8). (B) However, in SNS-gp130-/- C-fibers, the discharge pattern evoked by a heat ramp stimulus is unaltered after stimulation with OSM (left panel). Furthermore, OSM perfusion failed to increase the mean cumulative discharge rate of heat-sensitive fibers in SNS-gp130-/- skin-nerve preparations (control; open circles, +OSM; filled circles, n = 8). (C) The discharge threshold temperature of gp130fl/fl (n = 8,) is significantly decreased after stimulation with OSM (5 ng/ml), whereas in SNS-gp130-/- the threshold temperature remained unchanged (left bar graph, n = 8). The temperature at which the maximal discharge rate was achieved was unaltered in both gp130fl/fl and SNS-gp130-/- (right bar graph, n = 8). * p < 0.05, Wilcoxon signed rank test.