Fig. 6. Examples of receptive fields (RFs) and responses of a high-threshold (HT) neuron to mechanical stimuli before and after the incision had been made and after spinal administration of bicuculline (15 μg/50 μl) ( A, B ). Mean percentage changes in the evoked responses to pinch (PI) stimuli and high-threshold RF sizes of HT neurons (n = 16) before and after the incision had been made and after spinal administration of bicuculline (15 μg/50 μl) ( C ). Mean firing rates in response to brush stimuli (BR) and low-threshold RF sizes of the HT neurons before and after the incision had been made and after spinal administration of bicuculline (15 μg/50 μl) ( D ). The HT neurons, which did not respond to innocuous stimulation after the incision had been made, began to respond to low-intensity stimulation (brush) and had low-threshold RFs after spinal administration of bicuculline. VF, stimulation using a 4-g von Frey hair; PP, pinprick stimulation using a 16-g tungsten tip. * P < 0.01, # P < 0.001 versus preincision values.