Figure 8.

Cutaneous mechanical receptive fields of neurons that responded to intraosseous balloon inflation. Cutaneous mechanical receptive fields (RFs) of the dorsal horn neurons that responded to balloon inflation in the medullary cavity of the femur at 200 kPa. The edge of the low-threshold RF was defined as the area in which light touch stimulation with the tip of a 4-g von Frey filament elicited a response 50% of the time. The edge of the high-threshold RF was defined as the area in which high-intensity mechanical stimulation with a tungsten tip attached to a nylon filament (calibrated force of 25 g) elicited a response 50% of the time (see text). Wide-dynamic-range (WDR) neurons had low-threshold and high-thresholds RFs, while HT neurons had a high-threshold RF. Both WDR and HT neurons had cutaneous RFs at the lower back, lumbosacral region, and thigh. The schemas were made by overlaying the map of the RF area of each neuron repeatedly. HT: high-threshold.