Knowledge regarding neural pain processing is primarily the result of studies involving
models of brief cutaneous pain; however, clinical pain generally originates in deep tissue
and is prolonged. This study measured the dynamic neural activation associated with a
muscular pain model incorporating both acute and tonic states. Hypertonic saline (5% NaCl)
was infused into the brachioradialis muscle of eleven healthy volunteers for 15min after an
initial bolus of 0.5 mL. Ten controls followed the same protocol with normal saline (0.9 …