Engaging pain fibers after a spinal cord injury fosters hemorrhage and expands the area of secondary injury.

Engaging pain fibers after a spinal cord injury fosters hemorrhage and expands the area of secondary injury. Exp Neurol. 2018 Sep 27;: Authors: Turtle JD, Henwood MK, Strain MM, Huang YJ, Miranda RC, Grau JW Abstract In humans, spinal cord injury (SCI) is often accompanied by additional tissue damage (polytrauma) that can engage pain (nociceptive) fibers. Prior work has shown that this nociceptive input can expand the area of tissue damage (secondary injury), undermine behavioral recovery, and enhance the development of chronic pain. Here, it is shown that nociceptive input given a day after a lower thoracic contusion injury in rats enhances the infiltration of red blood cells at the site of injury, producing an area of hemorrhage that expands secondary injury. Peripheral nociceptive fibers were engaged 24 h after injury by means of electrical stimulation (shock) applied at an intensity that engages unmyelinated pain (C) fibers or through the application of the irritant capsaicin. Convergent western immunoblot and cyanmethemoglobin colorimetric assays showed that both forms of stimulation increased the concentration of hemoglobin at the site of injury, with a robust effect observed 3-24 h after stimulation. Histopathology confirmed that shock treatment increased the area of hemorrhage and the infiltration of red blood cells. SCI can lead to hemorrhage by engaging the sulfonylurea receptor 1 (SUR1) transient receptor potential mel...
Source: Experimental Neurology - Category: Neurology Authors: Tags: Exp Neurol Source Type: research