Duration of Nerve Root Compressive Trauma Modulates the Subsequent Thermal Hyperalgesia and Spinal Expression of the Glutamate Transporter, GLT1

Mechanical compression of the cervical nerve roots is a common injury modality [1] and a frequent source of neck pain, affecting 30–50% of adults each year [2]. Since the nerve root is viscoelastic in compression (Fig. 1) [3,4], its response to loading from different injury scenarios is also likely a function of the duration of the applied tissue insult, which varies with the type of injury. For example, the nerve root undergoes brief periods of compression during sports and auto-related trauma, whereas a more prolonged compression occurs for a bulging disc or foraminal stenosis [1]. Similarly, mechanical sensitivity (i.e. pain) after root compression is has been shown to be duration-dependent [3,4]. Compression of the cervical nerve root is only sufficient to induce mechanical sensitivity in a rat model if the compression is applied for more than 3 minutes [3]. Yet, mechanical sensitivity is only one behavioral sequelae of radicular pain and it is not known whether the duration dependent response is similar for other types of evoked pain, such as thermal sensitivity.