Abstract

To investigate the contribution of glial cells in the spinal cord nociceptive transmission, the effect of intrathecally administered interleukin-1β (IL-1β) was studied in rats treated with the glial cell inactivator propentofylline and submitted to a C-fiber-mediated reflex paradigm evoked by single and repetitive (wind-up) electric stimulation. Intrathecal IL-1β did not modify the C reflex integrated activity in either group of animals, while producing increased wind-up in intact and decreased wind-up in propentofylline pre-treated rats. Results suggest that the excitatory effect of IL-1β on spinal wind-up activity in healthy rats is produced by a glial mediator, whereas the inhibitory effect resulted from a direct effect of the cytokine on dorsal horn neurons. Copyright © 2007 Informa Healthcare.