Somatosensory Systems, PainSpinal GABAB-receptor antagonism increases nociceptive transmission in vivoSokal, David M.CA; Chapman, VictoriaAuthor Information School of Biomedical Sciences, E Floor, Medical School, University of Nottingham, Nottingham NG7 2UH, UK CACorresponding Author Received 18 July 2001; accepted 9 August 2001 NeuroReport: October 29th, 2001 - Volume 12 - Issue 15 - p 3247-3250 Buy Abstract GABAB receptors modulate primary afferent fibre evoked responses of spinal neurones. Here effects of the selective GABAB receptor antagonist, CGP-35348, on electrically-evoked responses of spinal neurones in control and carrageenan-inflamed rats were studied. Spinal CGP-35348 (0.1–10 μg/50 μl) did not alter Aβ- or Aδ-fibre evoked neuronal responses in control rats, although C-fibre evoked responses and post discharge responses of spinal neurones were significantly facilitated by 3.0 and 10.0 μg/50 μl CGP-35348 (p < 0.05). In carrageenan-treated animals, spinal CGP-35348 did not alter electrically evoked responses of spinal neurones at any dose. Our data suggest that following acute peripheral inflammation there is loss of endogenous GABAB receptor mediated inhibition of C-fibre transmission at the level of the spinal cord. © 2001 Lippincott Williams & Wilkins, Inc.