Fig. 4. Effect of intrathecal DL-threo-β-benzyloxyaspartate (TBOA) on thermal hyperalgesia induced by complete Freund's adjuvant. Intrathecal TBOA significantly and dose-dependently attenuated the induced decrease in ipsilateral paw withdrawal latency at 6 (A ) and 24 (B ) h after injection with complete Freund's adjuvant. TBOA at the doses used (1, 5, or 10 μg/10 μl) did not affect basal paw withdrawal response to thermal stimulation on the contralateral side (A and B ). *P < 0.05 or **P < 0.01 versus saline (0).