Fig. 8.  Effect of intrathecal (RS)-α-methylserine-O-phosphate (MSOP), a group III metabotropic glutamate receptor antagonist, on the antinociception of intrathecal DL-threo-β-benzyloxyaspartate (TBOA) in formalin- and complete Freund's adjuvant (CFA)–induced inflammatory pain. **P < 0.01 versus  saline. #P < 0.01 versus  TBOA. (A ) Intrathecal TBOA significantly reduced the number of formalin-evoked flinches and shakes in the second phase of the observational session. This effect was markedly blocked by coadministration of intrathecal MSOP. (B ) Intrathecal TBOA significantly attenuated the CFA-induced decrease in paw withdrawal latency at 6 h post-CFA on the ipsilateral side. This effect was significantly blocked by coadministration of intrathecal MSOP. However, neither MSOP, TBOA, nor their coadministration significantly changed basal paw withdrawal response to thermal stimulation on the contralateral side.