Figure 6

Vc activation is necessary for the development of ipsilateral hyperalgesia. Lesion of the ipsilateral Vc prior to CFA injection into the master muscle prevents the development of ipsilateral hyperalgesia. Ibotenic Acid (6.3 nmol) was administered to unilaterally to the Vc between vertebrae C1-C2, 7 days prior to ipsilateral CFA injection into the masseter muscle. Lesion of the ipsilateral Vc did not prevent the development of contralateral hyperalgesia (A). However, lesion of the ipsilateral Vc did prevent the development of ipsilateral hyperalgesia (B). *: Ibotenic Acid (6.3 nmol) vs. saline, p<;0.05; **: p<;0.01; ***: p<;0.001 (ANOVA with repeated measures and Student Neuman-Keuls post-hoc test).