Changes in the PWL by AP-5 and Ro 25-6981. (A) Representative coronal section of rat midbrain showing PAG injection sites. Scale bar, 500 μm. Aq: aqueduct; DMPAG: Dorsomed periaqueductal gray; LPAG: Lateral periaqueductal gray. (B) PWL in the CFA-treated paws (ipsilateral) by AP-5 and Ro25-6981 infusion. (C) PWL in the right hind paws (contralateral) by AP-5 and Ro25-6981 infusion. Values were significantly different from saline control * p < 0.05, ** p < 0.01; from CFA-injected alone # p < 0.05.