Inhibition of PKA signaling is sufficient to repress nocifensive head-withdrawal responses to mechanical stimulation mediated by CFA. Average nocifensive withdrawal responses ± SEM to 100g force applied to the cutaneous area over the TMJ capsule at 2 hours, and days 1, 5, 7, 14, and 21 after intrathecal injection of sterile saline (top panel) or CFA injection and intrathecal KT5720 (bottom panel) when compared to naïve control levels. * P < .05 when compared to basal levels and # P < .05 when compared to CFA values.