Figure 4
From: Substance P-driven feed-forward inhibitory activity in the mammalian spinal cord
Assessment of the role of SP-driven inhibitory activity in behavioral responses to noxious stimuli. a&b, Micrographs show NK1 receptor immunoreactivity in the lamina I region of a normal rat (a) and 14 days following intrathecal application of SP-SAP (b). c, Capsaicin-induced increases of IPSCs recorded from lamina V neurons of SP-SAP treated rats (n = 5). d, The first set of bars show baseline of reflexive lick/guard response to heat stimuli at 44.5°C in normal (open bar, n = 8) and SP-SAP rats (solid bar, n = 8). The second set of bars show sensitization of behavioral responses by capsaicin in normal rats (n = 8) and attenuation of the behavioral response in SP-SAP rats (n = 8). The third set of bars show that the NK1 receptor antagonist CP97 attenuated behavioral responses in normal rats (n = 8) but sensitize behavioral response in SP-SAP rats (n = 8) (see Additional file: 1).