Figure 2.

Electrophysiological analysis of excitability of peripheral nociceptive fibers in GABA_B(1)^fl/fl and SNS-GABA_B(1)^-/- mice in the skin nerve preparation. Shown are electrophysiological recordings of spike rates evoked by application of pressure via a nanomotor (expressed in terms of displacement) from c-mechanoceptors (C-fibers, panel A, B and C) and Aδ-type of mechanoceptors (panel D, E and F) in the skin-nerve preparation derived from the paws of GABA_B(1)^fl/fl and SNS-GABA_B(1)^-/- mice. Panel A and D represent analyses in naive GABA_B(1)^fl/fl and SNS-GABA_B(1)^-/-. Panels B and E represent analyses in GABA_B(1)^fl/fl mice at 4 h following CFA-induced hindpaw inflammation. Insets show the magnification of the firing properties for displacements from 6 to 48 μm. Panel C and E represent analyses in SNS-GABA_B(1)^-/- mice at 4 h following CFA-induced hindpaw inflammation. Representative traces of firing properties of C-fibers and Aδ-mechanoceptors for nanomotor displacement of 48 μm are shown below the quantitative summaries. * indicates significant statistical difference (p < 0.05; ANOVA followed by post-hoc Fisher's test). n represents the number of fiber type for each tested animal group.