Additional single-unit recordings.

(A, B) TTX blocks evoked spikes. Example traces of in vivo single unit recording from the DR aspect of a rat C fiber (A) or A fiber (B); stimulus electrode is placed in the spinal nerve. Parameters of stimulation and conduction velocity are indicated above the trace. TTX (1 μM, 3 μl; C) was injected into the DRG using a microsyringe at time points indicated by the bent arrow. Black circles indicate failed spikes. A fiber spike waveform for the A fiber recording is shown on the extended time scale within the dotted red box. (C, D) In the A-type fibers spike propagation through the DRG is not affects by GABA even at higher stimulation frequencies: 50 Hz (C) and 100 Hz (D). (E) Pie charts summarizing the percentage of C and A fibers in which TTX (from experiments shown in panels A and B) or GABA (data from the experiments shown in main Fig 5) produced a conduction block. (F) Spike failure rate before and during application of GABA to A fibers when stimulating at 50 and 100 Hz. No significant effects of GABA were found (n = 8; nonparametric Kruskal–Wallis ANOVA). Metadata for quantifications presented in this figure can be found at https://archive.researchdata.leeds.ac.uk/1042/.

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