Figure 5
From: Jedi-1 deficiency increases sensory neuron excitability through a non-cell autonomous mechanism
DRG neurons cultured from Jedi-1 KO mice are hyperexcitable. Patch clamp electrophysiology was used to record evoked action potentials from small diameter WT and KO DRG neurons. (A) Representative current-clamp recording from a Jedi-1 KO neuron. Stimulation with an excitatory current step (55 pA for 100 ms, lower trace) evoked a typical action potential (upper trace). The upper inset trace shows the action potential on an expanded time scale along with the 1st derivative of the trace. (B) Rheobase (defined as the smallest current step that evoked an action potential) was significantly smaller in Jedi-1 KO cells (*p = 0.03, Mann-Whitney test). Each point is from an individual cell and the box indicates median, 25% and 75% of the distribution. (C) Each point represents the number of action potentials evoked in an individual cell by a 1s current step at twice rheobase (see panel D). Significantly more action potentials were evoked in Jedi-1 KO neurons compared to WT (*p = 0.04, Mann-Whitney test). (D) Representative traces from a WT neuron (upper trace) and Jedi-1 KO neuron (lower trace) stimulated with a 1s current step at twice rheobase. The WT cell displayed phasic firing (a single action potential evoked at the onset of the stimulus) and the KO cell displayed tonic firing (8 action potentials evoked over the duration of the 1s stimulus). (E) The number of cells that displayed either phasic or tonic firing during a 1s stimulus (as in panel D) is shown. The proportion of Jedi-1 KO cells displaying tonic firing was significantly higher than WT (**p = 0.01, Fishers exact test).
