Figure 2. Electrogenic events in mechanoreceptor terminal and lamellar cells are carried out by different mechanisms.

(A) A suprathreshold mechanical stimulus (top), action potentials (APs) in the terminal (middle), and propagated APs from the connected afferent (bottom). (B) A suprathreshold mechanical stimulus applied in 1 μM tetrodotoxin (TTX; top), AP-absent voltage responses in the terminal in current-clamp (middle), and extracellular receptor potentials in the afferent (bottom). (C) A suprathreshold mechanical stimulus (top), current responses in the terminal while voltage-clamped at –60 mV without 1 μM TTX (middle), and with 1 μM TTX (bottom). (D) Voltage-indentation relationship in the absence or presence of 1 μM TTX (n=5 for each group). (E) The number of APs from increasing current injections in lamellar cells and afferent terminals (n=5 for each group). Inset shows exemplar action potentials from a lamellar cell (blue) and afferent (black). (F) Resting membrane potential (RMP), (G) peak AP amplitude, (H) AP width at the half-maximum, and (I) the maximum slope of the AP rise or decay in the afferent terminal versus lamellar cells of the corpuscle. The AP-current injection relationship, RMP, width at half-maximum, max rise slope, and max decay slope were significantly different between the afferent terminal and lamellar cells (p<0.05). Statistics: Mann-Whitney U test (F–I) or two-way ANOVA with Holm-Sidak post-hoc test (D and E). **p=0.0084, ***p=0.0004, ****p<0.0001. Symbols indicate data from individual cells. Data in D–I were obtained from at least three independent skin preparations and shown as mean ± SEM.