Figure 2.

Figure 2. No effects of Gpr156 deletion on mechanosensitivity were detected in LES hair cells.

(A) Leftrmal reversed bundle polarity at the LPR. Arrows, Directions of hair bundle motion that produce a depolarizing receptor potential. Right, Maps of recordings from LES zone, lateral to the LPR in heterozygotes, and similar location in null mutants, but without bundle reversal (arrows). (B–E) Exemplar I_MET recordings from voltage-clamped LES HCs of different type (I vs. II, columns) and genotype (het vs. null, rows), and ranging in age from P10 to P31. XY scales for all 4 are in D. Each panel shows I_MET current (average of 3 traces) evoked by 3 of many iterated bundle displacements (bottom of D, E): negatively and positively saturating stimuli (X_min, X_max) plus a step to ~ X_1/2 (midpoint) of the operating range. Red traces, fits of current decay for step to X_1/2 with Equations 2 or 3 (Methods). Voltage was clamped with the indicated holding currents at –94 mV (type I) and –84 mV (type II). (F,G) G(X) relations from type I (F) and type II (G) HCs. G, was peak MET conductance taken at the onset of each of 20 or 40 displacement steps (X), iterated by 100 nm or 35 nm, respectively, and averaged across 3 repeated stimulus families. Mean ± SEM; n=5–8 cells. Fitted G(X) parameters are statistically similar for Gpr156^del/+ and Gpr156^del/del HCs (see Supplementary file 2). Filled circles, X_1/2 values from fits. X_max: 1.1–1.3 µm. X_min; –0.2 to –0.45 µm.