Left panel shows the linear regression analysis (solid lines) of V1/2 of synaptic Ca2+-influx (B), glutamate release (C), threshold (D) and dynamic range of release (E) as a function of position along the pillar-modiolar axis. Shaded areas depict the associated 95% confidence intervals. Significance of correlation coefficients is reported by a two-tailed p-value. Right panel shows box and whisker plots of these properties of synapses grouped into pillar and modiolar halves of the IHCs. Box plots indicate first quartile (25th percentile), median and third quartile (75th percentile) with whiskers reaching from 10-90%. For comparison of pillar and modiolar synapses, either student's t-test (for normally distributed data) or Mann-Whitney-U test (for non-normally distributed data) was applied. * p ≤ 0.05, ** p ≤ 0.01, *** p ≤ 0.001 