Two types of stretch-evoked responses of normal DRG neurons. (a) Representative Fura-2 Ca2+ imaging after stretch stimulation (10 and 100 s) in isolated DRG neurons from TRPV2flox/flox mice. Arrowheads, fast-decay type; arrows, slow-decay type. (b) Typical Ca2+ response after stretch stimulus in two subsets of neurons. (c,d) Stretch threshold of fast- and slow-decay type neurons (fast, n = 23; slow n = 18): Cumulative distribution of the threshold (c), median and IQR (d) (***P < 0.001, Mann-Whitney U-test). (e) The difference in cell diameters of two types of stretch-sensitive sensory neurons in control mice. Data are mean ± S.E.M. (fast, n = 62; slow n = 46; ***P < 0.001, t-test). (f) Inhibition of the fast-decay stretch response by ruthenium red; ***P < 0.001, χ2-test. (g) Typical Ca2+ response to probenecid in cells showing fast- (i) and slow-decay (ii) type stretch responses.