Figure 4. Effect of hypertonicity on I_A.

A. The typical recordings show that I_A was reduced from 8.34 nA to 6.01 nA when the external solution was changed from 300mOsm to 350mOsm but the current almost did not recover (6.75 nA) after washout. B. I–V curve was shown before and during hypertonicity treatment. C. In the hypertonic solution G–V curve shifted to the hyperpolarization direction. V_0.5 was −3.98±0.25 mV and −9.43±0.99 mV (n=10, paired t test, P<0.05) for 300mOsm and 350mOsm, respectively; k was 19.16±0.81 and 20.38±0.94 (n=11, paired t test, P>0.05), respectively. Data were transformed from the I–V data shown in B. D. The typical recordings show that the amplitude of I_A was inhibited upon exposure to hypertonic stimulus and inactivation–voltage curve shifted to the hyperpolarizing direction. V_0.5 was −69.45±0.27 mV and −86.32±0.47 mV (n=12, paired t test, P<0.05) for 300mOsm and 350mOsm, respectively; k was −9.93±0.24 and −16.37±0.28 (n=10, paired t test, P<0.05), respectively.