Figure 5
Effects of PcTx1 and zinc on ASIC currents in cultured mouse medullary neurons.
(a) In one set of neurons tested (n = 39), 10 nM PcTx1 inhibited the mean peak amplitude of ASIC currents (p < 0.001; left panel) triggered by dropping pH from 7.4 to 6.0. 10 nM PcTx1 inhibited ASIC currents in 21 out of 39 neurons with over 90% inhibition of the mean peak amplitude (p < 0.001; middle panel). In rest of the 18 neurons tested, 10 nM PcTx1 also inhibited ASIC currents with 30% to 90% inhibition of the mean peak amplitude (p < 0.05; right panel). (b) In another set of 28 neurons tested, 10 nM PcTx1 failed to affect the mean peak amplitude of the ASIC currents activated by drops in pH from 7.4 to 6.0 (p > 0.05; left panel). In 19 out of 28 neuron tested, 100 μM zinc potentiated the ASIC currents (p < 0.05; right panel). (c) Inhibition of the mean peak amplitude of ASIC currents by 10 nM PcTx1 (n = 8; p < 0.001). The ASIC currents were triggered by dropping the pH from 7.4 to 6.5 in cultured mouse medullary neurons. (d) Effects of PcTx1 on the time constant of ASIC currents. In one set of 39 neurons tested above (a), the PcTx1 decreased the time constant (p < 0.001; left panel). In another set of 28 neurons tested (b), PcTx1 also decreased the time constant in 16 out of 28 neurons (p < 0.01; middle panel). The rest of the 12 neurons, PcTx1 didn’t affect the time constant of the ASIC currents (p > 0.05; right panel).
