Table 1.
Single action potential | Action potential train | |||
---|---|---|---|---|
Current peak (nA) | Total charge (pC) | Current peak (nA) | Total charge (pC) | |
Apamin (n = 6) | −0.08 ± 0.03 | −6.7 ± 3.7 | −1.7 ± 0.4 | −279 ± 69 |
Apamin +ωCgtx GVIA | −0.09 ± 0.04 | −8.6 ± 5.1 | −1.5 ± 0.4 | −255 ± 80 |
Apamin (n = 10) | −0.11 ± 0.01 | −8.4 ± 0.9 | −2.0 ± 0.3 | −334 ± 58 |
ZApamin +ωAga IVA | −0.06 ± 0.01 ** | −3.5 ± 0.9 ** | −1.2 ± 0.2 ** | −165 ± 36 ** |
Apamin (n = 9) | −0.22 ± 0.06 | −20.9 ± 7.6 | −3.0 ± 0.6 | −490 ± 119 |
Apamin + nifedipine | −0.09 ± 0.03 ** | −6.6 ± 2.6 * | −1.5 ± 0.4 ** | −184 ± 53 ** |
Apamin (n = 5) | −0.24 ± 0.05 | −30.9 ± 7.9 | −2.8 ± 0.9 | −481 ± 158 |
Apamin + ryanodine | −0.09 ± 0.05 * | −7.6 ± 4.4 * | −2.2 ± 0.8 * | −319 ± 131 * |
Tail currents after a single action potential or after a train of six action potentials at 40 Hz were recorded in voltage clamp at a holding potential of −55 mV. Inward Ca2+activated Cl− currents were isolated by blocking gK,Ca1 with 100 nm apamin. Changes after adding nifedipine (10 μm), ωCgtx GVIA (300 nm),ωAga IVA (40 nm) or ryanodine (20 μm) were compared using Student's paired t test
P < 0.05
P < 0.01.