TABLE 3.Temperature effects on [Ca2+]i and the AHP in response to trains of APs
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RT | 32–34°C | Q10 | |
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[Ca2+]i | |||
Amplitude, nM | 235 ± 85 (13) | 155 ± 61 (13) | 0.63 ± 0.34 |
τdecay of [Ca2+]i | |||
τ1 | 1128 ± 825 (10) * | 389 ± 159 (11) | 0.31 ± 0.26 |
τ2 | 2429 ± 1423 (10) * | 772 ± 293 (11) | 0.28 ± 0.19 |
Only single τ | 929 ± 293 (3) * | 452 ± 97 (17) | 0.45 ± 0.17 |
Integral, nM*s | 137 ± 53 (13) * | 53 ± 21 (24) | 0.35 ± 0.19 |
sAHP | |||
Amplitude, mV | 7.5 ± 3.3 (13) * | 5.1 ± 2.0 (28) | 0.65 ± 0.43 |
TTP, ms | 926 ± 441 (7) * | 223 ± 101 (5) | 0.20 ± 0.14 |
τdecay | 3746 ± 2593 (13) * | 1522 ± 993 (28) | 0.37 ± 0.35 |
IsAHP | |||
Amplitude, nA1 | 43 ± 28 (5) | 47 ± 31 (7) | 1.19 ± 1.10 |
TTP, ms1 | 827 ± 203 (10) * | 333 ± 172 (10) | 0.21 ± 0.12 |
τrise, ms1 | 225 ± 49 (5) * | 122 ± 46 (7) | 0.35 ± 0.15 |
τdecay, ms1 | 3691 ± 1763 (5) * | 1729 ± 1128 (12) | 0.27 ± 0.22 |
Integral, nA*s1 | 115 ± 78 (6) * | 71 ± 52 (16) | 0.41 ± 0.40 |
Trains consisted of 10 suprathreshold 5-ms current injections at 50 Hz. [Ca2+]i determined from dF/F using Eq. 1 in METHODS. [Ca2+]i amplitude, change from resting [Ca2+]i. Data for the Integral of IsAHP provide an indicator of total charge movement. AP, action potential; RT, 22–24°C; mAHP, medium afterhyperpolarization; TTP,
time-to-peak; τ, time constant.
* , significant difference between temperatures (p < 0.05, unpaired t-test). 1IsAHP was measured in the presence of apamin (50–100 nM) to block ImAHP.