Control (Cd2+) | Cd2+ | Co2+ | Control (Co2+) | |
---|---|---|---|---|
Action potentialamplitude, mV | 79 ± 3 (6) | 80 ± 3 (6) | 79 ± 7 (6) | 79 ± 6 (6) |
half-width, ms | 1.1 ± 0.1 (6) | 1.1 ± 0 (6) | 1.2 ± 0.1 (6) | 1.2 ± 0.2 (6) |
threshold duration, ms | 1.9 ± 0.1 (6) | 1.9 ± 0.1 (6) | 3.8 ± 0.6 (6)* | 2.2 ± 0.6 (6) |
base duration, ms | 6 ± 3 (6) | 16 ± 7 (6)* | 27 ± 10 (6)* | 11 ± 5 (6) |
mAHP amplitude, mV | 5.4 ± 0.5 (6) | 1.4 ± 0.3 (6)* | 1.1 ± 1.1 (7)* | 3.7 ± 1.5 (7) |
Input resistance, MΩ | 47 ± 5 (6) | 49 ± 3 (6) | 63 ± 9 (6) | 56 ± 11 (6) |
10 Spikes, 100 HzmAHP, mV | 9 ± 2 (4) | 6 ± 2 (4)* | 2 ± 3 (6)* | 5 ± 2 (6) |
sAHP, mV | 3.8 ± 1 (6) | 0.8 ± 0.5 (4)* | 0.1 ± 0.3 (6)* | 3.7 ± 2 (6) |
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Effects of 400 μM Cd2+ and 2 mM Co2+/zero Ca2+ on properties of single action potentials and on after hyperpolarizations (AHPs) after 10 spikes at 100 Hz. Values are means ± SE with number of cells in parentheses. For Cd2+ (first 2 columns) or Co2+ (last 2 columns), different populations of cells were used with each cell its own control. Single action potentials (APs) were elicited by a 5-ms just-suprathreshold current injection. AP amplitude was measured from resting potential (RP) to peak amplitude. AP half width, width of spike at one half of maximum amplitude. AP threshold duration, spike width at spike voltage threshold. AP base duration, time between spike threshold and recrossing of the original RP. The medium AHP (mAHP) amplitude was measured as the maximum deviation from RP. Input resistance was calculated by dividing the peak voltage deflection by the current injected (−0.5 nA). The slow AHP (sAHP) was measured at 500 ms after the falling phase of the last spike. * Significant difference (α = 0.05) vs. control data from the same cells.