Table 2. Intrinsic electrophysiological properties of DAT-tdTomato neurons.
Mean values ± SEM of passive, action potential and repetitive firing properties for monophasic (putative AIS-negative, n = 15) and biphasic (putative AIS-positive, n = 11) DAT-tdTomato cells. Statistical differences between groups (monophasic vs biphasic) were calculated with a Student’s t test for normally-distributed data (‘t’) or with a Mann–Whitney test for non-normally distributed data (‘MW’). Bold type indicates statistically different measures, for which individual data points and example traces are presented in Figure 5.
| Intrinsic electrophysiological properties | |||
|---|---|---|---|
| Monophasic (mean ± sem) |
Biphasic (mean ± sem) |
Test type, p-value | |
| Passive properties | |||
| Soma area (μm2) | 57 ± 4.8 | 89 ± 6.8 | t,<0.01 |
| Membrane capacitance (pF) | 19 ± 2 | 22 ± 2 | t, 0.39 |
| Resting membrane potential (mV) | −78 ± 1.9 | −74 ± 2.9 | MW, 0.31 |
| Input Resistance (MΩ) | 960 ± 272 | 572 ± 115 | MW, 0.13 |
| Action potential properties | |||
| Threshold (pA/pF) | 7.5 ± 1.0 | 4.6 ± 0.4 | t, 0.02 |
| Threshold (mV) | −30 ± 1.0 | −33 ± 1.0 | t, 0.13 |
| Max voltage reached (mV) | 19 ± 2.4 | 18 ± 4.0 | t, 0.80 |
| Peak amplitude (mV) | 49 ± 2.2 | 50 ± 4.4 | t, 0.79 |
| Width at half-height (ms) | 0.55 ± 0.03 | 0.50 ± 0.04 | t, 0.37 |
| Rate of rise (max dV/dt) (mV/ms) | 230 ± 16 | 251 ± 31 | t, 0.53 |
| Onset rapidness (1/ms) | 3.95 ± 0.28 | 8.22 ± 1.66 | t, 0.03 |
| After hyper polarization AHP (mV) | −54 ± 1.4 | −55 ± 1.5 | t, 0.72 |
| AHP relative to threshold (mV) | 25 ± 1.3 | 24 ± 1.3 | t, 0.95 |
| Repetitive firing properties | |||
| Rheobase (pA/pF) | 3.6 ± 1.0 | 1.7 ± 0.8 | MW, 0.28 |
| Max number of action potentials | 10 ± 2 | 21 ± 4 | t, 0.01 |
| First action potential delay (ms) | 168 ± 38 | 273 ± 45 | t, 0.08 |
| Inter-spike interval CV | 0.28 ± 0.04 | 0.24 ± 0.03 | t, 0.46 |
| Slope of input/output curve (Hz/(pA/pF)) | 1.85 ± 0.54 | 3.53 ± 0.48 | t, 0.04 |