Table 3.
Intrinsic electrophysiological properties of L1 IN subtypes
| Electrophysiological property | NDNF/NPY |
NDNF/non-NPY |
α7 |
VIP |
|---|---|---|---|---|
| NGFC (n ≥ 22) | CANOPY (n ≥ 31) | (n ≥ 19) | (n ≥ 19) | |
| Resting Vm (mV) | −67.2 ± 0.8 | −63.9 ± 0.6 | −60.1 ± 0.9 | −60.2 ± 1.4 |
| Input resistance (MΩ) | 172.9 ± 10.3 | 141.9 ± 6.6 | 141.6 ± 10.8 | 351.1 ± 21.1 |
| Sag amplitude (%) | 8.0 ± 0.6 | 15.4 ± 1.3 | 21.5 ± 1.6 | 11.3 ± 1.3 |
| Time to sag min (ms) | 23.3 ± 2.7 | 22.5 ± 1.9 | 36.6 ± 4.6 | 72.7 ± 8.8 |
| Depolar hump amp (mV) | 1.8 ± 0.4 | 7.9 ± 0.5 | 17.3 ± 0.5 | 14.3 ± 0.6 |
| AP threshold (mV) | −32.3 ± 0.4 | −36.4 ± 0.4 | −35.9 ± 0.5 | −39.3 ± 0.7 |
| AP amplitude (mV) | 68.0 ± 1.0 | 74.3 ± 1.0 | 82.3 ± 1.1 | 95.0 ± 1.4 |
| AP half-width (ms) | 0.73 ± 0.03 | 0.45 ± 0.01 | 0.42 ± 0.02 | 0.44 ± 0.01 |
| Max spike slope (mV/ms) | 426.0 ± 17.6 | 500.5 ± 13.9 | 610.0 ± 20.2 | 805.3 ± 39.0 |
| Adaptation index | 1.01 ± 0.02 | 0.83 ± 0.02 | 0.60 ± 0.03 | 0.44 ± 0.05 |
| Time to first spike (ms) | 750.1 ± 28.6 | 31.2 ± 3.1 | 46.4 ± 4.5 | 116.1 ± 10.5 |
| ADP amplitude (mV) | 0.64 ± 0.04 | 1.74 ± 0.24 | 4.07 ± 0.65 | 5.74 ± 0.75 |
Values are shown as mean ± SEM. All cells were part of our database of 108 L1 INs. For some cells, complete analysis of their properties was not available, so n values are the minimum number of cells used to calculate any given parameter. See Materials and Methods for a description of how each parameter was computed. Cells were grouped by their firing pattern and named according to the molecular profile typically associated with that firing pattern (see Table 2). The Kruskal–Wallis test was used to determine the significance of differences in each electrophysiological parameter and subsequent pairwise comparisons were performed using Dunn's test with a Šidák correction. The results of Kruskal–Wallis tests for each parameter are as follows: resting Vm, p = 4.6e-7; input R, p = 8.0e-11; sag amplitude, p = 1.3e-7; time to sag min, p = 5.2e-9; depolarizing hump amplitude, p = 1.1e-18; AP threshold, p = 4.7e-11; AP amplitude, p = 4.1e-16; AP half-width, p = 1.4e-11; max spike slope, p = 3.1e-13; adaptation index, p = 1.8e-15; time to first spike, p = 2.1e-18; ADP amplitude, p = 8.2e-11. The results of each statistically significant pairwise comparison are as follows: resting Vm, NGFC-canopy (p = 0.033), NGFC-α7 (p = 2.5e-6), NGFC-VIP (p = 5.0e-5), canopy-α7 (p = 0.046); input R, NGFC-VIP (p = 5.6e-5), canopy-VIP (p = 1.1e-9), α7-VIP (p = 5.5e-9); sag amplitude, NGFC-canopy (p = 6.7e-4), NGFC-α7 (p = 1.1e-7), α7-VIP (p = 1.2e-3); time to sag min, NGFC-α7 (p = 0.040), NGFC-VIP (p = 2.5e-6), canopy-α7 (p = 7.5e-3), canopy-VIP (p = 4.0e-8); depolarizing hump amplitude, NGFC-canopy (p = 1.2e-3), NGFC-α7 (p = 0.0), NGFC-VIP (p = 1.7e-10), canopy-α7 (p = 2.6e-7), canopy-VIP (p = 2.8e-3); AP threshold, NGFC-canopy (p = 5.4e-6), NGFC-α7 (p = 1.4e-3), NGFC-VIP (p = 1.9e-11), canopy-VIP (p = 0.041), α7-VIP (p = 0.013); AP amplitude, NGFC-α7 (p = 1.4e-6), NGFC-VIP (p = 4.0e-15), canopy-α7 (p = 0.014), canopy-VIP (p = 6.3e-9), α7-VIP (p = 0.041); AP half-width, NGFC-canopy (p = 5.1e-8), NGFC-α7 (p = 1.1e-9), NGFC-VIP (p = 1.7e-7); max spike slope, NGFC-α7 (p = 1.3e-5), NGFC-VIP (p = 2.3e-12), canopy-α7 (p = 0.022), canopy-VIP (p = 1.7e-7); adaptation index, NGFC-canopy (p = 8.8e-3), NGFC-α7 (p = 2.0e-9), NGFC-VIP (p = 2.3e-13), canopy-α7 (p = 1.6e-3), canopy-VIP (p = 4.9e-6); time to first spike, NGFC-canopy (p = 0.0), NGFC-α7 (p = 1.6e-9), NGFC-VIP (p = 0.015), canopy-VIP (p = 2.9e-6), α7-VIP (p = 0.013); ADP amplitude, NGFC-canopy (p = 0.044), NGFC-α7 (p = 3.3e-6), NGFC-VIP (p = 6.2e-10), canopy-α7 (p = 0.032), canopy-VIP (p = 1.0e-4).