Table 1.
Comparison of physiological properties of PV+ and CCK+ interneurons
| P (Mann– | |||
|---|---|---|---|
| Parameters | PV+ | CCK+ | Whitney) |
| Input resistance (Mohm) | 55.64 (40.04, 67.32) | 107.89 (51.80, 151.44) | 0.001** |
| Membrane time constant (ms) | 8.80 (6.0, 11.0) | 11.40 (9.05, 15.85) | 0.002** |
| Relative amplitude of hyperpolarizing sag | 1.28 (1.16, 1.48) | 1.24 (1.14, 1.50) | NS |
| Relative amplitude of rebound response following hyperpolarization | 1.43 (1.28, 1.58) | 1.28 (1.17, 1.70) | NS |
| Relative amplitude of early overshoot for depolarizing steps | 1.15 (1.09, 1.29) | 1.19 (1.09, 1.39) | NS |
| Rheobase current (pA) | 125.0 (60.0, 162.0) | 150.0 (90.0, 200.0) | NS |
| Maximal action potential number for any input current | 145.50 (105.0, 162.0) | 58.0 (47.75, 74.25) | 1.5 × 10−7 *** |
| Voltage threshold (mV) | −43.11 (−48.68, −39.48) | −42.81 (−45.17, −41.45) | NS |
| Action potential amplitude (mV) | 62.92 (48.58, 71.48) | 74.27 (67.64, 79.80) | 0.1 × 10−3 *** |
| Action potential rise time (ms) | 0.0005 (0.0004, 0.0005) | 0.0005 (0.0005, 0.0006) | 0.003*** |
| Action potential half‐width (ms) | 0.32 (0.26, 0.37) | 0.50 (0.38, 0.60) | 1.4 × 10−6 *** |
| Action potential width (ms) | 1.32 (1.16, 1.39) | 1.73 (1.44, 2.09) | 3.9 × 10−6 *** |
| Voltage difference between start and end of action potential (mV) | 12.46 (9.54, 14.80) | 11.16 (8.57, 13.56) | NS |
| Maximal steepness of rising phase of action potential (mV ms−1) | 246.2 (181.1, 330.0) | 278.8 (230.0, 312.5) | NS |
| Voltage for maximal (positive) steepness of action potentials (mV) | −11.54 (−18.29, −3.12) | −3.66 (−12.61, 3.40) | 0.007** |
| Maximal (negative) steepness of falling phase of APs (mV ms−1) | −203.2 (−231.4, −178.9) | −135.5 (−188.9, −118.7) | 0.1 × 10−3 *** |
| Voltage for maximal negative steepness of APs (mV) | −7.61 (−18.01, 0.72) | 5.53 (−7.52, 16.29) | 0.9 × 10−3 *** |
| Amplitude of after‐hyperpolarization (mV) (old method) | −0.05 (−0.54, 0.21) | 0.45 (−0.02, 1.24) | 0.01* |
| Duration of after‐hyperpolarization (ms) (old method) | 0.30 (0.22, 0.39) | 0.41 (0.27, 4.83) | NS |
| Amplitude of after‐hyperpolarization (mV) (new method) | 12.46 (9.93, 15.01) | 12.68 (9.64, 14.55) | NS |
| Duration of after‐hyperpolarization (ms) (new method) | 1.59 (1.33, 1.80) | 2.38 (1.77, 6.94) | 0.003** |
| Latency of first action potential (ms) | 118.80 (36.40, 429.60) | 56.80 (33.10, 95.20) | 0.03* |
| Action potential number in ‘steady’ trace* | 23.0 (12.0, 34,0) | 15.0 (11.0, 21.0) | 0.01* |
| Average interspike interval (ms) in ‘steady’ trace* | 33.25 (22.48, 51.76) | 51.94 (38.20, 70.12) | 0.002** |
| Action potential half‐width (ms) in ‘steady’ trace* | 0.34 (0.29, 0.37) | 0.57 (0.46, 0.71) | 3.86 × 10−7 *** |
| Action potential amplitude (mV) in ‘steady’ trace* | 57.92 (52.51, 68.47) | 71.20 (66.31, 75.39) | 5.77 × 10−5 *** |
| Voltage threshold (mV) in ‘steady’ trace* | −42.04 (−44.05, −39.58) | −40.99 (−43.76, −39.65) | NS |
| Difference in threshold (mV) in ‘steady’ trace* | 24.81 (18.86, 26.54) | 27.03 (24.51, 32.25) | 0.2 × 10−4 *** |
| Action potential width (ms) in ‘steady’ trace* | 1.32 (1.19, 1.40) | 1.99 (1.66, 2.36) | 9.66 × 10−7 *** |
| Voltage difference between start and end of AP (mV) in ‘steady’ trace* | 13.74 (10.19, 15.90) | 10.22 (8.22, 13.48) | 0.006** |
| Amplitude of after‐hyperpolarization (mV) (old method, ‘steady’ trace*) | −0.08 (−0.28, 0.16) | 1.53 (−0.01, 2.88) | 6.59 × 10−5 *** |
| Duration of after‐hyperpolarization (ms) (old method, ‘steady’ trace*) | 0.26 (0.23, 0.33) | 5.64 (0.33, 9.02) | 0.1 × 10−3 *** |
| Spike frequency accommodation | 1.50 (0.60, 2.75) | 2.92 (1.76, 7.39) | 9.75 × 10−5 *** |
| Change in inter‐spike intervals between start and end of step (ms) | 16.39 (3.31, 34.38) | 54.44 (29.66, 107.49) | 3.37 × 10−5 *** |
| Steepness of interspike interval change vs. AP number relation (ms) | 0.36 (−0.05, 1.26) | 2.61 (1.06, 7.34) | 9.47 × 10−6 *** |
| Change in action potential half‐width during step (ms) | 0.01 (−0.003, 0.3) | 0.13 (0.06, 0.18) | 5.81 × 10−6 *** |
| Steepness of AP half‐width change vs. AP number relation (ms) | 0.0004 (−0.0002, 0.001) | 0.006 (0.002, 0.012) | 4.55 × 10−7 *** |
| Change in action potential amplitude during step (mV) | 1.56 (−4.79, 3.48) | −2.68 (−6.38, 4.24) | NS |
| Steepness of AP amplitude change vs. AP number relation (mV) | 0.04 (−0.10, 0.14) | −0.15 (−0.37, 0.19) | NS |
| Measure of cell excitability | 0.52 (0.23, 0.70) | 0.29 (0.19, 0.57) | NS |
Median values and interquartile ranges for PV+ and CCK+ cells are listed for each physiological feature. The last column shows the P values for comparisons between the medians according to a Mann–Whitney U test where P < 0.05 (NS, non‐significant otherwise); it also marks the level of significance with stars (*P < 0.05; **P < 0.01; ***P < 0.001). The ‘steady’ trace was the response to the smallest current step which evoked at least six action potentials.