Table 1.
Interneurone properties: summary of intrinsic properties recorded from 86 interneurones in the ventral horn of the lumbar spinal cord
| Property | All | Fully repetitive | Repetitive/burst | Initial-burst | Single-spiking | Significance |
|---|---|---|---|---|---|---|
| Age (days) | 15.0 ± 1.5 | 14.8 ± 1.6 | 15.4 ± 1.0 | 15.6 ± 1.5 | 14.3 ± 2.2 | — |
| n=76 | n=45 | n=13 | n=14 | n=4 | ||
| Vm,rest (mV) | −55 ± 8 | −54 ± 7 | −52 ± 4 | −54 ± 9 | — | — |
| n=26 | n=11 | n=5 | n=8 | |||
| Overshoot (mV) | 25.6 ± 8.1 | 26.0 ± 8.2 | 25.3 ± 8.7 | 24.3 ± 7.4 | 26.5 ± 10.0 | — |
| n=86 | n=52 | n=15 | n=15 | n=4 | ||
| Rate of Rise (mV s−1) | 166.5 ± 47.7 | 172.7 ± 48.3 | 140.6 ± 41.1 | 167.6 ± 43.6 | 179.4 ± 61.7 | r::r/b* |
| n=86 | n=52 | n=15 | n=15 | n=4 | ||
| AP Vthresh (mV) | −36.8 ± 5.1 | −38.2 ± 4.9 | −34.2 ± 4.6 | −33.9 ± 4.1 | — | r::r/b** |
| n=77 | n=52 | n=15 | n=9 | r::b* | ||
| F–I thresh curr (pA) | 10 ± 201 | −18 ± 67 | −9 ± 46 | 25 ± 42 | — | — |
| n=74 | n=51 | n=15 | n=7 | |||
| F–I gain (Hz nA−1) | 214 ± 120 | 210 ± 119 | 214 ± 112 | — | — | — |
| n=64 | n=51 | n=12 | ||||
| F–I curr hyst (pA) | 41 ± 36 | 40 ± 30 | 51 ± 59 | 18 ± 29 | — | — |
| n=64 | n=51 | n=10 | n=3 | |||
| AHP amplitude (mV) | 21.0 ± 3.9 | 20.3 ± 3.3 | 21.0 ± 4.1 | 22.3 ± 5.1 | — | — |
| n=78 | n=52 | n=15 | n=10 | |||
| Gleak (nS) | 4.2 ± 4.1 | 3.8 ± 3.1 | 2.9 ± 2.2 | 4.0 ± 1.6 | 15.6 ± 11.1 | — |
| n=70 | n=42 | n=13 | n=12 | n=3 | ||
| PIC ampl asc (pA) | −52 ± 62 | −73 ± 72 | −22 ± 14 | −22 ± 28 | −12 ± 18 | r::r/b‡‡, r::b††, r::s† |
| n=69 | n=41 | n=13 | n=12 | n=3 | ||
| V at peak PIC asc (mV) | −42.0 ± 6.9 | −39.7 ± 4 | −40.0 ± 3.6 | −48.9 ± 5.5 | — | r::b‡‡, r/b::b‡ |
| n=67 | n=41 | n=12 | n=12 | |||
| PIC ampl desc (pA) | −16 ± 39 | −19 ± 49 | −12 ± 14 | −9 ± 21 | −18 ± 17 | — |
| n=69 | n=42 | n=12 | n=12 | n=3 | ||
| V at peak PIC desc (mV) | −47.1 ± 8.6 | −44.6 ± 9.0 | −49.1 ± 7.3 | −53.0 ± 4.6 | — | r::b‡‡ |
| n=67 | n=42 | n=11 | n=12 | |||
| PIC onset voltage (mV) | −58.3 ± 4.9 | −58.0 ± 5.0 | −56.2 ± 5.6 | −60.4 ± 2.4 | — | — |
| n=68 | n=42 | n=12 | n=12 | |||
| PIC Vhyst (mV) | 5.0 ± 7.9 | 4.8 ± 7.6 | 9.1 ± 7.4 | 4.1 ± 5.7 | — | — |
| n=66 | n=41 | n=11 | n=12 | |||
| PIC Ihyst (pA) | 36 ± 70 | 53 ± 86 | 10 ± 10 | 12 ± 14 | −6 ± 22 | r::r/b†, |
| n=68 | n=41 | n=12 | n=12 | n=3 | r::b†, r::s* |
See Methods for definitions of each parameter. Values are listed as mean ±s.d. Parameters (properties) with less than three measurements are not included in the table. Significance: significant differences between firing types; r::r/b: repetitive-firing compared to repetitive/burst, r::b: repetitive-firing compared to initial-burst; r::s: repetitive-firing compared to single-spiking; r/b::b: repetitive/burst compared to initial-burst, r/b::s: repetitive/burst compared to single-spiking, b::s: initial-burst compared to single-spiking; n: number of observations; Vm,rest: resting membrane potential in quiescent cells only; AP Vthresh: action potential voltage threshold; F–I: frequency–current relation; F–I thresh curr: F–I threshold current; F–I curr hyst: F–I current hysteresis; Gleak: leak conductance; asc: ascending; desc: descending; PIC: persistent inward current; PIC ampl: peak PIC amplitude; V at peak PIC: voltage at peak PIC; PIC Vhyst: PIC voltage hysteresis; PIC Ihyst: PIC current hysteresis.
P < 0.0167
P < 0.01
P < 0.005
P < 0.001
P < 0.0005
P < 0.0001.