Table 1.
Effects of bath Ca2+ manipulation on active and passive membrane parameters on axotomized sensory neurons.
| Condition | RMP (mV) | CV (m/S) | APamp (mV) | AP95% (mS) | AHPamp (mV) | AHP80% (mS) | AHParea (mV•mS) | dV/dt (V/S) | Rin (MΩ) | Sag ratio (%) | Rheobase (nA) | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Aα/β n=14 |
BL | −65.3±8.1 | 17.3±4.4 | 64.0±6.7 | 1.15±0.35 | 9.1±3.5 | 13.2±9.7 | 89.0±62.3 | 297±110 | 62.5±38.6 | 15.4±12.0 | 2.3±1.5 |
| Low [Ca2+]o | −65.8±9.1 | 17.9±4.4* | 59.3±13.0 | 1.20±0.65 | 8.0±3.7* | 7.9±7.1** | 53.6±44.9** | 261±115 | 52.6±28.5 | 15.8±14.3 | 1.8±1.2*** | |
|
Aδ n=12 |
BL | −66.7±10.7 | 8.4±2.3 | 73.3±16.2 | 1.76±0.48 | 9.5±3.1 | 29.0±34.0 | 196.2±174.8 | 279±139 | 89.4±66.8 | 11.6±6.9 | 2.4±1.0 |
| Low [Ca2+]o | −69.8±10.7 | 8.7±2.2* | 72.9±13.1 | 1.65±0.65 | 8.8±4.2 | 9.5±3.5* | 78.4±38.7** | 259±112 | 118.5±107.5 | 11.2±9.3 | 1.3±0.7** | |
|
Aα/β n=24 |
BL | −69.7±7.7 | 19.2±6.6 | 73.1±9.8 | 1.25±0.61 | 8.8±3.2 | 18.4±20.9 | 141.0±146.0 | 351±133 | 63.9±55.6 | 21.9±15.6 | 1.4 ±0.7 |
| High [Ca2+]o | −69.1±7.9 | 17.4±5.6*** | 69.0±10.7*** | 1.23±0.54 | 10.5±3.3*** | 17.2±18.2 | 168.2±167.4* | 326±162* | 76.0±87.2 | 20.6±13.2 | 1.8±1.0*** | |
|
Aδ n=22 |
BL | −71.0±9.5 | 8.9±3.1 | 74.4±16.6 | 2.04±1.17 | 8.7±4.1 | 24.9±22.5 | 145±150 | 254±107 | 133.1±121.8 | 11.9±11.8 | 1.1±0.7 |
| High [Ca2+]o | −66.7±9.2** | 8.0±2.5** | 74.1±15.2 | 1.95±1.32 | 10.8±5.0*** | 26.8±30.4 | 199±198** | 232±87* | 105.5±95.2 | 10.1±10.9 | 1.4±0.9** | |
Values are given as mean ± SD. BL Baseline condition; RMP resting membrane potential; CV conduction velocity; APamp action potential amplitude; AP95% action potential duration at 95% of amplitude; AHPamp afterhyperpolarization amplitude; AHP80% afterhyperpolarization duration at 80% of amplitude; AHParea afterhyperpolarization area under the curve; dV/dt maximum action potential upstroke velocity; Rin input resistance.
*
P<0.05
**
P <0.01
***
P <0.001 vs. baseline.