Table 1
Composition (in mmol/l) of saline solutions used in bath and patch pipette
| NaCl | KCl* | MgCl2 | CaCl2 | HEPES | EGTA | pH* | |
|---|---|---|---|---|---|---|---|
| Extracellular | |||||||
| NaCl Ringer | 110 | 3.7 | 1 | 2 | 6 | – | 7.4 |
| Kext pCa3 | – | 107 | 1 | 1 | 10 | – | 7.4 |
| Internal Kint | |||||||
| pCa8 | – | 107 | 1.22 | 1.27 | 10 | 10 | 7.2 |
| pCa7 | – | 107 | 1.15 | 5.92 | 10 | 10 | 7.2 |
| pCa6 | – | 107 | 1.03 | 9.36 | 10 | 10 | 7.2 |
| pCa5 | – | 107 | 1.00 | 9.94 | 10 | 10 | 7.2 |
| Kgluc | KCl | MgCl2 | CaCl2 | NaAc | NaPyr | Asp | GTPgS | EGTA | HEPES | |
|---|---|---|---|---|---|---|---|---|---|---|
| *pH of Kint solutions was adjusted with KOH which increased the K+ concentration to 120 mmol/l. | ||||||||||
| Kgluc = potassium gluconate, NaAc = sodium acetate, NaPyr = sodium pyruvate, Asp = aspartic acid. | ||||||||||
| Note: In potassium gluconate solutions Ca2+ activity is reduced by 90% due to a chelating effect of gluconate (measured with a Ca2+ selective macroelectrode). To compensate for this, free calcium was present at 10-fold higher concentrations. | ||||||||||
| Whole cell pipette solutions | ||||||||||
| pH 7.2 | ||||||||||
| pCa8 | ||||||||||
| 100 | 20 | 1.22 | 2.96 | 3 | 5 | 5 | 0.01 | 5 | 10 | |
