Ionic composition of external solutions (in mm)a
| Perilymph | LCP | Cs+-perilymph | Endolymph | NMDG- endolymph | |
|---|---|---|---|---|---|
| Na+ | 110 | 110 | 100 | 2 | 2 |
| K+ | 2 | 2 | 2 | 118 | 3 |
| Ca2+ | 1.5 | 0.1 | 1.5 | 0.25 | 0.25 |
| Cl− | 113 | 113 | 113 | 118 | 112 |
| Na+-pyruvate | 1 | 1 | 1 | — | — |
| Creatine | 1 | 1 | 1 | — | — |
| Cs+ | — | — | 10 | — | — |
| NMDG | — | — | — | — | 110 |
↵aEach solution also contained 3 mm d-glucose and 5 mm HEPES, was adjusted to pH 7.3 with NaOH (perilymph-based) or KOH (endolymph-based), and had an osmolality of 230 mmol/kg.