Abstract
Amiloride is a known blocker of the mechano-electrical transduction current in sensory hair cells. Measurements of cupular motion in the lateral line organ of fish now show that amiloride concurrently changes the micromechanical properties of the hair cell bundles. The effects of amiloride on the mechanics and receptor potentials of the hair cells resemble those previously observed for the aminoglycoside drug dihydrostreptomycin (DHSM) and are similarly antagonized by Ca2+.
We hypothesize that amiloride and DHSM act on hair cells in two correlated ways, which manifest themselves in both the electrical and mechanical properties of the transduction process. One action is the reduction of the transduction current with a concurrent increase in hair bundle stiffness. The other action is a shift of the hair cell's operating point on a current-displacement curve, with a concomitant shift along the associated hair bundle stiffness-displacement curve. The latter action has the opposite effect to that of the first and thus may lead, at relatively low blocker concentrations, to both an increase of transduction current and a decrease in hair bundle stiffness.
Original language | English |
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Pages (from-to) | 615-623 |
Number of pages | 9 |
Journal | Proceedings of the Royal Society B |
Volume | 265 |
Issue number | 1396 |
DOIs | |
Publication status | Published - 7-Apr-1998 |
Keywords
- hair cell
- hair bundle mechanics
- gating spring
- lateral line
- amiloride
- aminoglycosides
- MECHANOELECTRICAL TRANSDUCTION CHANNELS
- BULLFROGS SACCULUS
- ADAPTATION
- STEREOCILIA
- CALCIUM
- CUPULA
- ANTIBIOTICS
- BLOCKS
- CHICK
- SITE