Membrane properties of a barnacle photoreceptor examined by the voltage clamp technique

摘要: 1. Electrical properties of the membrane photoreceptor cells in lateral ocelli barnacles, Balanus amphitrite and B. eburneus were investigated by intracellular recording, polarization voltage-clamp techniques. 2. The resting potential a dark adapted cell was 36·3 ± 6·6 mV ( S.D.) depended mainly on external K+ concentration. 3. Current—voltage relations obtained from voltage—clamp experiments absence light non-linear varied with time after onset step change potential; steady state reached about 0·5 sec. 4. Illumination resulted under current clamp (light-initiated (L.I.C.): total illumination minus without illumination) conditions. Amplitudes course L.I.C. intensity as well potential. 5. L.I.C.-voltage relation corresponded slope conductance increase increasing positive potential. 6. reversal independent illumination; average value normal saline +26·9 5·0 mV. 7. estimated instantaneous agreed chord relation. 8. Decreasing Na+ concentration decreased inward component but not outward component. 9. Ca2+ increased L.I.C. 10. shifted negative direction decreasing (the rate 10–15 for tenfold concentration) augmented did exceed 21 mV. 11. changes negligible media significant (rate high 20 mV). 12. Alteration or Cl− concentrations affect amplitude L.I.C. 13. results indicate that increases permeability to ions primary effect is suppression increase; may slightly during illumination.