Desensitization and Dark Recovery of the Photoreceptor Current in Chlamydomonas reinhardtii.

摘要: Photoexcitation of rhodopsin in Chlamydomonas reinhardtii triggers a complex rapid bioelectric processes the cell membrane. Photoreceptor and flagellar currents are major components this cascade basis for phototaxis photoshock response, respectively. Desensitization dark recovery extracellularly recorded photoreceptor current were investigated double-flash excitation experiments. The data obtained show that desensitization is determined by membrane depolarization rather than bleaching. At external K+ concentrations less 0.6 mM, generation transient, depolarization-activated efflux contributes to repolarization after light excitation. Acceleration at 5 10 mM Ca2+ can be partially attributed blockade influx, which triggered higher concentrations. constitute novel component rhodopsin-mediated signaling system C. involved process adaptation system.