Calcium imaging demonstrates colocalization of calcium influx and extrusion in fly photoreceptors.

ABSTRACT: During illumination, Ca(2+) enters fly photoreceptor cells through light-activated channels that are located in the rhabdomere, the compartment specialized for phototransduction. From the rhabdomere, Ca(2+) diffuses into the cell body. We visualize this process by rapidly imaging the fluorescence in a cross section of a photoreceptor cell injected with a fluorescent Ca(2+) indicator in vivo. The free Ca(2+) concentration in the rhabdomere shows a very fast and large transient shortly after light onset. The free Ca(2+) concentration in the cell body rises more slowly and displays a much smaller transient. After approximately 400 ms of light stimulation, the Ca(2+) concentration in both compartments reaches a steady state, indicating that thereafter an amount of Ca(2+), equivalent to the amo

SUBMITTER: Oberwinkler J 

PROVIDER: S-EPMC26990 | biostudies-literature | 2000 Jul

REPOSITORIES: biostudies-literature