Dependent Sources

2016 ◽  
pp. 93-120
Keyword(s):  
Dependent Sources

scholarly journals Generalization of DT Equations for Time Dependent Sources

Sensors ◽  
2010 ◽  
Vol 10 (12) ◽  
pp. 10828-10836 ◽  
Author(s):  
Lorenzo Neri ◽  
Salvatore Tudisco ◽  
Francesco Musumeci ◽  
Agata Scordino ◽  
Giorgio Fallica ◽  
...  
Keyword(s):  
Time Dependent ◽  
Dependent Sources

Calcium gradients and light-evoked calcium changes outside rods in the intact cat retina

1994 ◽  
Vol 11 (4) ◽  
pp. 753-761 ◽  
Author(s):  
Ron P. Gallemore ◽  
Jian-Dong Li ◽  
Victor I. Govardovskii ◽  
Roy H. Steinberg
Keyword(s):  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Plexiform Layer ◽  
Rapid Onset ◽  
Subretinal Space ◽  
Inner Plexiform Layer ◽  
Rod Outer Segments ◽  
Volume Increase ◽  
Cat Retina ◽  
Dependent Sources

AbstractWe have studied light-evoked changes in extracellular Ca2+ concentration in the intact cat eye using ion-sensitive double-barreled microelectrodes. Two prominent changes in Ca2+ concentration were observed that differed in retinal location. There was a light-evoked increase in accompanied by brief ON and OFF transients, which was maximal in the inner plexiform layer and was not further studied. There was an unexpected sustained light-evoked decrease in of relatively rapid onset and offset, which was maximal in the distalmost region of the subretinal space (SRS). in the SRS was 1.0 mM higher than in the vitreous humor during dark adaptation and this transretinal gradient disappeared during rod-saturating illumination. After correcting for the light-evoked increase in the volume of the SRS, an increase in the total Ca2+ content of the SRS during illumination was revealed, which presumably represents the Ca2+ released by rods. To explain the light-evoked changes, we used the diffusion model described in the accompanying paper (Li et al., 1994b), with the addition of light-dependent sources of Ca2+ at the retina/retinal pigment epithelium (RPE) border and rod outer segments. We conclude that a drop in around photoreceptors, which persists during illumination and reduces a transretinal Ca2+ gradient, is the combined effect of the light-evoked SRS volume increase, Ca2+ release from photoreceptors, and an unidentified mechanism(s), which is presumably Ca2+ transport by the RPE. The relatively rapid onset and offset of the decrease remains unexplained. These steady-state shifts in should have significant effects on photoreceptor function, especially adaptation.

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