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. 1973 Feb;229(1):221–239. doi: 10.1113/jphysiol.1973.sp010135

Isolation of components of admittance change in rod outer segments

G Falk, P Fatt
PMCID: PMC1350220  PMID: 4540196

Abstract

1. Rods were separated by equilibration on a bovine serum albumin (BSA) density gradient into two major fractions, differing in their response to light.

2. In one fraction the response, measured as a change in the real part of admittance ΔG, appeared to consist exclusively of component I, while in the other, component II was prominent.

3. Evidence is presented that component I arose in damaged rods. This follows from observations on rods which have been deliberately damaged by freezing followed by thawing, or by fragmentation.

4. In such damaged rods, component II was absent while component I was increased in amplitude.

5. The frequency dependence of component I in isolation was characterized as a positive ΔG of constant amplitude from low frequencies up to the characteristic frequency fY for the major dispersion of admittance. Above this frequency, it declined to a variable extent.

6. The frequency dependence of component II observed in isolation was consistent with the previous analysis.

7. A negative-going ΔG is described which was linear with the amount of rhodopsin bleached and which was frequency independent up to the highest frequency of measurement (17 MHz).

8. The origins of component I and the negative component are discussed.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Falk G., Fatt P. An analysis of light-induced admittance changes in rod outer segments. J Physiol. 1973 Feb;229(1):185–220. doi: 10.1113/jphysiol.1973.sp010134. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Falk G., Fatt P. Conductance changes produced by light in rod outer segments. J Physiol. 1968 Oct;198(3):647–699. doi: 10.1113/jphysiol.1968.sp008631. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. SIDMAN R. L. The structure and concentration of solids in photoreceptor cells studied by refractometry and interference microscopy. J Biophys Biochem Cytol. 1957 Jan 25;3(1):15–30. doi: 10.1083/jcb.3.1.15. [DOI] [PMC free article] [PubMed] [Google Scholar]

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