Abstract

The molecular mechanisms of transduction in cone photoreceptors of the vertebrate retina will be investigated. Specifically two aspects of these mechanisms will be studied: 1) the role of Ca ion and 2) the properties of both light dependent and light insensitive ionic channels in the cone plasma membrane. The possible role of Ca ions will be studied by investigating the physiological consequences of buffering changes in intracellular Ca concentration and by attempting to measure light-induced changes in the concentration of Ca ions both in the space immediately outside the cone outer segment and in its intracellular space. The ionic channels of the cone plasma membrane will be studied with patch electrodes. At first the macroscopic ionic currents flowing through these channels will be determined and this will serve as the basis to identify individual channels. Each individual channel type will be investigated to determine its kinetics, current-voltage characteristics and ion selectivity.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY005498-04
Application #
3260608
Study Section
(SSS)
Project Start
1984-07-01
Project End
1989-06-30
Budget Start
1987-07-01
Budget End
1989-06-30
Support Year
4
Fiscal Year
1987
Total Cost
Indirect Cost

  Institution

Name
University of California San Francisco
Department
Type
Schools of Medicine
DUNS #
073133571
City
San Francisco
State
CA
Country
United States
Zip Code
94143

  Publications

Korenbrot, Juan I; Mehta, Milap; Tserentsoodol, Nomingerel et al. (2013) EML1 (CNG-modulin) controls light sensitivity in darkness and under continuous illumination in zebrafish retinal cone photoreceptors. J Neurosci 33:17763-76
Korenbrot, Juan I (2012) Speed, sensitivity, and stability of the light response in rod and cone photoreceptors: facts and models. Prog Retin Eye Res 31:442-66
Rebrik, Tatiana I; Botchkina, Inna; Arshavsky, Vadim Y et al. (2012) CNG-modulin: a novel Ca-dependent modulator of ligand sensitivity in cone photoreceptor cGMP-gated ion channels. J Neurosci 32:3142-53
Korenbrot, Juan I (2012) Speed, adaptation, and stability of the response to light in cone photoreceptors: the functional role of Ca-dependent modulation of ligand sensitivity in cGMP-gated ion channels. J Gen Physiol 139:31-56
Miller, J L; Korenbrot, J I (1993) In retinal cones, membrane depolarization in darkness activates the cGMP-dependent conductance. A model of Ca homeostasis and the regulation of guanylate cyclase. J Gen Physiol 101:933-60
Picones, A; Korenbrot, J I (1992) Permeation and interaction of monovalent cations with the cGMP-gated channel of cone photoreceptors. J Gen Physiol 100:647-73
Maricq, A V; Korenbrot, J I (1990) Inward rectification in the inner segment of single retinal cone photoreceptors. J Neurophysiol 64:1917-28
Maricq, A V; Korenbrot, J I (1990) Potassium currents in the inner segment of single retinal cone photoreceptors. J Neurophysiol 64:1929-40
Maricq, A V; Korenbrot, J I (1988) Calcium and calcium-dependent chloride currents generate action potentials in solitary cone photoreceptors. Neuron 1:503-15
Hestrin, S; Korenbrot, J I (1987) Effects of cyclic GMP on the kinetics of the photocurrent in rods and in detached rod outer segments. J Gen Physiol 90:527-51

Showing the most recent 10 out of 12 publications