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Paul Witkovsky

Paul Witkovsky

Neuroscience Institute

Research Professor, Department of Ophthalmology

Professor Emeritus of Ophthalmology, Department of Ophthalmology

dopamine-induced modulation of retinal function

The retina functions over an enormous range of stimulus intensities from dim starlight to bright sunlight. Rod photoreceptors mediate dim light vision, while cones subserve daytime vision. Dopamine, an intrinsic retinal neurochemical, alters retinal information processing by increasing the activity of cone circuits, while suppressing that of rods. The studies of our laboratory are directed at uncovering the cellular mechanisms of dopamine's actions. We showed that the release of dopamine is increased by light and suppressed by prolonged darkness. Dopamine, acting through a D1 receptor coupled to a cAMP-dependent pathway, increases the postsynaptic efficacy of glutamate at the junction between cones and second order retinal neurons. We demonstrated that dopamine also alters the permeability of gap junctions between rod and cone photoreceptors, a mechanism dependent on a D2 dopamine receptor. We also showed that dopamine is one of a host of modulators that alter the properties of intrinsic time- and voltage-dependent currents in retinal neurons. Presently, we are investigating the process of glutamate release by photoreceptors and its dependence on light, voltage, and calcium and exploring the possibility that dopamine can modulate glutamate release. Our overall conclusion is that dopamine is a chemical messenger for light adaptation and it acts through multiple cellular mechanisms.

These focus areas and their associated publications are derived from medical subject headings from PubMed.
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Research Professor, Department of Ophthalmology

Professor Emeritus of Ophthalmology, Department of Ophthalmology

Stouffer, Melissa A; Woods, Catherine A; Patel, Jyoti C; Lee, Christian R; Witkovsky, Paul; Bao, Li; Machold, Robert P; Jones, Kymry T; de Vaca, Soledad Cabeza; Reith, Maarten E A; Carr, Kenneth D; Rice, Margaret E

Nature communications. 2015 Oct 27; 6:8543

Lee, Christian R; Machold, Robert P; Witkovsky, Paul; Rice, Margaret E

Journal of neuroscience. 2013 Jan 16; 33(3):1157-68

Patel, Jyoti C; Witkovsky, Paul; Coetzee, William A; Rice, Margaret E

Journal of neurochemistry. 2011 Sep; 118(5):721-36

LeSauter, Joseph; Silver, Rae; Cloues, Robin; Witkovsky, Paul

Journal of neurophysiology. 2011 Aug; 106(2):576-88

Ryskamp DA; Witkovsky P; Barabas P; Huang W; Koehler C; Akimov NP; Lee SH; Chauhan S; Xing W; Renteria RC; Liedtke W; Krizaj D

Journal of neuroscience. 2011 May 11; 31(19):7089-101

Gallagher, Shannon K; Witkovsky, Paul; Roux, Michel J; Low, Malcolm J; Otero-Corchon, Veronica; Hentges, Shane T; Vigh, Jozsef

Journal of comparative neurology. 2010 Aug 01; 518(15):3130-48