Paul Witkovsky

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Paul Witkovsky

Research Professor, Department of Ophthalmology;Professor Emeritus of Ophthalmology, Department of Ophthalmology
Neuroscience Institute

Contact Info

212/263-6488
Paul.Witkovsky2@nyumc.org

Research Summary

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.

Research Interests

Dopamine-Induced Modulation of Retinal Function

TRPM2 Channels Are Required for NMDA-Induced Burst Firing and Contribute to H2O2-Dependent Modulation in Substantia Nigra Pars Reticulata GABAergic Neurons
Lee, Christian R; Machold, Robert P; Witkovsky, Paul; Rice, Margaret E
2013-02-05; 0270-6474,Journal of neuroscience - id: 213462, year: 2013 Journal Article

Phase waves in the suprachiasmatic nucleus (commentary on Hong et al.)
Silver, Rae; Witkovsky, Paul
2014-04-25; 0953-816x,European journal of neuroscience - id: 902322, year: 2012 Comment; Journal Article

Regulation of Substantia Nigra Pars Reticulata GABAergic Neuron Activity by H(2)O(2) via Flufenamic Acid-Sensitive Channels and K(ATP) Channels
Lee, Christian R; Witkovsky, Paul; Rice, Margaret E
2012-02-05; 1662-5137,Frontiers in systems neuroscience - id: 131804, year: 2011

Light exposure induces short- and long-term changes in the excitability of retinorecipient neurons in suprachiasmatic nucleus
LeSauter, Joseph; Silver, Rae; Cloues, Robin; Witkovsky, Paul
2012-02-05; 1522-1598,Journal of neurophysiology - id: 137872, year: 2011

Subsecond regulation of striatal dopamine release by pre-synaptic K(ATP) channels
Patel, Jyoti C; Witkovsky, Paul; Coetzee, William A; Rice, Margaret E
2012-02-05; 1471-4159,Journal of neurochemistry - id: 136636, year: 2011