PUBLICATION
Dopamine modulates voltage-activated potassium currents in zebrafish retinal on bipolar cells
- Authors
- Yu, C.J., and Li, L.
- ID
- ZDB-PUB-051012-6
- Date
- 2005
- Source
- Journal of neuroscience research 82(3): 368-376 (Journal)
- Registered Authors
- Li, Lei
- Keywords
- potassium current, dopamine, retinal bipolar cell, zebrafish
- MeSH Terms
-
- 8-Bromo Cyclic Adenosine Monophosphate/pharmacology
- Animals
- Cells, Cultured
- Cyclic AMP/metabolism
- Dopamine/metabolism*
- Dopamine/pharmacology
- Dopamine Agonists/pharmacology
- Guanosine 5'-O-(3-Thiotriphosphate)/pharmacology
- Membrane Potentials/drug effects
- Membrane Potentials/physiology
- Patch-Clamp Techniques
- Potassium Channels, Voltage-Gated/drug effects
- Potassium Channels, Voltage-Gated/metabolism*
- Reaction Time/drug effects
- Reaction Time/physiology
- Receptors, Dopamine D1/agonists
- Receptors, Dopamine D1/metabolism*
- Receptors, G-Protein-Coupled/agonists
- Receptors, G-Protein-Coupled/metabolism*
- Retina/drug effects
- Retina/metabolism*
- Retinal Bipolar Cells/drug effects
- Retinal Bipolar Cells/metabolism*
- Zebrafish
- PubMed
- 16206280 Full text @ J. Neurosci. Res.
Citation
Yu, C.J., and Li, L. (2005) Dopamine modulates voltage-activated potassium currents in zebrafish retinal on bipolar cells. Journal of neuroscience research. 82(3):368-376.
Abstract
We report a study of the characterization of voltage-activated potassium (K(+)) currents in retinal ON bipolar cells in zebrafish. At single-channels levels, the open probability of the K(+) channels increased when the membrane potential was increased. The maximal open proportion was 0.76 +/- 0.05 under our testing conditions. In whole-cell recordings, the K(+) current displayed two exponential components with the activation time constants of 11-22 msec (tau1) and 0.8-4 msec (tau2). Dopamine modulated the K(+) current. Dopamine reduced the time constant tau2 when the membrane potential was depolarized to high voltages. A decrease in K(+) current was seen when dopamine D(1) receptors were selectively activated by SKF38393 or when the D(1) receptor-coupled G-proteins were activated by GTP-gamma-S. The activation of adenylate cyclase by forskolin or the increase of intracellular cAMP concentrations by 8-Br-cAMP or Sp-cAMPS also resulted in a decrease in K(+) current. Together, the data suggest that dopamine modulates the K(+) current via D(1) receptor-coupled G-protein pathways.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping