|ZFIN ID: ZDB-PUB-051012-6|
Dopamine modulates voltage-activated potassium currents in zebrafish retinal on bipolar cells
Yu, C.J., and Li, L.
|Source:||Journal of neuroscience research 82(3): 368-376 (Journal)|
|Registered Authors:||Li, Lei|
|Keywords:||potassium current, dopamine, retinal bipolar cell, zebrafish|
|PubMed:||16206280 Full text @ J. Neurosci. Res.|
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.
ABSTRACTWe 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.
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