Cation Cl- cotransporters in the dendrites of goldfish bipolar cells.
Bipolar cells receive an input from gamma-aminobutyric acid ergic horizontal cells in distal retinas. gamma-Aminobutyric acid can induce either an inhibitory or an excitatory Cl(-) response based on the intracellular Cl(-) concentration in the bipolar dendrites. Two cation Cl(-) cotransporters, Na-K-2Cl(-) and K-2Cl(-), differently control local Cl(-) levels in neurons by uptaking or extracting Cl(-), respectively. By using immunocytochemical techniques, we found that Na-K-2Cl(-) and K-2Cl(-) were preferentially distributed in On-bipolar and Off-bipolar dendrites in goldfish retinas. Na-K-2Cl(-) was colocalized with protein kinase C in On-bipolar dendrites, whereas K-2Cl(-) was located in Off-bipolar dendrites, fully overlapping with ionotropic glutamate receptor GluR4. Possibly, an internal Cl(-) level is higher in the On-bipolar dendrites than in the Off-bipolar dendrites. gamma-Aminobutyric acid inputs in the distal retina might excite On-bipolar cells, but inhibit Off-bipolar cells.
Li
Baoqin
B
Department of Biomedical Science, Florida Atlantic University, Boca Raton, Florida 33431, USA.
Shen
Wen
W
D000818:Animals; D015153:Blotting, Western; D003712:Dendrites / Q000378:metabolism*; D018698:Glutamic Acid / Q000378:metabolism; D006054:Goldfish; D007150:Immunohistochemistry; D008564:Membrane Potentials / Q000502:physiology; D051245:Retinal Bipolar Cells / Q000378:metabolism*; D028021:Sodium-Potassium-Chloride Symporters / Q000378:metabolism*; D013116:Spinal Cord / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D028021:Sodium-Potassium-Chloride Symporters; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid