Synaptic transmission from rods to rod-dominated bipolar cells in the tiger salamander retina.
Synaptic transmission between photoreceptors and bipolar cells was studied in dark-adapted tiger salamander retinas. Based on the relative light sensitivity, bipolar cells, either depolarizing (DBC) or hyperpolarizing (HBC), fell into two groups: one receives inputs primarily from rods (rod-dominated bipolar cells, DBCR and HBCR) and the other receives inputs primarily from cones (cone-dominated bipolar cells, DBCC and HBCC). The input-output relations of the rod-DBCR and rod-HBCR synapses were determined by plotting the voltage responses of the rod and DBCR (or HBCR) to dim 500-nm light steps, which polarizes only the rods but not the cones. The slope gains of both synapses were the highest near the dark rod voltage (-2.5 for the rod-DBCR synapse and 4.0 for the rod-HBCR synapse), and they (the absolute values) became progressively smaller at more hyperpolarized rod voltages.
Yang
X L
XL
Cullen Eye Institute, Baylor College of Medicine, Houston, TX 77030.
Wu
S M
SM
D000064:Acclimatization; D000557:Ambystoma; D000818:Animals; D003624:Darkness; D066298:In Vitro Techniques; D010775:Photic Stimulation; D012160:Retina / Q000166:cytology / Q000502:physiology*; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology*; D009435:Synaptic Transmission