Directional Summation in Non-direction Selective Retinal Ganglion Cells
Figure 12
Variations in the parameter set show that DS is robust. A)
Varying Na conductance shows its effect in amplifying the directional difference. Left, a 15% increase in Na conductance (solid gray trace) amplified both peaks but more so for the centrifugal direction. A 15% decrease (dashed gray trace) reduced the amplification more for the centrifugal direction. B) Summary of charge (black bars) and amplitude (gray bars) differences plotted against % DS. The increase in Na conductance magnified both charge and amplitude differences. The decrease in Na conductance diminished both. C) For a 25% change in HCN conductance the DS slightly increased or decreased, due to the shift in resting membrane potential. D) Summary of charge and amplitude in response to changes in HCN conductance. E) A 25% change in K conductance had the inverse effect of a change in Na conductance, because a larger K conductance canceled the regenerative effects of the Na channels. F) Charge and amplitude summary for changes in K conductance.