Directional Summation in Non-direction Selective Retinal Ganglion Cells
Figure 3
Dendritic summation has a directional component.
A) A single confocal plane of an On cell showing uncaging locations over 3 dendrites. B) Individual EPSPs moving either away (black) or toward (grey) the soma for the dendrite in A (400 ms delay between locations; averages of 8 trials). C) Summed EPSPs moving away (black) or toward the soma (50 ms delay between locations; averages of 8 trials). D) A plot of the amplitude ratio (summed EPSP/3x single EPSP). 0.88±0.05 away, 0.73±0.04 toward; paired t-test p<0.005; N = 14 On cells; P14–18). E) A plot of the charge ratio for summed depolarizations moving away from or toward the soma. 1.39±0.08 away, 1.10±0.05 toward; paired t-test; p<0.005; N = 15 On cells.