Summary of visual and electrical stimulation results for ON and OFF parasol cells
| n | Retinal eccentricity (mm) | Spike amplitude (μV) | Electrical image diameter (μm) | Visual stimulation | Electrical stimulation | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Receptive field diameter (μm) | Time of STA peak (ms) | Stim. electrode diameter (μm) | Stim. electrode distance to soma (μm) | Threshold charge (pC) | Threshold charge density (mC/cm2) | Latency (ms) | |||||
| ON parasol | 16 | 9.1 ± 0.3 | 422 ± 51 | 84.4 ± 4.1 | 109.0 ± 4.5 | 40.2 ± 0.9 | 13.5 ± 0.5 | 48.8 ± 5.0 | 59.0 ± 5.7 | 0.044 ± 0.005 | 0.18 ± 0.01 |
| OFF parasol | 9 | 9.8 ± 0.4 | 298 ± 34 | 90.7 ± 4.6 | 99.5 ± 4.6 | 45.6 ± 0.8 | 12.9 ± 0.8 | 54.7 ± 8.0 | 73.4 ± 5.5 | 0.062 ± 0.008 | 0.19 ± 0.02 |
| p value | 0.13 | 0.14 | 0.56 | 0.32 | 0.001 | 0.71 | 0.84 | 0.10 | 0.08 | 0.88 | |
Most parameters refer to values discussed in Materials and Methods and Results. Retinal eccentricity is the estimated distance from the fovea. Electrical image size is presumed to correspond to the somatodendritic extent of the cell. Time of STA peak refers to the time between the peak and the occurrence of a spike and is equivalent to the latency of light-evoked responses. All electrical stimulation results are obtained by stimulating with an electrode adjacent to the primary electrode. p values are from a Wilcoxon–Mann–Whitney test (bottom row). Stim., Stimulation.