Table 1.
Characteristics of the ON and OFF Ganglion Cells under Control Conditions
| Light Response Type | n | Maintained Rate (Hz) | n | Flash Sensitivity (imp/s per Rh*) | n | Latency (s) |
|---|---|---|---|---|---|---|
| ON fast sustained | 17 | 1.84 ± 2.59 | 15 | 156.9 ± 261.5 | 14 | 0.071 ± 0.019 |
| ON slow sustained | 16 | 7.96 ± 11.24 | 9 | 155.4 ± 171.3 | 10 | 0.108 ± 0.034 |
| ON fast transient | 13 | 14.58 ± 8.65 | 13 | 1353.5 ± 983.7 | 14 | 0.058 ± 0.011 |
| ON slow transient | 68 | 21.03 ± 16.67 | 63 | 960.6 ± 1041.0 | 67 | 0.060 ± 0.015 |
| OFF (sust. and trans.) | 37 | 10.4 ± 11.8 | — | NA | — | NA |
| Total or average | 151 | 14.34 ± 14.93 | 100 | 818.6 ± 982.1 | 107 | 0.066 ± 0.023 |
The maintained firing rate in darkness was calculated for 500 ms before each flash and averaged. Light responses were fitted with the Naka-Rushton equation, equation 2, and flash sensitivity, Sf, was determined as described in Methods. Latencies were calculated from the averaged responses to the fourth stimulus strength in each trial. The data from OFF sustained and transient cells are combined in the table. Only maintained activity is reported for the OFF cells, because flash sensitivity and latency were not reliably measured for them, sust., sustained; trans., transient; NA, not available.