Table 1.
Response properties of Opn1mwR, Opn4−/−, and rd/rd cl mice
|
Opn1mwR |
Opn4−/− 460 nm | rd/rd cl 460 nm | ||
|---|---|---|---|---|
| 460 nm | 655 nm | |||
| Baseline FR | 4.56 ± 0.21 | 4.42 ± 0.22 | 3.33 ± 0.86 | 3.71 ± 0.28 |
| Peak FR | 22.52 ± 1.31 | 15.58 ± 0.99 | 20.48 ± 1.82 | 11.08 ± 1.78 |
| Sustained FR | 8.99 ± 0.81 | 4.71 ± 0.48 | 5.78 ± 0.90 | 7.12 ± 0.90 |
| Sustained ΔFR | 4.65 ± 0.62 | 0.03 ± 0.22 | 2.22 ± 0.43 | 3.03 ± 0.65 |
| Response latency (s) | 0.17 ± 0.01 | 0.21 ± 0.02 | 0.23 ± 0.03 | 7.82 ± 1.16 |
| Off latency (s) | 1.30 ± 0.15 | N/A | 2.33 ± 0.65 | 12.97 ± 1.91 |
Data reflect elements of the response of sustained units in the PON to 30 s pulses of 460 or 655 nm light at 14.8 or 15.6 log10 photons/cm2/s, respectively (note that these stimuli are calculated to be isoluminant for LWS opsin in Opn1mwR). All firing rates (FR) are expressed as spikes per second. Baseline FR was defined as the mean firing rate over the 20 s before stimulus presentation; peak FR as the maximum rate achieved during the 30 s light pulse (bin size, 50 ms) and the sustained FR as the mean over the last 10 s of the 30 s stimulus. Sustained activity is also reported in terms of a change in FR (sustained ΔFR) calculated by subtracting baseline FR from sustained FR. Response latency was defined as time-to-peak FR after stimulus onset and off latency as the time taken for the sustained FR to fall 90% toward baseline after stimulus termination. All genotypes showed clear responses to steps of 460 nm light. Neither Opn4−/− or rd/rd cl mice responded to 655 nm (data not shown). Opn1mwR animals did respond to 655 nm, but this response lacked a sustained component, precluding calculation of “off latency” for this condition. Data show mean ± SEM. Opn1mwR, n = 151 sustained cells from 6 animals; Opn4−/−, n = 68 sustained cells from 6 animals; rd/rd cl, n = 63 sustained cells from 8 animals.