Table 2. Mechanisms increasing ipRGCs’ or reducing conventional RGCs’ final-to-peak photoresponse ratios.
| Mechanism | ipRGCs | TRHR+ RGCs | Hoxd10+ ON RGCs | Hoxd10+ ON-OFF RGCs |
|---|---|---|---|---|
| Center/surround antagonism | X | |||
| Spike frequency adaptation | ||||
| Regulation of spiking by resting potential | X | X | ||
| Intracellular Ca2+ | ||||
| Melanopsin | Not tested | Not tested | Not tested | |
| Tonic versus transient bipolar input | X | X | X | X |
| Presence or absence of presynaptic inhibition | X | X | X | |
| Dopaminergic modulation | X | |||
| AMPA/kainate receptor desensitization | ||||
| NMDA receptors | Not tested | Not tested | Not tested | |
| mGluR7 on presynaptic bipolar cell terminals | X | |||
| Glutamate uptake by transporters |