Light control of eye dopamine that does not rely on melanopsin signaling

Light treatment led to a substantial increase in dopamine release in the retina, as indicated by an increased DOPAC:DA ratio.

• Light exposure for 90 minutes resulted in widespread induction of c-fos in dopamine amacrine cells in wild-type mice.
• Mice lacking melanopsin still showed light-induced dopamine release, suggesting melanopsin is not essential for this process.
• Mice without rod phototransduction exhibited reduced dopamine responses to light compared to wild-types.
• No detectable light response was observed in mice lacking both rods and cones, indicating their critical role in dopamine regulation.
• The findings suggest that the light regulation of dopamine is primarily dependent on rods and cones rather than melanopsin.

Simplified