Learned arbitrary responses to light in mice without rods or cones.

Area of Science:

• Neuroscience
• Vision Science
• Animal Behavior

Background:

• Classical photoreceptors, rods and cones, are essential for vision.
• Rodless-coneless mice were generated using coneless (cl) transgene and retinal degeneration (rd) gene mutations.

Purpose of the Study:

• To determine if mice lacking both rods and cones can be trained to respond to light cues.
• To investigate the role of classical photoreceptors in light-mediated behavioral responses.

Main Methods:

• Generating coneless-rodless mice by mating specific transgenic and mutant strains.
• Training mice to use light as a signal to avoid an impending shock.
• Comparing the performance of coneless-rodless mice with wildtype controls.

Main Results:

• Coneless-rodless mice successfully used light to avoid shock, indicating non-classical photoreceptor involvement.
• Their initial performance was less efficient than wildtype controls, highlighting the importance of rods and cones.
• Performance dropped to chance level when light cues were obscured, confirming light's role in avoidance.

Conclusions:

• Non-classical photoreceptors can mediate light-driven behavioral avoidance in mammals.
• Rods and cones are primarily used for such responses, but other photoreceptors offer partial compensation.
• This study sheds light on the adaptability of sensory systems in the absence of primary photoreceptors.