Science Advances published evidence that blind Mexican cavefish become more active in light, reversing the dark-triggered activity seen in sighted surface fish.
FAU researchers linked that light-evoked photokinesis to dopamine signaling and found neurons that react to darkness in surface fish instead react to light in cavefish.
Hybrid populations showed the same response pattern, indicating the behavior is genetically inherited rather than a purely environmental adaptation.
The findings suggest evolution repurposed an existing vertebrate brain pathway for cave life, offering a model for sensory processing and disorders including Parkinson's, schizophrenia, autism and ADHD.