A research team is the first to reveal that a molecule in the brain—ophthalmic acid—unexpectedly acts like a neurotransmitter similar to dopamine in regulating motor function, offering a new therapeutic target for Parkinson's. The researchers observed that ophthalmic acid binds to and activates calcium-sensing receptors in the brain, reversing the movement impairments of Parkinson's mouse models for more than 20 hours. The disabling neurogenerative disease affects millions worldwide over the age of 50. L-dopa, the front-line drug for treatment, acts by replacing the lost dopamine and has a duration of two to three hours. While initially successful, the effect of...