A New Threat to Dopamine Neurons: The Downside of Artificial Light.

•Artificial light could indirectly damage dopamine neurons blunting the circadian rhythms of melatonin secretion.•Artificial light could directly damage dopamine neuron by photoactivating biological relevant molecules.•Light can modify the firing rate of dopamine neurons by activating opsins expressed in the substantia nigra.•Excessive artificial light could be an adjunctive environmental risk factor for Parkinson’s disease.