How bright-light treatment ameliorates motor and non-motor deficits in Parkinson’s disease

Bright-light therapy effectively alleviate motor and non-motor symptoms of Parkinson’s disease (PD) but, the neural mechanisms underlying these effects remain unclear.

The researchers demonstrate that bright light alleviates PD symptoms in mice via distinct visual circuits

They show that non-motor symptoms, such as depressive-like behaviors and spatial memory deficits alleviated via ventral lateral geniculate nucleus whereas improvement in motor symptoms with bright-light treatment depends on a separate, disynaptic visual pathway that connects the superficial layers of the superior colliculus to the substantia nigra pars compacta (SNc) by upregulating HCN2 expression, a mechanism essential for motor improvements. 

https://www.cell.com/cell-reports/fulltext/S2211-1247(25)00636-9

https://sciencemission.com/Bright-light-treatment-ameliorates-PD