Neurodegeneration in Parkinson's disease: are we looking at the right spot?

Abstract

Parkinson's disease (PD) is recognized as the fastest-growing neurodegenerative disorder, impacting millions of individuals worldwide. It is primarily characterized by cardinal motor symptoms, including bradykinesia (slowness of movement), tremor, rigidity, and postural instability, which significantly impair the quality of life of those affected. Traditionally, the prevailing hypothesis has attributed these motor symptoms to the degeneration and subsequent loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc). Currently, emerging research suggests that this neuron-centric view may be overly simplistic and not entirely accurate. In light of this, growing attention has turned to the role of axons within the nigrostriatal pathway-an extensive network connecting the substantia nigra to the striatum, essential for both dopamine transmission and the overall functioning of the motor control by the brain. By directing a focus toward this aspect, in this nano review article we examine why nigrostriatal axons deserve increased attention and should be considered a pivotal target for further therapeutic strategies in PD.