The Pathology of the Gut-Brain Axis in Parkinson's Disease

Abstract

Neurodegenerative diseases affect approximately 50 million Americans per year, with Parkinson's disease (PD) as the second most common following Alzheimer's disease (Brown, Lockwood, & Sonawane, 2005). The incidence and prevalence rates of PD are predicted to grow at a rapid rate, therefore understanding the biological underpinnings is crucial. Most research has attributed motor and nonmotor symptoms of Parkinson's disease to the degeneration of dopaminergic neurons within the basal ganglia. However, recent research shows the gut microbiome significantly contributes to the etiology of PD. Here I review the current research on links between the gut microbiome and the brain with respect to PD. Gut-related factors such as nutrition, environmental toxins, and inflammation have been found to increase the risk of developing PD. One specific hypothesis suggests the misfolding of alpha-synuclein protein creates destructive Lewy bodies (LBs) within the dopaminergic neurons in the gut, which travel back to the brain via the vagus nerve killing dopaminergic neurons (Miraglia & Colla, 2019). Prior research has largely neglected the potential for areas outside of the central nervous system to be explored. It is crucial to continue the investigation between the gut-brain axis and neurodegenerative diseases as many novel findings suggest direct connections between the microbiome and the early onset, progression, and treatment for PD.

Sabrina Nogueira | Psychological Sciences | Faculty Sponsor Michael Hove