The Effects of Roundup® on Progression of Parkinson's Disease Symptoms in a Mouse Model

Glyphosate-Based Herbicides (GBH) are the most widely used herbicides worldwide. Concerns about the effects of GBH on human health have grown, specifically pointing towards a connection between chronic exposure and neurodegenerative diseases like Parkinson’s disease (PD). PD is characterized by the accumulation of phosphorylated alpha synuclein (aSyn). Previous rodent experiments have shown that introduction of aSyn pre-formed fibrils (PFFs) can induce progressive accumulation of PD-like pathology. We explored the effects of chronic, low-dose GBH exposure in a mouse model of PD. We induced PD-like pathology in male and female wildtype mice by injecting PFFs into the striatum. A control group received saline injections. Half of the mice received drinking water with a low dose of Roundup® (0.075% w/v); the other half received standard drinking water. Motor function, learning and memory were assessed at 1-, 3-, and 6-months post injection. We hypothesized that PFF-injected mice would show impaired learning and memory, and that GBH exposure would exacerbate these deficits and induce alterations in saline-injected mice. Lastly, we hypothesized that males would be more affected than females. Our results show that GBH increased body weight in both males and females, but induced sex-dependent effects in anxiety-like behavior and hippocampus-dependent memory.