VEGFA and amyotrophic lateral sclerosis: Furthermore, GLP-1R activation provides neurotrophic actions and not only elevates expression of cholinergic markers and protects neurons from trophic factor withdrawal, but has additionally been reported to promote vascular endothelial growth factor (VEGF) production [69], a trophic protein whose levels are diminished in the plasma and CSF of ALS patients [70] and whose elevated expression appears to improve the survival of SOD1 (G93A) mice [71], [72].