CR is also shown to attenuate the effects of neurochemical and behavioral deficits in rhesus monkey models of Parkinson’s disease potentially through the upregulation of glial cell line-derived neurotrophic factor (GDNF) and BDNF and therefore stimulating neuroprotective signal transduction pathways in dopaminergic neurons (Maswood et al. 2004). This evidence concerns the gene GDNF and Parkinson disease.