1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine Induced Parkinson's Disease in Mouse: Potential Association between Neurotransmitter Disturbance and Gut Microbiota Dysbiosis.

Recent studies have revealed significant roles of neurotransmitters and gut microbiota along the gut-brain axis in Parkinson's disease (PD); however, the potential mechanisms remain poorly understood. In the current study, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) induced characteristic PD neurobehavior changes accompanied by increased α-synuclein, apoptotic protein Bim, and cleaved caspase-3 and decreased expression of tyrosine hydroxylase (TH). Meanwhile, the tryptophan (Trp) and tyrosine (Tyr) neurotransmitter metabolites involving kynurenine (KYN), serotonin (5-HT), and dopamine (DA) pathways were significantly changed in serum. Furthermore, the step-limited enzymes, which are responsible for the key metabolic pathways of these neurotransmitters, were obviously dysregulated. The 16S rRNA gene sequence results indicated that the abundance and diversity of the microbiota were obviously decreased in MPTP-treated mice, the presence of Ruminococcus, Parabacteroides and Parasutterella genera were obviously increased, while Coriobacteriaceae, Flavonifractor, Lachnospiraceae, Lactobacillaceae, and Rikenellaceae abundance was markedly decreased. The connectivity between the gut microbiota and neurotransmitter metabolism re...Continue Reading