File:Fneur-10-00574-g001.jpg

English: "The bidirectional interplay between the brain and the gut is mediated by neural, such as the vagus nerve (VN-gateway), and humoral pathways, such as the lymphatic tissue and the bloodstream (Non-VN gateways). A monolayer of epithelial cells separates the intestinal lumen and the complex gut microbiome from the underlying lymphoid and enteric nervous tissues. The structure of alpha-synuclein amyloid fibrils (PDB 2N0A) is based on atomic-resolution molecular data from NGL Viewer (19). Members of the gut microbiome and their extracellular compounds may trigger responses in the VN through enteroendocrine cells, which are contacted by vagus nerve terminals through specialized structures called neuropods (NP) (20). Microbial antigens can cross the gut epithelium through microfold cells, playing a central role in localized inflammatory responses [adapted from Bohórquez et al. (21)]. Toll-like receptors are microbe-sensing proteins, present in intestinal epithelial cells, mediating recognition of commensal bacteria from the harmful/inflammatory ones. ENS, enteric nervous system; M, microfold cells; NP, neuropods; PP, Peyer's patches; TLR4, Toll-like receptor 4; VN, vagus nerve." (Santos Susanne Fonseca, de Oliveira Hadassa Loth, Yamada Elizabeth Sumi, Neves Bianca Cruz, Pereira Antonio 2019.)