TNF and infection: Inflammation triggered by infections chronic or systemic diseases induces the production of inflammatory mediators such as IL-1β, TNF-α, and IL-6, and these proinflammatory mediators could signal the central nervous system through neural and humoral pathways, including crossing the blood–brain barrier, signaling via circumventricular organs, binding to endothelial receptors, and stimulating neural immune cells regulated by the vagus nerve (Xie et al., 2022).