TNF and memory impairment: LPS administration induces memory impairments and neuroinflammation via activated TLR4/NFκB signaling and regulates various downstream proinflammatory mediators, such as nitric oxide (NO), prostaglandin E2 (PGE2), and cyclooxygenase (COX)2, and proinflammatory cytokines, including interleukin-1 (IL-1), IL-6, and tumor necrosis factor-α (TNF-α) [14].