TNF and Cognitive impairment: Excessive TNF-α in brain tissue disrupts Aβ clearance mediated by brain microglia (Koenigsknecht-Talboo and Landreth, 2005) resulting in increased Aβ protein accumulation (Liao et al., 2004; Yamamoto et al., 2007), causing synaptic dysfunction (Ralay Ranaivo et al., 2006), thereby speeding up disease development and cognitive impairment (McGeer and McGeer, 2003).