TNF and Anxiety: Typically, TLR-mediated immune response involves an increase in circulating and central cytokines such as IL-1β, TNF and IL-6, as well as chemokines such as CXCL1, CCL2 and CXCL10 (15, 18, 19) and the induction of “sickness behavior,” i.e., reduced activity and exploration, and anxiety-like changes (15, 18–22).