Inflammation-induced depression also occurs after exposure of rodents to the viral mimetic poly I:C, which binds to TLR3 and the Rig-I-like receptor (RLR) MDA5 and has been associated with reduction in brain-derived neurotrophic factor (BDNF) signaling and increased levels of kynurenine [232]. Here, BDNF is linked to depressive symptom measurement.