TLR4 and brain ischemia: Application of Poly I:C, a synthetic analogue of dsRNA and TLR3 agonist, reduces cerebral injury through TLR3-mediated prevention of H-I-induced activation of Fas/FADD-mediated apoptotic signaling and microglia caspase-3 and -8 activities [199] as well as the downregulation of TLR4 signaling via TLR3 [200] in animal models of cerebral ischemia.