TLR4 and neurodegenerative disease: Because TLR4 activation causes neurodegeneration [46], and several neurodegenerative diseases (e.g. AD, ALS and MS) are associated with abnormal TLR4 function [24], [47], [48], [49], collectively, our data suggest that IH-induced TLR4 upregulation may play a previously unrecognized role in many CNS disorders.