TLR4 and Sepsis: For a long time, research on MD2 has been limited to peripheral inflammation-related diseases such as sepsis, diabetes, cardiovascular disease, and fatty liver disease [8, 34–36], and although an increase in the level of TLR4 and downstream inflammatory cascades have been implicated in hippocampus-dependent learning and memory deficits, including PND, the role of MD2 in the pathology of PND has been neglected.