Knockout Induces Synaptic Deficits and Cognitive Dysfunction by Influencing Brain Glucose Metabolism.

Selenium, a trace element associated with memory impairment and glucose metabolism, mainly exerts its function through selenoproteins. is a selenoprotein located in the endoplasmic reticulum (ER) lumen. Our study demonstrates for the first time that knockout decreases synaptic plasticity and causes memory impairment in 10-month-old mice. In addition, knockout causes hyperglycaemia and disturbs glucose metabolism, which is essential for synapse formation and transmission in the brain. Further research reveals that knockout leads to inhibition of the brain insulin signaling pathway [phosphatidylinositol 3-kinase (PI3K)/AKT/mTOR/p70 S6 kinase pathway], which may impair synaptic plasticity in mice. High-fat diet (HFD) feeding suppresses the brain insulin signaling pathway in knockout mice and leads to earlier onset of cognitive impairment at 5 months of age. In general, our study demonstrates that knockout induces synaptic deficits via the brain insulin signaling pathway, thus leading to cognitive dysfunction in mice. These data strongly suggest that plays a vital role in brain glucose metabolism and contributes substantially to synaptic plasticity.