Fig. 1

Specific mechanisms by which acute or chronic exercise improves AD glucose metabolism. The major transporter of glucose in brain capillary endothelial cells (ECs) and astrocytes is glucose transporter (GLUT) 1, whereas the major transporters of glucose in neurons and microglia are GLUT3 and GLUT5, respectively. Lactate is capable of crossing the BBB via monocarboxylate transporter (MCT) 1 on ECs to reach the extracellular compartment. Subsequently, lactate enters the cell via MCT1 on astrocytes, oligodendrocytes and microglia for energy metabolism. The entry of lactate into neurons is mediated by MCT2, which also mediates the transport of ketone bodies. In contrast, MCT4 is only expressed in astrocytes and plays fundamental roles in carrying lactate