In sleep-deprived mice, amyloid-β (Aβ)-injected aging mice, and kainic acid-induced brain damage mice, TSG restored memory impairment through the induced expressions of erythropoietin, PPAR-γ coactivator 1α (PGC-1α), and hemoglobin in astroglia and neurons of the hippocampus [45]. Here, EPO is linked to memory impairment.