SYN2 and Cognitive impairment: As summarized in Table 3 the present study suggested that changes in the aging score, TBARS, glial fibrillary acidic protein, GABA/glutamic acid ratio, glial high-affinity glutamate transporter, GST, calcium/calmodulin-dependent protein kinase type II, 3-monooxygenase/tryptophan 5-monooxygenase activation protein, dihydropteridine reductase, synapsin-2, tublin-alpha, and hemoglobin subunit beta and alpha in the hippocampus of SAMP8 could become markers which can evaluate the progress of aging and cognitive impairment.