The Effect Of Aerobic Exercise On Interactions Between Drebrin And Ras Of APP/PS1 Mice

Objective:To investigate the effect of aerobic exercise on interactions between Dre-brin and Ras in the cortex and hippocampus of 8-month-old APP/PS1 transgenic mice. Methods:40 APP/PS1 transgenic mice(8 months old) were randomly divided into ex-ercise and sedentary respectively,namely APP/PS1 sedentary group(AS),APP/PS1 exercise group(AE),and 20 C57BL/6J mice as the sedentary control group(CS).The exercise mice were subjected to a treadmill exercise protocol at the speed of 15m/min on a 0% slope for 10min/d then 18m/min for 50min/d. After exercise,the behavioral change was detected by step-down fear conditioning and rotarod test. The dendrite spine densities were tested with FD Golgi Staining Kit in the frontal and temporal lobes in the cerebral cortexes, and in the CA1 and CA3 areas of hippocampus of the mice.The expressions of Ras and Drebrin proteins were detected by the Western Blot. Results:(1) Behaviorally:Compared with the control group, the numbers of errors of 8-month-old mice were significantly increased (P<0.05), the standard-reaching rate was evidently decreased (P<0.01), and the run duration at the same rotating speed was significantly decreased (P<0.01) in the AS group. After 12-week aero-bic exercise,the mice performed significantly better than AS in both step-down fear conditioning (P<0.05) and rotarod test. (2) Compared with the control group, the dendrite spine densities in the frontal and temporal lobes, the CA1 area and the CA3 area were significantly reduced in the AS group (P<0.01). After 12-week aerobic exercise,the dendrite spine densities in the above all areas were significantly in-creased (P<0.01). (3) Compared to those of the control group, the expression of Drebrin protein (except for the frontal lobe) was greatly down-regulated and the ex-pression of Ras protein was greatly down-regulated in the AS group (P<0.01). Af-ter 12-week aerobic exercise,the expressions of Drebrin protein and Ras protein in the above areas were significantly up-regulated (P<0.01)Conclusions:The 12-week aerobic exercise can induce an increase of the dendrite spine densities in the cortex and hippocampus of 8-month-old APP/PS1 transgenic mice by up-regulated the expressions of Ras and Drebrin,which maybe the one of un-derlying mechanism of exercise-induced an improvement-the ability of learning and memory.