Effect of lactate administration and physical exercise training on hippocampal neurogenesis in adult male rats

Background and Aim : Physical exercise has been known to promote cognitive function and neurogenesis in adult rat brain. Although precise underlying mechanisms are still unknown, systemic exercise-induced signals proposed to be involved. Recently, lactate has been considered as a signaling molecule within the brain tissue. We aimed to investigate the effect of exogenous lactate administration as a potential exercise mimetic on hippocampal neurogenesis.Methods : Ault male Wistar rats were subjected to two weeks (5days/wk) of moderate-intensity exercise training consisted of treadmill running (15m/min, 60min/day) or daily injection of sodium-L-lactate (2gr/kg, IP). Sedentary animals used as the control group. Immunohistochemistry for doublecortin (DCX- a marker of developing immature neurons) and 5-bromo-2 -deoxyuridine (BrdU- a marker of proliferation) was performed to evaluate hippocampal neurogenesis.Results : Immunohistochemical analysis revealed that compared to the sedentary control animals, treadmill exercise training increases remarkably the number of BrdU- and DCX-positive cells in dentate gyrus of hippocampus. Administration of exogenous lactate increases immunoreactivity to DCX in compare to control sedentary group; however, BrdU immunoreativity remained unaffected in lactate group.Conclusion : Our results highlighted the possible role of systemic lactate as a mediator of exercise training effect on hippocampal neurogenesis. Future experimental investigation using lactate receptor blockade are warranted.

کلیدواژه ها:

Lactate ، Physical exercise ، Neurogenesis ، Hippocampus