The effect of different exercise training modes on dentate gyrus neurodegeneration and synaptic plasticity in morphine-dependent rats

Various impacts of exercise on brain performance have been documented following morphine dependence induction; however, the underlying neuronal mechanisms remain unclear. The present research was done to investigate the impact of different exercise training modes on neuronal maturation, and synaptic plasticity in the perforant pathway (PP)-dentate gyrus (DG) synapse in the morphine-dependent rats. Five groups, including a control group (Con, ten healthy rats) and forty morphine-dependent rats were considered as follows (n=10/group): 1) sedentary-dependent (Sed-D); 2) endurance exercise-dependent (En-D); 3) strength exercise-dependent (St-D); and 4) concurrent exercise-dependent (Co-D). The exercise training groups were subjected to endurance, strength, and concurrent training 5 days per week for 10 weeks. After training sessions, the field excitatory postsynaptic potential (fEPSP) slope and population spike (PS) amplitude in DG were determined in response to high-frequency stimulation (HFS) of the PP. For assessing neurogenesis NeuroD level was evaluated after performing all experiments. Concurrent training increased PS amplitude and EPSP than the control group. NeuroD in the morphine-dependent rats significantly decreased, but concurrent training returned the NeuroD to the healthy rat level. Concurrent training can ameliorate synaptic plasticity impairment in morphine-dependent rats through neurogenesis promotion. According to the results, concurrent training can be an appropriate novel candidate for treating opioid addiction.