Involuntary, forced and voluntary exercises are equally capable of inducing hippocampal plasticity and the recovery of cognitive function after stroke

Abstract

Objectives:Forced and voluntary exercises are known to improve cognition and induce neuroprotection after stroke, however, any effects of involuntary movement induced by functional electrical stimulation (FES) are unclear. The effects of involuntary exercise induced by FES, forced and voluntary exercise on the recovery of cognitive function in vascular dementia and the regional repair of ischaemic lesions were investigated using a rat model.Methods:Wistar rats were randomly assigned to a sham group, a vascular dementia control group (VD), an involuntary exercise group (I-Ex), a forced exercise group (F-Ex) or a voluntary exercise group (V-Ex). An object recognition test (ORT) and an object location test (OLT) were used to evaluate the recovery of cognitive function. Levels of synapsin I (SYN), synaptophysin (SYP), postsynaptic density 95 (PSD-95), microtubule-associated protein 2 (MAP-2) and Tau in the hippocampus were evaluated using western blotting and immunohistochemistry. Nissl staining was applied to visualise the loss of viable neurons from the hippocampus.Results:Involuntary exercise and voluntary exercise both improved cognition in terms of ORT and OLT results. Forced exercise only improved ORT results. The levels of SYN, PSD-95, MAP-2 and Tau in the hippocampus were enhanced by all three patterns of exercise training. Moreover, all three patterns reduced losses of dendrons and neurons in the hippocampal CA1 and CA2 zones, but without significant differences among the three exercise regimens.Conclusion:Involuntary exercise induced by FES has beneficial effects on cognitive function after vascular dementia comparable to those of forced and voluntary exercise.