The Effects Of Rehabilitation Training On Behavior, Synaptic Structure And Expression Of Synaptophysin After Focal Cerebral Infarction In Rats

Objective:This study was to observe the effects of rehabilitation training on recovery of the behavior, change of synaptic structure and expression of synaptophysin of the ischemic penumbra in the focal cerebral ischemia rats.Methods:Sprague-Dawley rats were randomly divided into two groups: the sham-operated group and model group. Rats in sham-operated group were only exposed and separated blood vessel and nerve. The model group was established by left middle cerebral artery occlusion(MCAO). And the model group was subdivided into two groups: the training group, in which the rats were trained on grasp, balancing and rotating exercise every day; and non training group, in which the rats could move freely in common cages. Each group was subdivided into four subgroups at days of 3, 7, 21 and 35. Neurological functions were measured in each group. Neuronal morphologic changes were observed by Nissl staining, immunohistochemical method and Western blot method was used to detect and analyze the synaptophysin expression in the ischemic penumbra of rat brain; Transmission electron microscope was used to observe the change of synaptic structure in the ischemic penumbra.Results:(1) There was no statistical significance in the scores of the neurological function between the training group and non training group at day 3 after MCAO (P > 0.05), but the scores of neurological function in the training group were lower than those in non training group at days 7,21 and 35 after MCAO(P < 0.05).(2) The number of neurons in the ischemic penumbra of two groups was gradually decreased following the increase of time. There were more neurons in the training group compared with non training group.(3) The level of synaptophysin expression was increased and reached peak at day 21, followed by decrease to the day 35 in the rehabilitation training group. There was no statistical significance in synaptophysin expression between the training group and non training group at day 3 after MCAO(P > 0.05). There was statistical significance between two groups at days7,21 and 35 after MCAO (P < 0.05).(4) The result of ultrastructures by electron microscope: Synaptic structures were obviously swollen. Presynaptic and postsynaptic membranes were unclear, synaptic vesicles were decreased in the ischemic penumbra of rat brain in non training group. In the training group, Presynaptic and postsynaptic membranes were relatively intact, Presynaptic membranes have more synaptic vesicles.Conclusion:Rehabilitation training may promote recovery of neurological function and contribute recovery of synaptic structure in the ischemic penumbra of cortex in the MCAO rats.