| Objective : Cerebral vascular accident is a common disease with a high rate of morbidity, mortality and mutilation. In China, the mutilation rate of cerebral vascular is the highest in the numerous diseases. The feature with fast developing, slow recovery and high rate of mortality, mutilation take galactic suffering and heavy burden to the patients, their family and society. The recent studies suggest that rehabilitative treatment has gained evident therapeutic effect in improving the sensation, movement and capability of patients with cerebral infarction. It is a important guidance thinking of rehabilitation medicine theory that making use of comprehensive rehabilitation maneuvers to treat the patients since a long-term ago. Samely in the animal experiments of cerebral ischemia, the researchers utilized movement training, enriched environment and medicine synthetically to observe therapeutic effect. In the animal experiments, there were irrefutably evidence indicated that: rats reared in enriched environment (EE) after MCAO revovered better than reared in standard environment. In the enriched environment, rats have the more chance for social communication, learning and various kinds of physical activity, but no special training.CNS plasticity is well known. At present thinking, the functional recovery post brain injury relates to the plasticity of brain structure and function, furthermore, some factors relate to plasticity have been discovered. For the recent years, people found that NSC possess various differentiated potentiality in the adult brain tissue. They occupy resting state in the standard condition, and self-renew when it comes foreign signal or the microenviorenment changing. Then they differentiate into neuron, astrocyte and oligodendrocyte in some conditions, and participate to the neurologic recovery. All of these indicate that the CNS has self recovery potentiality. Cerebral ischemia is the common factor that can cause nervous disfunction, so it is important to study and reaserch the reaction of NSC post cerebral ischemia. Nestin is known as the marker of nerve precursor cell, and utended as identifying NSC generally. NGF can promote nerve cell growth, and induce NSC migration. SYN correlates to neurotransmitter releasing, synapse formation and synaptic vesicle ion channel. The expression of SYN can reflect synapse function directly. There was no report about the effects of learning on nestin, NGF, SYN in rats after experimental cerebral infarction at present. Elucidating the effect of learning on functional recovery post brain injury and the mechanism is very significant for formulating rehabilitative strategy successfully. Methods: 80 male Sprague-Dawley rats were adopted. After making the model of MCAO by electric coagulation successfully, 60 rats were divided into learning group (n=30, 15 as a group living in a maze cage), control group (n=30, 5 as a group living in a standard cage) randomly. Other 20 rats as sham group living in standard cage. 15 rats were chosen randomly from each group respectively for Berderson test at the 1st, 7th, 14th, 28th day after operation, and water maze test from 21st day after operation. At the 1st, 7th, 14th, 28th day after MCAO, 5 rats were randomly killed respectively in learning group and control group. 5 rats in sham group were randomly killed separately at the 7th, 28th day after operation. The expression of nestin, NGF in the peri-ischemic cortex and synaptophysin in the peri-ischemic cortex , CA3 area of hippocampus were examined using immunohistochemistry straining.Results: 1.After MCAO, severe impairment of function occurred in operated groups and there was no significant abnormal in sham group. 2.Berderson test: In 1-7 days after MCAO, there were no significant difference among the operated groups (P>0.05). Since 14 to 28 days learning group scored better than control group (P<0.05). 3.Result of manual muscle test and balancing wood: The result of manual muscle test and balancing wood decreased in all the MCAO rats after operation. In 1-7 days after MCAO, there were no significant difference among the operated groups (P>0.05). Since 14 to 28 days learning group scored better than control group (P<0.05). There was no apparent abnormality in the sham group. 4.Water maze test: It is thus clear that the latent phase of the operated groups were longer than the sham group since 21st to 25th day in the testing phase (P<0.05). Compared to the control group, the latent phase of learning group was shorter since 21st to 25th day in the testing phase (P<0.05). The latent phase of the operated groups decrease quickly in the first 3 days, then tended to stable since the 24th day, and maintained at a constancy level.The expression of nestin: Small amounts of nestin expressed in the sham group. The time distribution of nestin in the MCAO rats showed that the number of nestin labeled cells got to the peak at the 7th day and decreased since 14th to 28th day after operation. In the learning group, the expression was higher than the control group at 7th and 14th day after operation (P<0.05), and no significant difference at 28th day (P>0.05).The expression of nerve growth factor: Small amounts of nerve growth factor expressed in the sham group. The expression of nerve grwoth factor increased at the 1st day after operation, and got to the peak at the 7th day. There was significant difference between learnig group and control group at 7th day (P<0.05). Then the expression of nerve growth factor decreased in the operated groups, and no significant difference between two groups at 28th day (P>0.05).The expression of synaptophysin: Small amounts of synaptophysin expressed in the sham group. The expression of synaptophysin in the MCAO rats increased at the 7th day after operation, and no significant difference between two groups (P>0.05). The expression increased obviously at 14th day and got to peak at 28th day in learning group and control group. There was significant difference between learnig group and control group at 14th day and 28th day (P<0.05).Conclusions:1. Modle of MCAO was made successfully by occluding MCA from the olfactory tract to lateral inferior cerebral vein with electric coagulation.2. Learning could enhance the functional recovery of local infarcted rats.3. Nestin is the identification marker of nerve stem cells, and it is important on recovery post brain injure. Learning could promote the expression of nestin in the rat post local cerebral infarction.4. Nerve growth factor is a important bioactive molecule in the nervous system. It maintains the normal biological function of the nervous system, and participates the regeneration and the fuctional recombination of the injured nerve. Learning could promote the expression of nerve growth factor in the rat post local cerebral infarction.5. Synaptophysin correlates to nerves growth, recovery, regeneration and synapsis remodeling closely. Cerebral infarction can promote the expression of synaptophysin. Learning could promote the expression of synaptophysin in the rat post local cerebral infarction. |
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