| Parkinson’s disease(PD), which is called paralysis agitans, is a neurodegenerative disease with high morbidity in the elderly. PD is primarily characterized by resting tremor, myotonia, bradykinesia and balance disturbance clinically. Its neural pathological basis is known by the severe degeneration of dopaminergic neuron in nigrostriatal pathway, which can cause basal ganglia neural pathway in balance disorder. Astrocyte is widely distributed in central nervous system(CNS). Recent findings have revealed that astrocytes not only provide nutrition, support, protection, isolation for neuron, but also play key roles in neural development, axon regeneration, synapse formation, signal transmission and stem cell differentiation. After type-2 astrocytes transplanted into PD rats, we study its influence on the improvement of the symptoms of PD rats and evaluate the space-change of neurotransmitters in the nigrostriatal pathway to further explore the effects of astrocytes in nigrostriatal pathway in PD rats.Objective: Firstly, the rat model of PD was established. Then, the change was studied in levels of monoamine neurotransmitter within the nigrostriatal pathway and the behavioral changes were evaluated in rat models of PD. After type-2 astrocytes transplanted into the PD rats, then observation was given to its neuroprotective effects on the nigrostriatal pathway.Methods: The unilateral rat models of PD were established by injecting 6-OHDA into the right medial forebrain bundle of adult SD rats. After establishing the successful rat models, we observed their abnormal behavior and evaluated the behavioral changes(elevated body swing test, average velocity, actuation time and time length of rotation behavior). Additionally, we assayed the levels of monoamine neurotransmitters in the nigrostriatal pathway of PD rats by high performance liquid chromatography. Type-2 astrocytes were transplanted into the striatum on the successful rat model with PD. Then, we detected the influence of type-2 astrocytes in nigrostriatal pathway in PD model.Results: PD rats had appeared some abnormal behavior such as stiffness of tail, akinesia or bradykinesia, tremor and the instable posture and gait, etc. Statistically, elevated body swing test was not significant for the evaluation of PD rat models, while average velocity, actuation time and time length of rotation behavior were significant for the evaluation and showed the time-dependence. The content of dopamine, homovanillic acid, 3, 4-two hydroxyl phenylacetic acid, 5-hydroxytryptamine in the lesion side of substantia nigra and striatum is holding unchanged, which is in the normal range. While the content of the lesion side were all reduced with a trend of gradual decline by time. The turnover ratio of DA(DOPAC/DA、HVA/DA、DOPAC+HVA/DA) in the lesion side were speeding up. We transplanted type-2 astrocytes into the striatum in rat models, implated cells could survive and rotational behavior were improved. The implanted cells migrated to the substantia nigra, lateral ventricle and other distant regions. In the lesion side, the content of monoamine neurotransmitters were led to be restored, and the turnover ratio of DA tended to be falling. Conclusions: PD rats have the human-like clinical motor symptoms of PD, and what can be the classic behavioral evaluation index of rotational behavior is average velocity, while actuation time and time length of rotation behavior play a supporting role in behavior evaluation of PD rat models. There is a decline in the content of monoamine neurotransmitters in the substantia nigra and the striatum in the lesion side. After type-2 astrocytes implanted into the PD model, the PD symptoms of rat were improved and the nigrostriatal pathway may have been restored, suggesting that astrocytes may be involved in the regulation of neurotransmitter and nerve repair in the course of PD disease. |
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