Abstract: ［Abstract］  ObjectiveTo compare Parkinson disease(PD) rat models via unilateral injection of 6hydroxydopamine(6OHDA) into three different brain regions from the aspects of neurobehavior, histopathology and biochemistry. MethodsHealthy male SD rats were randomly divided into three groups(n=10):striatum group， substantia nigra group，substantia nigra+ midbrain ventral tegmental area group. According to the stereotaxic atlas of the brain, the trace 6OHDA unilateral injection into rat substantia nigra and striatum were performed via single point position in striatum group and in substantia nigra group, and 6OHDA injection into rat substantia nigra and midbrain ventral tegmental area were performed by double point position in substantia nigra+midbrain ventral tegmental area group.The rotation behavior induced by apomorphine was observed in rats. The tyrosine positive neurons in the rat substantia nigra were detected by immunohistochemistry. The dopamine(DA) and its metabolic products 3, 4 dihydroxy phenyl acetic acid(DOPAC) and homovanillic acid(HVA) were measured by electrochemical highperformance liquid phase chromatography in rat striatum. ResultsIn the rats with unilateral injection 6OHDA into striatum viasingle point position, stablerotation appeared at 3 weeks, and a high rate of success in animal model was obtained. In the rats with substantia nigra injection model viasingle point and in the rats with substantia nigra + midbrain ventral tegmental area via double point position injection model, stable rotation appeared after 2 weeks, but animal model success rate is low. Three types of PD rat models in different brain regions injected by 6OHDA showed that the number of tyrosinehydroxylase neurons in substantia nigra area was severely deficient, and that the contents of DA and its metabolites(DOPAC, HVA) in striatum were significantly decreased. ConclusionRat model with unilateral injection 6OHDA into striatum via single point position is  highly successful, which can be used as a stable and reliable animal model for the study on PD.

Key words: Parkinson disease, hydroxydopamines, rats