BACKGROUND: Previous researches found that animal models with Parkinson disease (PD) could be established by injecting 6-hydroxydopamine (6-OHDA) into medial forebrain bundle (MFB), substantia nigra compacta (SNC) and caudate-putamen complex (CPU) of the nigrostriatal pathway. OBJECTIVE: To compare behavioral, biochemical and histological properties of these rats undergoing the 6-OHDA injections in the areas of MFB, SNC and CPU respectively. DESIGN: Controlled observational study. SETTING: Department of Neurology, First Affiliated Hospital of Guangxi Medical University. MATERIALS: A total of 64 adult female SD rats weighing 180-230 g were provided by the Animal Experimental Center of Guangxi Medical University. 6-OHDA (Sigma Company, USA); Brain solid positioner (Standard model 51600, Stoelting Co., IL, USA); rotational monitoring of little animal (type QL-1, USA); high liquid chromatography (HLC, Waters Company). METHODS: The experiment was carried out in the Medical Experimental Center of Guangxi Medical University from February to December 2005. ① According to digital table, 64 SD rats were divided into MFB group, SNC group, CPU group and control group with 16 in each group. On the basis of the brain atlas of Paxinos, rats in the first three groups were injected with 5 μL 6-OHDA into right MFB (0 mm of line of incisor tooth, A/P 4.4 mm, L/R 1.2 mm, O/V -7.8 mm), SNC (line of incisor tooth just equal to horizon, A/P -4.8 mm, L/R 1.6 mm, O/V -7.8 mm) and CPU (0 mm of line of incisor tooth, A/P 1.2 mm, L/R 2.7 mm, O/V -5.4 mm), respectively. The rats in control group were injected with 5 μL ascorbic acid solution (2 g/L). One week after operation, 0.1 g/L apomorphine (Apo, 0.05 mg/kg) was subcutaneously injected into neck and then rotational behavior induced by Apo was recorded once a week for 8 weeks. The PD models were considered successful only when rotational times more than or equal to 7 times per minute. ② Eight weeks after operation, micro-perfusion was used to obtain micro-perfusate in bilateral CPU and contents of 3,4-dihydroxyphenylacetic acid (3,4-DOPAC) and homovanillic acid (HVA) were also measured. In addition, amount of tyrosine hydroxylase positive cells (TH+) in SNC was counted with immunohistochemical staining. MAIN OUTCOME MEASURES: ① Successful rate of PD models; ② contents of dopamine and its metabolite in MFB, SNC and CPU groups and TH+ amount. RESULTS: All 64 SD rats were involved in the final analysis. ① Successful rate and rotational behavior: One week after operation, there were 6 successful models both in SNC and MFB groups; in the 2nd week, there were 6 both in SNC and MFB groups and 1 in CPU group; in the 3rd week, there were 1 in MFB group and 3 in CPU group; in the 4th week, there were 3 in CPU group. Otherwise, no successful case was found out in the next 3 weeks. Abnormal rotational behavior was not observed in control group. Four weeks after operation, successful rates were 81% (13/16) in MFB group, 75% (12/16) in SNC group and 44% (7/16) in CPU group. ② Contents of 3, 4-DOPAC and HVA: Eight weeks after operation, contents in the SNC area of the injured side were lower than those on non-lesion side (P < 0.01). ③ Changes of TH+ amount: Eight weeks after operation, TH+ amount in the SNC area of the lesion side was lower than that on non-lesion side (P < 0.01). CONCLUSION: Injecting 6-OHDA into MFB, SNC and CPU can damage dopaminergic cells and establish successful PD models. BACKGROUND: Previous researches found that animal models with Parkinson disease (PD) could be established by injecting 6-hydroxydopamine (6-OHDA) into medial forebrain bundle (MFB), substantia nigra compacta (SNC) and caudate- putamen complex the nigrostriatal pathway. OBJECTIVE: To compare behavioral, biochemical and histological properties of these rats undergoing the 6-OHDA injections in the areas of MFB, SNC and CPU respectively. DESIGN: Controlled observational study. SETTING: Department of Neurology, First Affiliated Hospital of MATERIALS: A total of 64 adult female SD rats weighing 180-230 g were provided by the Animal Experimental Center of Guangxi Medical University. 6-OHDA (Sigma Company, USA); Brain solid positioner (Standard model 51600, Stoelting Co., IL, USA; rotational monitoring of little animal (type QL-1, USA); high liquid chromatography (HLC, Waters Company). METHODS: The experiment was carried out in the Medical Experimental Cent er of Guangxi Medical University from February to December 2005. ① According to digital table, 64 SD rats were divided into MFB group, SNC group, CPU group and control group with 16 in each group. On the basis of the brain atlas of Paxinos, rats in the first three groups were injected with 5 μL 6-OHDA into right MFB (0 mm of line of incisor tooth, A / P 4.4 mm, L / R 1.2 mm, O / V -7.8 mm), SNC (line of A / P -4.8 mm, L / R 1.6 mm, O / V -7.8 mm) and CPU (0 mm of line of incisor tooth, A / P 1.2 mm, L / R 2.7 mm, O / V -5.4 mm), respectively. The rats in control group were injected with 5 μL of ascorbic acid solution (2 g / L). One week after operation, 0.1 g / L apomorphine (Apo, 0.05 mg / kg) was subcutaneously injected into neck and then rotational behavior induced by Apo was recorded once a week for 8 weeks. The PD models were considered successful when only times than more than or equal to 7 times per minute. ② Eight weeks after operation, micro-perfusion was usedTo obtain micro-perfusate in bilateral CPU and contents of 3,4-dihydroxyphenylacetic acid (3,4-DOPAC) and homovanillic acid (HVA) were also measured. In addition, amount of tyrosine hydroxylase positive cells (TH +) in SNC was RESULTS: Successful rate of PD models; ② contents of dopamine and its metabolite in MFB, SNC and CPU groups and TH + amount. RESULTS: All 64 SD rats were involved in the final analysis. ① Successful rate and in the 2nd week, there are 6 both in SNC and MFB groups and 1 in CPU group; in the 3rd week, there were 1 in MFB group, 3 in CPU group; in the 4th week, there were 3 in CPU group. Otherwise, no successful case was found out in the next 3 weeks. Four weeks after operation, successful rates were 81% (13/16) in MFB group, 75% (12 Contents of 3, 4-DOPAC and HVA: Eight weeks after operation, contents in the SNC area of ​​the injured side were lower than those on non- lesion side (P <0.01) .③ Changes of TH + amount: Eight weeks after operation, TH + amount in the SNC area of ​​the lesion side was lower than that on non-lesion side (P <0.01). CONCLUSION: Injecting 6-OHDA into MFB, SNC and CPU can damage dopaminergic cells and establish successful PD models.