成年大鼠骨髓基质干细胞诱导分化为神经元样细胞不同方法比较的研究

目的 研究成年大鼠骨髓基质干细胞(BMSCs)诱导分化为神经元样细胞不同的方法，寻找它向神经细胞分化的最佳条件。方法 取纯度较高的BMSCs，通过不同的神经营养因子诱导法和抗氧化剂诱导法，进行抗巢蛋白(nestin)、神经元特异烯醇化酶(NSE)、神经胶质纤维酸性蛋白(GFAP)、酪氨酸羟化酶(TH)免疫细胞化学染色，观察相应的阳性细胞数。结果 诱导第3天A组(EGF：表皮生长因子，bFGF：碱性成纤维细胞生长因子，RA：全反式维甲酸)，B组(GDNF：胶质细胞系源性神经营养因子，BDNF：脑源性神经营养因子)，C组(EGF，bFGF，GDNF，BDNF和RA)的Nestin阳性细胞数较多，其中以C组最多，而D组(抗氧化剂)Nestin阳性细胞数少于前三组。A，B，C组的NSE，GFAP染色阳性细胞数较D组少，但D组有部分细胞发生死亡。诱导第7天A，B，C组的NSE，GFAP阳性细胞数较第3天时明显增多，C组最多，B组其次，Nestin阳性细胞数比例较第3天时明显减少。而D组的NSE，GFAP阳性细胞数少于其第3天时；C组诱导成神经细胞比例较高，阴性对照组和空白对照组极少或无阳性细胞。此外，神经营养因子诱导法生成神经样细胞的比例都多于胶质样细胞。结论 抗氧化剂诱导法分化诱导快，而神经营养因子诱导法分化诱导效率高，诱导后细胞生长状态明显好于前者，各种神经营养因子联合作用影响BMSCs的增殖和分化。     

脑源性神经营养因子诱导大鼠骨髓基质细胞成为神经干细胞及其分化作用的实验研究

目的探讨脑源性神经营养因子（BDNF）诱导大鼠骨髓基质细胞（BMSCs）成为神经干细胞及其分化作用。方法取大鼠BMSCs。分别以BDNF和BDNF＋RA（维甲酸）作为诱导物诱导，于诱导3d、7d后行巢蛋白（Nestin）、神经元特异烯醇化酶（NSE）、胶质纤维酸性蛋白免疫细胞化学染色。结果后BDNF和BDNF＋RA诱导组均有大量Nestin染色阳性细胞，BDNF＋RA组阳性率高于BDNF组（P〈0．01）。NSE、GFAP免疫阳性细胞在诱导3d后也有少量表达。诱导7d后BDNF和BDNF＋RA诱导组Nestin阳性细胞明显减少．与诱导3d后比较差异有显著性（P〈0．01），而NSE、GFAP阳性细胞敷增多，与诱导3b比较差异有显著性（P〈0．01），且BDNF＋RA组阳性率高于BDNF组（P〈0．01）。结论联合应用BDNF与RA可提高BMscs神经转化．并促进其向神经元及星形胶质细胞细胞分化。     

成年骨髓间质干细胞体外诱导分化成神经细胞研究

目的：探索成年骨髓间质干细胞（ABMMSC）诱导分化为神经细胞（神经元和神经胶质细胞）的可行性，为ABMMSC在神经科学领域内的应用提供 参考。方法：以成年犬ABMMSC为实验对象，利用碱性成纤维细胞生长因子（bFGF）、表皮生长因子（FGF）、维甲酸（RA）、脑源性神经营养因子（BDNF）、胶质细胞系源性神经营养因子（GDNF）等作为增殖及分化诱导因子，采用两步法进行增殖培养，分化诱导；免疫细胞化学法进行细胞性质鉴定。结果：加入bFGF、EGF后增殖培养48h，换液、去除非粘附细胞，再增殖培养72h ,可见细胞分裂相（成纤维细胞样细胞）和簇样克隆形成（中小型细胞）。加入RA、BDNF、GDNF诱导3d，部分细胞有神经元特异性烯醇酶（NSE）、胶质纤维酸性蛋白（GFAP）成分表达；第10d可见有神经元、神经胶质形态样细胞形成。经细胞成分（NSE、GFAP）鉴定证实为神经元、神经胶质细胞。结论：ABMSC在体外培养条件下，经过bFGF、EGF、RA、BDNF、GDNF等因子的“程序性”作用，可以向神经元、神经胶质前体细胞及其终末细胞方向分化。     

神经干细胞向γ-氨基丁酸能神经元的诱导分化

目的探索海马神经干细胞在特定条件下分化成γ-氨基丁酸能神经元的情况,为颞叶癫痫的细胞替代学治疗奠定基础。方法新生大鼠海马组织中的神经干细胞在体外增殖后,加入特定的细胞因子进行诱导,使其向γ-氨基丁酸能神经元分化,对分化的细胞进行神经元烯醇化酶（NSE）、微管相关蛋白（MAP-2）、γ-氨基丁酸（GABA）、胶质纤维酸性蛋白（GFAP）和半乳糖脑苷脂酶（GalC）免疫荧光染色鉴定,判断其分化成γ-氨基丁酸能神经元的情况。结果海马神经干细胞诱导贴壁后即发生分化,其中几乎全部分化成神经元（γ-氨基丁酸能神经元）,只有极少的胶质细胞和少突胶质细胞形成。结论从海马神经干细胞中几乎可以完全诱导形成γ-氨基丁酸能神经元,这为颞叶癫痫的细胞替代学治疗奠定了基础。     

红景天苷和脑源性神经营养因子与神经干细胞共移植对致鼠神经干细胞定向分化的研究

目的：探讨红景天苷和脑源性神经营养因子（BDNF）、神经干细胞（NSCs）共移植对致鼠NSCs定向分化影响。方法：将戊四氮致大鼠分为模型组、NSCs组、NSCs＋BDNF组和NSCs＋BDNF＋红景天苷组。取新生大鼠海马组织,将培养的NSCs与BDNF＋红景天苷＋BDNF和基础培养基分别移植至致鼠海马组织中,苏木精-伊红染色及免疫组化检测不同时间点5-溴脱氧尿嘧啶核苷（BrdU）、谷氨酸脱羧酶（GAD65）阳性细胞数,并观察大鼠行为学改变。结果：NSCs＋BDNF＋红景天苷共移植组与其他组比较,各时间点BrdU、GAD65阳性细胞数均增多（P〈0.05）。第3周开始,大鼠癫发作次数最少（P〈0.05）。结论：BDNF与红景天苷联合有利于神经干细胞向γ-氨基丁酸能神经元分化。两者联合移植至致鼠后能减少大鼠的癫发作次数。     

碱性成纤维细胞生长因子预诱导对骨髓基质干细胞向多巴胺能神经元分化的影响

目的探讨碱性成纤维细胞生长因子（bFGF）预诱导对骨髓基质干细胞（MSCs）向多巴胺（DA）能神经元分化的影响。方法取雄性Wistar大鼠股骨和胫骨骨髓，进行MSCs的体外培养、传代扩增及纯化。bFGF预诱导24h后，依据加入的神经营养因子不同分为单唾液酸四己糖神经节苷脂（GMl）组、胶质源性神经营养因子（GDNF）组和GDNF＋GMl组，以及对照组。倒置显微镜下观察细胞形态变化，分别在预诱导第3d、7d进行神经元特异性烯醇化酶（NSE）、神经胶质酸性蛋白（GFAP）、酪氨酸羟化酶（TH）免疫细胞化学检测。计数NSE和TH阳性细胞数，并计算阳性细胞百分比。结果对照组见少量NSE阳性细胞。实验组于诱导第3d、7d见较多数量的NSE、TH阳性细胞，GFAP阴性。bFGF预诱导各组中GDNF＋GMl组NSE、TH阳性细胞率最高，GDNF组次之，GMl组最低，组间比较差异有统计学意义（均P〈0．01）。结论bF—GF预诱导不仅可明显促进GDNF、GMl诱导MSCs向神经元样细胞分化，表达神经元细胞标志物——NSE；还可促进MSCs向DA能神经元分化，表达DA能神经元标志物——TH。     

脑源性神经营养因子诱导大鼠骨髓基质细胞成为神经干细胞及其分化作用的实验研究

目的探讨脑源性神经营养因子(BDNF)诱导大鼠骨髓基质细胞(BMSCs)成为神经干细胞及其分化作用。方法取成年大鼠BMSCs,分别以BDNF和BDNF+RA(维甲酸)作为诱导物诱导,于诱导3d、7d后行巢蛋白(Nestin)、神经元特异烯醇化酶(NSE)、胶质纤维酸性蛋白免疫细胞化学染色。结果诱导3天后BDNF和BDNF+RA诱导组均有大量Nestin染色阳性细胞,BDNF+RA组阳性率高于BDNF组(P<0.01)。NSE、GFAP免疫阳性细胞在诱导3d后也有少量表达。诱导7天后BDNF和BDNF+RA诱导组Nestin阳性细胞明显减少,与诱导3天后比较差异有显著性(P<0.01),而NSE、GFAP阳性细胞数增多,与诱导3天后相比差异有显著性(P<0.01),且BDNF+RA组阳性率高于BDNF组(P<0.01)。结论联合应用BDNF与RA可提高BMSCs神经转化,并促进其向神经元及星形胶质细胞细胞分化。     

新生大鼠海马神经干细胞表达趋化因子受体CCR5的体外研究

目的探讨体外培养神经干细胞是否表达趋化因子受体CCR5。方法采用无血清方法分离、培养新生大鼠海马神经干细胞，细胞免疫荧光方法检测神经干细胞标志巢蛋白（nestin）表达及干细胞多向分化为神经元及胶质细胞的能力；后通过细胞免疫荧光及逆反转录酶一聚合酶链反应（RTPCR）方法检测神经干细胞表达趋化因子受体CCR5的情况。结果体外培养新生大鼠海马神经干细胞呈nestin阳性，可分化为神经丝蛋白200（NF200）阳性神经元、胶质纤维酸性蛋白（GFAP）阳性星形胶质细胞及2，3-环核苷酸磷酸二酯酶（CNP）阳性少突胶质细胞，CCR5细胞免疫荧光及RT-PCR证实神经干细胞表达趋化因子受体CCR5。结论新生大鼠海马神经干细胞表达趋化因子受体CCR5，为进一步研究其体内、外迁移提供理论依据。     

GDNF和NO对局灶性脑缺血大鼠皮质和尾壳核神经干细胞增殖和分化的影响

目的观察胶质细胞源性神经营养因子（GDNF）对局灶性脑缺血大鼠皮质和尾壳核神经干细胞（NSCs）增殖分化以及nNOS阳性神经元分布的影响，探讨GDNF和NO对内源性NSCs增殖分化影响的作用机制。方法制作右侧局灶性脑缺血模型，左侧脑室注射GDNF，5-溴脱氧尿嘧啶（BrdU）标记DNA合成期（S期）细胞，免疫组化观察正常组、假手术组、脑缺血组、生理盐水组和GDNF组大鼠局灶性脑缺血90min后再灌注时间分别为3d、7d、14d、21d、28d的BrdU／nNOS、BrdU／NeuN、BrdU／GFAP双标阳性细胞。结果GDNF组较脑缺血组和生理盐水组行为学恢复明显；脑缺血后皮质和尾壳核BrdU和nNOS阳性细胞增多，BrdU／nNOS（38．23％±6．87％）、Br—dU／NeuN（52．38％±13．29％）、BrdU／GFAP（13．51％±8．78％）双标细胞阳性率明显增加，与其它组比较均有显著性差异（P〈0．05）。结论局灶性脑缺血激活内源性NSCs，GDNF可调节NO释放，促进NSCs增殖、分化。     

Nurr1对小胶质细胞联合神经干细胞共培养促进神经干细胞向多巴胺神经元分化作用研究

目的探讨联合过表达核受体相关因子1(Nurr1)基因的小胶质细胞(MG)和神经干细胞(NSC)共培养对神经干细胞向多巴胺神经元分化的影响。方法原代培养SD大鼠神经干细胞和小胶质细胞,并过表达Nurr1基因。CCK-8法检测Nurr1过表达对神经干细胞以及小胶质细胞活率的影响。Transwell系统共培养神经干细胞和小胶质细胞,实验分为NSC组、NSC+MG组和N(NSC+MG)组。ELISA检测共培养后第3天、第6天和第9天各组脑源性神经营养因子(BDNF)、血小板源性神经营养因子(PDNF)和胶质细胞源性神经营养因子(GDNF)表达变化;RT-PCR和Western Blot检测各组第9天酪氨酸羟化酶(TH)、多巴胺转运蛋白(DAT)DAT和Nurr1的表达变化;细胞免疫荧光鉴定神经干细胞的分化,并对TH和DAT阳性细胞计数,计算各组神经干细胞向多巴胺神经元的分化效率。结果原代培养小胶质细胞以及神经干细胞并成功过表达Nurr1基因。CCK-8法检测结果表明,Nurr1过表达对神经干细胞以及小胶质细胞活率无明显影响。ELISA检测结果表明,N(NSC+MG)组在不同时间点神经营养因子(BDNF、PDNF和GDNF)表达量明显高于其他各组(P0.05)。RT-PCR和Westen Blot检测结果表明,N(NSC+MG)组TH、DAT和Nurr1的表达水平明显高于其他各组(P0.05)。细胞免疫荧光鉴定结果表明,N(NSC+MG)组TH阳性细胞率明显高于其他各组(P0.05)。结论Nurr1基因可促进神经干细胞和小胶质细胞共培养系统神经营养因子的分泌。过表达Nurr1基因的神经干细胞和小胶质细胞共培养可促进神经干细胞向多巴胺神经元的分化。     

Differential effects of GDNF and BDNF on cultured ventral mesencephalic neurons

Previous studies have shown that brain derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) can enhance the survival of dopaminergic neurons in the ventral mesencephalon (VM). Here we compared several non-survival functions of the two factors in VM neurons in culture. We found that both BDNF and GDNF elicited an increase in the depolarization-induced release of dopamine, but had no effect on GABA release, in the VM cultures. BDNF, but not GDNF, significantly enhanced the expression of the calcium binding protein calbindin and synaptic protein SNAP25. In contrast, treatment of the cultures with GDNF, but not BDNF, elicited a marked fasciculation of the processes of the VM neurons. Thus, although both act on VM neurons, BDNF and GDNF have distinct functions.     

Increased expression of BDNF and proliferation of dentate granule cells after bacterial meningitis

Proliferation and differentiation of neural progenitor cells is increased after bacterial meningitis. To identify endogenous factors involved in neurogenesis, expression of brain-derived neurotrophic factor (BDNF), TrkB, nerve growth factor (NGF), and glial cell line-derived neurotrophic factor (GDNF) was investigated. C57BL/6 mice were infected by intracerebral injection of Streptococcus pneumoniae. Mice were killed 30 hours later or treated with ceftriaxone and killed 4 days after infection. Hippocampal BDNF mRNA levels were increased 2.4-fold 4 days after infection (p = 0.026). Similarly, BDNF protein levels in the hippocampal formation were higher in infected mice than in control animals (p = 0.0003). This was accompanied by an elevated proliferation of dentate granule cells (p = 0.0002). BDNF protein was located predominantly in the hippocampal CA3/4 area and the hilus of the dentate gyrus. The density of dentate granule cells expressing the BDNF receptor TrkB as well as mRNA levels of TrkB in the hippocampal formation were increased 4 days after infection (p = 0.027 and 0.0048, respectively). Conversely, NGF mRNA levels at 30 hours after infection were reduced by approximately 50% (p = 0.004). No significant changes in GDNF expression were observed. In conclusion, increased synthesis of BDNF and TrkB suggests a contribution of this neurotrophic factor to neurogenesis after bacterial meningitis.     

GDNF is a major component of trophic activity in DA-depleted striatum for survival and neurite extension of DAergic neurons

Extracts from dopamine (DA)-depleted striatal tissue (lesion extract) and from intact striatal tissue (intact extract) were prepared, and trophic activities in these extracts were evaluated using survival and neurite extension of DAergic neurons as indices. Levels of brain-derived neurotrophic factor (BDNF), basic fibroblast growth factor (bFGF), glial cell-line derived neurotrophic factor (GDNF) and neurotrophin-3 (NT-3) in extracts were measured using enzyme-linked immunosorbent assay (ELISA). The lesion extract exhibited a stronger trophic activity on survival and neurite extension of DAergic neurons than intact extract. In lesion extract, bFGF was slightly and GDNF was significantly increased, while BDNF and NT-3 were the same level in each extract. The peak increase of bFGF and GDNF was during 2 to 3 weeks after DA depletion. Trophic activity of extract was strongly attenuated after immunoprecipitation of GDNF and partly attenuated after immunoprecipitation of bFGF. In parallel immunohistological study, no significant variations were found for striatal microtubule-associated protein-2 (MAP-2)- nor OX-41-immunoreactive cells, while the number of strongly labeled glial fibrillary acidic protein (GFAP)-immunoreactive cells were increased in DA-depleted striatum, suggesting reactive gliosis. Data suggest that bFGF is a minor, while GDNF is a major component of trophic activity for DAergic neurons in DA-depleted striatum, and increased bFGF and GDNF levels may be mediated partly by reactive gliosis.     

Effects of GDNF-Transfected Marrow Stromal Cells on Rats with Intracerebral Hemorrhage

Objective: The present study aimed to investigate the effects of Mesenchymal stem cells/glial cell line derived neurotrophic factor (MSCs/GDNF) transplantation on nerve reconstruction in rats with intracerebral hemorrhage. Methods: GDNF transduction to MSCs was using adenovirus vector pAdEasy-1-pAdTrack-CMV prepared. Intracerebral hemorrhage (ICH) was induced by injection of collagenase and heparin into the caudate putamen. At the third day after a collagenase-induced ICH, adult male SD rats were randomly divided into saline group, MSCs group and MSCs/GDNF group. Immunofluorescence and RT-PCR were performed to detect the differentiation of MSCs or MSCs with an adenovirus vector encoding GDNF gene in vivo and in vitro. Result: After 6 hours of induction, both MSCs and MSCs/GDNF expressed neuro or glial specific markers and synaptic-associated proteins (SYN, GAP-43, PSD-95); additionally, they secreted bioactive compounds (BDNF, NGF-β). MSCs/GDNF transplantation, compared to MSCs and saline solution injection, significantly improved neurological functions after ICH. The grafted MSCs or MSCs/GDNF survived in the striatum after 2 weeks of transplantation and expressed the neural cell-specific biomarkers NSE, MAP2, and GFAP. Conclusion: These findings demonstrate that MSCs/GDNF transplantation contributes to improved neurological function in experimental ICH rats. The mechanisms are possibly due to neuronal replacement and enhanced neurotrophic factor secretion.     

海马神经元条件培养液体外诱导大鼠骨髓间质干细胞向神经元样细胞和神经胶质样 细胞的分化：与含b-FGF培养基和无血清培养基的比较*☆

背景：目前关于骨髓间质干细胞能否向神经元方向分化的报道不多,且争论多集中在分化后的神经元是否仅具有神经元形态而不具有神经元功能。 目的：探讨海马神经元条件培养液诱导大鼠骨髓间质干细胞向神经元样细胞和神经胶质样细胞分化的可能性。 方法：将第5代大鼠骨髓间质干细胞分为4组：条件培养基组加入海马神经元和胶质细胞的培养液;b-FGF组加入含b-FGF的DMEM培养基;无血清培养组加入含Neurobasal和B27的无血清培养基;阴性对照组加入含胎牛血清的DMEM。各组诱导12,24 h后,应用免疫细胞化学染色行神经元特异性烯醇化酶、微管相关蛋白2、胶质纤维酸性蛋白的鉴定,Western-blot法检测细胞神经元特异性烯醇化酶、微管相关蛋白2和胶质纤维酸性蛋白的表达。 结果与结论：诱导12,24 h后,条件培养基组、b-FGF组、无血清培养组骨髓间质充干细胞微管相关蛋白2、胶质纤维酸性蛋白、神经元特异性烯醇化酶均呈阳性表达,阴性对照组未见表达。与阴性对照组比较,诱导后24 h,条件培养基组、b-FGF组、无血清培养组微管相关蛋白2表达均明显增强(P < 0.05),且条件培养基组增强幅度显著高于另两组(P < 0.05);条件培养基组、b-FGF组、无血清培养组神经元特异性烯醇化酶及胶质纤维酸性蛋白表达无明显差异。结果证实海马神经元条件培养液可体外诱导大鼠骨髓间质干细胞分化为神经元样细胞和神经胶质样细胞,与含b-FGF的培养基和无血清培养基相比,海马神经元条件培养基诱导的神经元和神经胶质细胞阳性率最高。     

Antipsychotic drugs cause glial cell line-derived neurotrophic factor secretion from C6 glioma cells

OBJECTIVE: Atypical antipsychotic drugs have been shown to protect PC12 cells from cell death induced by a variety of stimuli in culture. Recently, it has been postulated that trophic factors, such as brain-derived neurotrophic factor (BDNF), play a role in preventing cell death. It has been shown that antipsychotic drugs attenuate the decrease in rat hippocampal BDNF that results from immobilization-induced stress. We aimed to determine whether the neuroprotective effects of antipsychotic drugs could be mediated through glial cell line-derived neurotrophic factor (GDNF). METHODS: We investigated the effects of the atypical antipsychotic drugs quetiapine and clozapine and the typical antipsychotic haloperidol on the secretion of GDNF from rat C6 glioma cells. RESULTS: All 3 drugs increased the amount of GDNF secreted from C6 glioma cells into the medium after 48-hour culture. The intracellular content of GDNF was not altered by treatment with any of the antipsychotic drugs. None of the antipsychotic drugs decreased cell number. CONCLUSION: This study suggests that stimulation of GDNF release from glial cells by antipsychotic drugs might underlie some of their neuroprotective properties in situ.     

Role of BDNF and GDNF in drug reward and relapse: A review

Brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) are neurotrophic factors that are critical for the growth, survival, and differentiation of developing neurons. These neurotrophic factors also play important roles in the survival and function of adult neurons, learning and memory, and synaptic plasticity. Since the mid-1990s, investigators have studied the role of BDNF and GDNF in the behavioral effects of abused drugs and in the neuroadaptations induced by repeated exposure to drugs in the mesocorticolimbic dopamine system. Here, we review rodent studies on the role of BDNF and GDNF in drug reward, as assessed in the drug self-administration and the conditioned place preference procedures, and in drug relapse, as assessed in extinction and reinstatement procedures. Our main conclusion is that whether BDNF or GDNF would facilitate or inhibit drug-taking behaviors depends on the drug type, the brain site, the addiction phase (initiation, maintenance, or abstinence/relapse), and the time interval between site-specific BDNF or GDNF injections and the reward- and relapse-related behavioral assessments.     

Role of BDNF and GDNF in drug reward and relapse: A review

Brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) are neurotrophic factors that are critical for the growth, survival, and differentiation of developing neurons. These neurotrophic factors also play important roles in the survival and function of adult neurons, learning and memory, and synaptic plasticity. Since the mid-1990s, investigators have studied the role of BDNF and GDNF in the behavioral effects of abused drugs and in the neuroadaptations induced by repeated exposure to drugs in the mesocorticolimbic dopamine system. Here, we review rodent studies on the role of BDNF and GDNF in drug reward, as assessed in the drug self-administration and the conditioned place preference procedures, and in drug relapse, as assessed in extinction and reinstatement procedures. Our main conclusion is that whether BDNF or GDNF would facilitate or inhibit drug-taking behaviors depends on the drug type, the brain site, the addiction phase (initiation, maintenance, or abstinence/relapse), and the time interval between site-specific BDNF or GDNF injections and the reward- and relapse-related behavioral assessments.     

Comparison of the capability of GDNF, BDNF, or both, to protect nigrostriatal neurons in a rat model of Parkinson's disease

Both glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF) can protect nigrostriatal dopaminergic neurons from neurotoxins in rodent and monkey models of Parkinson's disease (PD). These two neurotrophic factors are usually tested individually. This study was designed to compare GDNF, BDNF, or both, for their capabilities to correct behavioral deficits and protect nigrostriatal dopaminergic neurons in a rat model of PD. Gene transfer used a helper virus-free Herpes Simplex Virus (HSV-1) vector system and a modified neurofilament heavy gene promoter that supports long-term expression in forebrain neurons. Rats received unilateral intrastriatal injections of HSV-1 vectors that express either GDNF or BDNF, or both vectors, followed by intrastriatal injections of 6-hydroxydopamine (6-OHDA). Recombinant GDNF or BDNF was detected in striatal neurons in rats sacrificed at 7 months after gene transfer. Of note, GDNF was significantly more effective than BDNF for both correcting behavioral deficits and protecting nigrostriatal dopaminergic neurons. Expression of both neurotrophic factors was no more effective than expression of only GDNF. These results suggest that GDNF is more effective than BDNF for correcting the rat model of PD, and that there are no detectable benefits from expressing both of these neurotrophic factors.