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Sample records for 6-ohda rat model

  1. The unilateral 6-OHDA rat model of Parkinson's disease revisited: an electromyographic and behavioural analysis.

    PubMed

    Metz, Gerlinde A; Tse, Arthur; Ballermann, Mark; Smith, Lori K; Fouad, Karim

    2005-08-01

    The characteristic locomotor disturbances of Parkinson's disease (PD) include shuffling gait, short steps and low walking velocity. In this study we investigated features of walking and turning in a rat model of PD caused by unilateral infusion of the neurotoxin 6-hydroxydopamine (6-OHDA). We assessed gait and electromyographic (EMG) patterns of the ankle flexor tibialis anterior and the knee extensor vastus lateralis of the hindlimb, and triceps brachii of the forelimb, during overground locomotion, spontaneous rotation (turning) and apomorphine-induced rotation. When compared with control rats, rats with unilateral dopamine depletion displayed a shuffling gait and short stride lengths. This locomotor pattern was accompanied by prolonged ankle flexor activity on the ipsilateral side, and prolonged activity of knee extensors on the contralateral side. The dopamine depletion also led to enhanced contraversive rotations after an apomorphine challenge. The EMG recordings during drug-induced rotation suggested that hindlimb stepping was a reflective response to an active drive produced by forelimbs. The EMG recordings of the contralateral side during rotation were marked by reduced ankle flexor activity and increased knee extensor activity. Furthermore, EMG recordings indicated that dopamine-agonists induce rotational bias by altering the coupling between ipsi- and contralateral hindlimbs, and between forelimbs. In straight walking, however, the gait of 6-OHDA lesion animals reflected normal, coupled hindlimb stepping as controlled by spinal pattern generators. The data suggest that the unilateral rat model of PD resembles key features of human parkinsonian gait, and that asymmetric descending input may underlie the observed changes in gait patterns.

  2. Protective effect of methanolic extract of Garcinia indica fruits in 6-OHDA rat model of Parkinson's disease.

    PubMed

    Antala, Bhaveshkumar V; Patel, Manishkumar S; Bhuva, Satish V; Gupta, Shiv; Rabadiya, Samir; Lahkar, Mangala

    2012-01-01

    Several studies have reported that antioxidants play an important role in Parkinson's disease (PD). Garcinia indica extract is a natural antioxidant, the present study was undertaken to evaluate the neuroprotective effect of methanolic extract of Garcinia indica (GIM) against 6-hydroxydopamine (6-OHDA) neurotoxicity for striatal dopaminergic neurons in the rat. Thirty adult Wistar rats were randomly divided into five groups namely control, 6-OHDA model, and GIM (100, 200, and 400 mg/kg body weight suspended in one ml of 0.1% carboxymethyl cellulose). The treatment was started three days before surgery and continued for next 14 days. The surgery was done on third day in all groups for administration of 6-OHDA into the right striatum and right substantia nigra, whereas control group injected with 6-OHDA vehicle. Various behavior and biochemical tests (Apomorphine-induced rotational behavior, Stepping test, Initiation time, Postural balance test, and Disengage time) were used to evaluate the neuroprotective effect of GIM. One-way analysis of variance (ANOVA) followed by Dunnett's test was used to compare inter-group differences. P<0.05 was considered as statistically significant. GIM had significant (P<0.05, P<0.01) preventive effect in biochemical tests, i.e., dopamine and its metabolites measurement and in various behavior tests, i.e., apomorphine-induced rotational behavior, stepping test, initiation time, postural balance test, and disengage time as compared to 6-OHDA-treated rats. Our results demonstrated that GIM acted as an effective neuroprotective agent for striatal dopaminergic neurons in 6-OHDA lesioned rat model of PD.

  3. Protective effect of methanolic extract of Garcinia indica fruits in 6-OHDA rat model of Parkinson's disease

    PubMed Central

    Antala, Bhaveshkumar V.; Patel, Manishkumar S.; Bhuva, Satish V.; Gupta, Shiv; Rabadiya, Samir; Lahkar, Mangala

    2012-01-01

    Context: Several studies have reported that antioxidants play an important role in Parkinson's disease (PD). Garcinia indica extract is a natural antioxidant, the present study was undertaken to evaluate the neuroprotective effect of methanolic extract of Garcinia indica (GIM) against 6-hydroxydopamine (6-OHDA) neurotoxicity for striatal dopaminergic neurons in the rat. Materials and Methods: Thirty adult Wistar rats were randomly divided into five groups namely control, 6-OHDA model, and GIM (100, 200, and 400 mg/kg body weight suspended in one ml of 0.1% carboxymethyl cellulose). The treatment was started three days before surgery and continued for next 14 days. The surgery was done on third day in all groups for administration of 6-OHDA into the right striatum and right substantia nigra, whereas control group injected with 6-OHDA vehicle. Various behavior and biochemical tests (Apomorphine-induced rotational behavior, Stepping test, Initiation time, Postural balance test, and Disengage time) were used to evaluate the neuroprotective effect of GIM. One-way analysis of variance (ANOVA) followed by Dunnett's test was used to compare inter-group differences. P<0.05 was considered as statistically significant. Results: GIM had significant (P<0.05, P<0.01) preventive effect in biochemical tests, i.e., dopamine and its metabolites measurement and in various behavior tests, i.e., apomorphine-induced rotational behavior, stepping test, initiation time, postural balance test, and disengage time as compared to 6-OHDA-treated rats. Conclusions: Our results demonstrated that GIM acted as an effective neuroprotective agent for striatal dopaminergic neurons in 6-OHDA lesioned rat model of PD. PMID:23248394

  4. T-Lymphocyte Deficiency Exacerbates Behavioral Deficits in the 6-OHDA Unilateral Lesion Rat Model for Parkinson’s Disease

    PubMed Central

    Wheeler, Christopher J; Seksenyan, Akop; Koronyo, Yosef; Rentsendorj, Altan; Sarayba, Danielle; Wu, Henry; Gragg, Ashley; Siegel, Emily; Thomas, Deborah; Espinosa, Andres; Thompson, Kerry; Black, Keith; Koronyo-Hamaoui, Maya; Pechnick, Robert; Irvin, Dwain K

    2014-01-01

    T-lymphocytes have been previously implicated in protecting dopaminergic neurons in the substantianigra from induced cell death. However, the role of T-cells in neurodegenerative models such as Parkinson’s disease (PD) has not been fully elucidated. To examine the role of T-lymphocytes on motor behavior in the 6-hydroxydopamine (6-OHDA) unilateral striatal partial lesion PD rat model, we assessed progression of hemi-parkinsonian lesions in the substantia nigra, induced by 6-OHDA striatal injections, in athymic rats (RNU−/−, T-lymphocyte-deficient) as compared to RNU−/+ rats (phenotypically normal). Motor skills were determined by the cylinder and D-amphetamine sulfate-induced rotational behavioral tests. Cylinder behavioral test showed no significant difference between unilaterally lesioned RNU−/− and RNU−/+ rats. However both unilaterally lesioned RNU−/− and RNU−/+ rats favored the use of the limb ipsilateral to lesion. Additionally, amphetamine-induced rotational test revealed greater rotational asymmetry in RNU−/− rats compared to RNU−/+ rats at two- and six-week post-lesion. Quantitative immunohistochemistry confirmed loss of striatal TH-immunopositive fibers in RNU−/− and RNU−/+ rat, as well as blood-brain-barrier changes associated with PD that may influence passage of immune cells into the central nervous system in RNU−/− brains. Specifically, GFAP immunopositive cells were decreased, as were astrocytic end-feet (AQP4) contacting blood vessels (laminin) in the lesioned relative to contralateral striatum. Flow cytometric analysis in 6-OHDA lesioned RNU−/+rats revealed increased CD4+ and decreased CD8+ T cells specifically within lesioned brain. These results suggest that both major T cell subpopulations are significantly and reciprocally altered following 6-OHDA-lesioning, and that global T cell deficiency exacerbates motor behavioral defects in this rat model of PD. PMID:25346865

  5. Caffeine improves attention deficit in neonatal 6-OHDA lesioned rats, an animal model of attention deficit hyperactivity disorder (ADHD).

    PubMed

    Caballero, Miguel; Núñez, Fabiana; Ahern, Siobhán; Cuffí, Maria L; Carbonell, Lourdes; Sánchez, Silvia; Fernández-Dueñas, Víctor; Ciruela, Francisco

    2011-04-20

    Nowadays the pharmacological treatment of the attention deficit hyperactivity disorder (ADHD) is based on amphetamine derivatives (i.e. methylphenidate). However, these drugs induce a large array of adverse side effects, thus less aggressive psychostimulant drugs (i.e. caffeine) are being proposed in the management of ADHD. Following this tendency, we decided to study the possible therapeutic use of caffeine in an animal model of ADHD, namely the neonatal 6-hydroxy-dopamine (6-OHDA)-lesioned rat. Therefore, at postnatal day 7 rats were lesioned at the left striatum with 6-OHDA or with saline. Thereafter, at postnatal day 25 their activity and attention were measured with the Olton maze before caffeine was administered ad libitum in the drinking water. Next, after 14 days of caffeine treatment, we repeated these measurements to assess the effect of caffeine on motor activity and attention deficit. Interestingly, while no changes in the motor activity measurements were observed before and after caffeine administration, a significant improvement in the attention deficit of the 6-OHDA lesioned rats was achieved after caffeine treatment. Thus, our results led us to hypothesize that caffeine might be useful to manage the attention deficit during the prepubertal period of ADHD.

  6. Astrocytic Expression of GSTA4 Is Associated to Dopaminergic Neuroprotection in a Rat 6-OHDA Model of Parkinson's Disease.

    PubMed

    Jewett, Michael; Jimenez-Ferrer, Itzia; Swanberg, Maria

    2017-06-26

    Idiopathic Parkinson's disease (PD) is a complex disease caused by multiple, mainly unknown, genetic and environmental factors. The Ventral root avulsion 1 (Vra1) locus on rat chromosome 8 includes the Glutathione S-transferase alpha 4 (Gsta4) gene and has been identified in crosses between Dark Agouti (DA) and Piebald Virol Glaxo (PVG) rat strains as being associated to neurodegeneration after nerve and brain injury. The Gsta4 protein clears lipid peroxidation by-products, a process suggested to being implicated in PD. We therefore investigated whether PVG alleles in Vra1 are neuroprotective in a toxin-induced model of PD and if this effect is coupled to Gsta4. We performed unilateral 6-hydroxydopamine (6-OHDA) partial lesions in the striatum and compared the extent of neurodegeration in parental (DA) and congenic (DA.VRA1) rats. At 8 weeks after 6-OHDA lesion, DA.VRA1 rats displayed a higher density of remaining dopaminergic fibers in the dorsolateral striatum compared to DA rats (44% vs. 23%, p < 0.01), indicating that Vra1 alleles derived from the PVG strain protect dopaminergic neurons from 6-OHDA toxicity. Gsta4 gene expression levels in the striatum and midbrain were higher in DA.VRA1 congenic rats compared to DA at 2 days post-lesion (p < 0.05). The GSTA4 protein co-localized with astrocytic marker GFAP, but not with neuronal marker NeuN or microglial marker IBA1, suggesting astrocyte-specific expression. This is the first report on Vra1 protective effects on dopaminergic neurodegeneration and encourages further studies on Gsta4 in relation to PD susceptibility.

  7. Comparison of the behavioural and histological characteristics of the 6-OHDA and α-synuclein rat models of Parkinson's disease.

    PubMed

    Decressac, M; Mattsson, B; Björklund, A

    2012-05-01

    Development of relevant models of Parkinson's disease (PD) is essential for a better understanding of the pathological processes underlying the human disease and for the evaluation of promising targets for therapeutic intervention. To date, most pre-clinical studies have been performed in the well-established rodent and non-human primate models using injection of 6-hydroxydopamine (6-OHDA) or 1-methyl-4-phenyl-1,2,3,6-tetrahydroxypyridine (MPTP). Overexpression of the disease-causing protein α-synuclein (α-syn), using adeno-associated viral (AAV) vectors, has provided a novel model that recapitulates many features of the human disease. In the present study we compared the AAV-α-syn rat model with models where the nigro-striatal pathway is lesioned by injection of 6-OHDA in the striatum (partial lesion) or the medial forebrain bundle (full lesion). Examination of the behavioural changes over time revealed a different progression and magnitude of the motor impairment. Interestingly, dopamine (DA) neuron loss is prominent in both the toxin and the AAV-α-syn models. However, α-syn overexpressing animals were seen to exhibit less cell and terminal loss for an equivalent level of motor abnormalities. Prominent and persistent axonal pathology is only observed in the α-syn rat model. We suggest that, while neuronal and terminal loss mainly accounts for the behavioural impairment in the toxin-based model, similar motor deficits result from the combination of cell death and dysfunction of the remaining nigro-striatal neurons in the AAV-α-syn model. While the two models have been developed to mimic DA neuron deficiency, they differ in their temporal and neuropathological characteristics, and replicate different aspects of the pathophysiology of the human disease. This study suggests that the AAV-α-syn model replicates the human pathology more closely than either of the other two 6-OHDA lesion models. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Catechin attenuates behavioral neurotoxicity induced by 6-OHDA in rats.

    PubMed

    Teixeira, M D A; Souza, C M; Menezes, A P F; Carmo, M R S; Fonteles, A A; Gurgel, J P; Lima, F A V; Viana, G S B; Andrade, G M

    2013-09-01

    This study was designed to investigate the beneficial effect of catechin in a model of Parkinson's disease. Unilateral, intrastriatal 6-hydroxydopamine (6-OHDA)-lesioned rats were pretreated with catechin (10 and 30 mg/kg) by intraperitoneal (i.p.) injection 2h before surgery and for 14 days afterwards. After treatments, apomorphine-induced rotations, locomotor activity, working memory and early and late aversive memories were evaluated. The mesencephalon was used to determine the levels of monoamines and measurement of glutathione (GSH). Immunohistochemical staining was also used to evaluate the expression of tyrosine hydroxylase (TH) in mesencephalic and striatal tissues. Catechin administration attenuated the increase in rotational behavior and the decrease in locomotor activity observed in lesioned rats. Although catechin did not rescue the impairment of late aversive memory, it protected the animals against 6-OHDA-induced working memory deficits. Furthermore, catechin treatment restored GSH levels, and significantly increased dopamine and DOPAC content, and TH-immunoreactivity in 6-OHDA-lesioned rats. Catechin protected 6-OHDA-lesioned rats due to its antioxidant action, indicating that it could be useful as an adjunctive therapy for the treatment of Parkinson's disease.

  9. A Novel Immunosuppressor, (5R)-5-Hydroxytriptolide, Alleviates Movement Disorder and Neuroinflammation in a 6-OHDA Hemiparkinsonian Rat Model.

    PubMed

    Su, Ruijun; Sun, Min; Wang, Wei; Zhang, Jianliang; Zhang, Li; Zhen, Junli; Qian, Yanjing; Zheng, Yan; Wang, Xiaomin

    2017-02-01

    Parkinson's disease (PD) is one of the most common age-related neurodegenerative diseases. Promising therapies for PD still need to be explored. Immune dysfunction has been found to be involved in PD pathogenesis. Here, a novel immunosuppressor, (5R)-5-hydroxytriptolide (LLDT8), was used to treat 6-hydroxydopamine (6-OHDA)-induced hemiparkinson rats. We found that oral administration of LLDT8 significantly alleviated apomorphine-induced rotations at a dose of 125 µg/kg, and improved performance in cylinder and rotarod tests at a lower dose of 31.25 µg/kg, in 6-OHDA hemiparkinsonian rats. Moreover, loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) of the 6-OHDA rat was attenuated in response to LLDT8 treatment in a dose-dependent manner. In addition, inflammatory factors IL-1β, IL-6 and TNF-α, were significantly inhibited in LLDT8-treated hemiparkisonian rats, compared with vehicle. Notably, the level of dopamine (DA) in the striatum of PD rats was restored by LLDT8 treatment. Furthermore, we also detected that the disequilibrium of peripheral lymphocytes was reversed by LLDT8 administration. Taken together, the results imply that the immunosuppressor, LLDT8, can rescue dopaminergic neurodegeneration in 6-OHDA hemiparkinsonian rats, thus providing a potential therapeutic strategy for PD.

  10. A Novel Immunosuppressor, (5R)-5-Hydroxytriptolide, Alleviates Movement Disorder and Neuroinflammation in a 6-OHDA Hemiparkinsonian Rat Model

    PubMed Central

    Su, Ruijun; Sun, Min; Wang, Wei; Zhang, Jianliang; Zhang, Li; Zhen, Junli; Qian, Yanjing; Zheng, Yan; Wang, Xiaomin

    2017-01-01

    Parkinson’s disease (PD) is one of the most common age-related neurodegenerative diseases. Promising therapies for PD still need to be explored. Immune dysfunction has been found to be involved in PD pathogenesis. Here, a novel immunosuppressor, (5R)-5-hydroxytriptolide (LLDT8), was used to treat 6-hydroxydopamine (6-OHDA)-induced hemiparkinson rats. We found that oral administration of LLDT8 significantly alleviated apomorphine-induced rotations at a dose of 125 µg/kg, and improved performance in cylinder and rotarod tests at a lower dose of 31.25 µg/kg, in 6-OHDA hemiparkinsonian rats. Moreover, loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) of the 6-OHDA rat was attenuated in response to LLDT8 treatment in a dose-dependent manner. In addition, inflammatory factors IL-1β, IL-6 and TNF-α, were significantly inhibited in LLDT8-treated hemiparkisonian rats, compared with vehicle. Notably, the level of dopamine (DA) in the striatum of PD rats was restored by LLDT8 treatment. Furthermore, we also detected that the disequilibrium of peripheral lymphocytes was reversed by LLDT8 administration. Taken together, the results imply that the immunosuppressor, LLDT8, can rescue dopaminergic neurodegeneration in 6-OHDA hemiparkinsonian rats, thus providing a potential therapeutic strategy for PD. PMID:28203480

  11. Enriched environment protects the nigrostriatal dopaminergic system and induces astroglial reaction in the 6-OHDA rat model of Parkinson's disease

    PubMed Central

    Anastasía, Agustín; Torre, Luciana; de Erausquin, Gabriel A.; Mascó, Daniel H.

    2009-01-01

    Enriched environment (EE) is neuroprotective in several animal models of neurodegeneration. It stimulates the expression of trophic factors and modifies the astrocyte cell population which has been said to exert neuroprotective effects. We have investigated the effects of EE on 6-hydroxydopamine (6-OHDA)-induced neuronal death after unilateral administration to the medial forebrain bundle, which reaches 85–95% of dopaminergic neurons in the substantia nigra after 3 weeks. Continuous exposure to EE 3 weeks before and after 6-OHDA injection prevents neuronal death (assessed by tyrosine hydroxylase staining), protects the nigrostriatal pathway (assessed by Fluorogold retrograde labeling) and reduces motor impairment. Four days after 6-OHDA injection, EE was associated with a marked increase in glial fibrillary acidic protein staining and prevented neuronal death (assessed by Fluoro Jade-B) but not partial loss of tyrosine hydroxylase staining in the anterior substantia nigra. These results robustly demonstrate that EE preserves the entire nigrostriatal system against 6-OHDA-induced toxicity, and suggests that an early post-lesion astrocytic reaction may participate in the neuro-protective mechanism. PMID:19245661

  12. Effect of memantine on L-DOPA-induced dyskinesia in the 6-OHDA-lesioned rat model of Parkinson's disease.

    PubMed

    Tronci, E; Fidalgo, C; Zianni, E; Collu, M; Stancampiano, R; Morelli, M; Gardoni, F; Carta, M

    2014-04-18

    An increasing body of experimental evidence demonstrates that the glutamatergic system is involved in the genesis of l-3,4-dihydroxyphenylalanine (L-DOPA)-induced dyskinesia (LID). Indeed, the N-methyl-d-aspartate (NMDA) receptor antagonist amantadine is the only anti-dyskinetic compound used in patients, albeit with limited efficacy and side effects. In this study, we investigated the anti-dyskinetic properties of memantine, a non-competitive NMDA receptor antagonist in clinical use for the treatment of dementia, in the 6-hydroxy-dopamine (6-OHDA)-lesion rat model of Parkinson's disease. For comparison, parallel experiments were also performed with amantadine. First, we investigated the acute effect of different doses of memantine (5, 10, 15 and 20mg/kg), and amantadine (10, 20, 40, 60mg/kg) on established dyskinesia induced by L-DOPA (6mg/kg plus benserazide). Results showed that both memantine and amantadine produced a significant reduction of LID. Afterward, drug-naïve and L-DOPA-primed 6-OHDA-lesioned rats were sub-chronically treated with daily injections of L-DOPA (6mg/kg plus benserazide) alone, or in combination with the effective doses of memantine, while amantadine was tested in already dyskinetic rats. Results showed that memantine significantly dampened dyskinesia in both drug-naïve and L-DOPA-primed rats, but only during the first few days of administration. In fact, the anti-dyskinetic effect of memantine was completely lost already at the fifth administration, indicating a rapid induction of tolerance. Interestingly, a 3-week washout period was not sufficient to restore the anti-dyskinetic effect of the drug. Similarly, amantadine was able to dampen already established dyskinesia only during the first day of administration. Moreover, memantine partially decreased the therapeutic effect of L-DOPA, as showed by the result of the stepping test. Finally, loss of the anti-dyskinetic effect of memantine was associated to increased synaptic GluN2A/GluN2B

  13. Antioxidant effect of Spirulina (Arthrospira) maxima in a neurotoxic model caused by 6-OHDA in the rat striatum.

    PubMed

    Tobón-Velasco, J C; Palafox-Sánchez, Victoria; Mendieta, Liliana; García, E; Santamaría, A; Chamorro-Cevallos, G; Limón, I Daniel

    2013-08-01

    There is evidence to support that an impaired energy metabolism and the excessive generation of reactive oxygen species (ROS) contribute to brain injury in neurodegenerative disorders such as Parkinson's disease (PD), whereas diets enriched in foods with an antioxidant action may modulate its progression. Several studies have proved that the antioxidant components produced by Spirulina, a microscopic blue-green alga, might prevent cell death by decreasing free radicals, inhibiting lipoperoxidation and upregulating the antioxidant enzyme systems. In our study, we investigated the protective effect of the Spirulina maxima (S. maxima) against the 6-OHDA-caused toxicity in the rat striatum. The S. maxima (700 mg/kg/day, vo) was administered for 40 days before and 20 days after a single injection of 6-OHDA (16 μg/2 μL) into the dorsal striatum. At 20-day postsurgery, the brain was removed and the striatum was obtained to evaluate the indicators of toxicity, such as nitric oxide levels, ROS formation, lipoperoxidation, and mitochondrial activity. These variables were found significantly stimulated in 6-OHDA-treated rats and were accompanied by declines in dopamine levels and motor activity. In contrast, the animals that received the chronic treatment with S. maxima had a restored locomotor activity, which is associated with the decreased levels of nitric oxide, ROS, and lipoperoxidation in the striatum, although mitochondrial functions and dopamine levels remained preserved. These findings suggest that supplementation with antioxidant phytochemicals (such as contained in S. maxima) represents an effective neuroprotective strategy against 6-OHDA-caused neurotoxicity vía free radical production to preserve striatal dopaminergic neurotransmission in vivo.

  14. Enriched environment induces cellular plasticity in the adult substantia nigra and improves motor behavior function in the 6-OHDA rat model of Parkinson's disease.

    PubMed

    Steiner, Barbara; Winter, Christine; Hosman, Kai; Siebert, Eberhard; Kempermann, Gerd; Petrus, Dominique S; Kupsch, Andreas

    2006-06-01

    The adult substantia nigra bears the capacity to generate new neural cells throughout adulthood. The mechanisms of cellular plasticity in this brain region remain unknown. In the adult dentate gyrus, dopamine was suggested to be one of the key players in neurogenesis. We therefore investigated nigral cellular plasticity in the 6-OHDA rat model of Parkinson's disease. The absolute numbers of newborn cells in the SN were not affected by dopamine depletion. Interestingly, we found a specific downregulation of generation of newborn nigral astrocytic cells. As enriched environment with physical activity are robust inducers of neuro- and gliogenesis in the adult DG, we investigated the role of these physiological stimuli in nigral cellular plasticity and in motor behavior of 6-OHDA lesioned rats. We describe a significant increase in numbers of newborn NG2-positive and GFAP-positive cells in the SN. Moreover, 6-OHDA lesioned animals living in enriched environment with physical activity for 7 weeks showed improved motor behavior compared to controls under standard conditions. Thus, physiological neurogenic and gliogenic stimuli induce significant microenvironmental changes in the adult SN and improve motor behavior in the 6-OHDA lesion model of PD.

  15. Exercise improves motor deficits and alters striatal GFAP expression in a 6-OHDA-induced rat model of Parkinson's disease.

    PubMed

    Dutra, Márcio Ferreira; Jaeger, Mariane; Ilha, Jocemar; Kalil-Gaspar, Pedro Ivo; Marcuzzo, Simone; Achaval, Matilde

    2012-10-01

    Astrocytic changes have been demonstrated in several neurodegenerative diseases, showing that these cells play an important role in functional recovery/maintenance against brain damage. Physical exercise is known to contribute to this process; however, the cellular mechanisms involved are not fully understood. This study investigated the effects of physical exercise on motor deficits and the expression of glial fibrillary acidic protein (GFAP) in a model of Parkinson's disease (PD). Rats were divided into four groups: sham sedentary (SS) and sham trained (ST); lesioned sedentary (LS) and lesioned trained (LT). 6-OHDA was infused unilaterally into the medial forebrain bundle. Behavioral tasks were applied to evaluate motor abilities. Tyrosine hydroxylase (TH-in substantia nigra) and GFAP (in striatum) immunoreactivities (ir) were semi-quantified using optical density. The animals submitted to treadmill training completed fewer pharmacological-induced rotations when compared with sedentary animals and they also showed ameliorated motor impairments. Interestingly, although no change in TH-ir, the exercise led to restored striatal GFAP expression in the LT group while there was no effect in the ST group. This study is the first study to show data indicating the recovery of GFAP expression post-exercise in this model and further research is necessary to determine the precise action mechanisms of exercise on astrocytes in the PD.

  16. Subthalamic 6-OHDA-induced lesion attenuates levodopa-induced dyskinesias in the rat model of Parkinson's disease.

    PubMed

    Marin, C; Bonastre, M; Mengod, G; Cortés, R; Rodríguez-Oroz, M C; Obeso, J A

    2013-12-01

    The subthalamic nucleus (STN) receives direct dopaminergic innervation from the substantia nigra pars compacta that degenerates in Parkinson's disease. The present study aimed to investigate the role of dopaminergic denervation of STN in the origin of levodopa-induced dyskinesias. Rats were distributed in four groups which were concomitantly lesioned with 6-OHDA or vehicle (sham) in the STN and in the medial forebrain bundle (MFB) as follows: a) MFB-sham plus STN-sham, b) MFB-sham plus STN-lesion, c) MFB-lesion plus STN-sham, and d) MFB-lesion plus STN-lesion. Four weeks after lesions, animals were treated with levodopa (6mg/kg with 15mg/kg benserazide i.p.) twice daily for 22 consecutive days. Abnormal involuntary movements were measured. In situ hybridization was performed measuring the expression of striatal preproenkephalin, preprodynorphin, STN cytochrome oxidase (CO) and nigral GAD67 mRNAs. STN 6-OHDA denervation did not induce dyskinesias in levodopa-treated MFB-sham animals but attenuated axial (p<0.05), limb (p<0.05) and orolingual (p<0.01) dyskinesias in rats with a concomitant lesion of the nigrostriatal pathway. The attenuation of dyskinesias was associated with a decrease in the ipsilateral STN CO mRNA levels (p<0.05). No significant differences between MFB-lesion plus STN-sham and MFB-lesion plus STN-lesion groups in the extent of STN dopaminergic denervation were observed. Moreover, intrasubthalamic microinfusion of dopamine in the MFB-lesion plus STN-lesion group triggered orolingual (p<0.01), but not axial or limb, dyskinesias. These results suggest that dopaminergic STN innervation influences the expression of levodopa-induced dyskinesias but also the existence of non dopaminergic-mediated mechanisms. STN noradrenergic depletion induced by 6-OHDA in the STN needs to be taken in account as a possible mechanism explaining the attenuation of dyskinesias in the combined lesion group.

  17. Behavioral and Neurochemical Effects of Alpha-Lipoic Acid in the Model of Parkinson's Disease Induced by Unilateral Stereotaxic Injection of 6-Ohda in Rat

    PubMed Central

    de Araújo, Dayane Pessoa; De Sousa, Caren Nádia Soares; Araújo, Paulo Victor Pontes; Menezes, Carlos Eduardo de Souza; Sousa Rodrigues, Francisca Taciana; Escudeiro, Sarah Souza; Lima, Nicole Brito Cortez; Patrocínio, Manoel Claúdio Azevedo; Aguiar, Lissiana Magna Vasconcelos; Viana, Glauce Socorro de Barros; Vasconcelos, Silvânia Maria Mendes

    2013-01-01

    This study aimed to investigate behavioral and neurochemical effects of α-lipoic acid (100 mg/kg or 200 mg/kg) alone or associated with L-DOPA using an animal model of Parkinson's disease induced by stereotaxic injection of 6-hydroxydopamine (6-OHDA) in rat striatum. Motor behavior was assessed by monitoring body rotations induced by apomorphine, open field test and cylinder test. Oxidative stress was accessed by determination of lipid peroxidation using the TBARS method, concentration of nitrite and evaluation of catalase activity. α-Lipoic acid decreased body rotations induced by apomorphine, as well as caused an improvement in motor performance by increasing locomotor activity in the open field test and use of contralateral paw (in the opposite side of the lesion produced by 6-OHDA) at cylinder test. α-lipoic acid showed antioxidant effects, decreasing lipid peroxidation and nitrite levels and interacting with antioxidant system by decreasing of endogenous catalase activity. Therefore, α-lipoic acid prevented the damage induced by 6-OHDA or by chronic use of L-DOPA in dopaminergic neurons, suggesting that α-lipoic could be a new therapeutic target for Parkinson's disease prevention and treatment. PMID:24023579

  18. The involvement of RGS9 in l-3,4-dihydroxyphenylalanine-induced dyskinesias in unilateral 6-OHDA lesion rat model.

    PubMed

    Yin, Lin-Lin; Geng, Xing-Chao; Zhu, Xing-Zu

    2011-11-25

    Chronic dopamine (DA) replacement therapy with L-3,4-dihydroxyphenylalanine (L-DOPA) in Parkinson's disease (PD) often leads to abnormal involuntary movements (AIMs) known as L-DOPA-induced dyskinesia (LID), mediated by DA receptors. However, mechanisms underlying LID occurrence are still unclear. Regulator of G-protein signaling RGS9, a member of the RGS family of GTPase accelerating proteins, is expressed specifically in the striatum, has been reported participated in LID. L-DOPA-induced AIMs can be modeled in rats with 6-hydroxydopamine (6-OHDA) lesions by chronic injection of L-DOPA. Herein, we compared the rotational responses and AIMs in 6-OHDA lesioned rats with L-DOPA/benserazide (10/2.5 mg/kg, once per day, i.p.) administration for 14 days whereas control animals received injections of saline. Furthermore, whether sub-chronic L-DOPA treatment impact RGS9 mRNA or protein expression in 6-OHDA lesion rats were also evaluated. As results shown, rotational behavior was not increased significantly, while an obvious AIMs were observed in rats with L-DOPA/benserazide (10/2.5mg/kg, i.p.) administration sub-chronically. In addition, expressions of RGS9 protein or mRNA analyzed by Western blot or real-time PCR with striatal extracts increased significantly after L-DOPA/benserazide. These data demonstrate that RGS9 expression can be modulated by sub-chronic L-DOPA/benserazide administration and increased RGS9 expression in striatum may be one of the reasons for the side effects such as dyskinesia induced by L-DOPA therapy.

  19. Effects of subthalamic deep brain stimulation on blink abnormalities of 6-OHDA lesioned rats.

    PubMed

    Kaminer, Jaime; Thakur, Pratibha; Evinger, Craig

    2015-05-01

    Parkinson's disease (PD) patients and the 6-hydroxydopamine (6-OHDA) lesioned rat model share blink abnormalities. In view of the evolutionarily conserved organization of blinking, characterization of blink reflex circuits in rodents may elucidate the neural mechanisms of PD reflex abnormalities. We examine the extent of this shared pattern of blink abnormalities by measuring blink reflex excitability, blink reflex plasticity, and spontaneous blinking in 6-OHDA lesioned rats. We also investigate whether 130-Hz subthalamic nucleus deep brain stimulation (STN DBS) affects blink abnormalities, as it does in PD patients. Like PD patients, 6-OHDA-lesioned rats exhibit reflex blink hyperexcitability, impaired blink plasticity, and a reduced spontaneous blink rate. At 130 Hz, but not 16 Hz, STN DBS eliminates reflex blink hyperexcitability and restores both short- and long-term blink plasticity. Replicating its lack of effect in PD patients, 130-Hz STN DBS does not reinstate a normal temporal pattern or rate to spontaneous blinking in 6-OHDA lesioned rats. These data show that the 6-OHDA lesioned rat is an ideal model system for investigating the neural bases of reflex abnormalities in PD and highlight the complexity of PD's effects on motor control, by showing that dopamine depletion does not affect all blink systems via the same neural mechanisms. Copyright © 2015 the American Physiological Society.

  20. Anti-dyskinetic mechanisms of amantadine and dextromethorphan in the 6-OHDA rat model of Parkinson’s disease: role of NMDA vs. 5-HT1A receptors

    PubMed Central

    Paquette, Melanie A.; Martinez, Alex A.; Macheda, Teresa; Meshul, Charles K.; Johnson, Steven W.; Berger, S. Paul; Giuffrida, Andrea

    2013-01-01

    Amantadine and dextromethorphan suppress levodopa (L-DOPA)-induced dyskinesia (LID) in patients with Parkinson’s disease (PD) and abnormal involuntary movements (AIMs) in the unilateral 6-hydroxydopamine (6-OHDA) rat model. These effects have been attributed to N-methyl-d-aspartate (NMDA) antagonism. However, amantadine and dextromethorphan are also thought to block serotonin (5-HT) uptake and cause 5-HT overflow, leading to stimulation of 5-HT1A receptors, which has been shown to reduce LID. We undertook a study in 6-OHDA rats to determine whether the anti-dyskinetic effects of these two compounds are mediated by NMDA antagonism and/or 5-HT1A agonism. In addition, we assessed the sensorimotor effects of these drugs using the Vibrissae-Stimulated Forelimb Placement and Cylinder tests. Our data show that the AIM-suppressing effect of amantadine was not affected by the 5-HT1A antagonist WAY-100635, but was partially reversed by the NMDA agonist d-cycloserine. Conversely, the AIM-suppressing effect of dextromethorphan was prevented by WAY-100635 but not by d-cycloserine. Neither amantadine nor dextromethorphan affected the therapeutic effects of L-DOPA in sensorimotor tests. We conclude that the anti-dyskinetic effect of amantadine is partially dependent on NMDA antagonism, while dextromethorphan suppresses AIMs via indirect 5-HT1A agonism. Combined with previous work from our group, our results support the investigation of 5-HT1A agonists as pharmacotherapies for LID in PD patients. PMID:22861201

  1. Coherence of neuronal firing of the entopeduncular nucleus with motor cortex oscillatory activity in the 6-OHDA rat model of Parkinson's disease with levodopa-induced dyskinesias.

    PubMed

    Jin, Xingxing; Schwabe, Kerstin; Krauss, Joachim K; Alam, Mesbah

    2016-04-01

    The pathophysiological mechanisms leading to dyskinesias in Parkinson's disease (PD) after long-term treatment with levodopa remain unclear. This study investigates the neuronal firing characteristics of the entopeduncular nucleus (EPN), the rat equivalent of the human globus pallidus internus and output nucleus of the basal ganglia, and its coherence with the motor cortex (MCx) field potentials in the unilateral 6-OHDA rat model of PD with and without levodopa-induced dyskinesias (LID). 6-hydroxydopamine-lesioned hemiparkinsonian (HP) rats, 6-OHDA-lesioned HP rats with LID (HP-LID) rats, and naïve controls were used for recording of single-unit activity under urethane (1.4 g/kg, i.p) anesthesia in the EPN "on" and "off" levodopa. Over the MCx, the electrocorticogram output was recorded. Analysis of single-unit activity in the EPN showed enhanced firing rates, burst activity, and irregularity compared to naïve controls, which did not differ between drug-naïve HP and HP-LID rats. Analysis of EPN spike coherence and phase-locked ratio with MCx field potentials showed a shift of low (12-19 Hz) and high (19-30 Hz) beta oscillatory activity between HP and HP-LID groups. EPN theta phase-locked ratio was only enhanced in HP-LID compared to HP rats. Overall, levodopa injection had no stronger effect in HP-LID rats than in HP rats. Altered coherence and changes in the phase lock ratio of spike and local field potentials in the beta range may play a role for the development of LID.

  2. Anti-dyskinetic mechanisms of amantadine and dextromethorphan in the 6-OHDA rat model of Parkinson's disease: role of NMDA vs. 5-HT1A receptors.

    PubMed

    Paquette, Melanie A; Martinez, Alex A; Macheda, Teresa; Meshul, Charles K; Johnson, Steven W; Berger, S Paul; Giuffrida, Andrea

    2012-11-01

    Amantadine and dextromethorphan suppress levodopa (L-DOPA)-induced dyskinesia (LID) in patients with Parkinson's disease (PD) and abnormal involuntary movements (AIMs) in the unilateral 6-hydroxydopamine (6-OHDA) rat model. These effects have been attributed to N-methyl-d-aspartate (NMDA) antagonism. However, amantadine and dextromethorphan are also thought to block serotonin (5-HT) uptake and cause 5-HT overflow, leading to stimulation of 5-HT(1A) receptors, which has been shown to reduce LID. We undertook a study in 6-OHDA rats to determine whether the anti-dyskinetic effects of these two compounds are mediated by NMDA antagonism and/or 5-HT(1A) agonism. In addition, we assessed the sensorimotor effects of these drugs using the Vibrissae-Stimulated Forelimb Placement and Cylinder tests. Our data show that the AIM-suppressing effect of amantadine was not affected by the 5-HT(1A) antagonist WAY-100635, but was partially reversed by the NMDA agonist d-cycloserine. Conversely, the AIM-suppressing effect of dextromethorphan was prevented by WAY-100635 but not by d-cycloserine. Neither amantadine nor dextromethorphan affected the therapeutic effects of L-DOPA in sensorimotor tests. We conclude that the anti-dyskinetic effect of amantadine is partially dependent on NMDA antagonism, while dextromethorphan suppresses AIMs via indirect 5-HT(1A) agonism. Combined with previous work from our group, our results support the investigation of 5-HT(1A) agonists as pharmacotherapies for LID in PD patients. © 2012 The Authors. European Journal of Neuroscience © 2012 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  3. [Stromal cell transplant in the 6-OHDA lesion model].

    PubMed

    Pavón-Fuentes, N; Blanco-Lezcano, L; Martínez-Martín, L; Castillo-Díaz, L; de la Cuétara-Bernal, K; García-Miniet, R; Lorigados-Pedre, L; Coro-Grave de Peralta, Y; García-Varona, A Y; Rosillo-Martí, J C; Macías-González, R

    A good deal of evidence currently exists to show that transplanting foetal mesencephalic tissue can produce symptomatic benefits both in patients and in disease models. Nevertheless, the technical and ethical difficulties involved in obtaining enough suitable foetal cerebral tissue have been a serious obstacle to its application. Stromal cells derived from bone marrow, due to their potential capacity to generate different types of cells, could be an ideal source of material for cell restoration in neurodegenerative diseases. Our aim was to evaluate the effect of transplanting stromal cells derived from bone marrow on the behaviour of 6-OHDA rats, when they are inserted into the striatum. In this study we used rats with a lesion in the substantia nigra induced by 6-hydroxydopamine, divided into several experimental groups. Rotary activity induced by D-amphetamine (5 mg/kg, intraperitoneally) was evaluated before and throughout the three months following the transplant in all the experimental groups, except in the group of healthy controls. Hemiparkinsonian rats received a total of 350 000 foetal ventral mesencephalic cells and 8 x 10(4) stromal cells/microL, which were implanted in the striatum. Animals with stromal cells transplanted in the body of the striatum significantly reduced the number of turns induced by amphetamine (p < 0.05); yet this reduction was not greater than that induced by foetal mesencephalic cell transplants. We were also unable to demonstrate any significant improvement in the motor skills of the forelimbs.

  4. Treadmill Exercise Prevents Increase of Neuroinflammation Markers Involved in the Dopaminergic Damage of the 6-OHDA Parkinson's Disease Model.

    PubMed

    Real, Caroline Cristiano; Garcia, Priscila Crespo; Britto, Luiz R G

    2017-08-11

    Parkinson's disease (PD) involves loss of dopaminergic neurons in the substantia nigra (SN), which can be correlated to neuroinflammatory changes with the aging of the nervous system. On the other hand, exercise can reduce the deleterious effects promoted by age, but the mechanism involved is still unclear. This study investigated the preventive exercise-induced changes on neuroinflammatory processes in a rat model of PD induced by unilateral striatal injections of 6-hydroxydopamine (6-OHDA). Adult male Wistar rats were divided into two groups: (1) sedentary (SED) or (2) exercised (EX), animals that did treadmill exercise three times per week, every other day, for 4 weeks prior to 6-OHDA or saline injection. The rats were then divided into four sub-groups: (1) sedentary saline (SED), (2) sedentary 6-OHDA (SED + 6-OHDA), (3) exercised saline (EX), and (4) exercised 6-OHDA (EX + 6-OHDA). Seven and 30 days after surgery, brains were collected for immunohistochemistry and immunoblotting for dopaminergic and neuroinflammatory markers into SN and striatum. The SED + 6-OHDA animals presented an increase in the astrocyte, microglial, and oxidative species activation. On the other hand, EX + 6-OHDA animals did not present neuroinflammatory responses and performed better apormorphine test. Our data suggest that treadmill exercise throughout life can markedly reduce the chances of dopamine decrease, reinforcing studies that showed a lower incidence of Parkinson's disease in patients who were active during life.

  5. Reduction of GABAergic transmission and alterations in behavior after 6-OHDA treatment of rats.

    PubMed

    Podkletnova, I; Raevsky, V; Alho, H

    1996-07-20

    We studied the effects of neonatal administration of 6-hydroxydopamine (6-OHDA) upon gamma-aminobutyric acid (GABA) and noradrenergic neurotransmission in the developing rat brain. After 6-OHDA administration tyrosine hydroxylase (TH) immunolabelling revealed more than 70% loss of catecholaminergic terminals in cortex. Glutamic acid decarboxylase (GAD) immunolabelling showed that the intensity of staining and the density of labelled terminals were decreased by approximately 50% in the prefrontal cortex of 6-OHDA treated animals, but in visual and somatosensory zones there was no difference between lesioned and control cortex. The open field test revealed an altered development of the searching activity after neonatal 6-OHDA injections. A significant difference was found between 6-OHDA treated and control rats in searching, orienting and skills performance. Our results indicate that the behavioral changes observed in young rats after 6-OHDA treatment may be reflections not only of reduced catecholaminergic transmission but also of GABAergic disturbance, occurring in the frontal cortex.

  6. Cardiovascular and autonomic alterations in rats with Parkinsonism induced by 6-OHDA and treated with L-DOPA.

    PubMed

    Silva, A S; Ariza, D; Dias, D P M; Crestani, C C; Martins-Pinge, M C

    2015-04-15

    Evaluate the effects caused by L-DOPA on cardiovascular and autonomic parameters in an animal model of Parkinsonism induced by 6-hydroxydopamine (6-OHDA). Adult male Wistar rats were subjected to bilateral microinfusion of 6-OHDA or saline (sham group) in the substantia nigra, and treated by gavage with L-DOPA or water for 7 days after surgery. On the 6th day the rats were subjected to femoral artery catheterization for cardiovascular recording. Mean arterial pressure (MAP) and heart rate (HR) were evaluated at baseline and during head up tilt (HUT) protocol. Spectral analysis of cardiovascular variability was performed using the V2.4 CardioSeries software v2.4. The lesion was quantified by dopamine levels in the striatum. Dopamine levels in the striatum were decreased in 6-OHDA rats (sham: 4.79 ± 0.49 ng/mg; 6-OHDA: 1.99 ± 0.68 ng/mg) and were not recovered by Prolopa treatment. Baseline values of MAP and HR were not different between groups. HUT induced an increase in MAP and HR (ΔMAP: 17 ± 1 mm Hg, ΔHR: 39 ± 4 bpm) that were attenuated in 6-OHDA and in Prolopa treated animals. At baseline, the systolic arterial pressure (SAP) variance was lower in the 6-OHDA AND sham prolopa groups. Spontaneous baroreflex sensitivity was higher at baseline in the 6-OHDA group as compared to all studied groups. Our data suggest that treatment with Prolopa did not interfere with cardiovascular variables at baseline. However, during HUT, the 6-OHDA and Prolopa control animals presented a lower cardiovascular compensation, suggesting a possible autonomic impairment in Parkinsonism induced by 6-OHDA.

  7. Antagonism of quercetin against tremor induced by unilateral striatal lesion of 6-OHDA in rats.

    PubMed

    Mu, Xin; Yuan, Xia; Du, Li-Da; He, Guo-Rong; Du, Guan-Hua

    2016-01-01

    Quercetin, a flavonoid present in many plants, is reported to be effective in models of neurodegenerative diseases. The aim of the present study was to evaluate the anti-tremor effects of quercetin in 6-hydroxydopamine (6-OHDA)-induced rat model of Parkinson's disease. In rats, quercetin had no effect on apomorphine-induced rotations, but it could significantly attenuate muscle tremor of 6-OHDA lesioned rats. Interestingly, quercetin could decrease the burst frequency in a dose- and time-dependent manner. These results suggest that quercetin may have a protective effect on models to mimic muscle tremors of Parkinson's disease. This effect of quercetin may be associated with serotonergic system, but further study is needed.

  8. Intrastriatal Grafting of Chromospheres: Survival and Functional Effects in the 6-OHDA Rat Model of Parkinson's Disease.

    PubMed

    Boronat-García, Alejandra; Palomero-Rivero, Marcela; Guerra-Crespo, Magdalena; Millán-Aldaco, Diana; Drucker-Colín, René

    2016-01-01

    Cell replacement therapy in Parkinson's disease (PD) aims at re-establishing dopamine neurotransmission in the striatum by grafting dopamine-releasing cells. Chromaffin cell (CC) grafts produce some transitory improvements of functional motor deficits in PD animal models, and have the advantage of allowing autologous transplantation. However, CC grafts have exhibited low survival, poor functional effects and dopamine release compared to other cell types. Recently, chromaffin progenitor-like cells were isolated from bovine and human adult adrenal medulla. Under low-attachment conditions, these cells aggregate and grow as spheres, named chromospheres. Here, we found that bovine-derived chromosphere-cell cultures exhibit a greater fraction of cells with a dopaminergic phenotype and higher dopamine release than CC. Chromospheres grafted in a rat model of PD survived in 57% of the total grafted animals. Behavioral tests showed that surviving chromosphere cells induce a reduction in motor alterations for at least 3 months after grafting. Finally, we found that compared with CC, chromosphere grafts survive more and produce more robust and consistent motor improvements. However, further experiments would be necessary to determine whether the functional benefits induced by chromosphere grafts can be improved, and also to elucidate the mechanisms underlying the functional effects of the grafts.

  9. Intrastriatal Grafting of Chromospheres: Survival and Functional Effects in the 6-OHDA Rat Model of Parkinson's Disease

    PubMed Central

    Boronat-García, Alejandra; Palomero-Rivero, Marcela; Guerra-Crespo, Magdalena; Millán-Aldaco, Diana; Drucker-Colín, René

    2016-01-01

    Cell replacement therapy in Parkinson’s disease (PD) aims at re-establishing dopamine neurotransmission in the striatum by grafting dopamine-releasing cells. Chromaffin cell (CC) grafts produce some transitory improvements of functional motor deficits in PD animal models, and have the advantage of allowing autologous transplantation. However, CC grafts have exhibited low survival, poor functional effects and dopamine release compared to other cell types. Recently, chromaffin progenitor-like cells were isolated from bovine and human adult adrenal medulla. Under low-attachment conditions, these cells aggregate and grow as spheres, named chromospheres. Here, we found that bovine-derived chromosphere-cell cultures exhibit a greater fraction of cells with a dopaminergic phenotype and higher dopamine release than CC. Chromospheres grafted in a rat model of PD survived in 57% of the total grafted animals. Behavioral tests showed that surviving chromosphere cells induce a reduction in motor alterations for at least 3 months after grafting. Finally, we found that compared with CC, chromosphere grafts survive more and produce more robust and consistent motor improvements. However, further experiments would be necessary to determine whether the functional benefits induced by chromosphere grafts can be improved, and also to elucidate the mechanisms underlying the functional effects of the grafts. PMID:27525967

  10. 6-OHDA injections into A8-A9 dopaminergic neurons modelling early stages of Parkinson's disease increase the harmaline-induced tremor in rats.

    PubMed

    Kolasiewicz, Wacław; Kuter, Katarzyna; Berghauzen, Klemencja; Nowak, Przemysław; Schulze, Gert; Ossowska, Krystyna

    2012-10-05

    The aim of the present study was to examine the influence of a unilateral 6-hydroxydopamine (6-OHDA)-induced partial lesion of both the substantia nigra pars compacta (SNc, A9) and retrorubral field (RRF, A8) on the tremor evoked by harmaline. 6-OHDA (8μg/2μl) was injected unilaterally into the region of the posterior part of the SNc and RRF. Harmaline was administered in a dose of 7.5mg/kg ip on the eighth day after the operation and tremor of forelimbs, head and trunk was measured. We found that the lesion increased intensity of the tremor induced by harmaline but did not influence its character. Stereological examination of the lesion extent revealed losses of dopaminergic (tyrosine hydroxylase-immunoreactive) neurons in the anterior (30%) and posterior (72%) SNc, as well as in RRF (72% on the average). Levels of dopamine and all its metabolites, as well as noradrenaline concentrations, were ipsilaterally moderately decreased in the caudate-putamen in the lesioned animals, however, dopamine and DOPAC in the anterior cerebellum were increased. In the caudate-putamen, the ipsi/contra ratio of dopamine level correlated negatively, while that of dopamine turnover positively with the tremor intensity. However, in the anterior cerebellum an inverse relationship was found. Moreover, this symptom correlated positively with the serotonin level and negatively with the 5-HIAA/serotonin ratio on the contralateral side of the posterior cerebellum. The present results seem to indicate that the modulation of dopaminergic and serotonergic transmissions by the lesion modelling early stages of Parkinson's disease may influence tremor triggered in the cerebellum.

  11. ACTIVATION OF PPAR GAMMA RECEPTORS REDUCES LEVODOPA-INDUCED DYSKINESIAS IN 6-OHDA-LESIONED RATS

    PubMed Central

    Martinez, A. A.; Morgese, M. G.; Pisanu, A.; Macheda, T.; Paquette, M. A.; Seillier, A.; Cassano, T.; Carta, A.R.; Giuffrida, A.

    2014-01-01

    Long-term administration of L-3,4-dihydroxyphenylalanine (levodopa), the mainstay treatment for Parkinson’s disease (PD), is accompanied by fluctuations in its duration of action and motor complications (dyskinesia) that dramatically affect the quality of life of patients. Levodopa-induced dyskinesias (LID) can be modeled in rats with unilateral 6-OHDA lesions via chronic administration of levodopa, which causes increasingly severe axial, limb and oro-facial abnormal involuntary movements (AIMs) over time. In previous studies, we showed that direct activation of CB1 cannabinoid receptors alleviated rat AIMs. Interestingly, elevation of the endocannabinoid anandamide by URB597 (URB), an inhibitor of endocannabinoid catabolism, produced an anti-dyskinetic response that was only partially mediated via CB1 receptors and required the concomitant blockade of transient receptor potential vanilloid type-1 (TRPV1) channels by capsazepine (CPZ) [1]. In this study, we showed that stimulation of peroxisome proliferator-activated receptors (PPAR), a family of transcription factors activated by anandamide, contributes to the anti-dyskinetic effects of URB+CPZ, and that direct activation of the PPARγ subtype by rosiglitazone (RGZ) alleviates levodopa-induced AIMs in 6-OHDA rats. AIM reduction was associated with an attenuation of levodopa-induced increase of dynorphin, zif-268 and of ERK phosphorylation in the denervated striatum. RGZ treatment did not decrease striatal levodopa and dopamine bioavailability, nor did it affect levodopa antiparkinsonian activity. Collectively, these data indicate that PPARγ may represent a new pharmacological target for the treatment of LID. PMID:25486547

  12. The effect of electroacupuncture on proteomic changes in the motor cortex of 6-OHDA Parkinsonian rats.

    PubMed

    Li, Min; Li, Lijuan; Wang, Ke; Su, Wenting; Jia, Jun; Wang, Xiaomin

    2017-10-15

    Electroacupuncture (EA) has been reported to alleviate motor deficits in Parkinson's disease (PD) patients, and PD animal models. However, the mechanisms by which EA improves motor function have not been investigated. We have employed a 6-hydroxydopamine (6-OHDA) unilateral injection induced PD model to investigate whether EA alters protein expression in the motor cortex. We found that 4weeks of EA treatment significantly improved spontaneous floor plane locomotion and rotarod performance. High-throughput proteomic analysis in the motor cortex was employed. The expression of 54 proteins were altered in the unlesioned motor cortex, and 102 protein expressions were altered in the lesioned motor cortex of 6-OHDA rats compared to sham rats. Compared to non-treatment PD control, EA treatment reversed 6 proteins in unlesioned and 19 proteins in lesioned motor cortex. The present study demonstrated that PD induces proteomic changes in the motor cortex, some of which are rescued by EA treatment. These targeted proteins were mainly involved in increasing autophagy, mRNA processing and ATP binding and maintaining the balance of neurotransmitters. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Enhanced Efficacy of the CDNF/MANF Family by Combined Intranigral Overexpression in the 6-OHDA Rat Model of Parkinson's Disease

    PubMed Central

    Cordero-Llana, Óscar; Houghton, Benjamin C; Rinaldi, Federica; Taylor, Hannah; Yáñez-Muñoz, Rafael J; Uney, James B; Wong, Liang-Fong; Caldwell, Maeve A

    2015-01-01

    Cerebral Dopamine Neurotrophic Factor (CDNF) and Mesencephalic Astrocyte-derived Neurotrophic factor (MANF) are members of a recently discovered family of neurotrophic factors (NTFs). Here, we used intranigral or intrastriatal lentiviral vector-mediated expression to evaluate their efficacy at protecting dopaminergic function in the 6-OHDA model of Parkinson's disease (PD). In contrast to the well-studied Glial-Derived Neurotrophic Factor (GDNF), no beneficial effects were demonstrated by striatal overexpression of either protein. Interestingly, nigral overexpression of CDNF decreased amphetamine-induced rotations and increased tyroxine hydroxylase (TH) striatal fiber density but had no effect on numbers of TH+ cells in the SN. Nigral MANF overexpression had no effect on amphetamine-induced rotations or TH striatal fiber density but resulted in a significant preservation of TH+ cells. Combined nigral overexpression of both factors led to a robust reduction in amphetamine-induced rotations, greater increase in striatal TH-fiber density and significant protection of TH+ cells in the SN. We conclude that nigral CDNF and MANF delivery is more efficacious than striatal delivery. This is also the first study to demonstrate that combined NTF can have synergistic effects that result in enhanced neuroprotection, suggesting that multiple NTF delivery may be more efficacious for the treatment of PD than the single NTF approaches attempted so far. PMID:25369767

  14. Decreased synaptic plasticity in the medial prefrontal cortex underlies short-term memory deficits in 6-OHDA-lesioned rats.

    PubMed

    Matheus, Filipe C; Rial, Daniel; Real, Joana I; Lemos, Cristina; Ben, Juliana; Guaita, Gisele O; Pita, Inês R; Sequeira, Ana C; Pereira, Frederico C; Walz, Roger; Takahashi, Reinaldo N; Bertoglio, Leandro J; Da Cunha, Cláudio; Cunha, Rodrigo A; Prediger, Rui D

    2016-03-15

    Parkinson's disease (PD) is characterized by motor dysfunction associated with dopaminergic degeneration in the dorsolateral striatum (DLS). However, motor symptoms in PD are often preceded by short-term memory deficits, which have been argued to involve deregulation of medial prefrontal cortex (mPFC). We now used a 6-hydroxydopamine (6-OHDA) rat PD model to explore if alterations of synaptic plasticity in DLS and mPFC underlie short-term memory impairments in PD prodrome. The bilateral injection of 6-OHDA (20μg/hemisphere) in the DLS caused a marked loss of dopaminergic neurons in the substantia nigra (>80%) and decreased monoamine levels in the striatum and PFC, accompanied by motor deficits evaluated after 21 days in the open field and accelerated rotarod. A lower dose of 6-OHDA (10μg/hemisphere) only induced a partial degeneration (about 60%) of dopaminergic neurons in the substantia nigra with no gross motor impairments, thus mimicking an early premotor stage of PD. Notably, 6-OHDA (10μg)-lesioned rats displayed decreased monoamine levels in the PFC as well as short-term memory deficits evaluated in the novel object discrimination and in the modified Y-maze tasks; this was accompanied by a selective decrease in the amplitude of long-term potentiation in the mPFC, but not in DLS, without changes of synaptic transmission in either brain regions. These results indicate that the short-term memory dysfunction predating the motor alterations in the 6-OHDA model of PD is associated with selective changes of information processing in PFC circuits, typified by persistent changes of synaptic plasticity. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Targeted inhibition of RAGE in substantia nigra of rats blocks 6-OHDA-induced dopaminergic denervation.

    PubMed

    Gasparotto, Juciano; Ribeiro, Camila Tiefensee; Bortolin, Rafael Calixto; Somensi, Nauana; Rabelo, Thallita Kelly; Kunzler, Alice; Souza, Natália Cabral; Pasquali, Matheus Augusto de Bittencourt; Moreira, José Claudio Fonseca; Gelain, Daniel Pens

    2017-08-18

    The receptor for advanced glycation endproducts (RAGE) is a pattern-recognition receptor associated with inflammation in most cell types. RAGE up-regulates the expression of proinflammatory mediators and its own expression via activation of NF-kB. Recent works have proposed a role for RAGE in Parkinson's disease (PD). In this study, we used the multimodal blocker of RAGE FPS-ZM1, which has become available recently, to selectively inhibit RAGE in the substantia nigra (SN) of rats intracranially injected with 6-hydroxydopamine (6-OHDA). FPS-ZM1 (40 μg per rat), injected concomitantly with 6-OHDA (10 μg per rat) into the SN, inhibited the increase in RAGE, activation of ERK1/2, Src and nuclear translocation of NF-kB p65 subunit in the SN. RAGE inhibition blocked glial fibrillary acidic protein and Iba-1 upregulation as well as associated astrocyte and microglia activation. Circulating cytokines in serum and CSF were also decreased by FPS-ZM1 injection. The loss of tyrosine hydroxylase and NeuN-positive neurons was significantly inhibited by RAGE blocking. Finally, FPS-ZM1 attenuated locomotory and exploratory deficits induced by 6-OHDA. Our results demonstrate that RAGE is an essential component in the neuroinflammation and dopaminergic denervation induced by 6-OHDA in the SN. Selective inhibition of RAGE may offer perspectives for therapeutic approaches.

  16. Activation of PPAR gamma receptors reduces levodopa-induced dyskinesias in 6-OHDA-lesioned rats.

    PubMed

    Martinez, A A; Morgese, M G; Pisanu, A; Macheda, T; Paquette, M A; Seillier, A; Cassano, T; Carta, A R; Giuffrida, A

    2015-02-01

    Long-term administration of l-3,4-dihydroxyphenylalanine (levodopa), the mainstay treatment for Parkinson's disease (PD), is accompanied by fluctuations in its duration of action and motor complications (dyskinesia) that dramatically affect the quality of life of patients. Levodopa-induced dyskinesias (LID) can be modeled in rats with unilateral 6-OHDA lesions via chronic administration of levodopa, which causes increasingly severe axial, limb, and orofacial abnormal involuntary movements (AIMs) over time. In previous studies, we showed that the direct activation of CB1 cannabinoid receptors alleviated rat AIMs. Interestingly, elevation of the endocannabinoid anandamide by URB597 (URB), an inhibitor of endocannabinoid catabolism, produced an anti-dyskinetic response that was only partially mediated via CB1 receptors and required the concomitant blockade of transient receptor potential vanilloid type-1 (TRPV1) channels by capsazepine (CPZ) (Morgese et al., 2007). In this study, we showed that the stimulation of peroxisome proliferator-activated receptors (PPAR), a family of transcription factors activated by anandamide, contributes to the anti-dyskinetic effects of URB+CPZ, and that the direct activation of the PPARγ subtype by rosiglitazone (RGZ) alleviates levodopa-induced AIMs in 6-OHDA rats. AIM reduction was associated with an attenuation of levodopa-induced increase of dynorphin, zif-268, and of ERK phosphorylation in the denervated striatum. RGZ treatment did not decrease striatal levodopa and dopamine bioavailability, nor did it affect levodopa anti-parkinsonian activity. Collectively, these data indicate that PPARγ may represent a new pharmacological target for the treatment of LID.

  17. FTY720 Attenuates 6-OHDA-Associated Dopaminergic Degeneration in Cellular and Mouse Parkinsonian Models.

    PubMed

    Ren, Manru; Han, Minxing; Wei, Xinbing; Guo, Ying; Shi, Huanying; Zhang, Xiumei; Perez, Ruth G; Lou, Haiyan

    2017-02-01

    FTY720 (fingolimod) is the first oral drug approved for treating relapsing-remitting forms of multiple sclerosis. It is also protective in other neurological models including ischemia, Alzheimer's disease, Huntington disease and Rett syndrome. However, whether it might protect in a 6-hydroxydopamine (6-OHDA) mouse model associated with the dopaminergic pathology of Parkinson's disease (PD), has not been explored. Therefore, in the present study, we investigated the effects of FTY720 on 6-OHDA-induced neurotoxicity in cell cultures and mice. Here we show that FTY720 protected against 6-OHDA cytotoxicity and apoptosis in SH-SY5Y cells. We also show that prior administration of FTY720 to 6-OHDA lesioned mice ameliorated both motor deficits and nigral dopaminergic neurotoxicity, while also reducing 6-OHDA-associated inflammation. The protective effects of FTY720 were associated with activation of AKT and ERK1/2 pro-survival pathways and an increase in brain derived neurotrophic factor (BDNF) expression in vitro and in vivo. These findings suggest that FTY720 holds promise as a PD therapeutic acting, at least in part, through AKT/ERK1/2/P-CREB-associated BDNF expression.

  18. Caffeine and CSC, adenosine A2A antagonists, offer neuroprotection against 6-OHDA-induced neurotoxicity in rat mesencephalic cells.

    PubMed

    Nobre, Hélio Vitoriano; Cunha, Geanne Matos de Andrade; de Vasconcelos, Lissiana Magna; Magalhães, Hemerson Iury Ferreira; Oliveira Neto, Raimundo Nogueira; Maia, Flávio Damasceno; de Moraes, Manoel Odorico; Leal, L Kalyne A Moreira; Viana, Glauce Socorro de Barros

    2010-01-01

    In this study, the cytoprotective effects of caffeine (CAF) and 8-(3-chlorostyryl)-caffeine (CSC), A(2A) receptor antagonists, were tested against 6-OHDA-induced cytotoxicity, in rat mesencephalic cells. Both drugs significantly increased the number of viable cells, after their exposure to 6-OHDA, as measured by the MTT assay. While nitrite levels in the cells were drastically increased by 6-OHDA, their concentrations were brought toward normality after CAF or CSC, indicating that both drugs block 6-OHDA-induced oxidative stress which leads to free radicals generation. A complete blockade of 6-OHDA-induced lipid peroxidation, considered as a major source of DNA damage, was observed after cells treatment with CAF or CSC. 6-OHDA decreased the number of normal cells while increasing the number of apoptotic cells. In the CAF plus 6-OHDA group, a significant recover in the number of viable cells and a decrease in the number of apoptotic cells were seen, as compared to the group treated with 6-OHDA alone. A similar effect was observed after cells exposure to CSC in the presence of 6-OHDA. Unexpectedly, while a significant lower number of activated microglia was observed after cells exposure to CAF plus 6-OHDA, this was not the case after cells exposure to CSC under the same conditions. While CAF lowered the percentage of reactive astrocytes increased by 6-OHDA, CSC presented no effect. The effects of these drugs were also examined on the releases of myeloperoxidase (MPO), an inflammatory marker, and lactate dehydrogenase (LDH), a marker for cytotoxicity, in human neutrophils, in vitro. CSC and CAF (0.1, 1 and 10 microg/ml) produced inhibitions of the MPO release from PMA-stimulated cells, ranging from 45 to 83%. In addition, CSC and CAF (5, 50 and 100 microg/ml) did not show any cytotoxicity in the range of concentrations used, as determined by the LDH assay. All together, our results showed a strong neuroptrotection afforded by caffeine or CSC, on rat mesencephalic

  19. Neuroprotective effect of Spirulina fusiform and amantadine in the 6-OHDA induced Parkinsonism in rats.

    PubMed

    Chattopadhyaya, I; Gupta, Sumeet; Mohammed, Asad; Mushtaq, N; Chauhan, S; Ghosh, Saikat; Ghosh, Saikant

    2015-08-25

    Multi-factorial etiology exists in pathophysiology of neurodegenerative diseases. The imbalance of anti-oxidant enzymes and dopamine level leads to Parkinsonism. The objective of this study was to assess the protective effect of Spirulina fusiform alone and in combination with amantadine against Parkinsonism effect in 6-hydroxydopamine (6-OHDA) induced rat model. S. fusiform was administered in different groups (500 mg/kg, once daily and twice daily) and a combination of spirulina (500 mg/kg, once daily) with amantadine (20 mg/kg once daily) for 30 days before and 14 days after a single injection of 6-OHDA into the dorsal striatum. Post lesion produced rotational behavior which was measured at two week intervals (37th and 44th day). Locomotors activity was also done at 44th and muscle coordination at 48th day. Dorsal striatum was isolated from rat brain for evaluating the antioxidant assays and dopamine content at 49th day. Both the body rotations (ipsilateral and contralateral) were found to have a statistically significant (p<0.001) decrease by 34.26 and 52% after treatment with spirulina (Twice a day) in spirulina treated lesioned group. A higher percentage of improvement was shown in the reduction of ipsilateral (57.34%) and contralateral (78.3%) rotations in combination of spirulina with amantadine treated lesioned group rather than spirulina alone treated lesioned groups when compared with positive control lesioned group. Body movements and locomotor activity were improved statistically (p<0.0001) significant in both treated lesioned groups (Combination of spirulina with amantadine and spirulina twice daily). Similar results were also seen in anti-oxidant levels which later on reached to the normal value. The levels of dopamine content had a statistically significant (p<0.0001) increase by 78.3% only in case of spirulina with amantadine treated lesioned group. Spirulina is a potent nutraceutical supplement all over the world, so my preclinical study may

  20. Chemoreflex and baroreflex alterations in Parkinsonism induced by 6-OHDA in unanesthetized rats.

    PubMed

    Ariza, Deborah; Lopes, Fernanda Novi Cortegoso; Crestani, Carlos Cesar; Martins-Pinge, Marli Cardoso

    2015-10-21

    Parkinson's disease (PD) is mainly characterized by motor signals. However, non-motor signals also affect and decrease the quality of life of PD patients. Among these non-motor signs are cardiovascular disorders as orthostatic hypotension, postprandial hypotension and cardiac arrhythmias, which may be due to the involvement of both central nervous system and peripheral autonomic nervous system. In the present study we investigated the cardiovascular function, evaluating cardiovascular reflexes (chemoreflex and baroreflex), in an animal model of Parkinsonism induced by bilateral infusion of the toxin 6-hydroxydopamine (6-OHDA), in the substantia nigra pars compacta (SNpc). The results showed that the animals induced to Parkinsonism had lower arterial pressure (AP) and heart rate HR) compared to control animals. We showed that after activation of the baroreceptors by phenylephrine (Phe) and sodium nitroprusside (SNP), the baroreflex sensitivity index was not changed between the groups. However, there was a greater increase in the AP when stimulated with Phe and greater tachycardia when stimulated with SNP in 6-OHDA animals. After activation of the peripheral chemoreceptors through KCN injection (cytotoxic hypoxia), there was a higher increase in pressor and bradycardic response in injured animals with bilateral 6-OHDA. These changes in the cardiovascular reflexes may be important adjustments mechanisms to maintain the cerebral blood flow in those animals, and may be a result of denervation supersensitivity to catecholamines in autonomic targets.

  1. Ceftriaxone increases glutamate uptake and reduces striatal tyrosine hydroxylase loss in 6-OHDA Parkinson’s model

    PubMed Central

    Chotibut, Tanya; Davis, Richard W.; Arnold, Jennifer C.; Frenchek, Zachary; Gurwara, Shawn; Bondada, Vimala; Geddes, James W.

    2015-01-01

    Excess glutamatergic neurotransmission may contribute to excitotoxic loss of nigrostriatal neurons in Parkinson’s disease (PD). Here, we determined if increasing glutamate uptake could reduce the extent of tyrosine hydroxylase (TH) loss in PD progression. The beta-lactam antibiotic, ceftriaxone, increases the expression of glutamate transporter 1 (GLT-1), a glutamate transporter that plays a major role in glutamate clearance in central nervous system and may attenuate adverse behavioral or neurobiological function in other neurodegenerative disease models. In association with >80 % TH loss, we observed a significant decrease in glutamate uptake in the established 6-hydroxydopamine (6-OHDA) PD model. Ceftriaxone (200 mg/kg, i.p.) increased striatal glutamate uptake with ≥ 5 consecutive days of injection in nonlesioned rats and lasted out to 14 days postinjection, a time beyond that required for 6-OHDA to produce >70 % TH loss (~9 days). When ceftriaxone was given at the time of 6-OHDA, TH loss was ~57 % compared to ~85 % in temporally matched vehicle-injected controls and amphetamine-induced rotation was reduced about 2-fold. This attenuation of TH loss was associated with increased glutamate uptake, increased GLT-1 expression, and reduced Serine 19 TH phosphorylation, a calcium-dependent target specific for nigrostriatal neurons. These results reveal that glutamate uptake can be targeted in a PD model, decrease the rate of TH loss in a calcium-dependent manner, and attenuate locomotor behavior associated with 6-OHDA lesion. Given that detection of reliable PD markers will eventually be employed in susceptible populations, our results give credence to the possibility that increasing glutamate uptake may prolong the time period before locomotor impairment occurs. PMID:24297323

  2. Caffeine neuroprotective effects on 6-OHDA-lesioned rats are mediated by several factors, including pro-inflammatory cytokines and histone deacetylase inhibitions.

    PubMed

    Machado-Filho, João Ananias; Correia, Alyne Oliveira; Montenegro, Anyssa Brilhante Aires; Nobre, Maria Elizabeth Pereira; Cerqueira, Gilberto Santos; Neves, Kelly Rose Tavares; Naffah-Mazzacoratti, Maria da Graça; Cavalheiro, Esper Abrão; de Castro Brito, Gerly Anne; de Barros Viana, Glauce Socorro

    2014-05-01

    Several lines of evidences have shown the inversion association between coffee consumption and Parkinson's disease (PD) development. Caffeine is a methylxanthine known as a non-selective inhibitor of A2A and A1 adenosine receptors in the brain and shown to be a neuroprotective drug. The objectives were to study caffeine effects in a unilateral 6-OHDA model of PD in rats. Male rats were divided into the following groups: sham-operated (SO), striatal 6-OHDA-lesioned and 6-OHDA-lesioned and treated for 2 weeks with caffeine (10 and 20mg/kg, p.o.). Then, animals were subjected to behavioral (open field and apomorphine-induced rotations), neurochemical (striatal determinations of DA and DOPAC), histological (cresyl violet staining) and immunohistochemical (TH, TNF-α, IL-1β and HDAC) evaluations. The results showed that while the 6-OHDA group presented a decreased locomotor activity and a high number of apomorphine-induced rotations, these behaviors were partially blocked by caffeine. Caffeine itself increased DA contents and reversed the decrease in striatal DA observed in the 6-OHDA-lesioned group. Furthermore, it improved the hippocampal neuronal viability and significantly increased TH immunoreactivity in the striatum of the 6-OHDA-lesioned group. In addition, caffeine treatment also decreased the number of immunopositive cells for HDAC and pro-inflammatory cytokines TNF-α and IL-1β. All these effects points out to a neuroprotective effect of caffeine and its potential benefit in the prevention and treatment of PD.

  3. Pentoxifylline Neuroprotective Effects Are Possibly Related to Its Anti-Inflammatory and TNF-Alpha Inhibitory Properties, in the 6-OHDA Model of Parkinson's Disease.

    PubMed

    Neves, Kelly Rose Tavares; Nobre, Hélio Vitoriano; Leal, Luzia Kalyne A M; de Andrade, Geanne Matos; Brito, Gerly Anne de Castro; Viana, Glauce Socorro de Barros

    2015-01-01

    Pentoxifylline (PTX) is a phosphodiesterase inhibitor with anti-TNF-alpha activity, associated with its anti-inflammatory action. Considering Parkinson's disease (PD) as a neuroinflammatory disorder, the objectives were to evaluate PTX neuroprotective properties, in a model of PD. Male Wistar rats, divided into sham-operated (SO), untreated 6-OHDA, and 6-OHDA treated with PTX (10, 25, and 50 mg/kg) groups, received a unilateral 6-OHDA injection, except the SO group administered with saline. Treatments started 24 h after surgery and continued for 15 days when the animals were submitted to apomorphine-induced rotations, open field, and forced swimming tests. At the next day, they were euthanized and their striata processed for neurochemical (DA and DOPAC determinations), histological, and immunohistochemical (Fluoro-Jade, TH, DAT, OX-42, TNF-alpha, COX-2, and iNOS) studies. PTX reversed the behavioral changes observed in the untreated 6-OHDA animals. Furthermore, PTX partially reversed the decrease in DA contents and improved neuronal viability. In addition, decreases in immunostaining for TH and dopamine transporter (DAT) were reversed. The untreated 6-OHDA group showed intense OX-42, TNF-alpha, COX-2, and iNOS immunoreactivities, which were attenuated by PTX. In conclusion, we demonstrated a neuroprotective effect of PTX, possibly related to its anti-inflammatory and antioxidant actions, indicating its potential as an adjunct treatment for PD.

  4. Selective 6OHDA-induced destruction of mesolimbic dopamine neurons: abolition of psychostimulant-induced locomotor activity in rats.

    PubMed

    Kelly, P H; Iversen, S D

    1976-11-01

    Selective large scale destruction of mesolimbic dopamine-containing terminals is produced by bilateral injection of 8 mug of 6-hydroxydopamine (6OHDA) into the nucleus accumbens septi (NAS) of rats pretreated with pargyline and desipramine (DMI). The DMI prevents the destruction of the noradrenergic innervation of the forebrain normally produced by the NAS 6OHDA lesion, without affecting the destruction of dopamine-containing neurons. The locomotor stimulation produced by the psychostimulants d-amphetamine (1.5 mg/kg) and cocaine (20 mg/kg) is blocked in rats with selective destruction of the mesolimbic dopamine system. In contrast the locomotor stimulation produced by the directly acting dopamine agonist apomorphine (1.0 mg/kg) is enhanced, which may indicate supersensitivity of the denervated dopamine receptors. These results lend further support to the view that psychostimulant-induced locomotr stimulation in rats results from effects on mesolimbic dopamine neurons. In addition, the protection by DMI of noradrenergic neurons from the toxic effects of 6OHDA is evidence that 6OHDA, as used here, destroys catecholamine neurons mainly by an uptake-dependent specific mechanism.

  5. Effects of Cultured Adrenal Chromaffin Cell Implants on Hindlimb Reflexes of the 6-OHDA Lesioned Rat

    PubMed Central

    Pulford, Bruce E.; Mihajlov, Andrea R.; Nornes, Howard O.; Whalen, L. Ray

    1994-01-01

    The effects of implantation of cultured adrenal medullary cells on the recovery of neurotransmitter specific reflex activity were studied in the rat spinal cord using electrophysiological testing methods. Cell suspensions of cultured neonatal adrenal medullary chromaffin (AM) cells (which produce catecholamines), or Schwann (Sc) cells (controls) were implanted into the lumbar region of the spinal cord 2 weeks after catecholamine (CA) denervation by intracisternal injection of 6-hydroxydopamine (6-OHDA). All cells were taken from 7 day neonates and cultured for 10 days in the presence of nerve growth factor (NGF). Three months after implantation, the extent of implant-associated recovery of reflex activity was determined by measuring electromyogram (EMG) activity and force associated with the long latency component of the hindlimb withdrawal reflex (which is CA modulated). After the electrophysiological testing, rats were anesthetized, and the spinal cords were rapidly removed and frozen. Spinal cords were sectioned longitudinally, and implanted cells were visualized using glyoxylic acid techniques. Labelled sections were examined to determine cell survival. Results indicate that 1) chromaffin cells survive for 3 months in the segments of the cord into which they have been implanted and 2) rats implanted with AM cells have significantly more forceful withdrawal reflexes than those that received Sc cells or received no implant after lesioning. PMID:7703294

  6. A novel therapeutic approach to 6-OHDA-induced Parkinson's disease in rats via supplementation of PTD-conjugated tyrosine hydroxylase

    SciTech Connect

    Wu Shaoping; Fu Ailing; Wang Yuxia; Yu Leiping; Jia Peiyuan; Li Qian; Jin Guozhang; Sun Manji . E-mail: Sunmj@nic.bmi.ac.cn

    2006-07-21

    The present study aimed to evaluate whether the protein transduction domain (PTD)-conjugated human tyrosine hydroxylase (TH) fusion protein was effective on the 6-hydroxydopamine (6-OHDA)-induced Parkinson's disease (PD) model rats. An expression vector pET-PTD-TH harbouring the PTD-TH gene was constructed and transformed to the Escherichia coli BL21 cells for expression. The expressed recombinant PTD-TH with a molecular weight of 61 kD was successfully transduced (1 {mu}M) into the dopaminergic SH-sy5y human neuroblastoma cells in vitro and visualized by immunohistochemical assay. An in vivo experiment in rats showed that the iv administered PTD-TH protein (8 mg/kg) permeated across the blood-brain barrier, penetrated into the striatum and midbrain, and peaked at 5-8 h after the injection. The behavioral effects of PTD-TH on the apomorphine-induced rotations in the PD model rats 8 weeks after the 6-OHDA lesion showed that a single bolus of PTD-TH (8 mg/kg) iv injection caused a decrement of 60% of the contralateral turns on day 1 and 40% on days 5-17. The results imply that iv delivery of PTD-TH is therapeutically effective on the 6-OHDA-induced PD in rats, the PTD-mediated human TH treatment opening a promising therapeutic direction in treatment of PD.

  7. Valproic Acid Neuroprotection in the 6-OHDA Model of Parkinson's Disease Is Possibly Related to Its Anti-Inflammatory and HDAC Inhibitory Properties

    PubMed Central

    Ximenes, José Christian Machado; Neves, Kelly Rose Tavares; Leal, Luzia Kalyne A. M.; do Carmo, Marta Regina Santos; Brito, Gerly Anne de Castro; Naffah-Mazzacoratti, Maria da Graça; Cavalheiro, Ésper Abrão; Viana, Glauce Socorro de Barros

    2015-01-01

    Parkinson's disease is a neurodegenerative disorder where the main hallmark is the dopaminergic neuronal loss. Besides motor symptoms, PD also causes cognitive decline. Although current therapies focus on the restoration of dopamine levels in the striatum, prevention or disease-modifying therapies are urgently needed. Valproic acid (VA) is a wide spectrum antiepileptic drug, exerting many biochemical and physiological effects. It has been shown to inhibit histone deacetylase which seems to be associated with the drug neuroprotective action. The objectives were to study the neuroprotective properties of VA in a model of Parkinson's disease, consisting in the unilateral striatal injection of the neurotoxin 6-OHDA. For that, male Wistar rats (250 g) were divided into the groups: sham-operated (SO), untreated 6-OHDA-lesioned, and 6-OHDA-lesioned treated with VA (25 or 50 mg/kg). Oral treatments started 24 h after the stereotaxic surgery and continued daily for 2 weeks, when the animals were subjected to behavioral evaluations (apomorphine-induced rotations and open-field tests). Then, they were sacrificed and had their mesencephalon, striatum, and hippocampus dissected for neurochemical (DA and DOPAC determinations), histological (Fluoro-Jade staining), and immunohistochemistry evaluations (TH, OX-42, GFAP, TNF-alpha, and HDAC). The results showed that VA partly reversed behavioral and neurochemical alterations observed in the untreated 6-OHDA-lesioned rats. Besides, VA also decreased neuron degeneration in the striatum and reversed the TH depletion observed in the mesencephalon of the untreated 6-OHDA groups. This neurotoxin increased the OX-42 and GFAP immunoreactivities in the mesencephalon, indicating increased microglia and astrocyte reactivities, respectively, which were reversed by VA. In addition, the immunostainings for TNF-alpha and HDAC demonstrated in the untreated 6-OHDA-lesioned rats were also decreased after VA treatments. These results were

  8. Pre-treatment with silymarin reduces brain myeloperoxidase activity and inflammatory cytokines in 6-OHDA hemi-parkinsonian rats.

    PubMed

    Haddadi, Rasool; Mohajjel Nayebi, Alireza; Brooshghalan, Shahla Eyvari

    2013-10-25

    Most chronic neurodegenerative diseases such as Parkinson's disease (PD) are accompanied by neuroinflammation which is associated with glial cells activation and production of different inflammatory cytokines. In the present study we evaluated the anti-cataleptic effect of silymarin pre-treatment in 6-hydroxydopamine (6-OHDA)-lesioned rats, striatum myeloperoxidase (MPO) activity and cerebrospinal fluid (CSF) levels of inflammatory cytokines. Male Wistar rats were pre-treated with intraperitoneal (i.p.) injections of silymarin (100, 200 and 300mg/kg) for 5 consecutive days. Then, catalepsy was induced by unilateral infusion of 6-OHDA (8μg/2μl/rat) into the central region of the SNc. The anti-cataleptic effect of silymarin was assessed by the bar test 3-weeks after neurotoxin injection. Striatal myeloperoxidase activity and CSF levels of TNF-α and IL-6 were assessed at the end of behavioral experiments. Our data demonstrated that silymarin pre-treatment decreased catalepsy. The most anti-cataleptic effect was observed at the dose of 300mg/kg of silymarin (p<0.001). There was a significant (p<0.001) increase in MPO activity of 6-OHDA-lesioned rats whereas; in silymarin (in all 3 doses, i.p. for 5 days) pre-treated hemi-parkinsonian rats' MPO activity was decreased markedly (p<0.001). Furthermore the CSF levels of TNF-α and IL-6 were decreased (p<0.001) in silymarin (100, 200 and 300mg/kg) pre-treated rats up to the range of normal non-parkinsonian animals. From these results, it may be concluded that pre-treatment with silymarin attenuates 6-OHDA-induced catalepsy by decreasing striatal MPO activity and restores CSF concentration of inflammatory cytokines, TNF-α and IL-6 to the levels of normal non-parkinsonian rats. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  9. Capsaicin Protects Against Oxidative Insults and Alleviates Behavioral Deficits in Rats with 6-OHDA-Induced Parkinson's Disease via Activation of TRPV1.

    PubMed

    Zhao, ZhenXiang; Wang, JianFeng; Wang, LingLing; Yao, XiaoMei; Liu, YiLin; Li, Ye; Chen, Si; Yue, Tao; Wang, XiaoTang; Yu, WenFei; Liu, YiMing

    2017-08-31

    Increasing evidence suggests that capsaicin may play a role in modulating neuronal function and controlling motor behavior. However, the underlying mechanism is still unclear and the activation of transient receptor potential vanilloid 1 (TRPV1) might be involved in. This study investigated the potential neuroprotective role of capsaicin in a rat model of 6-hydroxydopamine (6-OHDA)-induced Parkinson's disease (PD). Capsaicin was treated intraperitoneally for the 6-OHDA induced PD rats and the locomotor activity and abnormal involuntary movements were found alleviated. Besides, brain oxidative stress (lipid peroxidation, superoxide dismutase and catalase) was also assessed, and oxidative insults were investigated relieved. Both the expression of tyrosine hydroxylase and TRPV1 were increased in the striatal and substantia nigra areas of 6-OHDA induced rats after the treatment of capsaicin by the semi-quantitative analysis of Western Blot. And the immunostaining of substantia nigra further suggested that capsaicin might protect against dopaminergic neuronal loss. Our results showed that TRPV1 might be a novel therapeutic target for PD.

  10. The Effects of Crocin on 6-OHDA-Induced Oxidative/Nitrosative Damage and Motor Behaviour in Hemiparkinsonian Rats

    PubMed Central

    Hosseini, Maryam; Rajaei, Ziba; Alaei, Hojjatallah; Tajadini, Mohamadhasan

    2016-01-01

    Background Crocin is considered to prevent oxidative stress-related diseases, such as ischemia and Alzheimer’s. The aim of the present investigation was to evaluate the effects of crocin on motor behaviour and 6-OHDA-induced oxidative/nitrosative damage to the striatum in an experimental model of Parkinson’s disease. Methods Left medial forebrain bundle was lesioned by microinjection of 6-OHDA (16μg in 0.2% ascorbate-saline). Crocin (30 and 60 mg/kg) was injected intraperitoneally three days before surgery until six weeks. Rotational behaviour and biochemical analysis were used to evaluate the effect of crocin in a unilateral 6-OHDA-induced model of Parkinson’s disease. Results The contralateral rotations induced by apomorphine in 6-OHDA lesioned group were highly significant (P < 0.001) as compared to the sham group. Moreover, chronic administration of crocin at doses of 30 and 60 mg/kg over six weeks did not change the rotations. The TBARS and nitrite levels in the striatum were also significantly (P < 0.05) increased in lesioned group. Treatment with crocin at a dose of 60 mg/kg significantly decreased the nitrite levels (P < 0.05) in the striatum. Conclusion Crocin at a dose of 60 mg/kg could be effective in preventing the nitrosative damage in the striatum. Further investigations using higher doses of crocin is suggested to get the full neuroprotective effects of crocin in Parkinson’s disease. PMID:28090177

  11. Silymarin improved 6-OHDA-induced motor impairment in hemi-parkisonian rats: behavioral and molecular study.

    PubMed

    Haddadi, Rasool; Nayebi, Alireza Mohajjel; Farajniya, Safar; Brooshghalan, Shahla Eyvari; Sharifi, Hamdolah

    2014-04-11

    Neuroinflammation and oxidative stress has been shown to be associated with the development of Parkinson disease (PD). In the present study, we investigated the effect of intraperitoneal (i.p.) administration of silymarin, on 6-OHDA-induced motor-impairment, brain lipid per-oxidation and cerebrospinal fluid (CSF) levels of inflammatory cytokine in the rats. The results showed that silymarin is able to improve motor coordination significantly (p < 0.001) in a dose dependent manner. There was a significant (p < 0.001) increase in MDA levels of 6-OHDA-lesioned rats whereas; in silymarin (100, 200 and 300 mg/kg, i.p. for 5 days) pre-treated hemi-parkinsonian rats MDA levels was decreased markedly (p < 0.001). Furthermore the CSF levels of IL-1β was decreased (p < 0.001) in silymarin (100, 200 and 300 mg/kg) pre-treated rats up to the range of normal non-parkinsonian animals. We found that pre-treatment with silymarin could improve 6-OHDA-induced motor imbalance by attenuating brain lipid per-oxidation as well as CSF level of IL-1β as a pro-inflammatory cytokine. We suggest a potential prophylactic effect for silymarin in PD. However, further clinical trial studies should be carried out to prove this hypothesis.

  12. Silymarin improved 6-OHDA-induced motor impairment in hemi-parkisonian rats: behavioral and molecular study

    PubMed Central

    2014-01-01

    Background Neuroinflammation and oxidative stress has been shown to be associated with the development of Parkinson disease (PD). In the present study, we investigated the effect of intraperitoneal (i.p.) administration of silymarin, on 6-OHDA-induced motor-impairment, brain lipid per-oxidation and cerebrospinal fluid (CSF) levels of inflammatory cytokine in the rats. Results The results showed that silymarin is able to improve motor coordination significantly (p < 0.001) in a dose dependent manner. There was a significant (p < 0.001) increase in MDA levels of 6-OHDA-lesioned rats whereas; in silymarin (100, 200 and 300 mg/kg, i.p. for 5 days) pre-treated hemi-parkinsonian rats MDA levels was decreased markedly (p < 0.001). Furthermore the CSF levels of IL-1β was decreased (p < 0.001) in silymarin (100, 200 and 300 mg/kg) pre-treated rats up to the range of normal non-parkinsonian animals. Conclusion We found that pre-treatment with silymarin could improve 6-OHDA-induced motor imbalance by attenuating brain lipid per-oxidation as well as CSF level of IL-1β as a pro-inflammatory cytokine. We suggest a potential prophylactic effect for silymarin in PD. However, further clinical trial studies should be carried out to prove this hypothesis. PMID:24726284

  13. Peripheral administration of the selective inhibitor of soluble Tumor Necrosis Factor (TNF) XPro®1595 attenuates nigral cell loss and glial activation in 6-OHDA hemiparkinsonian rats

    PubMed Central

    Barnum, Christopher J.; Chen, Xi; Chung, Jaegwon; Chang, Jianjun; Williams, Martha; Grigoryan, Nelly; Tesi, Raymond J.; Tansey, Malú G.

    2014-01-01

    BACKGROUND Parkinson's disease (PD) is a complex multi-system age-related neurodegenerative disorder. Targeting the ongoing neuroinflammation in PD patients is one strategy postulated to slow down or halt disease progression. Proof-of-concept studies from our group demonstrated that selective inhibition of soluble Tumor Necrosis Factor (solTNF) by intranigral delivery of dominant negative TNF (DN-TNF) inhibitors reduced neuroinflammation and nigral dopamine (DA) neuron loss in endotoxin and neurotoxin rat models of nigral degeneration. OBJECTIVE As a next step toward human clinical trials, we aimed to determine the extent to which peripherally administered DN-TNF inhibitor XPro®1595 could: i) cross the blood-brain-barrier in therapeutically relevant concentrations, ii) attenuate neuroinflammation (microglia and astrocyte), and iii) mitigate loss of nigral DA neurons in rats receiving a unilateral 6-hydroxydopamine (6-OHDA) striatal lesion. METHODS Rats received unilateral 6-OHDA (20 μg into the right striatum). Three or 14 days after lesion, rats were dosed with XPro®1595 (10 mg/kg in saline, subcutaneous) every third day for 35 days. Forelimb asymmetry was used to assess motor deficits after the lesion; brains were harvested 35 days after the lesion for analysis of XPro®1595 levels, glial activation, and nigral DA neuron number. RESULTS Peripheral subcutaneous dosing of XPro®1595 achieved plasma levels of 1–8 μg/mL and CSF levels of 1–6 ng/mL depending on the time the rats were killed after final XPro®1595 injection. Irrespective of start date, XPro®1595 significantly reduced microglia and astrocyte number in SNpc whereas loss of nigral DA neurons was attenuated when drug was started 3, but not 14 days after the 6-OHDA lesion. CONCLUSIONS Our data suggest that systemically administered XPro®1595 may have disease-modifying potential in PD patients where inflammation is part of their pathology. PMID:25061061

  14. Progressive impairment in motor skill learning at 12 and 20 weeks post 6-OHDA- SNc lesion in rats.

    PubMed

    Gambhir, Hardeep; Mathur, Rashmi; Behari, Madhuri

    2011-07-01

    Deficiency in skilled motor activity is primarily attributed to the loss of dopaminergic neurons in the pars compacta of substantia nigra (SNc), which can be detected by performance of the rotarod test. Previous reports have demonstrated impaired skilled motor behavior in rats during the pre-motor stage of Parkinson's disease (PD) (3-8 weeks post 6-OHDA lesion of striatum). We studied skilled motor learning in 6-hydroxydopamine (6-OHDA) SNc lesion rats at 12 and 20 weeks by rotarod task after providing sufficient training to give allowance for ageing (3 sessions/day for 14 consecutive days). On each day, the stay duration on rotarod was noted and compared between the groups (Group 1 = Control, Group 2 = Post lesion (PL) week 12, Group 3 = PL week 20). In Group 2 rats, the duration of stay on rotarod gradually increased from day 1 through 7 {day 7 = 193.1 (81.8-247.4) vs. control group day 7 = 202.1 (87.7-279.8), p = 0.771} and declined thereafter. While, the stay duration in Group 3 rats remained lower {day 7 = 32.5 (20.4-52.1), p = 0.011} than that of the control rats throughout the study period. The results of our study suggest a slower brief learning of skilled motor tasks at post lesion week 12 whereas no learning at all at post-lesion week 20.

  15. Neuroprotective Properties of the Standardized Extract from Camellia sinensis (Green Tea) and Its Main Bioactive Components, Epicatechin and Epigallocatechin Gallate, in the 6-OHDA Model of Parkinson's Disease.

    PubMed

    Bitu Pinto, Natália; da Silva Alexandre, Bruno; Neves, Kelly Rose Tavares; Silva, Aline Holanda; Leal, Luzia Kalyne A M; Viana, Glauce S B

    2015-01-01

    Camellia sinensis (green tea) is largely consumed, mainly in Asia. It possesses several biological effects such as antioxidant and anti-inflammatory properties. The objectives were to investigate the neuroprotective actions of the standardized extract (CS), epicatechin (EC) and epigallocatechin gallate (EGCG), on a model of Parkinson's disease. Male Wistar rats were divided into SO (sham-operated controls), untreated 6-OHDA-lesioned and 6-OHDA-lesioned treated for 2 weeks with CS (25, 50, or 100 mg/kg), EC (10 mg/kg), or EGCG (10 mg/kg) groups. One hour after the last administration, animals were submitted to behavioral tests and euthanized and their striata and hippocampi were dissected for neurochemical (DA, DOPAC, and HVA) and antioxidant activity determinations, as well as immunohistochemistry evaluations (TH, COX-2, and iNOS). The results showed that CS and catechins reverted behavioral changes, indicating neuroprotection manifested as decreased rotational behavior, increased locomotor activity, antidepressive effects, and improvement of cognitive dysfunction, as compared to the untreated 6-OHDA-lesioned group. Besides, CS, EP, and EGCG reversed the striatal oxidative stress and immunohistochemistry alterations. These results show that the neuroprotective effects of CS and its catechins are probably and in great part due to its powerful antioxidant and anti-inflammatory properties, pointing out their potential for the prevention and treatment of PD.

  16. Neuroprotective Properties of the Standardized Extract from Camellia sinensis (Green Tea) and Its Main Bioactive Components, Epicatechin and Epigallocatechin Gallate, in the 6-OHDA Model of Parkinson's Disease

    PubMed Central

    Bitu Pinto, Natália; da Silva Alexandre, Bruno; Neves, Kelly Rose Tavares; Silva, Aline Holanda; Leal, Luzia Kalyne A. M.; Viana, Glauce S. B.

    2015-01-01

    Camellia sinensis (green tea) is largely consumed, mainly in Asia. It possesses several biological effects such as antioxidant and anti-inflammatory properties. The objectives were to investigate the neuroprotective actions of the standardized extract (CS), epicatechin (EC) and epigallocatechin gallate (EGCG), on a model of Parkinson's disease. Male Wistar rats were divided into SO (sham-operated controls), untreated 6-OHDA-lesioned and 6-OHDA-lesioned treated for 2 weeks with CS (25, 50, or 100 mg/kg), EC (10 mg/kg), or EGCG (10 mg/kg) groups. One hour after the last administration, animals were submitted to behavioral tests and euthanized and their striata and hippocampi were dissected for neurochemical (DA, DOPAC, and HVA) and antioxidant activity determinations, as well as immunohistochemistry evaluations (TH, COX-2, and iNOS). The results showed that CS and catechins reverted behavioral changes, indicating neuroprotection manifested as decreased rotational behavior, increased locomotor activity, antidepressive effects, and improvement of cognitive dysfunction, as compared to the untreated 6-OHDA-lesioned group. Besides, CS, EP, and EGCG reversed the striatal oxidative stress and immunohistochemistry alterations. These results show that the neuroprotective effects of CS and its catechins are probably and in great part due to its powerful antioxidant and anti-inflammatory properties, pointing out their potential for the prevention and treatment of PD. PMID:26167188

  17. Intrastriatal 6-OHDA lesion differentially affects dopaminergic neurons in the ventral tegmental area of prenatally stressed rats.

    PubMed

    Baier, Carlos J; Pallarés, María Eugenia; Adrover, Ezequiela; Katunar, María R; Raisman-Vozari, Rita; Antonelli, Marta C

    2014-10-01

    Exposure to a variety of stressful events during the last week of pregnancy in rats interferes with the correct progeny development, which in turn leads to delays in motor development, impaired adaptation to stressful conditions, altered sexual behaviour, learning deficits, neuronal development and brain morphology. Many of these alterations have been attributed to changes in dopamine (DA) neurotransmission and occur primarily in the mesolimbic system. We found that prenatally stressed offspring showed higher levels of cells expressing tyrosine hydroxylase (TH) in the ventral tegmental area (VTA) and that these cells were more susceptible to a neurochemical insult with 6-hydroxy-DA (6-OHDA) in adulthood. Moreover, prenatally stressed rats presented differences in terms of the number and asymmetry of neuronal nitric oxide synthase-expressing cells in the VTA and nucleus accumbens, respectively. Similar to the results described for TH-expressing cells, the nitrergic systems were differentially regulated after 6-OHDA lesion in control and prenatally stressed rats. These results indicated that prenatal stress affects the dopaminergic and nitrergic systems in the mesolimbic pathway. In addition, we propose that the mesolimbic areas are more susceptible than the motor areas to a neurochemical insult during adult life.

  18. Striatal mRNA expression patterns underlying peak dose L-DOPA-induced dyskinesia in the 6-OHDA hemiparkinsonian rat.

    PubMed

    Smith, L M; Parr-Brownlie, L C; Duncan, E J; Black, M A; Gemmell, N J; Dearden, P K; Reynolds, J N J

    2016-06-02

    L-DOPA is the primary pharmacological treatment for relief of the motor symptoms of Parkinson's disease (PD). With prolonged treatment (⩾5 years) the majority of patients will develop abnormal involuntary movements as a result of L-DOPA treatment, known as L-DOPA-induced dyskinesia. Understanding the underlying mechanisms of dyskinesia is a crucial step toward developing treatments for this debilitating side effect. We used the 6-hydroxydopamine (6-OHDA) rat model of PD treated with a three-week dosing regimen of L-DOPA plus the dopa decarboxylase inhibitor benserazide (4 mg/kg and 7.5 mg/kgs.c., respectively) to induce dyskinesia in 50% of individuals. We then used RNA-seq to investigate the differences in mRNA expression in the striatum of dyskinetic animals, non-dyskinetic animals, and untreated parkinsonian controls at the peak of dyskinesia expression, 60 min after L-DOPA administration. Overall, 255 genes were differentially expressed; with significant differences in mRNA expression observed between all three groups. In dyskinetic animals 129 genes were more highly expressed and 14 less highly expressed when compared with non-dyskinetic and untreated parkinsonian controls. In L-DOPA treated animals 42 genes were more highly expressed and 95 less highly expressed when compared with untreated parkinsonian controls. Gene set cluster analysis revealed an increase in expression of genes associated with the cytoskeleton and phosphoproteins in dyskinetic animals compared with non-dyskinetic animals, which is consistent with recent studies documenting an increase in synapses in dyskinetic animals. These genes may be potential targets for drugs to ameliorate L-DOPA-induced dyskinesia or as an adjunct treatment to prevent their occurrence.

  19. Differential induction of dyskinesia and neuroinflammation by pulsatile versus continuous l-DOPA delivery in the 6-OHDA model of Parkinson's disease.

    PubMed

    Mulas, Giovanna; Espa, Elena; Fenu, Sandro; Spiga, Saturnino; Cossu, Giovanni; Pillai, Elisabetta; Carboni, Ezio; Simbula, Gabriella; Jadžić, Dragana; Angius, Fabrizio; Spolitu, Stefano; Batetta, Barbara; Lecca, Daniela; Giuffrida, Andrea; Carta, Anna R

    2016-12-01

    Neuroinflammation is associated with l-DOPA treatment in Parkinson's disease (PD), suggesting a role in l-DOPA-induced dyskinesia (LID), however it is unclear whether increased inflammation is specifically related to the dyskinetic outcome of l-DOPA treatment. Diversely from oral l-DOPA, continuous intrajejunal l-DOPA infusion is associated with very low dyskinetic outcome in PD patients. We reproduced these regimens of administration in 6-OHDA-lesioned hemiparkinsonian rats, where dyskinetic responses and striatal neuroinflammation induced by chronic pulsatile (DOPAp) or continuous (DOPAc) l-DOPA were compared. Moreover, we investigated the contribution of a peripheral inflammatory challenge with lipopolysaccharide (LPS), to DOPAp-induced dyskinetic and neuroinflammatory responses. Rats 6-OHDA-infused in the medial forebrain bundle received two weeks treatment with DOPAp, DOPAc via subcutaneous osmotic minipumps, or DOPAp followed by DOPAc. l-DOPA plasma levels were measured in all experimental groups. An independent group of rats received one peripheral dose of LPS 24h before DOPAp treatment. Abnormal involuntary movements (AIMs) were evaluated as a rat model of LID. Immunoreactivity (IR) for OX-42, microglial and neuronal TNF-α, iNOS and GFAP was quantified in denervated and contralateral striatum. In addition, serum TNF-α was measured. The 6-OHDA denervation induced a mild microgliosis in the striatum two weeks after neurotoxin infusion, and increased TNF-α IR in microglia. Rats receiving the DOPAp treatment developed AIMs and displayed increased striatal OX-42, microglial TNF-α, iNOS and GFAP. Moreover, TNF-α IR was also increased in a subpopulation of striatal neurons. Conversely, DOPAc did not induce AIMs or inflammatory responses in either drug-naïve animals or rats that were previously dyskinetic when exposed to DOPAp. Serum TNF-α was not altered by any l-DOPA treatment. LPS pre-treatment increased the degree of DOPAp-induced AIMs and striatal IR

  20. Neuroprotective effects of aqueous extracts of Uncaria tomentosa: Insights from 6-OHDA induced cell damage and transgenic Caenorhabditis elegans model.

    PubMed

    Shi, Zhenhua; Lu, Zhongbing; Zhao, Yashuo; Wang, Yueqi; Zhao-Wilson, Xi; Guan, Peng; Duan, Xianglin; Chang, Yan-Zhong; Zhao, Baolu

    2013-06-01

    Previous pharmacological studies have indicated that AC11 (a standardized aqueous extract of Uncaria tomentosa) has beneficial effects on DNA repair and immune function. However, its benefits go beyond this. The present study utilized electron spin resonance (ESR) and spin trapping technique, as well as the 6-OHDA-induced cell damage and transgenic Caenorhabditis elegans models, towards exploring the antioxidant and neuroprotective ability of AC11. Our results showed that AC11 could scavenge several types of free radicals, especially hydroxyl radicals (60% of hydroxyl radicals were scavenged by 30 μg/ml of AC11). In SH-SY5Y cells, we found that AC11 could dose dependently protect 6-OHDA induced cell damage by increase cell viability and mitochondrial membrane potential. AC11 pretreatment also significantly decreased the level of lipid peroxidation, intracellular reactive oxygen species and nitric oxide in 6-OHDA treated cells. In NL5901 C. elegans, 10 μg/ml AC11 could reduce the aggregation of α-synuclein by 40%. These findings encourage further investigation on AC11 and its active constituent compounds, as possible therapeutic intervention against Parkinson's disease. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Nitrosative and cognitive effects of chronic L-DOPA administration in rats with intra-nigral 6-OHDA lesion.

    PubMed

    Ramírez-García, G; Palafox-Sánchez, V; Limón, I D

    2015-04-02

    Besides motor disturbances, other symptoms found in the early stage of Parkinson's disease (PD) are deficits in both learning and memory. The nigro-striatal-cortical pathway is affected in this pathology, with this neuronal circuit involved in cognitive processes such as spatial working memory (SWM). However, cognitive dysfunction appears even when the patients are receiving L-DOPA treatment. There is evidence that the dopamine metabolism formed by L-DOPA generates free radicals such as nitric oxide, which may cause damage through the nitrosative stress (NS). The aim of this study was to evaluate both the effects of chronic L-DOPA administration on SWM and the production of NS in rats using an intra-nigral lesion caused by 6-hydroxydopamine (6-OHDA). Post-lesion, the animals were administered orally with L-DOPA/Carbidopa (100-mg/kg) for 20 days. An SWM task in a Morris water maze was conducted post-treatment. Nitrite levels and immunoreactivity of 3-Nitrotyrosine (3-NT), Inducible Nitric Oxide Synthase (iNOS), Glial Fibrillary Acidic Protein (GFAP), and Tyrosine Hydroxylase (TH) were evaluated in the substantia nigra pars compacta, the dorsal striatum and the medial prefrontal cortex. Our results show that chronic L-DOPA administration in rats with intra-nigral 6-OHDA-lesion caused significant increases in SWM deficit, nitrite levels and the immunoreactivity of 3-NT, iNOS and GFAP in the nigro-striatal-cortical pathway. These facts suggest that as L-DOPA can induce NS in rats with dopaminergic intra-nigral lesion, it could play a key role in the impairment of the SWM, and thus can be considered as a toxic mechanism that induces cognitive deficit in PD patients. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  2. Effect of adenosine A(2A) receptor antagonists and L-DOPA on hydroxyl radical, glutamate and dopamine in the striatum of 6-OHDA-treated rats.

    PubMed

    Gołembiowska, Krystyna; Dziubina, Anna

    2012-02-01

    A(2A) adenosine receptor antagonists have been proposed as a new therapy of PD. Since oxidative stress plays an important role in the pathogenesis of PD, we studied the effect of the selective A(2A) adenosine receptor antagonists 8-(-3-chlorostyryl)caffeine (CSC) and 4-(2-[7-amino-2-(2-furyl)[1,2,4]triazolo[2,3-a][1,3,5]triazin-5-ylamino]ethyl)phenol (ZM 241385) on hydroxyl radical generation, and glutamate (GLU) and dopamine (DA) extracellular level using a microdialysis in the striatum of 6-OHDA-treated rats. CSC (1 mg/kg) and ZM 241385 (3 mg/kg) given repeatedly for 14 days decreased the production of hydroxyl radical and extracellular GLU level, both enhanced by prior 6-OHDA treatment in dialysates from the rat striatum. CSC and ZM 241385 did not affect DA and its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanilic acid (HVA) extracellular levels in the striatum of 6-OHDA-treated rats. L-DOPA (6 mg/kg) given twice daily for two weeks in the presence of benserazide (3 mg/kg) decreased striatal hydroxyl radical and glutamate extracellular level in 6-OHDA-treated rats. At the same time, L-DOPA slightly but significantly increased the extracellular levels of DOPAC and HVA. A combined repeated administration of L-DOPA and CSC or ZM 241385 did not change the effect of L-DOPA on hydroxyl radical production and glutamate extracellular level in spite of an enhancement of extracellular DA level by CSC and elevation of extracellular level of DOPAC and HVA by ZM 241385. The data suggest that the 6-OHDA-induced damage of nigrostriatal DA-terminals is related to oxidative stress and excessive release of glutamate. Administration of L-DOPA in combination with CSC or ZM 241385, by restoring striatal DA-glutamate balance, suppressed 6-OHDA-induced overproduction of hydroxyl radical.

  3. [Effects of hypothalamic microinjections of 6-hydroxydopamine (6-OHDA) on estral cycle and morphology of the genital tract in the female rat (author's transl)].

    PubMed

    Sala, M A; Oteui, J T; Benedetti, W I

    1975-01-01

    To determine whether central catecholaminergic pathways are involved in the neural contral of gonadotrophin secretion, they were interrupted at the hypothalamic level by microinjections of 6-hydroxydopamine (6-OHDA). The effects on ovulation, estral cycle and ovarian and uterine histology were studied. Microinjections of 50 mug of 6-OHDA hydrobromyde were made bilaterally into the anterolateral hypothalamus in a group of rats. Another group was injected with 25 mug of 6-OHDA, while a control group recieved an equivalent volume (5 mul) of saline with ascorbic acid. Animals injected with 50 mug of 6-OHDA showed blockade of ovulation, vaginal cytology characteristics of persistent estrous, polyfollicular ovaries and enlarged uteri with hypertrophic endometrial glands. In the group injected with 25 mug, similiar effects were demonstrated, but the number of affected animals was smaller than that in the 50 mug group. Control animals dit not show modifications, either in estral cycle or in ovarian and uterine histology. These results suggest that 6-OHDA injected into the anterolateral hypothalmus interferes with catecholaminergic pathways that participate in the neural control of ovulation.

  4. The "motor complication syndrome" in rats with 6-OHDA lesions treated chronically with L-DOPA: relation to dose and route of administration.

    PubMed

    Lindgren, Hanna S; Rylander, Daniella; Ohlin, K Elisabet; Lundblad, Martin; Cenci, M Angela

    2007-02-12

    L-DOPA-induced motor complications can be modelled in rats with 6-hydroxydopamine (6-OHDA) lesions by chronic injections of L-DOPA. We have compared the sensitisation and duration of rotational responses, and the occurrence of dose-failure episodes and abnormal involuntary movements (AIMs) in 6-OHDA-lesioned rats with regard to the dose and route of administration of L-DOPA. Rats were treated with either low (6mg/kg) or high (25mg/kg) doses of L-DOPA twice daily for 21 days whereas control animals received injections of either saline or bromocriptine (2.5mg/kg). A dose-dependent and gradual development of AIMs and contralateral turning was observed in rats treated chronically with l-DOPA. Rats treated with bromocriptine exhibited rotational sensitisation but no AIMs. A shortening of motor response duration was not seen in any of the drug-treated groups. In contrast, dose-failure episodes occurred frequently in both L-DOPA- and bromocriptine-treated animals. Changing the route of L-DOPA administration from intraperitoneal to subcutaneous completely abolished failures in motor response without affecting the development of dyskinesia. Based on the hypothesis that higher doses of L-DOPA may be toxic to dopaminoceptive structures, we compared the total number of neurons and the levels of activated microglia in the striatum. No signs of neurodegenerative changes could be seen in any of the treatment groups. In conclusion, both body AIMs and rotations were dose-dependently evoked by L-DOPA. Only AIMs, however, provided a specific measure of dyskinesia since rotations also were induced by bromocriptine, a drug with low dyskinesiogenic potential. Dose-failure episodes were not specific to L-DOPA treatment and could be attributed to erratic drug absorption from the peritoneal route.

  5. Anti-Inflammatory Modulation of Microglia via CD163-Targeted Glucocorticoids Protects Dopaminergic Neurons in the 6-OHDA Parkinson's Disease Model.

    PubMed

    Tentillier, Noemie; Etzerodt, Anders; Olesen, Mads N; Rizalar, F Sila; Jacobsen, Jan; Bender, Dirk; Moestrup, Søren K; Romero-Ramos, Marina

    2016-09-07

    Increasing evidence supports a decisive role for inflammation in the neurodegenerative process of Parkinson's disease (PD). The immune response in PD seems to involve, not only microglia, but also other immune cells infiltrated into the brain. Indeed, we observed here the infiltration of macrophages, specifically CD163+ macrophages, into the area of neurodegeneration in the 6-hydroxydopamine (6-OHDA) PD model. Therefore, we investigated the therapeutic potential of the infiltrated CD163+ macrophages to modulate local microglia in the brain to achieve neuroprotection. To do so, we designed liposomes targeted for the CD163 receptor to deliver dexamethasone (Dexa) into the CD163+ macrophages in the 6-OHDA PD model. Our data show that a fraction of the CD163-targeted liposomes were carried into the brain after peripheral intravenous injection. The 6-OHDA-lesioned rats that received repeated intravenous CD163-targeted liposomes with Dexa for 3 weeks exhibited better motor performance than the control groups and had minimal glucocorticoid-driven side effects. Furthermore, these animals showed better survival of dopaminergic neurons in substantia nigra and an increased number of microglia expressing major histocompatibility complex II. Therefore, rats receiving CD163-targeted liposomes with Dexa were partially protected against 6-OHDA-induced dopaminergic neurodegeneration, which correlated with a distinctive microglia response. Altogether, our data support the use of macrophages for the modulation of brain neurodegeneration and specifically highlight the potential of CD163-targeted liposomes as a therapeutic tool in PD. The immune response now evident in the progression of Parkinson's disease comprises both local microglia and other immune cells. We provide evidence that CD163+ macrophages can be a target to modulate brain immune response to achieve neuroprotection in the 6-hydroxydopamine model. To do so, we targeted the CD163+ population, which to a low but significant

  6. High correlation between in vivo [123I]β-CIT SPECT/CT imaging and post-mortem immunohistochemical findings in the evaluation of lesions induced by 6-OHDA in rats

    PubMed Central

    2013-01-01

    Background 6-Hydroxydopamine (6-OHDA) is widely used in pre-clinical animal studies to induce degeneration of midbrain dopamine neurons to create animal models of Parkinson's disease. The aim of our study was to evaluate the potential of combined single-photon emission computed tomography/computed tomography (SPECT/CT) for the detection of differences in 6-OHDA-induced partial lesions in a dose- and time-dependent manner using the dopamine transporter (DAT) ligand 2β-carbomethoxy-3β-(4-[123I]iodophenyl)tropane ([123I]β-CIT). Methods Rats were unilaterally lesioned with intrastriatal injections of 8 or 2 × 10 μg 6-OHDA. At 2 or 4 weeks post-lesion, 40 to 50 MBq [123I]β-CIT was administered intravenously and rats were imaged with small-animal SPECT/CT under isoflurane anesthesia. The striatum was delineated and mean striatal activity in the lesioned side was compared to the intact side. After the [123I]β-CIT SPECT/CT scan, the rats were tested for amphetamine-induced rotation asymmetry, and their brains were immunohistochemically stained for DAT and tyrosine hydroxylase (TH). The fiber density of DAT- and TH-stained striata was estimated, and TH-immunoreactive cells in the rat substantia nigra pars compacta (SNpc) were stereologically counted. Results The striatal uptake of [123I]β-CIT differed significantly between the lesion groups and the results were highly correlated to both striatal DAT- and TH-immunoreactive fiber densities and to TH-immunoreactive cell numbers in the rat SNpc. No clear progression of the lesion could be seen. Conclusions [123I]β-CIT SPECT/CT is a valuable tool in predicting the condition of the rat midbrain dopaminergic pathway in the unilateral partial 6-OHDA lesion model of Parkinson's disease and it offers many advantages, allowing repeated non-invasive analysis of living animals. PMID:23758882

  7. Squamosamide derivative FLZ protected dopaminergic neuron by activating Akt signaling pathway in 6-OHDA-induced in vivo and in vitro Parkinson's disease models.

    PubMed

    Bao, Xiu-Qi; Kong, Xiang-Chen; Kong, Li-Bing; Wu, Liang-Yu; Sun, Hua; Zhang, Dan

    2014-02-14

    Parkinson's disease (PD) is a neurodegenerative disease affecting up to 80% of dopaminergic neurons in the nigrostriatal pathway. FLZ, a novel synthetic squamosamide derivative from a Chinese herb, has been shown to have neuroprotective effects in experimental PD models. In this study, we carried out a set of in vitro and in vivo experiments to address the neuroprotective effect of FLZ and related mechanism. The results showed that FLZ significantly improved motor dysfunction and dopaminergic neuronal loss of rats injured by 6-hydroxydopamine (6-OHDA). The beneficial effects of FLZ attributed to the elevation of dopaminergic neuron number, dopamine level and tyrosine hydroxylase (TH) activity. Mechanistic study showed that FLZ protected TH activity and dopaminergic neurons through decreasing α-synuclein (α-Syn) expression and the interaction between α-Syn and TH. Further studies indicated the involvement of phosphoinositide 3-kinases (PI3K)/Akt signaling pathway in the protective effect of FLZ since it showed that blocking PI3K/Akt signaling pathway prevented the expression of α-Syn and attenuated the neuroprotection of FLZ. In addition, FLZ treatment reduced the expression of RTP801, an important protein involved in the pathogenesis of PD. Taken together, these results revealed that FLZ suppressed α-Syn expression and elevated TH activity in dopaminergic neuron through activating Akt survival pathway in 6-OHDA-induced PD models. The data also provided evidence that FLZ had potent neuroprotecive effects and might become a new promising agent for PD treatment.

  8. The CB1 cannabinoid receptor agonist reduces L-DOPA-induced motor fluctuation and ERK1/2 phosphorylation in 6-OHDA-lesioned rats.

    PubMed

    Song, Lu; Yang, Xinxin; Ma, Yaping; Wu, Na; Liu, Zhenguo

    2014-01-01

    The dopamine precursor L-3,4-dihydroxyphenylalanine (L-DOPA) has been used as an effective drug for treating dopamine depletion-induced Parkinson's disease (PD). However, long-term administration of L-DOPA produces motor complications. L-DOPA has also been found to modify the two key signaling cascades, protein kinase A/dopamine- and cAMP-regulated phosphoprotein of 32 kDa (DARPP-32) and extracellular signal-regulated kinases 1 and 2 (ERK1/2), in striatal neurons, which are thought to play a pivotal role in forming motor complications. In the present study, we tested the possible effect of a CB1 cannabinoid receptor agonist on L-DOPA-stimulated abnormal behavioral and signaling responses in vivo. Intermittent L-DOPA administration for 3 weeks induced motor fluctuation in a rat model of PD induced by intrastriatal infusion of dopamine-depleting neurotoxin 6-hydroxydopamine (6-OHDA). A single injection of a CB1 cannabinoid receptor agonist WIN-55,212-2 had no effect on L-DOPA-induced motor fluctuation. However, chronic injections of WIN-55,212-2 significantly attenuated abnormal behavioral responses to L-DOPA in 6-OHDA-lesioned rats. Similarly, chronic injections of WIN-55,212-2 influence the L-DOPA-induced alteration of DARPP-32 and ERK1/2 phosphorylation status in striatal neurons. These data provide evidence for the active involvement of CB1 cannabinoid receptors in the regulation of L-DOPA action during PD therapy.

  9. Dopaminergic neurotoxicant 6-OHDA induces oxidative damage through proteolytic activation of PKC{delta} in cell culture and animal models of Parkinson's disease

    SciTech Connect

    Latchoumycandane, Calivarathan; Anantharam, Vellareddy; Jin, Huajun; Kanthasamy, Anumantha; Kanthasamy, Arthi

    2011-11-15

    The neurotoxicant 6-hydroxydopamine (6-OHDA) is used to investigate the cellular and molecular mechanisms underlying selective degeneration of dopaminergic neurons in Parkinson's disease (PD). Oxidative stress and caspase activation contribute to the 6-OHDA-induced apoptotic cell death of dopaminergic neurons. In the present study, we sought to systematically characterize the key downstream signaling molecule involved in 6-OHDA-induced dopaminergic degeneration in cell culture and animal models of PD. Treatment of mesencephalic dopaminergic neuronal N27 cells with 6-OHDA (100 {mu}M) for 24 h significantly reduced mitochondrial activity and increased cytosolic cytochrome c, followed by sequential activation of caspase-9 and caspase-3. Co-treatment with the free radical scavenger MnTBAP (10 {mu}M) significantly attenuated 6-OHDA-induced caspase activities. Interestingly, 6-OHDA induced proteolytic cleavage and activation of protein kinase C delta (PKC{delta}) was completely suppressed by treatment with a caspase-3-specific inhibitor, Z-DEVD-FMK (50 {mu}M). Furthermore, expression of caspase-3 cleavage site-resistant mutant PKC{delta}{sup D327A} and kinase dead PKC{delta}{sup K376R} or siRNA-mediated knockdown of PKC{delta} protected against 6-OHDA-induced neuronal cell death, suggesting that caspase-3-dependent PKC{delta} promotes oxidative stress-induced dopaminergic degeneration. Suppression of PKC{delta} expression by siRNA also effectively protected N27 cells from 6-OHDA-induced apoptotic cell death. PKC{delta} cleavage was also observed in the substantia nigra of 6-OHDA-injected C57 black mice but not in control animals. Viral-mediated delivery of PKC{delta}{sup D327A} protein protected against 6-OHDA-induced PKC{delta} activation in mouse substantia nigra. Collectively, these results strongly suggest that proteolytic activation of PKC{delta} is a key downstream event in dopaminergic degeneration, and these results may have important translational value for

  10. Protective effects of quercetin glycosides, rutin, and isoquercetrin against 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in rat pheochromocytoma (PC-12) cells.

    PubMed

    Magalingam, Kasthuri Bai; Radhakrishnan, Ammu; Haleagrahara, Nagaraja

    2016-03-01

    There is increasing evidence that free radicals induced oxidative stress is a major causative agent in the pathogenesis of neurodegenerative diseases, particularly Parkinson's disease. Quercetin glycosides, namely rutin and isoquercitrin, are flavonoid polyphenol compounds found ubiquitously in fruits and vegetables and have been known to possess antioxidant effects. This study was designed to compare the neuroprotective effects of quercetin glycosides rutin and isoquercitrin in 6-OHDA-induced rat pheochromocytoma (PC-12) cells. The results showed that both rutin and isoquercitrin significantly increased antioxidant enzymes, catalase, superoxide dismutase, glutathione peroxidase, and glutathione level that were attenuated by 6-OHDA in PC-12 cells. There was no significant difference in the activation of glutathione and glutathione peroxidase enzymes between rutin and isoquercitrin. These two glycosides were equally effective in suppressing lipid peroxidation in 6-OHDA-induced PC-12 cells as both compounds suppressed the malondialdehyde generation and prevented cell damage. In conclusion, quercetin glycosides rutin and isoquercetrin are having a significant neuroprotective effect against 6-OHDA toxicity in PC-12 cells.

  11. [Criteria of efficiency of transplantation of embryonic nervous tissue preparations in rats with 6-OHDA-impaired dopaminergic nigrostriatal system].

    PubMed

    Chekhonin, V P; Lebedev, S V; Dmitrieva, T B; Baklaushev, V P; Savchenko, E A; Lazarenko, I P; Gurina, O I; Belopasov, V V

    2002-01-01

    Effectiveness of transplantation of cells from embryonal nervous tissue of the ventral mesencephalon (VM ENT) and striatum (STR ENT) by apomorphin-induced motor asymmetry (APO-test), consolidation of the transplant (the degree of glyal reaction and amount of dopaminergic neurons) and blood serum levels of GFAP was studied for 3 months in Wistar rats with 6-OHDA-impaired dopaminergic nigrostriatal system. Marked therapeutic effectiveness was registered in VM ENT transplantation in the denervated striatum and in combined transplantation of VM ENT into the lateral cerebral ventricle simultaneously with STR ENT transplantation in the striatum. Separate transplantation of VM ENT in the lateral ventricle and STR ENT in the striatum had no positive effect on recovery of the dopaminergic nigrostriatal system. A correlation was found between the degree of glial reaction of ENT transplants, severity of rotation asymmetry and serum levels of gliofibrillary protein (GFAP). GFAP in the serum for lifetime assessment of transplant consolidation and prognosis of neurotransplantation efficiency was assayed.

  12. (6aR)-11-amino-N-propyl-noraporphine, a new dopamine D2 and serotonin 5-HT1A dual agonist, elicits potent antiparkinsonian action and attenuates levodopa-induced dyskinesia in a 6-OHDA-lesioned rat model of Parkinson's disease.

    PubMed

    Zhao, Rui; Lu, Weijian; Fang, Xing; Guo, Lin; Yang, Zhi; Ye, Na; Zhao, Jiahao; Liu, Zhili; Jia, Jia; Zheng, Longtai; Zhao, Bin; Zhang, Ao; Zhen, Xuechu

    2014-09-01

    Parkinson's disease (PD) drug therapy remains a challenge. Dual modulation of dopamine and 5-HT receptors has emerged as a promising approach in anti-PD drug development. Taking advantage of the newly discovered aporphine analogue(s), (6aR)-11-amino-N-propyl-noraporphine (SOMCL-171), which exhibited dual D2/5-HT1A receptor agonistic activity, we studied the effects of the compound on levodopa-induced dyskinesia (LID) in a PD animal model. The results demonstrated that SOMCL-171 elicited a potent anti-PD effect in a 6-OHDA-lesioned rat model. Chronic use of SOMCL-171 reduced LID without compromising the antiparkinsonian efficacy. Furthermore, we found that the antidyskinesia effect of SOMCL-171 is associated with its 5-HT1A agonistic activity and the up-regulation of the striatal 5-HT1A receptor. The present data indicated that chronic SOMCL-171 alone produced potent antiparkinsonian effects with weak dyskinesia, compared with that of levodopa. In addition, chronic SOMCL-171 application attenuated the development of levodopa-induced LID at no expense to the antiparkinsonian efficacy. Taken together, our data suggested that dual modulation of D2/5-HT1A receptors may provide a novel approach for drug development in PD and LID.

  13. Use of [18F]FDOPA-PET for in vivo evaluation of dopaminergic dysfunction in unilaterally 6-OHDA-lesioned rats

    PubMed Central

    2011-01-01

    Background We evaluated the utility of L-3,4-dihydroxy-6-[18F]fluoro-phenylalanine ([18F]FDOPA) positron emission tomography (PET) as a method for assessing the severity of dopaminergic dysfunction in unilaterally 6-hydroxydopamine (6-OHDA)-lesioned rats by comparing it with quantitative biochemical, immunohistochemical, and behavioral measurements. Methods Different doses of 6-OHDA (0, 7, 14, and 28 μg) were unilaterally injected into the right striatum of male Sprague-Dawley rats. Dopaminergic functional activity in the striatum was assessed by [18F]FDOPA-PET, measurement of striatal dopamine (DA) and DA metabolite levels, tyrosine hydroxylase (TH) immunostaining, and methamphetamine-induced rotational testing. Results Accumulation of [18F]FDOPA in the bilateral striatum was observed in rats pretreated with both aromatic L-amino acid decarboxylase and catechol-O-methyltransferase (COMT) inhibitors. Unilateral intrastriatal injection of 6-OHDA produced a significant site-specific reduction in [18F]FDOPA accumulation. The topological distribution pattern of [18F]FDOPA accumulation in the ipsilateral striatum agreed well with the pattern in TH-stained corresponding sections. A significant positive relationship was found between Patlak plot Ki values and striatal levels of DA and its metabolites (r = 0.958). A significant negative correlation was found between both Ki values (r = -0.639) and levels of DA and its metabolites (r = -0.719) and the number of methamphetamine-induced rotations. Conclusions Ki values determined using [18F]FDOPA-PET correlated significantly with the severity of dopaminergic dysfunction. [18F]FDOPA-PET makes it possible to perform longitudinal evaluation of dopaminergic function in 6-OHDA-lesioned rats, which is useful in the development of new drugs and therapies for Parkinson's disease (PD). PMID:22214344

  14. Intrastriatal DNQX induces rotation and pallidal Fos in the 6-OHDA model of Parkinson's disease.

    PubMed

    Schuller, J J; Marshall, J F

    1995-12-15

    The 6-hydroxydopamine rat model of Parkinson's disease was combined with intracerebral drug infusions to examine the influence of glutamate receptors on striatal output activity. When infused into the dopamine-denervated striatum, the AMPA-kainate receptor antagonist DNQX dose-dependently elicited contralateral rotation and ipsilateral Fos immunoreactivity (Fos-IR) in the globus pallidus, a target nucleus of striatal output. DNQX did not elicit rotation or Fos-IR in unlesioned or partially lesioned rats. In addition, the NMDA receptor antagonist AP-5 failed to induce rotation and had minimal effects on pallidal Fos-IR in lesioned rats. These results suggest a role for striatal AMPA-kainate receptors in the pathology and treatment of Parkinson's disease.

  15. Dopaminergic neurons derived from human induced pluripotent stem cells survive and integrate into 6-OHDA-lesioned rats.

    PubMed

    Cai, Jingli; Yang, Ming; Poremsky, Elizabeth; Kidd, Sarah; Schneider, Jay S; Iacovitti, Lorraine

    2010-07-01

    Cell replacement therapy could be an important treatment strategy for Parkinson's disease (PD), which is caused by the degeneration of dopamine neurons in the midbrain (mDA). The success of this approach greatly relies on the discovery of an abundant source of cells capable of mDAergic function in the brain. With the paucity of available human fetal tissue, efforts have increasingly focused on renewable stem cells. Human induced pluripotent stem (hiPS) cells offer great promise in this regard. If hiPS cells can be differentiated into authentic mDA neuron, hiPS could provide a potential autologous source of transplant tissue when generated from PD patients, a clear advantage over human embryonic stem (hES) cells. Here, we report that mDA neurons can be derived from a commercially available hiPS cell line, IMR90 clone 4, using a modified hES differentiation protocol established in our lab. These cells express all the markers (Lmx1a, Aldh1a1, TH, TrkB), follow the same mDA lineage pathway as H9 hES cells, and have similar expression levels of DA and DOPAC. Moreover, when hiPS mDA progenitor cells are transplanted into 6-OHDA-lesioned PD rats, they survive long term and many develop into bona fide mDA neurons. Despite their differentiation and integration into the brain, many Nestin+ tumor-like cells remain at the site of the graft. Our data suggest that as with hES cells, selecting the appropriate population of mDA lineage cells and eliminating actively dividing hiPS cells before transplantation will be critical for the future success of hiPS cell replacement therapy in PD patients.

  16. Dimethyl fumarate attenuates 6-OHDA-induced neurotoxicity in SH-SY5Y cells and in animal model of Parkinson's disease by enhancing Nrf2 activity.

    PubMed

    Jing, X; Shi, H; Zhang, C; Ren, M; Han, M; Wei, X; Zhang, X; Lou, H

    2015-02-12

    Oxidative stress is central to the pathology of several neurodegenerative diseases, including Parkinson's disease (PD), and therapeutics designed to enhance antioxidant potential could have clinical value. In this study, we investigated whether dimethyl fumarate (DMF) has therapeutic effects in cellular and animal model of PD, and explore the role of nuclear transcription factor related to NF-E2 (Nrf2) in this process. Treatment of animals and dopaminergic SH-SY5Y cells with DMF resulted in increased nuclear levels of active Nrf2, with subsequent upregulation of antioxidant target genes. The cytotoxicity of 6-hydroxydopamine (6-OHDA) was reduced by pre-treatment with DMF in SH-SY5Y cells. The increase in the reactive oxygen species caused by 6-OHDA treatment was also attenuated by DMF in SH-SY5Y cells. The neuroprotective effects of DMF against 6-OHDA neurotoxicity were dependent on Nrf2, since treatment with Nrf2 siRNA failed to block against 6-OHDA neurotoxicity and induce Nrf2-dependent cytoprotective genes in SH-SY5Y cells. In vivo, DMF oral administration was shown to upregulate mRNA and protein levels of Nrf2 and Nrf2-regulated cytoprotective genes, attenuate 6-OHDA induced striatal oxidative stress and inflammation in C57BL/6 mice. Moreover, DMF ameliorated dopaminergic neurotoxicity in 6-OHDA-induced PD animal models as evidenced by amelioration of locomotor dysfunction, loss in striatal dopamine, and reductions in dopaminergic neurons in the substantia nigra and striatum. Taken together, these data strongly suggest that DMF may be beneficial for the treatment of neurodegenerative diseases like PD. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  17. LPA signaling is required for dopaminergic neuron development and is reduced through low expression of the LPA1 receptor in a 6-OHDA lesion model of Parkinson's disease.

    PubMed

    Yang, Xiao-Yun; Zhao, Ethan Y; Zhuang, Wen-Xin; Sun, Feng-Xiang; Han, Hai-Lin; Han, Hui-Rong; Lin, Zhi-Juan; Pan, Zhi-Fang; Qu, Mei-Hua; Zeng, Xian-Wei; Ding, Yuchuan

    2015-11-01

    Lysophosphatidic acid (LPA) is a bioactive phospholipid that activates at least five known G-protein-coupled receptors (GPCRs): LPA1-LPA5. The nervous system is a major locus for LPA1 expression. LPA has been shown to regulate neuronal proliferation, migration, and differentiation during central nervous system development as well as neuronal survival. Furthermore, deficient LPA signaling has been implicated in several neurological disorders including neuropathic pain and schizophrenia. Parkinson's disease (PD) is a neurodegenerative movement disorder that results from the loss of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNc). The specific molecular pathways that lead to DA neuron degeneration, however, are poorly understood. The influence of LPA in the differentiation of mesenchymal stem cells (MSCs) into DA neurons in vitro and LPA1 expression in a 6-hydroxydopamine (6-OHDA) lesion model of PD in vivo were examined in the present study. LPA induced neuronal differentiation in 80.2 % of the MSC population. These MSCs developed characteristic neuronal morphology and expressed the neuronal marker, neuron-specific enolase (NSE), while expression of the glial marker, glial fibrillary acidic protein (GFAP), was absent. Moreover, 27.6 % of differentiated MSCs were positive for tyrosine hydroxylase (TH), a marker for DA neurons. In the 6-OHDA PD rat model, LPA1 expression in the substantia nigra was significantly reduced compared to control. These results suggest LPA signaling via activation of LPA1 may be necessary for DA neuron development and survival. Furthermore, reduced LPA/LPA1 signaling may be involved in DA neuron degeneration thus contributing to the pathogenesis of PD.

  18. Neuroprotective activity of Stereospermum suaveolens DC against 6-OHDA induced Parkinson's disease model.

    PubMed

    Shalavadi, M H; Chandrashekhar, V M; Avinash, S P; Sowmya, C; Ramkishan, A

    2012-01-01

    To evaluate the neuroprotective effect of Stereospermum suaveolens DC on 6-hydroxy dopamine induced Parkinson's disease model. The study was conducted on Sprague-Dawley rats where parkinson's disease was induced by producing the striatal 6-hydroxy dopamine lesions. The test animals received methanolic extract of Stereospermum suaveolens at dose of 125, 250 and 500 mg/kg for 42 days. Behavioral assessment, spontaneous locomotor activity and muscular coordination were studied. Antioxidant levels, striatal infraction area were assessed and histopathological studies were carried out. The Stereospermum suaveolens DC methanolic extract showed significant dose dependent increase in behavioral activity, improved muscular coordination. Significant reduction of lipid peroxidation (LPO), increased antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT) and non-enzymatic activity of glutathione (GSH) and total thiol levels in extract treated groups was observed in test groups as compared to control group. Striatal infarction area was significantly reduced in extract treated groups as compared to control group. The methanolic extract of Stereospermum suaveolens DC showed neuroprotective activity against 6-hydroxy dopamine induced Parkinson's disease in rats.

  19. Decreased behavioral response to intranigrally administered GABAA agonist muscimol in the lactacystin model of Parkinson's disease may result from partial lesion of nigral non-dopamine neurons: comparison to the classical neurotoxin 6-OHDA.

    PubMed

    Konieczny, Jolanta; Czarnecka, Anna; Kamińska, Kinga; Lenda, Tomasz; Nowak, Przemysław

    2015-04-15

    Lactacystin is a selective UPS inhibitor recently used to destroy dopamine (DA) neurons in animal models of Parkinson's disease (PD). However, both in vitro and in vivo studies show discrepancies in terms of the sensitivity of non-DA neurons to its toxicity. Therefore, our study was aimed to examine the toxic effect of intranigral administration of lactacystin on DA and non-DA neurons in the rat substantia nigra (SN), compared to the classic neurotoxin 6-OHDA. Tissue DA levels in the striatum and SN and GABA levels in the SN were also examined. Moreover, behavioral response of nigral GABAA receptors to locally administered muscimol was evaluated in these two PD models. We found that both lactacystin and 6-OHDA induced a strong decrease in DA level in the lesioned striatum and SN but only lactacystin slightly reduced GABA levels in the SN. A stereological analysis showed that both neurotoxins highly decreased the number of DA neurons in the SN, while only lactacystin moderately reduced the number of non-DA ones. Finally, in the lactacystin group, the number of contralateral rotations after intranigrally administrated muscimol was decreased in contrast to the increased response in the 6-OHDA model. Our study proves that, although lactacystin is not a fully selective to DA neurons, these neurons are much more vulnerable to its toxicity. Partial lesion of nigral non-DA neurons in this model may explain the decreased behavioral response to the GABAA agonist muscimol.

  20. Induction and expression of abnormal involuntary movements is related to the duration of dopaminergic stimulation in 6-OHDA-lesioned rats.

    PubMed

    Papathanou, Maria; Rose, Sarah; McCreary, Andrew; Jenner, Peter

    2011-06-01

    Dyskinesia induction in Parkinson's disease (PD) appears less marked with long-acting dopamine agonists than with short-acting L-Dopa, but the relationship to duration of drug action is unknown. It is also unclear whether the duration of drug action affects the expression of established dyskinesia. This study compared the ability of L-Dopa and four dopamine agonists of different duration of action to induce abnormal involuntary movements (AIMs) in 6-hydroxydopamine (6-OHDA)-lesioned rats, and their ability to express established AIMs following prior exposure to L-Dopa. 6-OHDA-lesioned rats were treated with saline, L-Dopa/benserazide, apomorphine, ropinirole, pramipexole or pergolide once daily for 15 days. Repeated administration of the short-acting dopamine agonists, apomorphine (duration 80 min) and ropinirole (duration 90 min) induced marked axial, limb and orolingual AIMs at peak effect. L-Dopa (duration 100 min) produced moderate AIMs at peak effect, while administration of the long-acting dopamine agonists, pramipexole (duration 150 min) and pergolide (duration 240 min) resulted in mild AIMs. In rats primed to exhibit severe AIMs following repeated L-Dopa administration, acute administration of apomorphine, ropinirole and L-Dopa induced severe AIMs. By contrast, pramipexole and pergolide evoked only mild-moderate AIMs. Again, there was a negative correlation between duration of effect and the severity of AIMs expressed. These studies show that both the induction and expression of AIMs in 6-OHDA-lesioned rats are related to the duration of action of dopaminergic drugs. These findings suggest that continuous dopaminergic stimulation could be used both to avoid dyskinesia induction and to improve motor function in late-stage PD when troublesome dyskinesia is evident.

  1. Depressive-like behaviors alterations induced by intranigral MPTP, 6-OHDA, LPS and rotenone models of Parkinson's disease are predominantly associated with serotonin and dopamine.

    PubMed

    Santiago, Ronise M; Barbieiro, Janaína; Lima, Marcelo M S; Dombrowski, Patrícia A; Andreatini, Roberto; Vital, Maria A B F

    2010-08-16

    Depression is a frequently encountered non-motor feature of Parkinson's disease (PD) and it can have a significant impact on patient's quality of life. Considering the differential pathophysiology of depression in PD, it prompts the idea that a degenerated nigrostriatal system plays a role in depressive-like behaviors, whilst animal models of PD are employed. Therefore, we addressed the question of whether dopamine (DA) depletion, promoted by the neurotoxins 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), 6-hydroxydopamine (6-OHDA), lipopolysaccharide (LPS) and rotenone are able to induce depressive-like behaviors and neurotransmitters alterations similarly that encountered in PD. To test this rationale, we performed intranigral injections of each neurotoxin, followed by motor behavior, depressive-like behaviors, histological and neurochemical tests. After the motor recovery period, MPTP, 6-OHDA and rotenone were able to produce anhedonia and behavioral despair. These altered behavioral responses were accompanied by reductions of striatal DA, homovanillic acid (HVA) and 3,4-dihydroxyphenylacetic acid (DOPAC) restricted to the 6-OHDA group. Additionally, decreases on the hippocampal serotonin (5-HT) content were detected for the MPTP, 6-OHDA and rotenone groups. Notably, strong correlations were detected among the groups when 5-HT and DA were correlated with swimming (r=+0.97; P=0.001) and immobility (r=-0.90; P=0.012), respectively. Our data indicate that MPTP, 6-OHDA and rotenone, but not LPS were able to produce depressive-like behaviors accompanied primarily by hippocampal 5-HT reductions. Moreover, DA and 5-HT strongly correlated with "emotional" impairments suggesting an important participation of these neurotransmitters in anhedonia and behavioral despair after nigral lesions promoted by the neurotoxins.

  2. Genetic, temporal and diurnal influences on L-dopa-induced dyskinesia in the 6-OHDA model.

    PubMed

    Monville, Christelle; Torres, Eduardo M; Pekarik, Vladimir; Lane, Emma L; Dunnett, Stephen B

    2009-03-16

    Current treatments for Parkinson's disease rely on a dopamine replacement strategy and are reasonably effective, particularly in the early stages of the disease. However, chronic dopaminergic therapy is limited by the development of a range of side effects, including the onset of abnormal movements ('dyskinesia'). The neural mechanisms that underlie dyskinesia are far from clear but they have been associated with pulsatile stimulation of dopamine receptors, downstream changes in proteins and genes, and abnormalities in non-dopamine transmitter systems. However, there has been no pathophysiological explanation for the worsening motor symptoms in the afternoon and evening reported by Parkinsonian patients in long-term L-dopa therapy, and no direct relationship has been found with the pharmacokinetics of the drug. Moreover, there continues to be a debate about whether the development of dyskinesias in patients is dependent upon the duration of L-dopa treatment or on the degree of denervation/advanced stage of the disease, both factors that are difficult to resolve experimentally in the human disease. The objective of this study was to characterise, in an animal model, factors that predispose some individuals to develop dyskinesia after a prolonged treatment with L-dopa, whereas others continue to exhibit symptom alleviation without the side effects. We report that none of the parameters studied--genetic variation within and between strains, delay of treatment onset after lesion, or time of day of the drug treatment--were found to influence directly the formation of dyskinesias after L-dopa treatment. We conclude that a complex combination of individual factors are likely to interact to regulate the onset and development of abnormal movements in some animals but not others.

  3. The H3 receptor agonist immepip does not affect l-dopa-induced abnormal involuntary movements in 6-OHDA-lesioned rats.

    PubMed

    Papathanou, Maria; Jenner, Peter; Iravani, Mahmoud; Jackson, Michael; Stockwell, Kim; Strang, Isabel; Zeng, Bai-Yun; McCreary, Andrew C; Rose, Sarah

    2014-10-15

    The treatment of dyskinesia in Parkinson׳s disease remains poor but H3 receptor agonists have been suggested as a novel pharmacological approach. We examined the effects of the H3 agonist, immepip, in 6-OHDA-lesioned rats exhibiting AIMs (abnormal involuntary movements), a rat analogue of dyskinesia, in response to l-dopa compared to the known anti-dyskinetic agents amantadine, MK-801 and 8-OHDPAT. We then attempted to extend these studies in to dyskinetic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treated common marmosets. Amantadine, MK-801 and 8-OHDPAT all dose-dependently reduced l-dopa-induced axial, lingual and oral (ALO) AIMs in 6-OHDA-lesioned animals accompanied by a reduction in contralateral rotation with higher doses of amantadine and MK-801. By contrast, immepip had no effect on AIMs expression or contralateral rotation. In the MPTP-treated common marmoset exhibiting dyskinesia to l-dopa, immepip alone induced retching and in combination with l-dopa administered subcutaneously or orally induced the rapid onset of retching and vomiting which was not controlled by pretreatment with domperidone. Administration of the unrelated H3 agonist, imetit had the same effect. Despite causing negative side-effects, it appears that both agonists reduced the antiparkinsonian response to l-dopa resulting in reduced dyskinesia. H3 agonists appear unlikely candidates for the treatment of dyskinesia in PD based on lack of evidence of efficacy and potential adverse effects.

  4. Levodopa/benserazide microsphere (LBM) prevents L-dopa induced dyskinesia by inactivation of the DR1/PKA/P-tau pathway in 6-OHDA-lesioned Parkinson's rats.

    PubMed

    Xie, Cheng-long; Wang, Wen-Wen; Zhang, Su-fang; Yuan, Ming-Lu; Che, Jun-Yi; Gan, Jing; Song, Lu; Yuan, Wei-En; Liu, Zhen-Guo

    2014-12-16

    L-3, 4-dihydroxyphenylalanine (L-dopa) is the gold standard for symptomatic treatment of Parkinson's disease (PD), but long-term therapy is associated with the emergence of L-dopa-induced dyskinesia (LID). In the present study, L-dopa and benserazide were loaded by poly (lactic-co-glycolic acid) microspheres (LBM), which can release levodopa and benserazide in a sustained manner in order to continuous stimulate dopaminergic receptors. We investigated the role of striatal DR1/PKA/P-tau signal transduction in the molecular event underlying LID in the 6-OHDA-lesioned rat model of PD. We found that animals rendered dyskinetic by L-dopa treatment, administration of LBM prevented the severity of AIM score, as well as improvement in motor function. Moreover, we also showed L-dopa elicits profound alterations in the activity of three LID molecular markers, namely DR1/PKA/P-tau (ser396). These modifications are totally prevented by LBM treatment, a similar way to achieve continuous dopaminergic delivery (CDD). In conclusion, our experiments provided evidence that intermittent administration of L-dopa, but not continuous delivery, and DR1/PKA/p-tau (ser396) activation played a critical role in the molecular and behavioural induction of LID in 6-OHDA-lesioned rats. In addition, LBM treatment prevented the development of LID by inhibiting the expression of DR1/PKA/p-tau, as well as PPEB mRNA in dyskintic rats.

  5. Neuroprotection of inositol hexaphosphate and changes of mitochondrion mediated apoptotic pathway and α-synuclein aggregation in 6-OHDA induced parkinson's disease cell model.

    PubMed

    Zhang, Zheng; Hou, Lin; Li, Xianghong; Ju, Chuanxia; Zhang, Jinyu; Li, Xin; Wang, Xiuli; Liu, Cun; Lv, Yuqiang; Wang, Yuehua

    2016-02-15

    Animal and cell experiments showed that inositol hexaphosphate (IP6) was protective on neurons in parkinson's disease (PD) model, but the underlying mechanism of this action was not extensively elucidated. To address this question, we established 6-hydroxydopamine (6-OHDA) induced human dopaminergic cell line SH-SY5Y as PD cell model and testified the neuroprotection of IP6. Through hoechst nuclear stain method and flow cytometric analysis, apoptosis induced by 6-OHDA was blocked by IP6 pretreatment. Significant protection against reactive oxygen species (ROS) and lipid peroxidation product malondialdehyde (MDA) was observed in 6-OHDA induced cells pretreated with IP6. To further investigate the mechanism of anti-apoptotic effect of IP6, expression of mediators in mitochondrion dependent apoptotic pathway was detected. Results indicated that loss of mitochondrial membrane potential, cytochrome c releasing, upregulation of Bcl-2-associated X protein (Bax), downregulation of B-cell CLL/lymphoma 2 (Bcl-2) and caspases activation were reversed by IP6. In addition, using flow cytometric method and western blot approach, our data showed that IP6 attenuated the rise of calcium and α-synuclein aggregation in cytosol. Collectively, IP6 exerted its neuroprotection on dopaminergic cells in PD cell model and the mechanism may be associated with changes of mitochondrion mediated apoptotic pathway and α-synuclein aggregation. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. The mitochondria-targeted anti-oxidant MitoQ reduces aspects of mitochondrial fission in the 6-OHDA cell model of Parkinson's disease.

    PubMed

    Solesio, María E; Prime, Tracy A; Logan, Angela; Murphy, Michael P; Del Mar Arroyo-Jimenez, María; Jordán, Joaquín; Galindo, María F

    2013-01-01

    Parkinson's disease (PD) is a neurodegenerative disorder for which available treatments provide symptom relief but do not stop disease progression. Mitochondria, and in particular mitochondrial dynamics, have been postulated as plausible pharmacological targets. Mitochondria-targeted antioxidants have been developed to prevent mitochondrial oxidative damage, and to alter the involvement of reactive oxygen species (ROS) in signaling pathways. In this study, we have dissected the effect of MitoQ, which is produced by covalent attachment of ubiquinone to a triphenylphosphonium lipophilic cation by a ten carbon alkyl chain. MitoQ was tested in an in vitro PD model which involves addition of 6-hydroxydopamine (6-OHDA) to SH-SY5Y cell cultures. At sublethal concentrations of 50μM, 6-OHDA did not induce increases in protein carbonyl, mitochondrial lipid peroxidation or mitochondrial DNA damage. However, after 3h of treatment, 6-OHDA disrupts the mitochondrial morphology and activates the machinery of mitochondrial fission, but not fusion. Addition of 6-OHDA did not increase the levels of fission 1, mitofusins 1 and 2 or optic atrophy 1 proteins, but does lead to the translocation of dynamin related protein 1 from the cytosol to the mitochondria. Pre-treatment with MitoQ (50nM, 30min) results in the inhibition of the mitochondrial translocation of Drp1. Furthermore, MitoQ also inhibited the translocation of the pro-apoptotic protein Bax to the mitochondria. These findings provide mechanistic evidence for a role for redox events contributing to mitochondrial fission and suggest the potential of mitochondria-targeted therapeutics in diseases that involve mitochondrial fragmentation due to oxidative stress.

  7. Histamine H3 receptor agonist- and antagonist-evoked vacuous chewing movements in 6-OHDA-lesioned rats occurs in an absence of change in microdialysate dopamine levels.

    PubMed

    Nowak, Przemysław; Dabrowska, Joanna; Bortel, Aleksandra; Biedka, Izabela; Szczerbak, Grazyna; Słomian, Grzegorz; Kostrzewa, Richard M; Brus, Ryszard

    2006-12-15

    In rats lesioned neonatally with 6-hydroxydopamine (6-OHDA), repeated treatment with SKF 38393 (1-phenyl-2,3,4,5-tetrahydro-(1H)-3-benzazepine-7,8-diol), a dopamine D(1)/D(5) receptor agonist, produces robust stereotyped and locomotor activities. The gradual induction of dopamine D(1) receptor supersensitivity is known as a priming phenomenon, and this process is thought to underlie not only the appearance of vacuous chewing movements in humans with tardive dyskinesia, but also the onset of motor dyskinesias in L-dihydroxyphenylalanine (L-DOPA)-treated Parkinson's disease patients. The object of the present study was to determine the possible influence of the histaminergic system on dopamine D(1) agonist-induced activities. We found that neither imetit (5.0 mg/kg i.p.), a histamine H(3) receptor agonist, nor thioperamide (5.0 mg/kg i.p.), a histamine H(3) receptor antagonist/inverse agonist, altered the numbers of vacuous chewing movements in non-primed-lesioned rats. However, in dopamine D(1) agonist-primed rats, thioperamide alone produced a vacuous chewing movements response (i.e., P < 0.05 vs SKF 38393, 1.0 mg/kg i.p.), but did not modify the SKF 38393 effect. Notably, both imetit and thioperamide-induced catalepsy in both non-primed and primed 6-OHDA-lesioned rats, comparable in magnitude to the effect of the dopamine D(1)/D(5) receptor antagonist SCH 23390 (7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine; 0.5 mg/kg i.p.). Furthermore, in primed animals both imetit and thioperamide intensified SCH 23390-evoked catalepsy. In vivo microdialysis established that neither imetit nor thioperamide altered extraneuronal levels of dopamine and its metabolites in the striatum of 6-OHDA-lesioned rats. On the basis of the present study, we believe that histaminergic systems may augment dyskinesias induced by dopamine receptor agonists, independent of direct actions on dopaminergic neurons.

  8. Inhibition of Endoplasmic Reticulum Stress is Involved in the Neuroprotective Effect of bFGF in the 6-OHDA-Induced Parkinson’s Disease Model

    PubMed Central

    Cai, Pingtao; Ye, Jingjing; Zhu, Jingjing; Liu, Dan; Chen, Daqing; Wei, Xiaojie; Johnson, Noah R.; Wang, Zhouguang; Zhang, Hongyu; Cao, Guodong; Xiao, Jian; Ye, Junming; Lin, Li

    2016-01-01

    Parkinson's disease (PD) is a progressive neurodegenerative disorder with complicated pathophysiologic mechanisms. Endoplasmic reticulum (ER) stress appears to play a critical role in the progression of PD. We demonstrated that basic fibroblast growth factor (bFGF), as a neurotropic factor, inhibited ER stress-induced neuronal cell apoptosis and that 6-hydroxydopamine (6-OHDA)-induced ER stress was involved in the progression of PD in rats. bFGF administration improved motor function recovery, increased tyrosine hydroxylase (TH)-positive neuron survival, and upregulated the levels of neurotransmitters in PD rats. The 6-OHDA-induced ER stress response proteins were inhibited by bFGF treatment. Meanwhile, bFGF also increased expression of TH. The administration of bFGF activated the downstream signals PI3K/Akt and Erk1/2 in vivo and in vitro. Inhibition of the PI3K/Akt and Erk1/2 pathways by specific inhibitors partially reduced the protective effect of bFGF. This study provides new insight towards bFGF translational drug development for PD involving the regulation of ER stress. PMID:27493838

  9. Chronic pramipexole treatment induces compulsive behavior in rats with 6-OHDA lesions of the substantia nigra and ventral tegmental area.

    PubMed

    Dardou, D; Reyrolle, L; Chassain, C; Durif, F

    2017-08-14

    Dopamine replacement therapy (DRT) reduces motor symptoms in Parkinson's disease (PD), but also induces impulsive-compulsive behavior (ICB) in up to 25% of PD patients. These non-motor side effects of DRT generally follow a gradual transition from impulsive to compulsive-like-i.e. repetitive, compelled, and non-pleasurable-behavior. Here, we investigated the effect of chronic pramipexole (PPX) treatment on the onset of compulsive-like behavior, measured via the post-training signal attenuation (PTSA) procedure, in rats with dopaminergic lesions. Accordingly, we aimed to mimic chronic DRT in a PD context, and obtain data on the brain regions that potentially sustain this type of compulsive behavior pattern in rats. We observed that the lesion or treatment alone did not induce compulsive lever pressing in rats. However, rats with lesions of the substantia nigra and ventral tegmental area as well as with chronic PPX treatment developed strong compulsive lever-pressing behavior, as measured via PTSA. Furthermore, when chronic PPX treatment was discontinued before the PTSA test, the lesioned rats showed the same level of compulsive behavior as sham-operated rats. In fact, lesioned, treated, and compulsive-like rats showed significantly higher Fos expression in the orbitofrontal cortex and dorsal striatum. Thus, chronic PPX treatment in PD rats induced a strong compulsive-like behavior. Furthermore, Fos expression mapping suggests that the behavior was sustained via the activation of the orbitofrontal cortex and dorsal striatum. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Behavioral and biochemical correlates of the dyskinetic potential of dopaminergic agonists in the 6-OHDA lesioned rat.

    PubMed

    Carta, Anna R; Frau, Lucia; Lucia, Frau; Pinna, Annalisa; Annalisa, Pinna; Pontis, Silvia; Silvia, Pontis; Simola, Nicola; Nicola, Simola; Schintu, Nicoletta; Nicoletta, Schintu; Morelli, Micaela; Micaela, Morelli

    2008-07-01

    Prolonged treatment with L-DOPA induces highly disabling dyskinesia in Parkinson's disease (PD) patients. In contrast, dopaminergic agonists display variably dyskinetic outcome, depending on pharmacokinetic/pharmacodynamic profile. The present study was aimed at assessing behavioral and biochemical correlates of intense or mild dyskinesia displayed by the different dopamine (DA) receptors stimulation in a rat model of PD. The effect of subchronic stimulation of the D(1) receptor by SKF38393, and the D(2)/D(3) receptor by ropinirole was evaluated in unilaterally 6-hydroxyDA-lesioned rats. Sensitization of contralateral turning (SCT) behavior and abnormal involuntary movements (AIMs) were assessed as behavioral correlates of dyskinetic responses. Opioid peptides mRNA in the dorsolateral striatum (dlStr) and glutamic acid decarboxylase (GAD67) mRNA content in globus pallidus (GP), were evaluated as an index of neuroadaptive changes occurring in the direct and indirect basal ganglia pathways. Subchronic SKF38393 caused AIMs and SCT whereas ropinirole elicited SCT only, indicating that both drugs induced some dyskinetic response, albeit of different type. Peptides mRNA evaluation in dlStr, showed that SKF38393 subchronic treatment was associated to an overexpression of both dynorphin (DYN) and enkephalin (ENK) mRNAs, in the direct and indirect striatal pathway respectively. In contrast, a decrease in DYN mRNA levels only was observed after treatment with ropinirole. Analysis of GAD67 mRNA levels in the GP showed an increase after both D(1) and D(2)/D(3) agonist treatments. Results suggest that presence of SCT alone or SCT plus AIMs might represent correlates of the differential severity of dyskinetic movements induced by treatment with low (ropinirole) or high (SKF38393) dyskinetic potential. Neuroadaptive increases in opioid peptide expression in both direct and indirect striatal pathways were associated to the appearance of AIMs alone. In contrast, increase of GAD67 m

  11. Inhibition of Glycogen Synthase Kinase-3β (GSK-3β) as potent therapeutic strategy to ameliorates L-dopa-induced dyskinesia in 6-OHDA parkinsonian rats

    PubMed Central

    Xie, Cheng-long; Lin, Jing-Ya; Wang, Mei-Hua; Zhang, Yu; Zhang, Su-fang; Wang, Xi-Jin; Liu, Zhen-Guo

    2016-01-01

    Levodopa (L-dopa) is the dominating therapy drug for exogenous dopaminergic substitution and can alleviate most of the manifestations of Parkinson’s disease (PD), but long-term therapy is associated with the emergence of L-dopa-induced dyskinesia (LID). Evidence points towards an involvement of Glycogen Synthase Kinase-3β (GSK-3β) in development of LID. In the present study, we found that animals rendered dyskinetic by L-dopa treatment, administration of TDZD8 (2mg/kg) obviously prevented the severity of AIM score, as well as improvement in motor function (P < 0.05). Moreover, the TDZD8-induced reduction in dyskinetic behavior correlated with a reduction in molecular correlates of LID. TDZD8 reduced the phosphorylation levels of tau, DARPP32, ERK and PKA protein, which represent molecular markers of LID, as well as reduced L-dopa-induced FosB mRNA and PPEB mRNA levels in the lesioned striatum. In addition, we found that TDZD8 antidyskinetic properties were overcome by D1 receptor, as pretreatment with SKF38393 (5 mg/kg, 10 mg/kg, reapectively), a D1 receptor agonist, blocked TDZD8 antidyskinetic actions. This study supported the hypothesis that GSK-3β played an important role in the development and expression of LID. Inhibition of GSK-3β with TDZD8 reduced the development of ALO AIM score and associated molecular changes in 6-OHDA-lesioned rats. PMID:26997328

  12. Characterisation of spatial neglect induced by unilateral 6-OHDA lesions on a choice reaction time task in rats.

    PubMed

    Heuer, Andreas; Dunnett, Stephen B

    2013-01-15

    Unilateral dopamine depletion and excitotoxic lesions of the striatum have been shown to induce a contralateral neglect when rats have to respond in a choice reaction time setting. Whereas, in a lateralised setting when response options are to either side of the animal's head all contralateral responding is impaired, testing animals only on one side of the head per day but with a near and far response option, rats are able to correctly respond to contralateral stimuli, but rather bias their responses towards the near hole. Here, we further investigated the nature of the contralateral neglect in egocentric space coding in more detail. Firstly, we tested the effects of near-complete unilateral dopamine depletion on this type of task. Secondly, previous observations suggested that lesioned rats shifted their response strategy which resulted in a response bias towards the most proximal location in contralateral space. In order to "encourage" dopamine depleted rats to respond to the neglected response location we implemented an error correction procedure to the task. Near-complete unilateral dopamine depletion, via 6-hydroxydopamine infusions into the medial forebrain bundle of female Lister Hood rats, resulted in a reduction of usable trials, a near hole bias when animals were tested on the side contralateral to the lesion, as well as increased reaction and movement time latencies. The introduction of an error-correction procedure had no effect on the animals' response bias towards the near contralateral location. Probe trials showed that the bias is most likely the result of responses being misdirected when in a choice situation. The findings further highlight the role of dopamine and an intact striatum to code responses into egocentrically defined space.

  13. BDNF over-expression induces striatal serotonin fiber sprouting and increases the susceptibility to l-DOPA-induced dyskinesia in 6-OHDA-lesioned rats.

    PubMed

    Tronci, Elisabetta; Napolitano, Francesco; Muñoz, Ana; Fidalgo, Camino; Rossi, Francesca; Björklund, Anders; Usiello, Alessandro; Carta, Manolo

    2017-11-01

    In addition to its role in neuronal survival, the brain neurotrophic factor (BDNF) has been shown to influence serotonin transmission and synaptic plasticity, events strongly implicated in the appearance of l-DOPA-induced dyskinesia (LID), a motor complication occurring in parkinsonian patients after long-term treatment with the dopamine precursor. In order to evaluate a possible influence of BDNF in the appearance of LID, 6-OHDA-lesioned rats received a striatal injection of different concentrations of an adeno-associated viral (AAV) vector over-expressing either BDNF or GFP, as control vector. Eight weeks later, animals started to receive a daily treatment with l-DOPA (4-6mg/kg plus benserazide 4-6mg/kg, s.c.) or saline, and dyskinesias, as well as l-DOPA-induced rotations, were evaluated at several time-points. Moreover, molecular changes in striatal D1 receptor-dependent cAMP/PKA and ERK/mTORC signaling pathways, as well as, sprouting of striatal serotonin axons, were measured. Results showed that the AAV-BDNF vector injection induced striatal over-expression of BDNF, as well as striatal and pallidal serotonin axon hyperinnervation. Moreover, rats that over-expressed BDNF were more prone to develop LID and l-DOPA-induced rotations, compared to the GFP-treated control group. Finally, rats that over-expressed BDNF showed increased levels of striatal D1R-dependent signaling phospho-proteins in response to l-DOPA administration. This study suggests that BDNF over-expression, by inducing changes in pre-synaptic serotonin axonal trophism, is able to exacerbate maladaptive responses to l-DOPA administration. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Early L-dopa, but not pramipexole, restores basal ganglia activity in partially 6-OHDA-lesioned rats.

    PubMed

    Marin, C; Bonastre, M; Mengod, G; Cortés, R; Giralt, A; Obeso, J A; Schapira, A H

    2014-04-01

    The most appropriate time for the initiation of dopaminergic symptomatic therapy in Parkinson's disease remains debatable. It has been suggested that early correction of basal ganglia pathophysiological abnormalities may have long-term beneficial effects. To test this hypothesis, we investigated the early and delayed actions of L-dopa and pramipexole, using a delayed-start protocol of treatment. The effects of early and delayed administration of these drugs on motor response, development of dyskinesias, neurogenesis and molecular markers in basal ganglia were studied in rats with a unilateral and partial 6-hydroxydopamine-induced nigrostriatal lesion. Ten days after lesioning, rats received treatment with: a) L-dopa methyl ester (25mg/kg with 6.25mg/kg of benserazide, i.p., twice a day); b) pramipexole (0.5mg/kg, sc, twice a day) or c) saline for 4weeks. Four weeks after treatment initiation, rats from the saline group were distributed in three groups that then received the following treatments: d) L-dopa, e) pramipexole or f) saline, for 4weeks more. Three animals in each treatment arm received 5-bromo-2-deoxyuridine injections (200mg/kg) 3days before starting treatment. When compared with delayed-start L-dopa, early-start L-dopa treatment induced a lower rotational response (p<0.01), an improvement in limb akinesia (p<0.05), a lower level of dyskinesia (p<0.01) and a normalization of lesion-induced molecular changes in basal ganglia. When compared with delayed-start pramipexole, early-start pramipexole induced a higher rotational response (p<0.01), but did not improve limb akinesia, induce dyskinesia nor normalize lesion-induced molecular changes. Neither significant modifications of striatal dopamine D1-D3 receptor heteromerization nor subventricular zone neurogenesis was found after any L-dopa or pramipexole treatments. Our data support a possible restoration of basal ganglia physiological mechanisms by early-start L-dopa therapy. Copyright © 2014 Elsevier Inc

  15. Effects of prolonged neuronal nitric oxide synthase inhibition on the development and expression of L-DOPA-induced dyskinesia in 6-OHDA-lesioned rats.

    PubMed

    Padovan-Neto, Fernando Eduardo; Cavalcanti-Kiwiatkoviski, Roberta; Carolino, Ruither Oliveira Gomes; Anselmo-Franci, Janete; Del Bel, Elaine

    2015-02-01

    It is well known that nitric oxide (NO) interacts with dopamine (DA) within the striatal circuitry. The anti-dyskinetic properties of NO synthase (NOS) inhibitors demonstrate the importance of NO in L-3,4-dihydroxyphenylalanine (L-DOPA)-induced dyskinesia (LID). Here, we investigated the ability of a daily co-treatment of the preferential neuronal NOS (nNOS) inhibitor, 7-nitroindazole (7-NI, 30 mg/kg), with L-DOPA (30 mg/kg) to counteract LID in unilaterally 6-OHDA-lesioned rats. We analyzed striatal nNOS-expressing interneurons, DA and 5-HT neurochemistry in the striatum and alterations of the Fos-B/ΔFosB expression in the corticostriatal, nigrostriatal and mesolimbic pathways. Prolonged administration of 7-NI inhibited the manifestation of chronic L-DOPA treatment-induced abnormal involuntary movements (AIMs). LID was associated with an up-regulation in the number of nNOS-expressing interneurons in the lateral but not medial striatum. nNOS inhibition reduced the number of nNOS-expressing interneurons. The anti-dyskinetic effects of 7-NI correlated with a reduction in DA and 5-HT turnover in the striatum. At postsynaptic striatal sites, 7-NI prevented L-DOPA-induced Fos-B/ΔFosB up-regulation in the motor cortex, nucleus accumbens and striatum. Finally, 7-NI blocked Fos-B/ΔFosB expression in nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d)-positive interneurons in the striatum. These results provide further evidence of the molecular mechanisms by which NOS-inhibiting compounds attenuate LID. The involvement of NO with DA and 5-HT neurochemistry may contribute to the understanding of this new, non-dopaminergic therapy for the management of LID.

  16. Dual effects of intermittent or continuous L-DOPA administration on gene expression in the globus pallidus and subthalamic nucleus of adult rats with a unilateral 6-OHDA lesion.

    PubMed

    Nielsen, Kirsten M; Soghomonian, Jean-Jacques

    2003-09-15

    Intermittent oral doses of levodopa (L-DOPA) are routinely used to treat Parkinson's disease, but with prolonged use can result in adverse motor complications, such as dyskinesia. Continuous administration of L-DOPA achieves therapeutic efficacy without producing this effect, yet the molecular mechanisms are unclear. This study examined, by in situ hybridization histochemistry, the effects of continuous or intermittent L-DOPA administration on gene expression in the globus pallidus and subthalamic nucleus of adult rats with a unilateral 6-hydroxydopamine (6-OHDA) lesion of the nigrostriatal pathway. Results were compared to 6-OHDA-treated rats receiving vehicle. Our results provide original evidence that continuous L-DOPA normalizes the 6-OHDA-lesion-induced increase in mRNA levels encoding for the 67 kDa isoform of glutamate decarboxylase in neurons of the globus pallidus and cytochrome oxidase subunit I mRNA levels in the subthalamic nucleus. The extent of normalization did not differ between the continuous and intermittent groups. In addition, intermittent L-DOPA induced an increase in the mRNA levels encoding for the 65 kDa isoform of glutamate decarboxylase in globus pallidus neurons ipsilateral to the lesion and a bilateral increase in c-fos mRNA expression in the subthalamic nucleus. These results suggest that continuous L-DOPA tends to normalize the 6-OHDA-lesion-induced alterations in cell signaling in the pallido-subthalamic loop. On the other hand, we propose that chronic intermittent L-DOPA exerts a dual effect by normalizing cell signaling in a subpopulation of neurons in the globus pallidus and subthalamic nucleus while inducing abnormal signaling in another subpopulation.

  17. Disrupted brain metabolic connectivity in a 6-OHDA-induced mouse model of Parkinson’s disease examined using persistent homology-based analysis

    PubMed Central

    Im, Hyung-Jun; Hahm, Jarang; Kang, Hyejin; Choi, Hongyoon; Lee, Hyekyoung; Hwang, Do Won; Kim, E. Edmund; Chung, June-Key; Lee, Dong Soo

    2016-01-01

    Movement impairments in Parkinson’s disease (PD) are caused by the degeneration of dopaminergic neurons and the consequent disruption of connectivity in the cortico-striatal-thalamic loop. This study evaluated brain metabolic connectivity in a 6-Hydroxydopamine (6-OHDA)-induced mouse model of PD using 18F-fluorodeoxy glucose positron emission tomography (FDG PET). Fourteen PD-model mice and ten control mice were used for the analysis. Voxel-wise t-tests on FDG PET results yielded no significant regional metabolic differences between the PD and control groups. However, the PD group showed lower correlations between the right caudoputamen and the left caudoputamen and right visual cortex. Further network analyses based on the threshold-free persistent homology framework revealed that brain networks were globally disrupted in the PD group, especially between the right auditory cortex and bilateral cortical structures and the left caudoputamen. In conclusion, regional glucose metabolism of PD was preserved, but the metabolic connectivity of the cortico-striatal-thalamic loop was globally impaired in PD. PMID:27650055

  18. L-DOPA-induced dyskinesia in adult rats with a unilateral 6-OHDA lesion of dopamine neurons is paralleled by increased c-fos gene expression in the subthalamic nucleus.

    PubMed

    Soghomonian, Jean-Jacques

    2006-05-01

    Levodopa (L-DOPA), the metabolic precursor of dopamine, is widely used as a pharmacological agent for the symptomatic treatment of Parkinson's disease. However, long-term L-DOPA use results in abnormal involuntary movements such as dyskinesias. There is evidence that abnormal cell signaling in the basal ganglia is involved in L-DOPA-induced dyskinesia. The subthalamic nucleus (STN) plays a key role in the circuitry of the basal ganglia and in the pathophysiology of Parkinson's disease. However, the contribution of the STN to L-DOPA-induced dyskinesias remains unclear. The objective of this work was to study the effects of acute or chronic systemic administration of L-DOPA to adult rats with a unilateral 6-hydroxydopamine (6-OHDA) lesion of dopamine neurons on c-fos expression in the STN and test the hypothesis that these effects correlate with L-DOPA-induced dyskinesias. c-fos mRNA expression was measured in the STN by in situ hybridization histochemistry at the single cell level. Our results confirm earlier evidence that the chronic administration of L-DOPA to rats with a unilateral 6-OHDA lesion increases c-fos expression in the STN. We also report that c-fos expression can be increased following an acute injection of L-DOPA to 6-OHDA-lesioned rats but not following a chronic injection of L-DOPA to sham-operated, unlesioned rats. Finally, we provide evidence that the occurrence and severity of dyskinesia is correlated with c-fos mRNA levels in the ipsilateral STN. These results suggest that altered cell signaling in the STN is involved in some of the behavioral effects induced by systemic L-DOPA administration.

  19. Cardiac Sympathetic Denervation in 6-OHDA-Treated Nonhuman Primates

    PubMed Central

    Joers, Valerie; Dilley, Kristine; Rahman, Shahrose; Jones, Corinne; Shultz, Jeanette; Simmons, Heather; Emborg, Marina E.

    2014-01-01

    Cardiac sympathetic neurodegeneration and dysautonomia affect patients with sporadic and familial Parkinson's disease (PD) and are currently proposed as prodromal signs of PD. We have recently developed a nonhuman primate model of cardiac dysautonomia by iv 6-hydroxydopamine (6-OHDA). Our in vivo findings included decreased cardiac uptake of a sympathetic radioligand and circulating catecholamines; here we report the postmortem characterization of the model. Ten adult rhesus monkeys (5–17 yrs old) were used in this study. Five animals received 6-OHDA (50 mg/kg iv) and five were age-matched controls. Three months post-neurotoxin the animals were euthanized; hearts and adrenal glands were processed for immunohistochemistry. Quantification of immunoreactivity (ir) of stainings was performed by an investigator blind to the treatment group using NIH ImageJ software (for cardiac bundles and adrenals, area above threshold and optical density) and MBF StereoInvestigator (for cardiac fibers, area fraction fractionator probe). Sympathetic cardiac nerve bundle analysis and fiber area density showed a significant reduction in global cardiac tyrosine hydroxylase-ir (TH; catecholaminergic marker) in 6-OHDA animals compared to controls. Quantification of protein gene protein 9.5 (pan-neuronal marker) positive cardiac fibers showed a significant deficit in 6-OHDA monkeys compared to controls and correlated with TH-ir fiber area. Semi-quantitative evaluation of human leukocyte antigen-ir (inflammatory marker) and nitrotyrosine-ir (oxidative stress marker) did not show significant changes 3 months post-neurotoxin. Cardiac nerve bundle α-synuclein-ir (presynaptic protein) was reduced (trend) in 6-OHDA treated monkeys; insoluble proteinase-K resistant α-synuclein (typical of PD pathology) was not observed. In the adrenal medulla, 6-OHDA monkeys had significantly reduced TH-ir and aminoacid decarboxylase-ir. Our results confirm that systemic 6-OHDA dosing to nonhuman primates

  20. 6-OHDA-induced hemiparkinsonism and chronic L-DOPA treatment increase dopamine D1-stimulated [(3)H]-GABA release and [(3)H]-cAMP production in substantia nigra pars reticulata of the rat.

    PubMed

    Rangel-Barajas, Claudia; Silva, Isaac; García-Ramírez, Martha; Sánchez-Lemus, Enrique; Floran, Leonor; Aceves, Jorge; Erlij, David; Florán, Benjamín

    2008-10-01

    It has been proposed that striatonigral GABAergic transmission in the substantia nigra reticulata (SNr) is enhanced during Parkinson's disease and subsequent L-DOPA treatment. To evaluate this proposal we determined the effects of activating dopamine D1 receptors on depolarization induced [(3)H]-GABA release and on [(3)H]-cAMP accumulation in slices of SNr of rats with unilateral 6-OHDA lesions with and without l-DOPA treatment. Denervation increased depolarization induced D1-stimulated [(3)H]-GABA release, while repeated L-DOPA treatment further enhanced this response. Both also enhanced the effects of forskolin on [(3)H]-cAMP production and [(3)H]-GABA release, while neither modified the stimulating effects of 8-Br-cAMP on the release. These results shown that, after 6-OHDA lesions and l-DOPA treatment, cAMP signaling is enhanced. Furthermore, the results suggest that activation of sites in the signaling cascade downstream of cAMP synthesis is not required to increase release.

  1. An enteric nervous system progenitor cell implant promotes a behavioral and neurochemical improvement in rats with a 6-OHDA-induced lesion.

    PubMed

    Parra-Cid, Carmen; García-López, Julieta; García, Esperanza; Ibarra, Clemente

    2014-01-01

    The enteric nervous system (ENS) of mammals is derived from neural crest (NC) cells during embryogenesis and at the beginning of postnatal life. However, neural progenitor cells from the ENS (or ENSPC) are also found in the adult intestine and can be used for neuronal regeneration in diseases that lead to a loss of cell population, such as Parkinson's disease (PD), in which there is a decrease of dopaminergic neurons. The objective of this study was to evaluate the capacity of ENSPC to restore damaged nervous tissue and to show that they are functional for a behavioral and neurochemical recovery. We found that animals with ENSPC implants exhibited a motor recovery of 35% vs. the lesion group. In addition, DA levels were partially restored in 34%, while Homovanillic acid (HVA) levels remained at 21% vs. the group with a 6-Hydroxydopamine (6-OHDA)-induced lesion, suggesting that ENSPC represent a possible alternative in the study of cell transplants and the preservation of functional dopaminergic neurons in PD. Copyright © 2014. Published by Elsevier Inc.

  2. RETRACTED: 6-OHDA-induced apoptosis and mitochondrial dysfunction are mediated by early modulation of intracellular signals and interaction of Nrf2 and NF-κB factors.

    PubMed

    Tobón-Velasco, Julio C; Limón-Pacheco, Jorge H; Orozco-Ibarra, Marisol; Macías-Silva, Marina; Vázquez-Victorio, Genaro; Cuevas, Elvis; Ali, Syed F; Cuadrado, Antonio; Pedraza-Chaverrí, José; Santamaría, Abel

    2013-02-08

    6-Hydroxydopamine (6-OHDA) is a neurotoxin that generates an experimental model of Parkinson's disease in rodents and is commonly employed to induce a lesion in dopaminergic pathways. The characterization of those molecular mechanisms linked to 6-OHDA-induced early toxicity is needed to better understand the cellular events further leading to neurodegeneration. The present work explored how 6-OHDA triggers early downstream signaling pathways that activate neurotoxicity in the rat striatum. Mitochondrial function, caspases-dependent apoptosis, kinases signaling (Akt, ERK 1/2, SAP/JNK and p38) and crosstalk between nuclear factor kappa B (NF-κB) and nuclear factor-erythroid-2-related factor 2 (Nrf2) were evaluated at early times post-lesion. We found that 6-OHDA initiates cell damage via mitochondrial complex I inhibition, cytochrome c and apoptosis-inducing factor (AIF) release, as well as activation of caspases 9 and 3 to induce apoptosis, kinase signaling modulation and NF-κB-mediated inflammatory responses, accompanied by inhibition of antioxidant systems regulated by the Nrf2 pathway. Our results suggest that kinases SAP/JNK and p38 up-regulation may play a role in the early stages of 6-OHDA toxicity to trigger intrinsic pathways for apoptosis and enhanced NF-κB activation. In turn, these cellular events inhibit the activation of cytoprotective mechanisms, thereby leading to a condition of general damage.

  3. Prostaglandin receptor EP2 protects dopaminergic neurons against 6-OHDA-mediated low oxidative stress

    PubMed Central

    Carrasco, Emilce; Werner, Peter; Casper, Diana

    2008-01-01

    Dopaminergic neurons in the substantia nigra (SN) selectively die in Parkinson’s disease (PD), but it is unclear how and why this occurs. Recent findings implicate prostaglandin E2 (PGE2) and two of its four receptors, namely EP1 and EP2, as mediators of degenerative and protective events in situations of acute and chronic neuronal death. EP1 activation can exacerbate excitotoxic damage in stroke models and our recent study showed that EP1 activation may explain the selective sensitivity of dopaminergic neurons to oxidative stress. Conversely, EP2 activation may be neuroprotective, although toxic effects have also been demonstrated. Here we investigated if and how EP2 activation might alter the survival of dopaminergic neurons following selective low-level oxidative injury evoked by the neurotoxin 6-hydroxydopamine (6-OHDA) in primary neuronal cultures prepared from embryonic rat midbrain. We found that cultured dopaminergic neurons displayed EP2 receptors. Butaprost, a selective EP2 agonist, significantly reduced 6-OHDA neurotoxicity. EP2 receptors are coupled to stimulatory G-proteins (Gs), which activate adenylate cyclase, increasing cAMP synthesis, which then activates protein kinase A (PKA). Both dibutyryl cAMP and forskolin reduced dopaminergic cell loss after 6-OHDA exposure. Conversely, KT5720 and H-89, two structurally distinct high-affinity PKA inhibitors, abolished the protective effect of butaprost, implicating cAMP-dependent PKA activity in the neuroprotection by EP2 activation. Finally, we show that melanized dopaminergic neurons in the human SN express EP2. This pathway warrants consideration as a neuroprotective strategy for PD. PMID:18597941

  4. Prostaglandin receptor EP2 protects dopaminergic neurons against 6-OHDA-mediated low oxidative stress.

    PubMed

    Carrasco, Emilce; Werner, Peter; Casper, Diana

    2008-08-15

    Dopaminergic neurons in the substantia nigra (SN) selectively die in Parkinson's disease (PD), but it is unclear how and why this occurs. Recent findings implicate prostaglandin E(2) (PGE(2)) and two of its four receptors, namely EP1 and EP2, as mediators of degenerative and protective events in situations of acute and chronic neuronal death. EP1 activation can exacerbate excitotoxic damage in stroke models and our recent study showed that EP1 activation may explain the selective sensitivity of dopaminergic neurons to oxidative stress. Conversely, EP2 activation may be neuroprotective, although toxic effects have also been demonstrated. Here we investigated if and how EP2 activation might alter the survival of dopaminergic neurons following selective low-level oxidative injury evoked by the neurotoxin 6-hydroxydopamine (6-OHDA) in primary neuronal cultures prepared from embryonic rat midbrain. We found that cultured dopaminergic neurons displayed EP2 receptors. Butaprost, a selective EP2 agonist, significantly reduced 6-OHDA neurotoxicity. EP2 receptors are coupled to stimulatory G-proteins (Gs), which activate adenylate cyclase, increasing cAMP synthesis, which then activates protein kinase A (PKA). Both dibutyryl cAMP and forskolin reduced dopaminergic cell loss after 6-OHDA exposure. Conversely, KT5720 and H-89, two structurally distinct high-affinity PKA inhibitors, abolished the protective effect of butaprost, implicating cAMP-dependent PKA activity in the neuroprotection by EP2 activation. Finally, we show that melanized dopaminergic neurons in the human SN express EP2. This pathway warrants consideration as a neuroprotective strategy for PD.

  5. High frequency electro-acupuncture enhances striatum DAT and D1 receptor expression, but decreases D2 receptor level in 6-OHDA lesioned rats.

    PubMed

    Rui, Gao; Guangjian, Zhang; Yong, Wang; Jie, Feng; Yanchao, Cui; Xi, Jia; Fen, Li

    2013-01-15

    The direct effects of electro-acupuncture (EA) on the dopaminergic neurotransmitter system in Parkinson's disease (PD) patients remain elusive. In the present study, 0, 2 or 100Hz EA was applied to acupoints Sanyinjiao (SP6), Yanglingquan (GB34) and Zusanli (ST36) in a rat model unilaterally lesioned by 6-hydroxydopamine. Rotational behavior tests were performed and the animals were then decapitated. Levels of striatal dopamine (DA), dopamine transporter, and D1- and D2-like DA receptors were subsequently evaluated. EA at 100 Hz was shown to significantly enhance survival of dopaminergic neurons in the substantia nigra (52.10 ± 11.41% of the level on the non-lesioned rats vs. 21.22 ± 5.52% in the non-EA group, P<0.05) and reduce motor deficits (207.80 ± 31.14 vs. 476.11 ± 68.80 turns/30 min, P<0.05), whereas it only slightly restored the 6-hydroxydopamine-induced loss of striatal DA (P>0.05 vs. the non-EA group). There was a 253.78% increase in dopamine transporter protein expression in the striatum in the 100 Hz EA group (P<0.05 vs. the non-EA group). Moreover, high frequency EA induced increases in striatal D1-like receptor mRNA and protein levels of 81.88% and 62.62%, respectively (P<0.001 and P<0.05 vs. the non-EA group). However, the D2-like DA receptor up-regulation observed in the non-EA group was suppressed in high frequency group (P>0.05 vs. the sham operation group). These findings suggest that high-frequency EA might work by acting on presynaptic dopamine transporter and postsynaptic dopamine receptors simultaneously to achieve a therapeutic effect in PD patients and models. This might shed some light on the mechanism by which EA affects the DA neurotransmitter system.

  6. Temporal Changes of CB1 Cannabinoid Receptor in the Basal Ganglia as a Possible Structure-Specific Plasticity Process in 6-OHDA Lesioned Rats

    PubMed Central

    Chaves-Kirsten, Gabriela P.; Mazucanti, Caio H. Y.; Real, Caroline C.; Souza, Bruna M.; Britto, Luiz R. G.; Torrão, Andréa S.

    2013-01-01

    The endocannabinoid system has been implicated in several neurobiological processes, including neurodegeneration, neuroprotection and neuronal plasticity. The CB1 cannabinoid receptors are abundantly expressed in the basal ganglia, the circuitry that is mostly affected in Parkinson’s Disease (PD). Some studies show variation of CB1 expression in basal ganglia in different animal models of PD, however the results are quite controversial, due to the differences in the procedures employed to induce the parkinsonism and the periods analyzed after the lesion. The present study evaluated the CB1 expression in four basal ganglia structures, namely striatum, external globus pallidus (EGP), internal globus pallidus (IGP) and substantia nigra pars reticulata (SNpr) of rats 1, 5, 10, 20, and 60 days after unilateral intrastriatal 6-hydroxydopamine injections, that causes retrograde dopaminergic degeneration. We also investigated tyrosine hydroxylase (TH), parvalbumin, calbindin and glutamic acid decarboxylase (GAD) expression to verify the status of dopaminergic and GABAergic systems. We observed a structure-specific modulation of CB1 expression at different periods after lesions. In general, there were no changes in the striatum, decreased CB1 in IGP and SNpr and increased CB1 in EGP, but this increase was not sustained over time. No changes in GAD and parvalbumin expression were observed in basal ganglia, whereas TH levels were decreased and the calbindin increased in striatum in short periods after lesion. We believe that the structure-specific variation of CB1 in basal ganglia in the 6-hydroxydopamine PD model could be related to a compensatory process involving the GABAergic transmission, which is impaired due to the lack of dopamine. Our data, therefore, suggest that the changes of CB1 and calbindin expression may represent a plasticity process in this PD model. PMID:24116178

  7. Dynamic of neurochemical alterations in striatum, hippocampus and cortex after the 6-OHDA mesostriatal lesion.

    PubMed

    Zhang, Sheng; Gui, Xue-Hong; Xue, Zhong-Feng; Huang, Li-Ping; Fang, Ruo-Ming; Ke, Xue-Hong; Li, Ling; Fang, Yong-Qi

    2014-08-01

    Immediate neurochemical alterations produced by 6-OHDA could explain the general toxic pattern in the central nervous system. However, no evidences describe the effects of 6-OHDA on early changes of neurotransmitters in rats' striatum, cortex and hippocampus. In our study, unilateral 6-OHDA injection into medial forebrain bundle (MFB) was used in rats, then five neurotransmitters were analyzed at 3, 6, 12, 24, 48 and 72 h, respectively. Results showed that 6-OHDA injection caused a sharp decline of striatal dopamine (DA) levels in the first 12h followed by a further reduction between 12 and 48 h. However, striatal levels of homovanillic acid (HVA) were stable in the first 12h and showed a marked reduction between 12 and 24h. Striatal levels of 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) decreased linearly for 72 h, whereas levels of norepinephrine (NE) showed a slight reduction in the first 48 h, and returned back to normal afterwards. Striatal HVA/DA ratio increased significantly in the first 12h, but 5-HIAA/5-HT ratio showed a sharp increase between 12 and 72 h. Besides, neurochemical alterations were also found in hippocampus and cortex, and the correlations of neurotransmitters were analyzed. Our study indicated that NE system had little influence in the early phase of 6-OHDA injection, moreover, early neurochemical alterations were involved with striatum, hippocampus and cortex.

  8. Carbidopa-based modulation of the functional effect of the AAV2-hAADC gene therapy in 6-OHDA lesioned rats.

    PubMed

    Ciesielska, Agnieszka; Sharma, Nitasha; Beyer, Janine; Forsayeth, John; Bankiewicz, Krystof

    2015-01-01

    Progressively blunted response to L-DOPA in Parkinson's disease (PD) is a critical factor that complicates long-term pharmacotherapy in view of the central importance of this drug in management of the PD-related motor disturbance. This phenomenon is likely due to progressive loss of one of the key enzymes involved in the biosynthetic pathway for dopamine in the basal ganglia: aromatic L-amino acid decarboxylase (AADC). We have developed a gene therapy based on an adeno-associated virus encoding human AADC (AAV2-hAADC) infused into the Parkinsonian striatum. Although no adverse clinical effects of the AAV2-hAADC gene therapy have been observed so far, the ability to more precisely regulate transgene expression or transgene product activity could be an important long-term safety feature. The present study was designed to define pharmacological regulation of the functional activity of AAV2-hAADC transgene product by manipulating L-DOPA and carbidopa (AADC inhibitor) administration in hemi-parkinsonian rats. Thirty days after unilateral striatal infusion of AAV2-hAADC, animals displayed circling behavior and acceleration of dopamine metabolism in the lesioned striatum after administration of a low dose of L-DOPA (5 mg/kg) co-administered with 1.25 mg/kg of carbidopa. This phenomenon was not observed in control AAV2-GFP-treated rats. Withdrawal of carbidopa from a daily L-DOPA regimen decreased the peripheral L-DOPA pool, resulting in almost total loss of L-DOPA-induced behavioral response in AAV2-hAADC rats and a significant decline in striatal dopamine turnover. The serum L-DOPA level correlated with the magnitude of circling behavior in AAV2-hAADC rats. Additionally, AADC activity in homogenates of lesioned striata transduced by AAV2-AADC was 10-fold higher when compared with AAV2-GFP-treated control striata, confirming functional transduction. Our data suggests that the pharmacological regulation of circulating L-DOPA might be effective in the controlling of

  9. Intracranial injection of drugs: comparison of diffusion of 6-OHDA and guanethidine.

    PubMed

    Evans, B K; Armstrong, S; Singer, G; Cook, R D; Burnstock, G

    1975-01-01

    Marked differences in extent of diffusion have been shown with the fluorescence histochemical method between guanethidine and 6-OHDA(64 mug in 2 mul) when injected acutely or chronically into the lateral hypothalamus, the substantia nigra or the amygdala of the rat brain. Cannulation damage up to 1 mm in diameter and attributed to the implantation of cannulae and placebo injection was observed. A further area of generalized damage occurred following the injection of drugs and was far greater for 6-OHDA (2 mm) than for guanethidien (0.3 mm). Guanethidine, but not 6-OHDA, caused specific damage to catecholamine-containing nerurons up to a distance of at least 3 mm and more from the cannula tip. These striking differences between the effects of intracranial injection of 6-OHDA and guanethidine are discussed in terms of the uptake and degradation of the two drugs and the anatomical features of the injection site; they are not explicable in terms of experimental conditions such as concentration, volume of injection, molecular weight or lipid solubility. The different patterns of damage would not easily be distinguished by biochemical analyses and the catecholamine specificity of 6-OHDA in studies of the central nervous system must be seriously questioned. Vascularization of chronically implanted cannula tracks and the presence of anatomical diffusion barriers are also discussed in relation to the diffusion of drugs injected intracranially.

  10. RING finger protein 11 (RNF11) modulates susceptibility to 6-OHDA-induced nigral degeneration and behavioral deficits through NF-κB signaling in dopaminergic cells.

    PubMed

    Pranski, Elaine L; Dalal, Nirjari V; Sanford, Carson Van; Herskowitz, Jeremy H; Gearing, Marla; Lazo, Carlos; Miller, Gary W; Lah, James J; Levey, Allan I; Betarbet, Ranjita S

    2013-06-01

    Chronic activation of the NF-κB pathway is associated with progressive neurodegeneration in Parkinson's disease (PD). Given the role of neuronal RING finger protein 11 (RNF11) as a negative regulator of the NF-κB pathway, in this report we investigated the function of RNF11 in dopaminergic cells in PD-associated neurodegeneration. We found that RNF11 knockdown in an in vitro model of PD mediated protection against 6-OHDA-induced toxicity. In converse, over-expression of RNF11 enhanced 6-OHDA-induced dopaminergic cell death. Furthermore, by directly manipulating NF-κB signaling, we showed that the observed RNF11-enhanced 6-OHDA toxicity is mediated through inhibition of NF-κB-dependent transcription of TNF-α, antioxidants GSS and SOD1, and anti-apoptotic factor BCL2. Experiments in an in vivo 6-OHDA rat model of PD recapitulated the in vitro results. In vivo targeted RNF11 over-expression in nigral neurons enhanced 6-OHDA toxicity, as evident by increased amphetamine-induced rotations and loss of nigral dopaminergic neurons as compared to controls. This enhanced toxicity was coupled with the downregulation of NF-κB transcribed GSS, SOD1, BCL2, and neurotrophic factor BDNF mRNA levels, in addition to decreased TNF-α mRNA levels in ventral mesenchephalon samples. In converse, knockdown of RNF11 was associated with protective phenotypes and increased expression of above-mentioned NF-κB transcribed genes. Collectively, our in vitro and in vivo data suggest that RNF11-mediated inhibition of NF-κB in dopaminergic cells exaggerates 6-OHDA toxicity by inhibiting neuroprotective responses while loss of RNF11 inhibition on NF-κB activity promotes neuronal survival. The decreased expression of RNF11 in surviving cortical and nigral tissue detected in PD patients, thus implies a compensatory response in the diseased brain to PD-associated insults. In summary, our findings demonstrate that RNF11 in neurons can modulate susceptibility to 6-OHDA toxicity through NF

  11. RING finger protein 11 (RNF11) modulates susceptibility to 6-OHDA-induced nigral degeneration and behavioral deficits through NF-κB signaling in dopaminergic cells

    PubMed Central

    Pranski, Elaine L.; Dalal, Nirjari V.; Van Sanford, Carson; Herskowitz, Jeremy H.; Gearing, Marla; Lazo, Carlos; Miller, Gary W.; Lah, James J.; Levey, Allan I.; Betarbet, Ranjita S.

    2013-01-01

    Chronic activation of the NF-κB pathway is associated with progressive neurodegeneration in Parkinson’s disease (PD). Given the role of neuronal RING finger protein 11 (RNF11) as a negative regulator of the NF-κB pathway, in this report we investigated the function of RNF11 in dopaminergic cells in PD-associated neurodegeneration. We found that RNF11 knock-down in an in vitro model of PD mediated protection against 6-OHDA-induced toxicity. In converse, over-expression of RNF11 enhanced 6-OHDA-induced dopaminergic cell death. Furthermore, by directly manipulating NF-κB signaling, we showed that the observed RNF11-enhanced 6-OHDA toxicity is mediated through inhibition of NF-κB-dependent transcription of TNF-α, antioxidants GSS and SOD1, and anti-apoptotic factor BCL2. Experiments in an in vivo 6-OHDA rat model of PD recapitulated the in vitro results. In vivo targeted RNF11 over-expression in nigral neurons enhanced 6-OHDA toxicity, as evident by increased amphetamine-induced rotations and loss of nigral dopaminergic neurons as compared to controls. This enhanced toxicity was coupled with down-regulation of NF-κB transcribed GSS, SOD1, BCL2, and neurotrophic factor BDNF mRNA levels, in addition to decreased TNF-α mRNA levels in ventral mesenchephalon samples. In converse, knockdown of RNF11 was associated with protective phenotypes and increased expression of above-mentioned NF-κB transcribed genes. Collectively, our in vitro and in vivo data suggest that RNF11-mediated inhibition of NF-κB in dopaminergic cells exaggerates 6-OHDA toxicity by inhibiting neuroprotective responses while loss of RNF11 inhibition on NF-κB activity promotes neuronal survival. The decreased expression of RNF11 in surviving cortical and nigral tissue detected in PD patients, thus implies a compensatory response in the diseased brain to PD-associated insults. In summary, our findings demonstrate that RNF11 in neurons can modulate susceptibility to 6-OHDA toxicity through NF

  12. Blockade of RyRs in the ER Attenuates 6-OHDA-Induced Calcium Overload, Cellular Hypo-Excitability and Apoptosis in Dopaminergic Neurons

    PubMed Central

    Huang, Lu; Xue, Ying; Feng, DaYun; Yang, RuiXin; Nie, Tiejian; Zhu, Gang; Tao, Kai; Gao, GuoDong; Yang, Qian

    2017-01-01

    Calcium (Ca2+) dyshomeostasis induced by endoplasmic reticulum (ER) stress is an important molecular mechanism of selective dopaminergic (DA) neuron loss in Parkinson’s disease (PD). Inositol 1,4,5-triphosphate receptors (IP3Rs) and ryanodine receptors (RyRs), which are located on the ER surface, are the main endogenous Ca2+ release channels and play crucial roles in regulating Ca2+ homeostasis. However, the roles of these endogenous Ca2+ release channels in PD and their effects on the function and survival of DA neurons remain unknown. In this study, using a 6-hydroxydopamine (6-OHDA)-induced in vitro PD model (SN4741 Cell line), we found that 6-OHDA significantly increased cytoplasmic Ca2+ levels ([Ca2+]i), which was attenuated by pretreatment with 4-phenyl butyric acid (4-PBA; an ER stress inhibitor) or ryanodine (a RyRs blocker). In addition, in acute midbrain slices of male Sprague-Dawley rats, we found that 6-OHDA reduced the spike number and rheobase of DA neurons, which were also reversed by pretreatment with 4-PBA and ryanodine. TUNEL staining and MTT assays also showed that 4-PBA and ryanodine obviously alleviated 6-OHDA-induced cell apoptosis and devitalization. Interestingly, a IP3Rs blocker had little effect on the above 6-OHDA-induced neurotoxicity in DA neurons. In conclusion, our findings provide evidence of the different roles of IP3Rs and RyRs in the regulation of endogenous Ca2+ homeostasis, neuronal excitability, and viability in DA neurons, and suggest a potential therapeutic strategy for PD by inhibiting the RyRs Ca2+ channels in the ER. PMID:28316566

  13. Post 6-OHDA lesion exposure to stress affects neurotrophic factor expression and aggravates motor impairment.

    PubMed

    Ngema, Phumzile Nomfundo; Mabandla, Musa Vuyisile

    2017-08-01

    Chronic exposure to stress amplifies locomotor deficits and exacerbates dopamine neuron loss in an animal model for Parkinson's disease. The release of neurotrophic factors such as glial cell-line derived neurotrophic factor (GDNF) and neurotrophin-3 (NT-3) following neuronal injury attenuates exacerbated degeneration of these neurons. In this study, the neurotoxin 6-hydroxydopamine (6-OHDA) was injected unilaterally into the medial forebrain bundle of male Sprague Dawley rats. A subset of these rats was subjected to post-lesion restraint stress after which the effect of exposure to stress on locomotor activity (forelimb akinesia test), neurotrophic factor (GDNF and NT-3) and corticosterone concentration was assessed. Exposure to post-lesion stress resulted in increased preference to use the unimpaired forelimb (forelimb ipsilateral to the lesioned hemisphere) in the forelimb akinesia test. The expected increase in both GDNF and NT-3 concentration following injury was not present in the stressed animals. However, both the non-stressed and stressed lesioned groups had decreased neurotrophic factor concentration at one and two weeks post lesion. This decrease was exaggerated in the stressed rats. The decrease in neurotrophic factor concentration was accompanied by an increase in corticosterone concentration in the stressed rats. These findings demonstrate that exposure to post-6-OHDA lesion stress exaggerates dopamine neurodegeneration and enhance motor impairment. This suggests that conditions that result in a hyper-activated hypothalamic-pituitary-adrenal axis such as depression which is concomitant to a Parkinson's disease diagnosis may be responsible for enhanced dopamine depletion by attenuating neurotrophic factor concentration elevation in the nigrostriatal pathway following neuronal injury.

  14. Intrastriatal grafts of fetal ventral mesencephalon improve allodynia-like withdrawal response to mechanical stimulation in a rat model of Parkinson's disease.

    PubMed

    Takeda, Ryuichiro; Ishida, Yasushi; Ebihara, Kosuke; Abe, Hiroshi; Matsuo, Hisae; Ikeda, Tetsuya; Koganemaru, Go; Kuramashi, Aki; Funahashi, Hideki; Magata, Yasuhiro; Kawai, Keiichi; Nishimori, Toshikazu

    2014-06-24

    We previously reported that a unilateral 6-hydroxydopamine (6-OHDA) rat model of Parkinson's disease showed allodynia-like withdrawal response to mechanical stimulation of the ipsilateral side of the rat hindpaw. The goal of this study was to investigate the effect of intrastriatal grafts of fetal ventral mesencephalon (VM) on the withdrawal response in 6-OHDA rats. The withdrawal threshold in response to the mechanical stimulation of the rat hindpaw was measured using von Frey filaments. In the ipsilateral side of the 6-OHDA lesions, the withdrawal threshold in response to mechanical stimulation significantly increased in 6-OHDA rats with VM grafts compared with those with sham grafts, but did not change in the contralateral side at 5 weeks after transplantation. The present results suggest that the intrastriatal grafts of fetal VM may relieve pain sensation induced by mechanical stimulation in 6-OHDA rats. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  15. Adrenal Medullary Grafts Restore Olfactory Deficits and Catecholamine Levels of 6-OHDA Amygdala Lesioned Animals

    PubMed Central

    Fernández-Ruiz, Juan; Guzmán, Rubén; Martínez, María Dolores; Miranda, María Isabel; Bermúdez-Rattoni, Federico; Drucker-Colín, René

    1993-01-01

    Aside from motor and cognitive deficits, Parkinson patients also manifest a little-studied olfactory deficit. Since in Parkinson's disease there is a dopamine depletion of the amygdala due to mesocorticolimbic system degeneration, we decided to test olfactory and taste performance of 6-OHDA amygdala lesioned rats, as well as the possible restoration of either function with adrenal medullary transplants. Two 6-OHDA lesioned groups and one control group were tested in the potentiation of odor by taste aversion paradigm. On taste aversion none of the groups showed any impairment. In contrast, the 6-OHDA lesioned rats showed a marked impairment in olfactory aversion. At this point, one of the lesioned groups received a bilateral adrenal medullary graft within the lesioned area. After two months, all groups were submitted again to the behavioral paradigm. Taste remained unaffected, but the lesioned only group did not recover either olfactory aversion or normal catecholamine levels. The grafted group, on the other hand, restored olfactory aversion and catecholamine levels. It can be concluded from this study that catecholamine depletion of the amygdala is sufficient to produce a selective olfactory deficit, not accompanied by taste impairments, and that such a deficit can be reversed by adrenal medullary transplants, which in turn restore catecholamine levels. PMID:7948179

  16. Early expression of the receptor for advanced glycation end products in a toxic model produced by 6-hydroxydopamine in the rat striatum.

    PubMed

    Serratos, Iris N; Castellanos, Pilar; Pastor, Nina; Millán-Pacheco, César; Colín-González, Ana Laura; Rembao, Daniel; Pérez-Montfort, Ruy; Cabrera, Nallely; Sánchez-García, Aurora; Gómez, Isabel; Rangel-López, Edgar; Santamaria, Abel

    2016-04-05

    The receptor for advanced glycation end products (RAGE) is commonly involved in different neurodegenerative and inflammatory disorders. The cellular signaling associated to RAGE activation may occur upon binding to different ligands. In this study we investigated whether the toxic model produced by 6-hydroxydopamine (6-OHDA) in rats comprises early noxious responses related to RAGE-mediated signaling cascades. In order to explore a possible interaction between 6-OHDA and RAGE, affinity parameters of RAGE with 6-OHDA were estimated by different means. The possible binding sites of 6-OHDA with the VC1 homodimer for both rat and human RAGE were also modeled. Our results show that the striatal infusion of 6-OHDA recruits RAGE upregulation, as evidenced by an early expression of the receptor. 6-OHDA was also found to bind the VC1 homodimer, although its affinity was moderate when compared to other ligands. This work contributes to the understanding of the role of RAGE activation for 6-OHDA-induced neurotoxicity.

  17. Fixed-ratio discrimination training as replacement therapy in Parkinson's disease: studies in a 6-hydroxydopamine-treated rat model.

    PubMed

    Van Keuren, K R; Stodgell, C J; Schroeder, S R; Tessel, R E

    1998-01-05

    Severe 6-hydroxydopamine (6-OHDA)-induced neostriatal dopamine (DA) depletion is generally held to be irreversible. Adult rats administered 6-OHDA soon after weaning, or neonatally, respectively model Parkinson's disease (PD) and Lesch-Nyhan syndrome (LNS). Prior studies in our laboratory indicate that prolonged training on incrementally more difficult fixed-ratio (FR) discriminations can reverse 'irreversible' 6-OHDA-induced neostriatal DA depletion in adult LNS rats. The present study evaluated the effects of such training on neostriatal DA depletion and its functional consequences in adult PD and control (vehicle-injected) rats. After recovery from 6-OHDA-induced hypophagia, rats were sacrificed to assess neostriatal DA depletion magnitude, or were food-deprived and either subjected to food-maintained operant FR discrimination training or allowed to remain in their home cages. 6-OHDA treatment antagonized amphetamine (AMP)-induced increases in brief rearing behavior and locomotor activity in 3-month-old PD rats prior to training, and reduced operant response rates throughout training without affecting learning rates. One week after training, AMP-increased locomotor and brief-rearing frequencies were augmented in all groups except trained controls, and the prior inhibitory effect of 6-OHDA treatment on AMP-increased behavioral frequencies was essentially eliminated. Cumulative apomorphine (APO) dose-effect curve (0.1-3.2 mg/kg) construction 3 weeks post-training revealed that 6-OHDA treatment abolished APO-induced intense licking behavior. However, training eliminated the hyperresponsiveness of 6-OHDA-treated rats to the locomotor- and brief-rearing stimulant effects of APO but did not affect the depletion of neostriatal DA. Nevertheless, 6-OHDA-induced increases in neostriatal DOPAC/DA and HVA/DA ratios were normalized by age/food-deprivation while that of 3MT/DA was not. These findings suggest that training reduces the functional responsiveness of at least some

  18. Intranasal Administration of GDNF Protects Against Neural Apoptosis in a Rat Model of Parkinson's Disease Through PI3K/Akt/GSK3β Pathway.

    PubMed

    Yue, Peijian; Gao, Lin; Wang, Xuejing; Ding, Xuebing; Teng, Junfang

    2017-02-28

    Glial cell line-derived neurotrophic factor (GDNF) plays important roles in protecting the damaged or dying dopamine neurons in the animal models of Parkinson's disease (PD). This study was to determine the effect and mechanisms of GDNF on the apoptosis of neurons in 6-hydroxydopamine (6-OHDA) induced Parkinson's disease model of rats. Healthy male Sprague-Dawley rats (220-240 g) were randomly divided into six groups (n = 10). 6-OHDA was used to establish the PD rat model. Tyrosine hydroxylase (TH) immunohistochemistry was used to assess the neuron loss in 6-OHDA-lesioned rats. TUNEL and western blot were used to identify the effects and mechanisms of GDNF in the rat model of PD. The numbers of TH-positive neurons in the 6-OHDA-injected lesioned substantia nigra (SN) decreased significantly compared with the Sham group. GDNF treatment effectively ameliorated the apoptosis of neuronal cells in SN induced by 6-OHDA. In addition, GDNF significantly increased serine protein kinase B (Akt) and glycogen synthase kinase 3 beta (GSK3β) phosphorylation induced by 6-OHDA. In contrast, application of LY294002 or triciribine reversed the roles of GDNF in PD models. The results implicated that the anti-apoptosis effects of GDNF in neurons might be mediated through PI3K/Akt/GSK3β pathway. Therefore, GDNF may be a promising agent for PD treatment.

  19. CD200-CD200R dysfunction exacerbates microglial activation and dopaminergic neurodegeneration in a rat model of Parkinson's disease

    PubMed Central

    2011-01-01

    Background Increasing evidence suggests that microglial activation may participate in the aetiology and pathogenesis of Parkinson's disease (PD). CD200-CD200R signalling has been shown to be critical for restraining microglial activation. We have previously shown that expression of CD200R in monocyte-derived macrophages, induced by various stimuli, is impaired in PD patients, implying an intrinsic abnormality of CD200-CD200R signalling in PD brain. Thus, further in vivo evidence is needed to elucidate the role of malfunction of CD200-CD200R signalling in the pathogenesis of PD. Methods 6-hydroxydopamine (6-OHDA)-lesioned rats were used as an animal model of PD. CD200R-blocking antibody (BAb) was injected into striatum to block the engagement of CD200 and CD200R. The animals were divided into three groups, which were treated with 6-OHDA/Veh (PBS), 6-OHDA/CAb (isotype control antibody) or 6-OHDA/BAb, respectively. Rotational tests and immunohistochemistry were employed to evaluate motor deficits and dopaminergic neurodegeneration in animals from each group. HPLC analysis was used to measure monoamine levels in striatum. Morphological analysis and quantification of CD11b- (or MHC II-) immunoreactive cells were performed to investigate microglial activation and possible neuroinflammation in the substantia nigra (SN). Finally, ELISA was employed to assay protein levels of proinflammatory cytokines. Results Compared with 6-OHDA/CAb or 6-OHDA/Veh groups, rats treated with 6-OHDA/BAb showed a significant increase in counts of contralateral rotation and a significant decrease in TH-immunoreactive (TH-ir) neurons in SN. A marked decrease in monoamine levels was also detected in 6-OHDA/BAb-treated rats, in comparison to 6-OHDA/Veh-treated ones. Furthermore, remarkably increased activation of microglia as well as up-regulation of proinflammatory cytokines was found concomitant with dopaminergic neurodegeneration in 6-OHDA/BAb-treated rats. Conclusions This study shows that

  20. Protein Kinase D1 (PKD1) Phosphorylation Promotes Dopaminergic Neuronal Survival during 6-OHDA-Induced Oxidative Stress

    PubMed Central

    Asaithambi, Arunkumar; Ay, Muhammet; Jin, Huajun; Gosh, Anamitra; Anantharam, Vellareddy; Kanthasamy, Arthi; Kanthasamy, Anumantha G.

    2014-01-01

    Oxidative stress is a major pathophysiological mediator of degenerative processes in many neurodegenerative diseases including Parkinson’s disease (PD). Aberrant cell signaling governed by protein phosphorylation has been linked to oxidative damage of dopaminergic neurons in PD. Although several studies have associated activation of certain protein kinases with apoptotic cell death in PD, very little is known about protein kinase regulation of cell survival and protection against oxidative damage and degeneration in dopaminergic neurons. Here, we characterized the PKD1-mediated protective pathway against oxidative damage in cell culture models of PD. Dopaminergic neurotoxicant 6-hydroxy dopamine (6-OHDA) was used to induce oxidative stress in the N27 dopaminergic cell model and in primary mesencephalic neurons. Our results indicated that 6-OHDA induced the PKD1 activation loop (PKD1S744/S748) phosphorylation during early stages of oxidative stress and that PKD1 activation preceded cell death. We also found that 6-OHDA rapidly increased phosphorylation of the C-terminal S916 in PKD1, which is required for PKD1 activation loop (PKD1S744/748) phosphorylation. Interestingly, negative modulation of PKD1 activation by RNAi knockdown or by the pharmacological inhibition of PKD1 by kbNB-14270 augmented 6-OHDA-induced apoptosis, while positive modulation of PKD1 by the overexpression of full length PKD1 (PKD1WT) or constitutively active PKD1 (PKD1S744E/S748E) attenuated 6-OHDA-induced apoptosis, suggesting an anti-apoptotic role for PKD1 during oxidative neuronal injury. Collectively, our results demonstrate that PKD1 signaling plays a cell survival role during early stages of oxidative stress in dopaminergic neurons and therefore, positive modulation of the PKD1-mediated signal transduction pathway can provide a novel neuroprotective strategy against PD. PMID:24806360

  1. Neuroprotective potential of atorvastatin and simvastatin (HMG-CoA reductase inhibitors) against 6-hydroxydopamine (6-OHDA) induced Parkinson-like symptoms.

    PubMed

    Kumar, Anil; Sharma, Neha; Gupta, Amit; Kalonia, Harikesh; Mishra, Jitendriya

    2012-08-30

    Neuro-inflammation and oxidative stress plays a key role in the pathophysiology of Parkinson's disease (PD). Studies demonstrated that neuro-inflammation and associated infiltration of inflammatory cells into central nervous system are inhibited by 3-hydroxy-3-methyl glutaryl co-enzyme A (HMG-CoA) reductase inhibitors. Based on these experimental evidences, the present study has been designed to evaluate the neuroprotective effect of HMG-CoA reductase inhibitors (atorvastatin and simvastatin) against 6-hydroxydopamine (6-OHDA) induced unilateral lesion model of PD. In the present study, the animals were divided into nine groups (n=15 per group). Group I: Naive (without treatment); Group II: Sham (surgery performed, vehicle administered); Group III: Atorvastatin (20mg/kg); Group IV: Simvastatin (30 mg/kg); Group V: Control [Intrastriatal 6-OHDA (20 μg; single unilateral injection)]; Groups VI and VII: 6-OHDA (20 μg)+atorvastatin (10mg/kg and 20mg/kg) respectively; Groups VIII and IX: 6-OHDA (20 μg)+simvastatin (15 mg/kg and 30 mg/kg) respectively. Intrastriatal administration of 6-OHDA (20 μg; 4 μl of 5 μg/μl) significantly caused impairment in body weight, locomotor activity, rota-rod performance, oxidative defense and mitochondrial enzyme complex activity, and increase in the inflammatory cytokine levels (TNF-α and IL-6) as compared to naive animals. Atorvastatin (20mg/kg) and simvastatin (30 mg/kg) drug treatment significantly improved these behavioral and biochemical alterations restored mitochondrial enzyme complex activities and attenuated neuroinflammatory markers in 6-OHDA (20 μg) treated animals as compared to control group. The findings of the present study demonstrate the neuroprotective potential of statins in experimental model of 6-OHDA induced Parkinson like symptoms.

  2. Botanical Drug Puerarin Attenuates 6-Hydroxydopamine (6-OHDA)-Induced Neurotoxicity via Upregulating Mitochondrial Enzyme Arginase-2.

    PubMed

    Zhao, Jia; Cheng, Yuanyuan; Yang, Chuanbin; Lau, Sam; Lao, Lixing; Shuai, Bo; Cai, Jing; Rong, Jianhui

    2016-05-01

    Inhibition of nitric oxide synthases (NOSs) shows promise to halt the progression of neurodegenerative diseases. The present study was designed to explore whether botanical isoflavone puerarin could attenuate nitric oxide (NO)-mediated neurotoxicity via modulating the enzymes in the L-arginine-NO pathway. Neurotoxin 6-hydroxydopamine (6-OHDA) is well known to induce neurodegeneration via a NO-dependent mechanism. We first validated that puerarin protected rat dopamingeric PC12 cells against 6-OHDA-induced neurotoxicity in a concentration-dependent manner. We subsequently profiled the cellular responses to puerarin by a proteomic response fingerprinting approach. A total of 16 protein spots with >1.5-fold change of intensity were selected and identified by mass spectrometry. As one of puerarin-upregulated proteins, mitochondrial arginase-2 hydrolyzes L-arginine to L-ornithine, thereby competing with neuronal NOS for substrate L-arginine in mitochondria. Thus, we hypothesize that puerain may attenuate nitric oxide (NO)-mediated mitochondrial injury via increasing arginase-2 expression. Western blot and reverse transcription polymerase chain reaction (RT-PCR) analyses confirmed that puerarin increased arginase-2 expression in a concentration- and time-dependent manner. Accordingly, puerarin suppressed 6-OHDA-induced NO production and neurotoxicity in PC12 cells and primary rat midbrain neurons. Arginase inhibitor BEC diminished the effect of puerarin on 6-OHDA-induced NO production and neurotoxicity. The activation of arginase-2 by puerarin represents an endogenous mechanism for specific control of NO-mediated mitochondrial damage. Thus, puerarin is a useful lead for suppressing NO-mediated neurotoxicity in neurodegenerative diseases. Graphical Abstract Arginase-2 dependent mechanism underlying the neuroprotective activity of puerarin.

  3. Intrastriatal chromospheres' transplant reduces nociception in hemiparkinsonian rats.

    PubMed

    Gómez-Paz, Alejandra; Drucker-Colín, René; Milán-Aldaco, Diana; Palomero-Rivero, Marcela; Ambriz-Tututi, Mónica

    2017-09-08

    The present study evaluates the possible antinociceptive effect of chromosphere transplants in rats injected with 6-hydroxydopamine (6-OHDA), a model of Parkinson's disease. Male adult Wistar rats received 40μg/0.5μl of 6-OHDA or 0.5μl of vehicle into the left substantia nigra (SNc). Rats were evaluated for mechanical allodynia, cold allodynia, thermal hyperalgesia and formalin. Rats with altered nociceptive threshold were transplanted with chromospheres. After transplant, rats were evaluated every week. Our results confirm that 6-OHDA injection into rat's SNc reduces mechanical, thermal, and chemical thresholds. Interestingly, chromospheres' transplant reverted 6-OHDA-induced allodynia and hyperalgesia. The antinociceptive effect induced by chromospheres was dopamine D2- and opioid-receptor dependent since sulpiride or naltrexone reverted its effect. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  4. Induction of depressive-like behavior by intranigral 6-OHDA is directly correlated with deficits in striatal dopamine and hippocampal serotonin.

    PubMed

    Santiago, Ronise M; Barbiero, Janaína; Gradowski, Raisa W; Bochen, Suelen; Lima, Marcelo M S; Da Cunha, Cláudio; Andreatini, Roberto; Vital, Maria A B F

    2014-02-01

    Among the non-motor phenomena of Parkinson's disease (PD) are depressive symptoms, with a prevalence of 40-70%. The reason for this high prevalence is not yet clear. The basal ganglia receives dopamine (DA) inputs from the substantia nigra pars compacta (SNpc), which is known to be impaired in PD patients. The neurotransmitter deficiency hypothesis of PD considers that low serotonin (5-hydroxytryptamine [5-HT]) activity in the brain in PD patients is a risk factor for depression. We investigated whether DA depletion promoted by the neurotoxin 6-hydroxydopamine (6-OHDA) is able to induce depressive-like behavior and neurotransmitter alterations that are similar to those observed in PD. To test this hypothesis, we performed intranigral injections of 6-OHDA in male Wistar rats and conducted motor behavior, depressive-like behavior, histological, and neurochemical tests. After the motor recovery period, 6-OHDA was able to produce anhedonia and behavioral despair 7, 14, and 21 days after neurotoxin infusion. These altered behavioral responses were accompanied by reductions of striatal DA. Additionally, decreases in hippocampal 5-HT content were detected in the 6-OHDA group. Notably, correlations were found between 5-HT and DA levels and swimming, immobility, and sucrose preference. Our results indicate that 6-OHDA produced depressive-like behavior accompanied by striatal DA and hippocampal 5-HT reductions. Moreover, DA and 5-HT levels were strongly correlated with "emotional" impairments, suggesting the important participation of these neurotransmitters in anhedonia and behavioral despair after 6-OHDA-induced nigral lesions. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Palmitoylethanolamide protects mice against 6-OHDA-induced neurotoxicity and endoplasmic reticulum stress: In vivo and in vitro evidence.

    PubMed

    Avagliano, Carmen; Russo, Roberto; De Caro, Carmen; Cristiano, Claudia; La Rana, Giovanna; Piegari, Giuseppe; Paciello, Orlando; Citraro, Rita; Russo, Emilio; De Sarro, Giovambattista; Meli, Rosaria; Mattace Raso, Giuseppina; Calignano, Antonio

    2016-11-01

    Several pathogenetic factors have been involved in the onset and progression of Parkinson's disease (PD), including inflammation, oxidative stress, unfolded protein accumulation, and apoptosis. Palmitoylethanolamide (PEA), an endogenous N-acylethanolamine, has been shown to be a neuroprotective and anti-inflammatory molecule, acting as a peroxisome proliferator activated receptor (PPAR)-α agonist. In this study we investigated the effects of PEA on behavioral alterations and the underlying pathogenic mechanisms in the 6-hydroxydopamine (6-OHDA)-induced model of PD in male mice. Additionally, we showed the involvement of PPAR-α in PEA protective effect on SH-SY5Y neuroblastoma against 6-OHDA damage. Here, we report that PEA (3-30mg/kg/days.c.) improved behavioral impairments induced by unilateral intrastriatal injection of 6-OHDA. This effect was accompanied by a significant increase in tyrosine hydroxylase expression at striatal level, indicating PEA preserving effect on dopaminergic neurons. Moreover, we found a reduction in the expression of pro-inflammatory enzymes, i.e. inducible nitric oxide synthase and cyclooxygenase-2, a modulation between pro- and anti-apoptotic markers, suggestive of PEA capability in controlling neuroinflammation and cell death. Interestingly, PEA also showed protective scavenging effect, through superoxide dismutase induction, and dampened unfolding protein response, interfering on glucose-regulated protein 78 expression and PERK-eIF2α pathway. Similar data were found in in vitro studies, where PEA treatment was found to rescue SH-SY5Y neuroblastoma cells from 6-OHDA-induced damage and death, partly by inhibiting endoplasmic reticulum stress detrimental response. Therefore, PEA, counteracting the pathogenetic aspects involved in the development of PD, showed its therapeutic potential, possibly integrating current treatments correcting dopaminergic deficits and motor dysfunction.

  6. Respiratory deficits in a rat model of Parkinson's disease.

    PubMed

    Tuppy, M; Barna, B F; Alves-Dos-Santos, L; Britto, L R G; Chiavegatto, S; Moreira, T S; Takakura, A C

    2015-06-25

    Parkinson's disease (PD) is a neurodegenerative disease characterized by loss of the dopaminergic nigrostriatal pathway. In addition to deficits in voluntary movement, PD involves a disturbance of breathing regulation. However, the cause and nature of this disturbance are not well understood. Here, we investigated breathing at rest and in response to hypercapnia (7% CO2) or hypoxia (8% O2), as well as neuroanatomical changes in brainstem regions essential for breathing, in a 6-hydroxydopamine (6-OHDA) rat model of PD. Bilateral injections of 6-OHDA (24μg/μl) into the striatum decreased tyrosine hydroxylase (TH(+))-neurons in the substantia nigra pars compacta (SNpc), transcription factor phox2b-expressing neurons in the retrotrapezoid nucleus and neurokinin-1 receptors in the ventral respiratory column. In 6-OHDA-lesioned rats, respiratory rate was reduced at rest, leading to a reduction in minute ventilation. These animals also showed a reduction in the tachypneic response to hypercapnia, but not to hypoxia challenge. These results suggest that the degeneration of TH(+) neurons in the SNpc leads to impairment of breathing at rest and in hypercapnic conditions. Our data indicate that respiratory deficits in a 6-OHDA rat model of PD are related to downregulation of neural systems involved in respiratory rhythm generation. The present study suggests a new avenue to better understand the respiratory deficits observed in chronic stages of PD. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  7. Cardiovascular dysfunction associated with neurodegeneration in an experimental model of Parkinson's disease.

    PubMed

    Falquetto, Barbara; Tuppy, Marina; Potje, Simone R; Moreira, Thiago S; Antoniali, Cristina; Takakura, Ana C

    2017-02-15

    Patients with Parkinson's disease (PD) exhibit both motor and non-motor symptoms. Among the non-motor symptoms, cardiovascular autonomic dysfunction is frequently observed. Here, we evaluated baroreflex function, vascular reactivity and neuroanatomical changes in brainstem regions involved in the neural control of circulation in the 6-hydroxydopamine (6-OHDA) model of PD. Male Wistar rats received a bilateral injection of 6-OHDA or vehicle into the striatum. After 61days, baroreflex function and vascular reactivity were assessed. The 6-OHDA and vehicle groups showed similar increases in mean arterial pressure (MAP) in response to phenylephrine (PE). However, the bradycardia observed in the vehicle group was blunted in the 6-OHDA-treated rats. Injection of sodium nitroprusside (SNP) decreased hypotension, tachycardia and vascular relaxation in 6-OHDA-treated rats. Bilateral intrastriatal 6-OHDA led to massive degeneration of tyrosine hydroxylase (TH)-immunoreactive neurons in the substantia nigra and to reductions in the numbers of A1/C1 and A5 catecholaminergic neurons while sparing A2 neurons within the nucleus of the solitary tract (NTS). 6-OHDA-treated rats also showed decreases in Phox2b-expressing neurons in the NTS and in choline acetyltransferase (ChAT) immunoreactivity in the nucleus ambiguus. Altogether, our data suggest that this model of PD includes neuroanatomical and functional changes that lead to cardiovascular impairment.

  8. 6-Hydroxydopamine (6-OHDA) induces Drp1-dependent mitochondrial fragmentation in SH-SY5Y cells.

    PubMed

    Gomez-Lazaro, Maria; Bonekamp, Nina A; Galindo, Maria F; Jordán, Joaquin; Schrader, Michael

    2008-06-01

    Mitochondrial alterations have been associated with the cytotoxic effect of 6-hydroxydopamine (6-OHDA), a widely used neurotoxin to study Parkinson's disease. Herein we studied the potential effects of 6-OHDA on mitochondrial morphology in SH-SY5Y neuroblastoma cells. By immunofluorescence and time-lapse fluorescence microscopy we demonstrated that 6-OHDA induced profound mitochondrial fragmentation in SH-SY5Y cells, an event that was similar to mitochondrial fission induced by overexpression of Fis1p, a membrane adaptor for the dynamin-related protein 1 (DLP1/Drp1). 6-OHDA failed to induce any changes in peroxisome morphology. Biochemical experiments revealed that 6-OHDA-induced mitochondrial fragmentation is an early event preceding the collapse of the mitochondrial membrane potential and cytochrome c release in SH-SY5Y cells. Silencing of DLP1/Drp1, which is involved in mitochondrial and peroxisomal fission, prevented 6-OHDA-induced fragmentation of mitochondria. Furthermore, in cells silenced for Drp1, 6-OHDA-induced cell death was reduced, indicating that a block in mitochondrial fission protects SH-SY5Y cells against 6-OHDA toxicity. Experiments in mouse embryonic fibroblasts deficient in Bax or p53 revealed that both proteins are not essential for 6-OHDA-induced mitochondrial fragmentation. Our data demonstrate for the first time an involvement of mitochondrial fragmentation and Drp1 function in 6-OHDA-induced apoptosis.

  9. Both Creatine and Its Product Phosphocreatine Reduce Oxidative Stress and Afford Neuroprotection in an In Vitro Parkinson’s Model

    PubMed Central

    Martín-de-Saavedra, Maria D.; Romero, Alejandro; Egea, Javier; Ludka, Fabiana K.; Tasca, Carla I.; Farina, Marcelo; Rodrigues, Ana Lúcia S.; López, Manuela G.

    2014-01-01

    Creatine is the substrate for creatine kinase in the synthesis of phosphocreatine (PCr). This energetic system is endowed of antioxidant and neuroprotective properties and plays a pivotal role in brain energy homeostasis. The purpose of this study was to investigate the neuroprotective effect of creatine and PCr against 6-hydroxydopamine (6-OHDA)-induced mitochondrial dysfunction and cell death in rat striatal slices, used as an in vitro Parkinson’s model. The possible involvement of the signaling pathway mediated by phosphatidylinositol-3 kinase (PI3K), protein kinase B (Akt), and glycogen synthase kinase-3β (GSK3β) was also evaluated. Exposure of striatal slices to 6-OHDA caused a significant disruption of the cellular homeostasis measured as 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide reduction, lactate dehydrogenase release, and tyrosine hydroxylase levels. 6-OHDA exposure increased the levels of reactive oxygen species and thiobarbituric acid reactive substances production and decreased mitochondrial membrane potential in rat striatal slices. Furthermore, 6-OHDA decreased the phosphorylation of Akt (Serine473) and GSK3β (Serine9). Coincubation with 6-OHDA and creatine or PCr reduced the effects of 6-OHDA toxicity. The protective effect afforded by creatine or PCr against 6-OHDA-induced toxicity was reversed by the PI3K inhibitor LY294002. In conclusion, creatine and PCr minimize oxidative stress in striatum to afford neuroprotection of dopaminergic neurons. PMID:25424428

  10. Both creatine and its product phosphocreatine reduce oxidative stress and afford neuroprotection in an in vitro Parkinson's model.

    PubMed

    Cunha, Mauricio Peña; Martín-de-Saavedra, Maria D; Romero, Alejandro; Egea, Javier; Ludka, Fabiana K; Tasca, Carla I; Farina, Marcelo; Rodrigues, Ana Lúcia S; López, Manuela G

    2014-01-01

    Creatine is the substrate for creatine kinase in the synthesis of phosphocreatine (PCr). This energetic system is endowed of antioxidant and neuroprotective properties and plays a pivotal role in brain energy homeostasis. The purpose of this study was to investigate the neuroprotective effect of creatine and PCr against 6-hydroxydopamine (6-OHDA)-induced mitochondrial dysfunction and cell death in rat striatal slices, used as an in vitro Parkinson's model. The possible involvement of the signaling pathway mediated by phosphatidylinositol-3 kinase (PI3K), protein kinase B (Akt), and glycogen synthase kinase-3β (GSK3β) was also evaluated. Exposure of striatal slices to 6-OHDA caused a significant disruption of the cellular homeostasis measured as 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide reduction, lactate dehydrogenase release, and tyrosine hydroxylase levels. 6-OHDA exposure increased the levels of reactive oxygen species and thiobarbituric acid reactive substances production and decreased mitochondrial membrane potential in rat striatal slices. Furthermore, 6-OHDA decreased the phosphorylation of Akt (Serine(473)) and GSK3β (Serine(9)). Coincubation with 6-OHDA and creatine or PCr reduced the effects of 6-OHDA toxicity. The protective effect afforded by creatine or PCr against 6-OHDA-induced toxicity was reversed by the PI3K inhibitor LY294002. In conclusion, creatine and PCr minimize oxidative stress in striatum to afford neuroprotection of dopaminergic neurons. © The Author(s) 2014.

  11. Tetramethylpyrazine Analogue CXC195 Protects Against Dopaminergic Neuronal Apoptosis via Activation of PI3K/Akt/GSK3β Signaling Pathway in 6-OHDA-Induced Parkinson's Disease Mice.

    PubMed

    Chen, Lin; Cheng, Li; Wei, Xinbing; Yuan, Zheng; Wu, Yanmei; Wang, Shuaishuai; Ren, Zhiping; Liu, Xinyong; Liu, Huiqing

    2016-12-22

    Parkinson's disease (PD) is a progressive neurodegenerative disorder and characterized by motor system disorders resulting in loss of dopaminergic (DA) neurons. CXC195, a novel tetramethylpyrazine derivative, has been shown strongest neuroprotective effects due to its anti-apoptotic activity. However, whether CXC195 protects against DA neuronal damage in PD and the mechanisms underlying its beneficial effects are unknown. The purpose of our study was to investigate the potential neuroprotective role of CXC195 and to elucidate its mechanism of action against 6-hydroxydopamine (6-OHDA)-induced mouse model of PD. CXC195 administration improved DA neurodegeneration in PD mice induced by 6-OHDA. Our further findings confirmed treatment of CXC195 at the dose of 10 mg/kg significantly inhibited the apoptosis by decreasing the level of cleaved caspase-3 and Bax, and increasing the level of Bcl-2 in 6-OHDA-lesioned mice. Meanwhile, 6-OHDA also decreased the amount of phosphorylated Akt while increased GSK-3β activity (the amount of phosphorylated GSK-3β at Ser9 was decreased) which was prevented by CXC195. Wortmannin, a specific PI3K inhibitor, dramatically abolished the changes induced by CXC195. Our study firstly demonstrated that CXC195 protected against DA neurodegeneration in 6-OHDA-induced PD model by its anti-apoptotic properties and PI3K/Akt/GSK3β signaling pathway was involved in it.

  12. Effects of (-)-sesamin on 6-hydroxydopamine-induced neurotoxicity in PC12 cells and dopaminergic neuronal cells of Parkinson's disease rat models.

    PubMed

    Park, Hyun Jin; Zhao, Ting Ting; Lee, Kyung Sook; Lee, Seung Ho; Shin, Keon Sung; Park, Keun Hong; Choi, Hyun Sook; Lee, Myung Koo

    2015-01-01

    The present study investigated the effects of (-)-sesamin on 6-hydroxydopamine (6-OHDA)-induced neurotoxicity using PC12 cells and dopaminergic neuronal cells of 6-OHDA-lesioned rat model of Parkinson's disease (PD). In PC12 cells, treatment with (-)-sesamin (25 µM) reduced 6-OHDA (100 µM)-induced cell death and induced transient extracellular signal-regulated kinase (ERK1/2) phosphorylation and Bad phosphorylation at Ser112 (BadSer112). In contrast, sustained ERK1/2 phosphorylation, p38 mitogen-activated protein kinase (p38MAPK) and c-Jun N-terminal kinase (JNK1/2) phosphorylation, and cleaved-caspase-3 activity, all of which were induced by 6-OHDA (100 µM), were inhibited by treatment with (-)-sesamin (25 µM). Furthermore, co-treatment with (-)-sesamin (30 mg/kg, p.o.) once a day for 28 days significantly increased the number of tyrosine hydroxylase-immunopositive neuronal cells and the levels of dopamine, norepinephrine, 3,4-dihydroxyphenylacetic acid, and homovanillic acid in the substantia nigra-striatum of 6-OHDA-lesioned rat model of PD with or without L-DOPA treatment. These results suggest that (-)-sesamin protects 6-OHDA-induced cytotoxicity via the activation of transient ERK1/2-BadSer112 system and the inhibition of sustained ERK-p38MAPK-JNK1/2-caspase-3 system in PC12 cells. (-)-Sesamin also shows protective effects on long-term L-DOPA therapy in dopaminergic neuronal cells of PD rat models. (-)-Sesamin may serve as adjuvant therapeutics in PD.

  13. Neuroprotective effect of the methanolic extract of Hibiscus asper leaves in 6-hydroxydopamine-lesioned rat model of Parkinson's disease.

    PubMed

    Hritcu, Lucian; Foyet, Harquin Simplice; Stefan, Marius; Mihasan, Marius; Asongalem, Acha Emmanuel; Kamtchouing, Pierre

    2011-09-01

    While the Hibiscus asper Hook.f. (Malvaceae) is a traditional herb largely used in tropical region of the Africa as vegetable, potent sedative, tonic and restorative, anti-inflammatory and antidepressive drug, there is very little scientific data concerning the efficacy of this. The antioxidant and antiapoptotic activities of the methanolic extract of Hibiscus asper leaves (50 and 100 mg/kg) were assessed using superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) specific activities, total glutathione (GSH) content, malondialdehyde (MDA) level (lipid peroxidation) and DNA fragmentation assays in male Wistar rats subjected to unilateral 6-hydroxydopamine (6-OHDA)-lesion. In 6-OHDA-lesioned rats, methanolic extract of Hibiscus asper leaves showed potent antioxidant and antiapoptotic activities. Chronic administration of the methanolic extract (50 and 100 mg/kg, i.p., daily, for 7 days) significantly increased antioxidant enzyme activities (SOD, GPX and CAT), total GSH content and reduced lipid peroxidation (MDA level) in rat temporal lobe homogenates, suggesting antioxidant activity. Also, DNA cleavage patterns were absent in the 6-OHDA-lesioned rats treated with methanolic extract of Hibiscus asper leaves, suggesting antiapoptotic activity. Taken together, our results suggest that the methanolic extract of Hibiscus asper leaves possesses neuroprotective activity against 6-OHDA-induced toxicity through antioxidant and antiapoptotic activities in Parkinson's disease model. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  14. Effect of antidepressant drugs on 6-OHDA-treated mice in the FST.

    PubMed

    Chenu, F; Dailly, E; Bourin, M

    2007-02-01

    There is growing evidence suggesting that dopamine could be indirectly involved in the appearance of behavioural effects of antidepressants. In this study, we induced a partial (over 70%) and non-reversible depletion of dopamine-containing neurons in mice by i.c.v. infusion of 6-OHDA. Then, we compared the antidepressant-like effect of drugs (citalopram, paroxetine, desipramine and imipramine) with or without dopamine depletion in the mice forced swimming test. Our results clearly show that lesion with 6-OHDA does not modify the response of mice to desipramine and imipramine, whereas dopamine depletion abolished the antidepressant-like effect of citalopram and paroxetine. It could then be suggested that antidepressant-like effect of selective serotonin reuptake inhibitors (paroxetine and citalopram) in the mice FST requires the activation of dopaminergic pathways to occur.

  15. Carnosic acid protects against 6-hydroxydopamine-induced neurotoxicity in in vivo and in vitro model of Parkinson's disease: involvement of antioxidative enzymes induction.

    PubMed

    Wu, Chi-Rei; Tsai, Chia-Wen; Chang, Shu-Wei; Lin, Chia-Yuan; Huang, Li-Chun; Tsai, Chia-Wen

    2015-01-05

    The neuroprotective effects of carnosic acid (CA), a phenolic diterpene isolated from rosemary (Rosmarinus officinalis), have been widely investigated in recent years, however, its protection in in vivo still unclear. In this study, we investigated the behavioral activity and neuroprotective effects of CA in a rat model of Parkinson's disease (PD) induced by 6-hydroxydopamine (6-OHDA). Rats were treated with 20mg/kg body weight of CA for 3 weeks before 6-OHDA exposure. Results indicated that CA improved the locomotor activity and reduced the apomorphine-caused rotation in 6-OHDA-stimulated rats. Significant protection against lipid peroxidation and GSH reduction was observed in the 6-OHDA rats pretreated with CA. Pretreatment with CA increased the protein expression of γ-glutamate-cysteine ligase catalytic subunit, γ-glutamate-cysteine ligase modifier subunit, superoxide dismutase, and glutathione reductase compared with 6-OHDA-stimulated rats and SH-SY5Y cells. Immunoblots showed that the reduction of the Bcl-2/Bax ratio, the induction of caspase 3 cleavage, and the induction of poly(ADP-ribose) polymerase (PARP) cleavage by 6-OHDA was reversed in the presence of SB203580 (a p38 inhibitor) or SP600125 (a JNK inhibitor) in SH-SY5Y cells. Rats treated with CA reversed the 6-OHDA-mediated the activation of c-Jun NH2-terminal kinase and p38, the down-regulation of the Bcl-2/Bax ratio, the up-regulation of cleaved caspase 3/caspase 3 and cleaved PARP/PARP ratio, and the down-regulation of tyrosine hydroxylase protein. However, BAM7, an activator of Bax, attenuated the effect of CA on apoptosis in SH-SY5Y cells. These results suggest that CA protected against 6-OHDA-induced neurotoxicity is attributable to its anti-apoptotic and anti-oxidative action. The present findings may help to clarify the possible mechanisms of rosemary in the neuroprotection of PD.

  16. Partial dopaminergic denervation-induced impairment in stimulus discrimination acquisition in parkinsonian rats: a model for early Parkinson's disease.

    PubMed

    Eagle, Andrew L; Olumolade, Oluyemi O; Otani, Hajime

    2015-03-01

    Parkinson's disease (PD) produces progressive nigrostriatal dopamine (DA) denervation resulting in cognitive and motor impairment. However, it is unknown whether cognitive impairments, such as instrumental learning deficits, are associated with the early stage PD-induced mild DA denervation. The current study sought to model early PD-induced instrumental learning impairments by assessing the effects of low dose (5.5μg), bilateral 6OHDA-induced striatal DA denervation on acquisition of instrumental stimulus discrimination in rats. 6OHDA (n=20) or sham (n=10) lesioned rats were tested for stimulus discrimination acquisition either 1 or 2 weeks post surgical lesion. Stimulus discrimination acquisition across 10 daily sessions was used to assess discriminative accuracy, or a probability measure of the shift toward reinforced responding under one stimulus condition (Sd) away from extinction, when reinforcement was withheld, under another (S(d) phase). Striatal DA denervation was assayed by tyrosine hydroxylase (TH) staining intensity. Results indicated that 6OHDA lesions produced significant loss of dorsal striatal TH staining intensity and marked impairment in discrimination acquisition, without inducing akinetic motor deficits. Rather 6OHDA-induced impairment was associated with perseveration during extinction (S(Δ) phase). These findings suggest that partial, bilateral striatal DA denervation produces instrumental learning deficits, prior to the onset of gross motor impairment, and suggest that the current model is useful for investigating mild nigrostriatal DA denervation associated with early stage clinical PD.

  17. Deep brain stimulation of the pedunculopontine tegmental nucleus modulates neuronal hyperactivity and enhanced beta oscillatory activity of the subthalamic nucleus in the rat 6-hydroxydopamine model.

    PubMed

    Alam, Mesbah; Heissler, Hans E; Schwabe, Kerstin; Krauss, Joachim K

    2012-01-01

    Deep brain stimulation (DBS) of the pedunculopontine nucleus (PPN) area has been introduced as a novel surgical therapy for dopamine refractory gait problems, freezing and postural instability in the late stage of Parkinson's disease (PD). Lesions of the pedunculopontine tegmental (PPTg) nucleus, the equivalent of the PPN in rodents, were shown to reduce the elevated discharge rate of the subthalamic nucleus (STN) in the 6-hydroxydopamine (6-OHDA) rat model of PD. In order to further elucidate the modulatory effect of the PPTg on the STN we examined the effect of 25 Hz low frequency PPTg stimulation on neuronal single unit activity and oscillatory local field potentials (LFPs) of the STN, and on the electrocorticogram (ECoG) of the primary motor cortex region in rats with unilateral 6-OHDA induced nigrostriatal lesions. Stimulation of the PPTg reduced the enhanced firing rate in the STN, without affecting the firing pattern or approximate entropy (ApEn). It also reduced the activity in the beta band (15-30 Hz) of the STN, which is elevated in 6-OHDA lesioned rats, without affecting beta activity in the motor cortex. We showed a modulatory effect of PPTg stimulation on altered neuronal STN activity in the PD 6-OHDA rat model, indicating that PPTg DBS may alter activity of the basal ganglia circuitry at least partially. It remains unclear, however, how these changes are exactly mediated and whether they are relevant with regard to the descending PPTg projections in the lower brainstem.

  18. Pituitary adenylate cyclase-activating polypeptide (PACAP) has a neuroprotective function in dopamine-based neurodegeneration in rat and snail parkinsonian models

    PubMed Central

    Kiss, Tibor; Jungling, Adel

    2017-01-01

    ABSTRACT Pituitary adenylate cyclase-activating polypeptide (PACAP) rescues dopaminergic neurons from neurodegeneration and improves motor changes induced by 6-hydroxy-dopamine (6-OHDA) in rat parkinsonian models. Recently, we investigated the molecular background of the neuroprotective effect of PACAP in dopamine (DA)-based neurodegeneration using rotenone-induced snail and 6-OHDA-induced rat models of Parkinson's disease. Behavioural activity, monoamine (DA and serotonin), metabolic enzyme (S-COMT, MB-COMT and MAO-B) and PARK7 protein concentrations were measured before and after PACAP treatment in both models. Locomotion and feeding activity were decreased in rotenone-treated snails, which corresponded well to findings obtained in 6-OHDA-induced rat experiments. PACAP was able to prevent the behavioural malfunctions caused by the toxins. Monoamine levels decreased in both models and the decreased DA level induced by toxins was attenuated by ∼50% in the PACAP-treated animals. In contrast, PACAP had no effect on the decreased serotonin (5HT) levels. S-COMT metabolic enzyme was also reduced but a protective effect of PACAP was not observed in either of the models. Following toxin treatment, a significant increase in MB-COMT was observed in both models and was restored to normal levels by PACAP. A decrease in PARK7 was also observed in both toxin-induced models; however, PACAP had a beneficial effect only on 6-OHDA-treated animals. The neuroprotective effect of PACAP in different animal models of Parkinson's disease is thus well correlated with neurotransmitter, enzyme and protein levels. The models successfully mimic several, but not all etiological properties of the disease, allowing us to study the mechanisms of neurodegeneration as well as testing new drugs. The rotenone and 6-OHDA rat and snail in vivo parkinsonian models offer an alternative method for investigation of the molecular mechanisms of neuroprotective agents, including PACAP. PMID:28067625

  19. Pituitary adenylate cyclase-activating polypeptide (PACAP) has a neuroprotective function in dopamine-based neurodegeneration in rat and snail parkinsonian models.

    PubMed

    Maasz, Gabor; Zrinyi, Zita; Reglodi, Dora; Petrovics, Dora; Rivnyak, Adam; Kiss, Tibor; Jungling, Adel; Tamas, Andrea; Pirger, Zsolt

    2017-02-01

    Pituitary adenylate cyclase-activating polypeptide (PACAP) rescues dopaminergic neurons from neurodegeneration and improves motor changes induced by 6-hydroxy-dopamine (6-OHDA) in rat parkinsonian models. Recently, we investigated the molecular background of the neuroprotective effect of PACAP in dopamine (DA)-based neurodegeneration using rotenone-induced snail and 6-OHDA-induced rat models of Parkinson's disease. Behavioural activity, monoamine (DA and serotonin), metabolic enzyme (S-COMT, MB-COMT and MAO-B) and PARK7 protein concentrations were measured before and after PACAP treatment in both models. Locomotion and feeding activity were decreased in rotenone-treated snails, which corresponded well to findings obtained in 6-OHDA-induced rat experiments. PACAP was able to prevent the behavioural malfunctions caused by the toxins. Monoamine levels decreased in both models and the decreased DA level induced by toxins was attenuated by ∼50% in the PACAP-treated animals. In contrast, PACAP had no effect on the decreased serotonin (5HT) levels. S-COMT metabolic enzyme was also reduced but a protective effect of PACAP was not observed in either of the models. Following toxin treatment, a significant increase in MB-COMT was observed in both models and was restored to normal levels by PACAP. A decrease in PARK7 was also observed in both toxin-induced models; however, PACAP had a beneficial effect only on 6-OHDA-treated animals. The neuroprotective effect of PACAP in different animal models of Parkinson's disease is thus well correlated with neurotransmitter, enzyme and protein levels. The models successfully mimic several, but not all etiological properties of the disease, allowing us to study the mechanisms of neurodegeneration as well as testing new drugs. The rotenone and 6-OHDA rat and snail in vivo parkinsonian models offer an alternative method for investigation of the molecular mechanisms of neuroprotective agents, including PACAP.

  20. Differential expression of Fos and Zif268 in the nigrostriatal system after methamphetamine administration in a rat model of Parkinson's disease.

    PubMed

    Ishida, Yasushi; Kawai, Keiichi; Magata, Yasuhiro; Ebihara, Kosuke; Takeda, Ryuichiro; Abe, Hiroshi; Yoshimoto, Mitsuyoshi; Hashiguchi, Hiroyuki; Odagiri, Kei; Matsuo, Hisae; Nishimori, Toshikazu

    2008-12-01

    The goal of this study was to examine the topological specificity of methamphetamine-induced activation of the immediate-early gene proteins, Fos and Zif268, in the nigrostriatal system in a unilateral 6-hydroxydopamine (6-OHDA) rat model of Parkinson's disease with or without intrastriatal grafts of fetal ventral mesencephalon. Methamphetamine (3 mg/kg, i.p.) induced Fos-like immunoreactivity (FLI) dominantly in the striatum and the globus pallidus (GP) on the intact side as well as in the substantia nigra pars reticulata (SNr) on the lesioned side in the 6-OHDA rats. Lower levels of methamphetamine-induced FLI in the striatum and GP on the lesioned side were restored by intrastriatal grafts which could completely suppress the methamphetamine-induced rotation. In the striatum, a similar tendency could be observed between Fos and Zif268 immunoreactivity following methamphetamine. However, sparse immunoreactivity of Zif268 could be detected in the GP and SNr on both sides in the 6-OHDA rats. Intrastriatal grafts had little influence on Zif268 expression in these two regions. The differential expression of Fos and Zif268 was observed among the three regions of the nigrostriatal system following methamphetamine in the 6-OHDA rats. This may suggest that Fos and Zif268 therefore possess gene-specific and region-specific functions in the basal ganglia nuclei.

  1. Neuroprotective Effects of Sulphated Agaran from Marine Alga Gracilaria cornea in Rat 6-Hydroxydopamine Parkinson's Disease Model: Behavioural, Neurochemical and Transcriptional Alterations.

    PubMed

    Souza, Ricardo Basto; Frota, Annyta Fernandes; Sousa, Rayane Siqueira; Cezario, Nayara Araújo; Santos, Tarcizio Brito; Souza, Luziana Mara Frota; Coura, Chistiane Oliveira; Monteiro, Valdécio Silvano; Cristino Filho, Gerardo; Vasconcelos, Silvânia Maria Mendes; da Cunha, Rodrigo Maranguape Silva; Aguiar, Lissiana Magna Vasconcelos; Benevides, Norma Maria Barros

    2017-02-01

    Parkinson's disease (PD) is a multifactorial disease associated with the degeneration of dopaminergic neurons and behavioural alterations. Natural bioactive compounds may provide new therapeutic alternatives for neurodegenerative disorders, such as PD. The sulphated polysaccharides isolated from marine algae are heterogenic molecules that show different biological activities. The red marine alga Gracilaria cornea has a sulphated polysaccharide (SA-Gc) with structure and anti-inflammatory and antinociceptive activities reported in the literature. Therefore, this study aimed to evaluate the neuroprotective effects of SA-Gc in rat model PD induced by 6-hydroxydopamine (6-OHDA). Firstly, we established the PD model in rats, induced by an intrastriatal injection (int.) of 6-OHDA, followed by a single administration of SA-Gc (15, 30 or 60 μg; int.). On the 14th day, behavioural tests were performed. After killing, brain areas were dissected and used for neurochemical and/or transcriptional analyses. The results showed that SA-Gc (60 μg, int.) promoted neuroprotective effects in vivo through reducing the oxidative/nitroactive stress and through alterations in the monoamine contents induced by 6-OHDA. Furthermore, SA-Gc modulated the transcription of neuroprotective and inflammatory genes, as well as returning behavioural activities and weight gain to normal conditions. Thus, this study reports the neuroprotective effects of SA-Gc against 6-OHDA in rats.

  2. On the role of P2X(7) receptors in dopamine nerve cell degeneration in a rat model of Parkinson's disease: studies with the P2X(7) receptor antagonist A-438079.

    PubMed

    Marcellino, Daniel; Suárez-Boomgaard, Diana; Sánchez-Reina, María Dolores; Aguirre, José A; Yoshitake, Takashi; Yoshitake, Shimako; Hagman, Beth; Kehr, Jan; Agnati, Luigi F; Fuxe, Kjell; Rivera, Alicia

    2010-06-01

    The role of the ATP-gated receptor, P2X(7), has been evaluated in the unilateral 6-OHDA rat model of Parkinson's disease using the P2X(7) competitive antagonist A-438079. Nigral P2X(7) immunoreactivity was mainly located in microglia but also in astroglia. A-438079 partially but significantly prevented the 6-OHDA-induced depletion of striatal DA stores. However, this was not associated with a reduction of DA cell loss. Blockade of P2X(7) receptors may represent a novel protective strategy for striatal DA terminals in Parkinson's disease and warrants further future investigation.

  3. The ameliorative effect of Monascus purpureus NTU 568-fermented rice extracts on 6-hydroxydopamine-induced neurotoxicity in SH-SY5Y cells and the rat model of Parkinson's disease.

    PubMed

    Tseng, Wei-Ting; Hsu, Ya-Wen; Pan, Tzu-Ming

    2016-02-01

    Oxidative stress and neuroinflammation underlie the major pathogenesis in Parkinson's disease (PD). Antioxidants are known to protect against the degeneration of dopaminergic neurons. Monascus purpureus-fermented rice, a traditional Chinese medicine as well as a health food, includes multifunctional metabolites. The present study was designed to investigate the effects of the antioxidant-containing M. purpureus NTU 568-fermented rice extract (extracted with 50% ethanol, so called R50E) in 6-hydrodopamine (6-OHDA)-induced neurotoxicity in vitro and in vivo. In vitro, treatment with R50E reduced 6-OHDA-induced SH-SY5Y cell death. In vivo, two doses of R50E (5.5 and 11.0 mg kg(-1)) were administered for a period of 28 days following 6-OHDA-induced lesioning. The administration of R50E reduced parkinsonian motor dysfunction and the number of tyrosine hydroxylase (TH)-immunoreactive neurons present in 6-OHDA-induced lesioned rats. Moreover, the administration of R50E reversed the elevation of reactive oxygen species (ROS) and malondialdehyde (MDA) levels and promoted the activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase, glutathione reductase, and glutathione peroxidase via down-regulation of p47 phox, NOX1, and NOX2 expression in the 6-OHDA-lesion rats. Furthermore, treatment with R50E attenuated nitric oxide (NO) and tumor necrosis factor (TNF-α) levels in the 6-OHDA-lesion rats. In conclusion, R50E may prevent neurodegeneration via anti-oxidative and anti-inflammatory mechanisms, suggesting its potential therapeutic value for PD treatment. This is the first study for evaluating the neuroprotective effects of red mold fermented products in PD models.

  4. Tetraspanin (TSP-17) Protects Dopaminergic Neurons against 6-OHDA-Induced Neurodegeneration in C. elegans

    PubMed Central

    Masoudi, Neda; Holmes, Alexander; Gartner, Anton

    2014-01-01

    Parkinson's disease (PD), the second most prevalent neurodegenerative disease after Alzheimer's disease, is linked to the gradual loss of dopaminergic neurons in the substantia nigra. Disease loci causing hereditary forms of PD are known, but most cases are attributable to a combination of genetic and environmental risk factors. Increased incidence of PD is associated with rural living and pesticide exposure, and dopaminergic neurodegeneration can be triggered by neurotoxins such as 6-hydroxydopamine (6-OHDA). In C. elegans, this drug is taken up by the presynaptic dopamine reuptake transporter (DAT-1) and causes selective death of the eight dopaminergic neurons of the adult hermaphrodite. Using a forward genetic approach to find genes that protect against 6-OHDA-mediated neurodegeneration, we identified tsp-17, which encodes a member of the tetraspanin family of membrane proteins. We show that TSP-17 is expressed in dopaminergic neurons and provide genetic, pharmacological and biochemical evidence that it inhibits DAT-1, thus leading to increased 6-OHDA uptake in tsp-17 loss-of-function mutants. TSP-17 also protects against toxicity conferred by excessive intracellular dopamine. We provide genetic and biochemical evidence that TSP-17 acts partly via the DOP-2 dopamine receptor to negatively regulate DAT-1. tsp-17 mutants also have subtle behavioral phenotypes, some of which are conferred by aberrant dopamine signaling. Incubating mutant worms in liquid medium leads to swimming-induced paralysis. In the L1 larval stage, this phenotype is linked to lethality and cannot be rescued by a dop-3 null mutant. In contrast, mild paralysis occurring in the L4 larval stage is suppressed by dop-3, suggesting defects in dopaminergic signaling. In summary, we show that TSP-17 protects against neurodegeneration and has a role in modulating behaviors linked to dopamine signaling. PMID:25474638

  5. PGE2 EP1 receptor deletion attenuates 6-OHDA-induced Parkinsonism in mice: old switch, new target.

    PubMed

    Ahmad, Abdullah Shafique; Maruyama, Takayuki; Narumiya, Shuh; Doré, Sylvain

    2013-04-01

    Recent experimental data on Parkinson's disease (PD) predicts the critical role of inflammation in the progression of neurodegeneration and the promising preventive effects of nonsteroidal anti-inflammatory drugs (NSAIDs). Previous studies suggest that NSAIDs minimize cyclooxygenase-2 (COX-2) activity and thereby attenuate free radical generation. Prostaglandin E2 (PGE2) is an important product of COX activity and plays an important role in various physiologic and pathophysiologic conditions through its EP receptors (EP1-EP4). Part of the toxic effect of PGE2 in the central nervous system has been reported to be through the EP1 receptor; however, the effect of the EP1 receptor in PD remains elusive. Therefore, in our pursuit to determine if deletion of the PGE2 EP1 receptor will attenuate 6-hydroxy dopamine (6-OHDA)-induced Parkinsonism, mice were given a unilateral 6-OHDA injection into the medial forebrain bundle. We found that apomorphine-induced contralateral rotations were significantly attenuated in the 6-OHDA-lesioned EP1(-/-) mice compared with the 6-OHDA-lesioned WT mice. Quantitative analysis showed significant protection of dopaminergic neurons in the substantia nigra pars compacta of the 6-OHDA-lesioned EP1(-/-) mice. To the best of our knowledge, this is the first in vivo study to implicate the PGE2 EP1 receptor in toxin-induced Parkinsonism. We propose the PGE2 EP1 receptor as a new target to better understand some of the mechanisms leading to PD.

  6. Tio2-dopamine complex implanted unilaterally in the caudate nucleus improves motor activity and behavior function of rats with induced hemiparkinsonism.

    PubMed

    Vergara-Aragón, Patricia; Domínguez-Marrufo, Leonardo Eduardo; Ibarra-Guerrero, Patricia; Hernandez-Ramírez, Heidi; Hernández-Téllez, Beatriz; López-Martínez, Irma Elena; Sánchez-Cervantes, Ivonne; Santiago-Jacinto, Patricia; García-Macedo, Jorge Alberto; Valverde-Aguilar, Guadalupe; Santiago, Julio

    2011-01-01

    Parkinson's disease (PD) is characterized by malfunction of dopaminergic systems, and the current symptomatic treatment is to replace lost dopamine. For investigating mechanisms of pathogenesis and alternative treatments to compensate lack of dopamine (DA) activity in PD, the 6-hydroxydopamine (6-OHDA)-lesioned rat model of PD has been useful, these animals display apomorphine-induced contralateral rotational behavior, when they are examined after lesion. The purpose of this study was to assess Titania-dopamine (TiO2-DA) complexes implanted on the caudate nucleus for diminishing motor behavior alterations of the 6-OHDA rat model. Rats with 6-OHDA unilateral lesions received TiO2 alone or TiO2-DA implants, and were tested for open field (OF) gross motor crossing and rearing behaviors, and apomorphine-induced rotation (G) behavior. TiO2 complex have no effects on rearing OF and G behaviors, and a significant reducing effect on crossing motor behavior of normal rats compared to control non-treated rats throughout 56 days of observation. Interestingly, TiO2-DA treatment significant recovered motor crossing and rearing behaviors in 6-OHDA-lesioned rats, and diminished the G behaviors during 56 days of examination. Additionally, in the 6-OHDA-lesioned rats TiO2 treatment had a moderate recovering effect only on crossing behavior compared to lesioned non treated rats. Our results suggest that continuous release of dopamine in the caudate nucleus from TiO2-DA complex is capable of reversing gross motor deficits observed in the 6-OHDA-lesioned rat model of PD. Thistype of delivery system of DA represents a promising therapy for PD in humans.

  7. Protective effect of caffeine against neurodegeneration in a model of Parkinson's disease in rat: behavioral and histochemical evidence.

    PubMed

    Joghataie, Mohammad Taghi; Roghani, Mehrdad; Negahdar, Fereidoun; Hashemi, Leila

    2004-12-01

    Epidemiological studies have consistently demonstrated an inverse association between coffee consumption and Parkinson's disease (PD). This study was designed to investigate the beneficial effect of caffeine at a dose comparable to that of human exposure in a model of PD. For this purpose, unilateral intrastriatal 6-hydroxydopamine (6-OHDA)-lesioned rats were pretreated with caffeine (20 mg/kg; i.p.) 1 h before surgery and treated twice a day (10 mg/kg) for 1 month. Apomorphine-induced rotations and number of Nissl-stained neurons of substantia nigra pars compacta (SNC) were counted. The results demonstrated that caffeine administration for 1 month could attenuate the rotational behavior in lesioned rats and protect the neurons of SNC against 6-OHDA toxicity.

  8. Effect of pre- and postnatal manganese exposure on brain histamine content in a rodent model of Parkinson's disease.

    PubMed

    Brus, Ryszard; Jochem, Jerzy; Nowak, Przemysław; Adwent, Marta; Boroń, Dariusz; Brus, Halina; Kostrzewa, Richard M

    2012-02-01

    Rats lesioned shortly after birth with 6-hydroxydopamine (6-OHDA; 134 μg icv) represent a near-ideal model of severe Parkinson's disease because of the near-total destruction of nigrostriatal dopaminergic fibers. There are scarce data that in Parkinson's disease, activity of the central histaminergic system is increased. The element manganese, an essential cofactor for many enzymatic reactions, itself in toxic amount, replicates some clinical features similar to those of Parkinson's disease. The aim of this study was to examine the effect of neonatal manganese exposure on 6-OHDA modeling of Parkinson's disease in rats, and to determine effects on histamine content in the brain of these rats in adulthood. Manganese (MnCl₂·4H₂O; 10,000 ppm) was included in the drinking water of pregnant Wistar rats from the time of conception until the 21st day after delivery, the age when neonatal rats were weaned. Control rats consumed tap water. Other groups of neonatal rat pups, on the 3rd day after birth, were pretreated with desipramine (20 mg/kg ip 1 h) prior to bilateral icv administration of 6-OHDA (60 or 134 μg) or its vehicle saline-ascorbic (0.1%) (control). At 2 months after birth, in rats lesioned with 60 or 134 μg 6-OHDA, endogenous striatal dopamine (DA) content was reduced, respectively, by 92 and 98% (HPLC/ED), while co-exposure of these groups to perinatal manganese did not magnify the DA depletion. However, there was prominent enhancement of histamine content in frontal cortex, hippocampus, hypothalamus, and medulla oblongata of adult rat brain after 6-OHDA (60 and 134 μg) injection on the day 3rd postnatal day. These findings indicate that histamine and the central histaminergic system are altered in the brain of rats lesioned to model Parkinson's disease, and that manganese enhances effects of 6-OHDA on histamine in brain.

  9. Neuronal Entropy-Rate Feature of Entopeduncular Nucleus in Rat Model of Parkinson's Disease.

    PubMed

    Darbin, Olivier; Jin, Xingxing; Von Wrangel, Christof; Schwabe, Kerstin; Nambu, Atsushi; Naritoku, Dean K; Krauss, Joachim K; Alam, Mesbah

    2016-03-01

    The function of the nigro-striatal pathway on neuronal entropy in the basal ganglia (BG) output nucleus, i.e. the entopeduncular nucleus (EPN) was investigated in the unilaterally 6-hyroxydopamine (6-OHDA)-lesioned rat model of Parkinson's disease (PD). In both control subjects and subjects with 6-OHDA lesion of dopamine (DA) the nigro-striatal pathway, a histological hallmark for parkinsonism, neuronal entropy in EPN was maximal in neurons with firing rates ranging between 15 and 25 Hz. In 6-OHDA lesioned rats, neuronal entropy in the EPN was specifically higher in neurons with firing rates above 25 Hz. Our data establishes that the nigro-striatal pathway controls neuronal entropy in motor circuitry and that the parkinsonian condition is associated with abnormal relationship between firing rate and neuronal entropy in BG output nuclei. The neuronal firing rates and entropy relationship provide putative relevant electrophysiological information to investigate the sensory-motor processing in normal condition and conditions such as movement disorders.

  10. Atomoxetine blocks motor hyperactivity in neonatal 6-hydroxydopamine-lesioned rats: implications for treatment of attention-deficit hyperactivity disorder.

    PubMed

    Moran-Gates, Taylor; Zhang, Kehong; Baldessarini, Ross J; Tarazi, Frank I

    2005-09-01

    We recently reported that selective inhibitors of neuronal transport of norepinephrine (NE), desipramine and nisoxetine, reversed motor hyperactivity in an animal model of attention-deficit hyperactivity disorder (ADHD). In this study, we examined behavioural effects of atomoxetine, a potent new NE reuptake blocker, in juvenile male rats with neonatal 6-hydroxydopamine (6-OHDA) lesions of dopamine projections to the forebrain. 6-OHDA (100 microg) was administered intracisternally on postnatal day (PD) 5 following desipramine (25 mg/kg s.c.) pretreatment to protect noradrenergic neurons. Atomoxetine (1 mg/kg) was given intraperitoneally before recording motor activity for 90 min at PD 23-26 in a novel environment. Atomoxetine greatly reduced motor hyperactivity in 6-OHDA-lesioned rats while exhibiting transient sedative effects in sham controls. The observed effects in this animal model for ADHD are consistent with the emerging clinical use of atomoxetine as a novel, non-stimulant treatment for ADHD.

  11. Ontogenetic exposure of rats to pre- and post-natal manganese enhances behavioral impairments produced by perinatal 6-hydroxydopamine.

    PubMed

    Nowak, Przemysław; Bojanek, Kamila; Szkilnik, Ryszard; Jośko, Jadwiga; Boroń, Dariusz; Adwent, Marta; Gorczyca, Piotr; Kostrzewa, Richard M; Brus, Ryszard

    2011-05-01

    Rats lesioned shortly after birth with 6-hydroxydopamine (6-OHDA; 134 μg icv) represent a near-ideal model of severe Parkinson's disease because of the near-total destruction of nigrostriatal dopaminergic fibers. The element manganese, an essential cofactor for many enzymatic reactions, itself in toxic amount, replicates some clinical features similar to those of Parkinson's disease. The aim of this study was to examine the effect of neonatal manganese exposure on 6-OHDA modeling of Parkinson's disease in rats. Manganese (MnCl(2)·4H(2)O) 10,000 ppm was included in the drinking water of pregnant Wistar rats from the time of conception until the 21st day after delivery, the age when neonatal rats were weaned. Control rats consumed tap water. Other groups of neonatal rat pups, on the 3rd day after birth, were pretreated with desipramine (20 mg/kg ip 1 h) prior to bilateral icv administration of 6-OHDA (30, 60, or 137 μg) or its vehicle saline-ascorbic (0.1%) (control). At 2 months after birth, in rats lesioned with 30, 60, or 134 μg 6-OHDA, endogenous striatal dopamine (DA) content was reduced, respectively, by 66, 92, and 98% (HPLC/ED), while co-exposure of these groups to perinatal manganese did not magnify the DA depletion. However, there was prominent enhancement of DA D(1) agonist (i.e., SKF 38393)-induced oral activity in the group of rats exposed perinatally to manganese and also treated neonatally with the 30 mg/kg dose of 6-OHDA. The 30 mg/kg 6-OHDA group, demonstrating cataleptogenic responses to SCH 23390 (0.5 mg/kg) and haloperidol (0.5 mg/kg ip), developed resistance if co-exposed to perinatal manganese. In the group exposed to manganese and lesioned with the 60 mg/kg dose of 6-OHDA, there was a reduction in D(2) agonist (i.e., quinpirole, 0.1 mg/kg)-induced yawning. The series of findings demonstrate that ontogenetic exposure to manganese results in an enhancement of behavioral toxicity to a moderate dose of 6-OHDA, despite the fact that

  12. Protective effects of Althaea officinalis L. extract in 6-hydroxydopamine-induced hemi-Parkinsonism model: behavioral, biochemical and histochemical evidence.

    PubMed

    Rezaei, Maryam; Alirezaei, Masoud

    2014-05-01

    It is well known that Parkinson's disease (PD) is the second most common neurodegenerative disorder in humans. In this regard, the neuroprotective effect of Althaea officinalis (AO) has already been reported. Therefore, this study examined whether administration of AO extract would improve behavioral, biochemical and structural abnormalities in an experimental animal model of PD in rats. For this purpose, we induced hemi-Parkinsonism by unilateral intranigral injection of 6-hydroxydopamine (6-OHDA, 8 μg/5 μl saline-ascorbate). The rats were pretreated i.p. with AO extract (10 mg/kg) started 6 days before surgery and continued until the 3rd day post-surgery. Regarding oxidative stress, brain MDA concentration (as a lipid peroxidation marker) increased significantly in the 6-OHDA-administered group in comparison with rats pretreated with AO extract. It was found that AO treatment attenuated rotational behavior in the 6-OHDA-administered group and protected the neurons of substantia nigra pars compacta against 6-OHDA toxicity. Overall, AO extract administration indicated neuroprotective effects against 6-OHDA-induced hemi-Parkinsonism in rats.

  13. Characterization of liraglutide, a glucagon-like peptide-1 (GLP-1) receptor agonist, in rat partial and full nigral 6-hydroxydopamine lesion models of Parkinson's disease.

    PubMed

    Hansen, Henrik H; Fabricius, Katrine; Barkholt, Pernille; Mikkelsen, Jens D; Jelsing, Jacob; Pyke, Charles; Knudsen, Lotte Bjerre; Vrang, Niels

    2016-09-01

    Exendin-4, a glucagon-like peptide-1 (GLP-1) receptor agonist, have been demonstrated to promote neuroprotection in the rat 6-hydroxydopamine (6-OHDA) neurotoxin model of Parkinson's disease (PD), a neurodegenerative disorder characterized by progressive nigrostriatal dopaminergic neuron loss. In this report, we characterized the effect of a long-acting GLP-1 receptor agonist, liraglutide (500µg/kg/day, s.c.) in the context of a partial or advanced (full) 6-OHDA induced nigral lesion in the rat. Rats received a low (3µg, partial lesion) or high (13.5µg, full lesion) 6-OHDA dose stereotaxically injected into the right medial forebrain bundle (n=17-20 rats per experimental group). Six weeks after induction of a partial nigral dopaminergic lesion, vehicle or liraglutide was administered for four weeks. In the full lesion model, vehicle dosing or liraglutide treatment was applied for a total of six weeks starting three weeks pre-lesion, or administered for three weeks starting on the lesion day. Quantitative stereology was applied to assess the total number of midbrain tyrosine hydroxylase (TH) positive dopaminergic neurons. As compared to vehicle controls, liraglutide had no effect on the rotational responsiveness to d-amphetamine or apomorphine, respectively. In correspondence, while numbers of TH-positive nigral neurons were significantly reduced in the lesion side (partial lesion ≈55%; full lesion ≈90%) liraglutide administration had no influence dopaminergic neuronal loss in either PD model setting. In conclusion, liraglutide showed no neuroprotective effects in the context of moderate or substantial midbrain dopaminergic neuronal loss and associated functional motor deficits in the rat 6-OHDA lesion model of PD.

  14. Selective COX-2 inhibition prevents progressive dopamine neuron degeneration in a rat model of Parkinson's disease

    PubMed Central

    Sánchez-Pernaute, Rosario; Ferree, Andrew; Cooper, Oliver; Yu, Meixiang; Brownell, Anna-Liisa; Isacson, Ole

    2004-01-01

    Several lines of evidence point to a significant role of neuroinflammation in Parkinson's disease (PD) and other neurodegenerative disorders. In the present study we examined the protective effect of celecoxib, a selective inhibitor of the inducible form of cyclooxygenase (COX-2), on dopamine (DA) cell loss in a rat model of PD. We used the intrastriatal administration of 6-hydroxydopamine (6-OHDA) that induces a retrograde neuronal damage and death, which progresses over weeks. Animals were randomized to receive celecoxib (20 mg/kg/day) or vehicle starting 1 hour before the intrastriatal administration of 6-OHDA. Evaluation was performed in vivo using micro PET and selective radiotracers for DA terminals and microglia. Post mortem analysis included stereological quantification of tyrosine hydroxylase, astrocytes and microglia. 12 days after the 6-OHDA lesion there were no differences in DA cell or fiber loss between groups, although the microglial cell density and activation was markedly reduced in animals receiving celecoxib (p < 0.01). COX-2 inhibition did not reduce the typical astroglial response in the striatum at any stage. Between 12 and 21 days, there was a significant progression of DA cell loss in the vehicle group (from 40 to 65%) that was prevented by celecoxib. Therefore, inhibition of COX-2 by celecoxib appears to be able, either directly or through inhibition of microglia activation to prevent or slow down DA cell degeneration. PMID:15285796

  15. Striatal Glutamate and GABA after High Frequency Subthalamic Stimulation in Parkinsonian Rat

    PubMed Central

    Lee, Kyung Jin; Shim, Insop; Sung, Jae Hoon; Hong, Jae Taek; Kim, Il sup; Cho, Chul Bum

    2017-01-01

    Objective High frequency stimulation (HFS) of the subthalamic nucleus (STN) is recognized as an effective treatment of advanced Parkinson’s disease. However, the neurochemical basis of its effects remains unknown. The aim of this study is to investigate the effects of STN HFS in intact and 6-hydroxydopamine (6-OHDA)-lesioned hemiparkinsonian rat model on changes of principal neurotransmitters, glutamate, and gamma-aminobutyric acid (GABA) in the striatum. Methods The authors examined extracellular glutamate and GABA change in the striatum on sham group, 6-OHDA group, and 6-OHDA plus deep brain stimulation (DBS) group using microdialysis methods. Results High-pressure liquid chromatography was used to quantify glutamate and GABA. The results show that HFS-STN induces a significant increase of extracellular glutamate and GABA in the striatum of 6-OHDA plus DBS group compared with sham and 6-OHDA group. Conclusion Therefore, the clinical results of STN-HFS are not restricted to the direct STN targets but involve widespread adaptive changes within the basal ganglia. PMID:28264233

  16. Differential pattern of motor impairments in neurotoxic, environmental and inflammation-driven rat models of Parkinson's disease.

    PubMed

    Naughton, Carol; Moriarty, Niamh; Feehan, Jennifer; O'Toole, Daniel; Dowd, Eilís

    2016-01-01

    One of the reasons proposed for the paucity of drug discovery for Parkinson's disease is the lack of relevant animal models of the condition. Parkinson's disease has been modelled extensively using the selective neurotoxin, 6-hydroxydopamine (6-OHDA). However, as this model bears little etiological resemblance to the human condition, there has been a drive to develop models with improved etiological validity. Two such models are those induced by the pesticide, rotenone, and the inflammagen, lipopolysaccharide (LPS). However, to date, these models have been poorly characterised in terms of their motor profiles and have never been directly compared to the more established models. Thus, the aim of this study was to characterise the behavioural profile of the rotenone and LPS models, and to compare them with the 6-OHDA model. Animals underwent baseline testing on the Stepping, Whisker, Corridor and Cylinder Tests of motor function. They were then grouped for unilateral intra-striatal infusion of 6-OHDA, rotenone or LPS. Motor testing continued for ten weeks after which the rats were processed for immunohistochemical analysis of nigrostriatal integrity. We found that, although all neurotoxins induced a similar level of nigrostriatal neurodegeneration, neither the rotenone nor LPS models were associated with amphetamine-induced rotation, and they were associated with significantly less pronounced and stable impairments in the spontaneous tasks than the 6-OHDA model. In conclusion, this study demonstrates key differences in the pattern of motor dysfunction induced by Parkinsonian neurotoxins which should be taken into consideration when selecting the most appropriate model for Parkinson's disease preclinical studies.

  17. ALCAR Exerts Neuroprotective and Pro-Neurogenic Effects by Inhibition of Glial Activation and Oxidative Stress via Activation of the Wnt/β-Catenin Signaling in Parkinsonian Rats.

    PubMed

    Singh, Sonu; Mishra, Akanksha; Shukla, Shubha

    2016-09-01

    Oxidative stress and neuroinflammation are known causative factors in progressive degeneration of dopaminergic (DAergic) neurons in Parkinson's disease (PD). Neural stem cells (NSCs) contribute in maintaining brain plasticity; therefore, survival of NSCs and neuroblasts during neurodegenerative process becomes important in replenishing the pool of mature neuronal population. Acetyl-L-carnitine (ALCAR), present in almost all body cells, increases endogenous antioxidants and regulates bioenergetics. Currently, no information is available about the putative mechanism and neuroprotective effects of ALCAR in 6-hydroxydopamine (6-OHDA)-induced rat model of PD-like phenotypes. Herein, we investigated the effect of ALCAR on death/survival of DAergic neurons, neuroblasts and NSCs and associates mechanism of neuroprotection in 6-OHDA-induced rat model of PD-like phenotypes. ALCAR (100 mg/kg/day, intraperitoneal (i.p.)) treatment started 3 days prior to 6-OHDA lesioning and continued for another 14 day post-lesioning. We found that ALCAR pretreatment in 6-OHDA-lesioned rats increased expression of neurogenic and the Wnt pathway genes in the striatum and substantia nigra pars compacta (SNpc) region. It suppressed the glial cell activation, improved antioxidant status, increased NSC/neuroblast population and rescued the DAergic neurons in nigrostriatal pathway. ALCAR pretreatment in 6-OHDA-lesioned rats decreased GSK-3β activation and increased nuclear translocation of β-catenin. Functional deficits were restored following ALCAR pretreatment in 6-OHDA-lesioned rats as demonstrated by improved motor coordination and rotational behaviour, confirming protection of DAergic innervations in lesioned striatum. These results indicate that ALCAR exerts neuroprotective effects through the activation of Wnt/β-catenin pathway, suggesting its therapeutic use to treat neurodegenerative diseases by enhancing regenerative capacity.

  18. Berberine protects against 6-OHDA-induced neurotoxicity in PC12 cells and zebrafish through hormetic mechanisms involving PI3K/AKT/Bcl-2 and Nrf2/HO-1 pathways.

    PubMed

    Zhang, Chao; Li, Chuwen; Chen, Shenghui; Li, Zhiping; Jia, Xuejing; Wang, Kai; Bao, Jiaolin; Liang, Yeer; Wang, Xiaotong; Chen, Meiwan; Li, Peng; Su, Huanxing; Wan, Jian-Bo; Lee, Simon Ming Yuen; Liu, Kechun; He, Chengwei

    2017-04-01

    Berberine (BBR) is a renowned natural compound that exhibits potent neuroprotective activities. However, the cellular and molecular mechanisms are still unclear. Hormesis is an adaptive mechanism generally activated by mild oxidative stress to protect the cells from further damage. Many phytochemicals have been shown to induce hormesis. This study aims to investigate whether the neuroprotective activity of BBR is mediated by hormesis and the related signaling pathways in 6-OHDA-induced PC12 cells and zebrafish neurotoxic models. Our results demonstrated that BBR induced a typical hormetic response in PC12 cells, i.e. low dose BBR significantly increased the cell viability, while high dose BBR inhibited the cell viability. Moreover, low dose BBR protected the PC12 cells from 6-OHDA-induced cytotoxicity and apoptosis, whereas relatively high dose BBR did not show neuroprotective activity. The hormetic and neuroprotective effects of BBR were confirmed to be mediated by up-regulated PI3K/AKT/Bcl-2 cell survival and Nrf2/HO-1 antioxidative signaling pathways. In addition, low dose BBR markedly mitigated the 6-OHDA-induced dopaminergic neuron loss and behavior movement deficiency in zebrafish, while high dose BBR only slightly exhibited neuroprotective activities. These results strongly suggested that the neuroprotection of BBR were attributable to the hormetic mechanisms via activating cell survival and antioxidative signaling pathways. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  19. Neuroprotective Effect of Thymoquinone, the Nigella Sativa Bioactive Compound, in 6-Hydroxydopamine-Induced Hemi-Parkinsonian Rat Model

    PubMed Central

    Sedaghat, Reza; Roghani, Mehrdad; Khalili, Mohsen

    2014-01-01

    Parkinson disease (PD) is the most common movement disorder with progressive degeneration of midbrain dopaminergic neurons for which current treatments afford symptomatic relief with no-prevention of disease progression. Due to the neuroprotective property of the Nigella sativa bioactive compound thymoquinone (TQ), this study was undertaken to evaluate whether TQ could improve behavioral and cellular abnormalities and markers of oxidative stress in an experimental model of early PD in rat. Unilateral intrastriatal 6-hydroxydopamine (6-OHDA)-lesioned rats were daily pretreated p.o. with TQ at doses of 5 and/or 10 mg/Kg three times at an interval of 24 h. After 1 week, apomorphine caused contralateral rotations, a reduction in the number of neurons on the left side of the substantia nigra pars compacta (SNC) was observed, malondialdehyde (MDA) and nitrite level in midbrain homogenate increased and activity of superoxide dismutase (SOD) reduced in the 6-OHDA lesion group. TQ pretreatment significantly improved turning behavior, prevented loss of SNC neurons, and lowered level of MDA. These results suggest that TQ could afford neuroprotection against 6-OHDA neurotoxicity that is partly due to the attenuation of lipid peroxidation and this may provide benefits, along with other therapies, in neurodegenerative disorders including PD. PMID:24734075

  20. Ellagic acid exerts protective effect in intrastriatal 6-hydroxydopamine rat model of Parkinson's disease: Possible involvement of ERβ/Nrf2/HO-1 signaling.

    PubMed

    Baluchnejadmojarad, Tourandokht; Rabiee, Nafiseh; Zabihnejad, Sedigheh; Roghani, Mehrdad

    2017-02-23

    Parkinson's disease (PD) is a prevalent movement disorder in the elderly with progressive loss of mesencephalic dopaminergic neurons and incapacitating motor and non-motor complications. Ellagic acid is a natural phenolic compound with potent antioxidant and anti-inflammatory properties. In this study, we investigated its possible neuroprotective effect in 6-hydroxydopamine (6-OHDA) rat model of PD. Intrastriatal 6-OHDA-lesioned rats were pretreated with ellagic acid at a dose of 50 mg/kg/day for 1 week. Results showed that ellagic acid attenuates apomorphine-induced rotational bias and lowers the latency to initiate and the total time in the narrow beam task and this beneficial effect was partially abrogated following intracerebroventricular microinjection of estrogen receptor β (ERβ) antagonist. Furthermore, ellagic acid reduced striatal malondialdehyde (MDA), reactive oxygen species (ROS), and DNA fragmentation, and improved monoamine oxidase B (MAO-B), nuclear factor (erythroid-derived 2)-like 2 (Nrf2), and heme oxygenase 1 (HO-1). Meanwhile, ellagic acid prevented loss of tyrosine hydroxylase (TH)-positive neurons within substantia nigra pars compacta (SNC). These findings indicate neuroprotective potential of ellagic acid in 6-OHDA rat model of PD via amelioration of apoptosis and oxidative stress, suppression of MAO-B, and its favorable influence is partly reliant on ERβ/Nrf2/HO-1 signaling cascade.

  1. Troxerutin exerts neuroprotection in 6-hydroxydopamine lesion rat model of Parkinson's disease: Possible involvement of PI3K/ERβ signaling.

    PubMed

    Baluchnejadmojarad, Tourandokht; Jamali-Raeufy, Nida; Zabihnejad, Sedigheh; Rabiee, Nafiseh; Roghani, Mehrdad

    2017-04-15

    Parkinson's disease (PD) is a neurodegenerative disease with progressive loss of mesencephalic dopaminergic neurons of the substantia nigra and with multiple incapacitating motor and non-motor symptoms. Troxerutin is a natural bioflavonoid with nephro- and hepato-protective, antioxidant, and anti-inflammatory properties. In this study, we evaluated its possible neuroprotective effect in 6-hydroxydopamine (6-OHDA) rat model of PD. Intrastriatal 6-OHDA-lesioned rats were pretreated with troxerutin at a dose of 150mg/kg/day for 1 week. Results showed that troxerutin mitigates apomorphine-induced motor asymmetry and lowered the latency to initiate and the total time in the narrow beam task and this beneficial effect was lost following central application of estrogen receptor β (ERβ) antagonist or phosphatidylinositol 3-kinase (PI3K) inhibitor. In addition, troxerutin reduced striatal malondialdehyde (MDA) as an index of lipid peroxidation, reactive oxygen species, glial fibrillary acid protein (GFAP) as a marker of astrogliosis, and DNA fragmentation as an apoptotic marker with no significant alteration of catalase activity and nitrite level. Meanwhile, troxerutin was capable to prevent loss of nigral tyrosine hydroxylase (TH)-positive neurons. These findings indicate neuroprotective potential of troxerutin in 6-OHDA rat model of PD through mitigation of apoptosis, astrogliosis, and oxidative stress and part of its effect is dependent on PI3K/ERβ signaling.

  2. Acetyl-l-carnitine protects dopaminergic nigrostriatal pathway in 6-hydroxydopamine-induced model of Parkinson's disease in the rat.

    PubMed

    Afshin-Majd, Siamak; Bashiri, Keyhan; Kiasalari, Zahra; Baluchnejadmojarad, Tourandokht; Sedaghat, Reza; Roghani, Mehrdad

    2017-02-12

    Parkinson's disease (PD) is a movement disorder and the second most common neurodegenerative disease worldwide in which nigrostriatal dopaminergic neurons within substantia nigra pars compacta (SNC) are lost, with clinical motor and non-motor symptoms including bradykinesia, resting tremor, rigidity, stooping posture and cognitive deficits. This study was undertaken to evaluate the neuroprotective potential of acetyl-l-carnitine (ALC) against unilateral striatal 6-hydroxydopamine (6-OHDA)-induced model of PD and to explore some involved mechanisms. In this experimental study, intrastriatal 6-OHDA-lesioned rats received ALC at doses of 100 or 200mg/kg/day for 1 week. ALC (200mg/kg) lowered apomorphine-induced rotational asymmetry and reduced the latency to initiate and the total time in the narrow beam test, reduced striatal malondialdehyde (MDA), increased catalase activity and glutathione (GSH) level, prevented reduction of nigral tyrosine hydroxylase (TH)-positive neurons and striatal TH-immunoreactivity, and lowered striatal glial fibrillary acidic protein (GFAP) and its immunoreactivity as an indicator of astrogliosis, and nuclear factor NF-kappa B and Toll-like receptor 4 (TLR4) as reliable markers of neuroinflammation. Meanwhile, ALC at both doses mitigated nigral DNA fragmentation as a valuable marker of apoptosis. The results of this study clearly suggest the neuroprotective effect of ALC in 6-OHDA-induced model of PD through abrogation of neuroinflammation, apoptosis, astrogliosis, and oxidative stress and it may be put forward as an ancillary therapeutic candidate for controlling PD.

  3. Restoring Spinal Noradrenergic Inhibitory Tone Attenuates Pain Hypersensitivity in a Rat Model of Parkinson's Disease

    PubMed Central

    Wang, Bing; Chen, Li-Hua

    2016-01-01

    In the present study, we investigated whether restoring descending noradrenergic inhibitory tone can attenuate pain in a PD rat model, which was established by stereotaxic infusion of 6-hydroxydopamine (6-OHDA) into the bilateral striatum (CPu). PD rats developed thermal and mechanical hypersensitivity at the 4th week after surgery. HPLC analysis showed that NE content, but not dopamine or 5-HT, significantly decreased in lumbar spinal cord in PD rats. Additional noradrenergic depletion by injection of N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4) aggravated pain hypersensitivity in PD rats. At the 5th week after injection of 6-OHDA, systemic treatment with pharmacological norepinephrine (NE) precursor droxidopa (L-DOPS) or α2 adrenoceptor agonist clonidine significantly attenuated thermal and mechanical pain hypersensitivity in PD rats. Furthermore, application of norepinephrine (NE) and 5-hydroxytryptamine (5-HT) reuptake inhibitors duloxetine, but not 5-HT selective reuptake inhibitors sertraline, significantly inhibited thermal and mechanical pain hypersensitivity in PD rats. Systemic administration of Madopar (L-DOPA) or the D2/D3 agonist pramipexole slightly inhibited the thermal, but not mechanical, hypersensitivity in PD rats. Thus, our study revealed that impairment of descending noradrenergic system may play a key role in PD-associated pain and restoring spinal noradrenergic inhibitory tone may serve as a novel strategy to manage PD-associated pain. PMID:27747105

  4. URB597 reduces biochemical, behavioral and morphological alterations in two neurotoxic models in rats.

    PubMed

    Maya-López, Marisol; Ruiz-Contreras, Hipolito A; de Jesús Negrete-Ruíz, María; Martínez-Sánchez, Julián Elías; Benítez-Valenzuela, Juan; Colín-González, Ana Laura; Villeda-Hernández, Juana; Sánchez-Chapul, Laura; Parra-Cid, Carmen; Rangel-López, Edgar; Santamaría, Abel

    2017-04-01

    URB597 is a compound largely linked to the inhibition of fatty acid amide hydrolase (FAAH), an enzyme responsible for the metabolic degradation of the endocannabinoid anandamide (AEA). Despite this pharmacological property accounts for its modulatory profile demonstrated in some neurotoxic paradigms, the possible protective properties of this agent have been poorly investigated, and deserve exploration in different neurotoxic models. In this study, we explored the effects of URB597 on oxidative damage to lipids and other major endpoints of toxicity in two neurotoxic models in vivo in rats (the first one produced by the mitochondrial neurotoxin 3-nitropropionic acid [3-NP], and the other generated by the striatal injection of the pro-oxidant toxin 6-hydroxidopamine [6-OHDA]) in order to provide further supporting evidence of its modulatory profile. Male Wistar adult rats were treated for 5 or 7 consecutive days with URB597 (0.3mg/kg, i.p.) and simultaneously exposed to three injections of 3-NP (30mg/kg, i.p.) or a single intrastriatal infusion of 6-OHDA (0.02mg/2μl), respectively. Twenty four hours after all treatments were administered, lipid peroxidation was measured in the striatum of 3-NP-treated rats, and in the midbrain of 6-OHDA-treated rats. Motor skills and histological assessment in the striatum were also evaluated in 3-NP-treated rats 6 and 7days after the last drug administration, respectively; whereas apomorphine-induced circling behavior and tyrosine hydroxylase immunolocalization in the striatum and substantia nigra were investigated 21 and 22days after the last drug infusion, respectively. URB597 prevented the oxidative damage to lipids induced by 3-NP in the striatum, and this effect could account for the attenuation of motor deficits in this model. Attenuation of motor disturbances induced by URB597 in both models was associated with the morphological preservation of the striatum in the 3-NP model and the partial preservation of tyrosine

  5. Anti-high mobility group box 1 antibody exerts neuroprotection in a rat model of Parkinson's disease.

    PubMed

    Sasaki, Tatsuya; Liu, Keyue; Agari, Takashi; Yasuhara, Takao; Morimoto, Jun; Okazaki, Mihoko; Takeuchi, Hayato; Toyoshima, Atsuhiko; Sasada, Susumu; Shinko, Aiko; Kondo, Akihiko; Kameda, Masahiro; Miyazaki, Ikuko; Asanuma, Masato; Borlongan, Cesario V; Nishibori, Masahiro; Date, Isao

    2016-01-01

    The high mobility group box-1 (HMGB1) exists as an architectural nuclear protein in the normal state, but displays an inflammatory cytokine-like activity in the extracellular space under pathological condition. Inflammation in the pathogenesis of Parkinson's disease (PD) has been documented. In this study, we investigated the involvement of HMGB1 in the pathology and the neuroprotective effects of neutralizing anti-HMGB1 monoclonal antibody (mAb) on an animal model of PD. Adult female Sprague-Dawley rats were initially injected with 6-hydroxydopmaine (6-OHDA, 20 μg/4 μl) into the right striatum, then anti-HMGB1 mAb (1 mg/kg), or control mAb was intravenously administered immediately, at 6 and 24 h after 6-OHDA injection. The treatment with anti-HMGB1 mAb significantly preserved dopaminergic neurons in substantia nigra pars compacta and dopaminergic terminals inherent in the striatum, and attenuated PD behavioral symptoms compared to the control mAb-treated group. HMGB1 was retained in the nucleus of neurons and astrocytes by inhibiting the proinflammation-induced oxidative stress in the anti-HMGB1 mAb-treated group, whereas HMGB1 translocation was observed in neurons at 1 day and astrocytes at 7 days after 6-OHDA injection in the control mAb-treated group. Anti-HMGB1 mAb inhibited the activation of microglia, disruption of blood-brain-barrier (BBB), and the expression of inflammation cytokines such as IL-1β and IL-6. These results suggested that HMGB1 released from neurons and astrocytes was at least partly involved in the mechanism and pathway of degeneration of dopaminergic neurons induced by 6-OHDA exposure. Intravenous administration of anti-HMGB1 mAb stands as a novel therapy for PD possibly acting through the suppression of neuroinflammation and the attenuation of disruption of BBB associated with the disease.

  6. An improved model to investigate the efficacy of antidyskinetic agents in hemiparkinsonian rats.

    PubMed

    Spinnewyn, Brigitte; Charnet, Christelle; Cornet, Sylvie; Roubert, Véronique; Chabrier, Pierre-Etienne; Auguet, Michel

    2011-10-01

    A number of experimental models of L-DOPA-induced dyskinesia have been proposed, but these models result in a low to medium rate of dyskinetic animals with mild to severe symptoms. The objective of this study was to combine a model of 6-OHDA-induced parkinsonism and of L-DOPA-induced dyskinesia in rats to establish a reliable preclinical model. Two stereotaxic injections of 6-OHDA were administered in the left striatum. This model led to 90-100% of rats with a marked contralateral circling behaviour, significant limb use asymmetry (20%), a decrease in ipsilateral striatal dopamine content (70%) and degeneration of dopamine neurons in the substantia nigra (70%). Chronic treatment with L-DOPA was administered for 35 days and consisted of three phases with incremental daily doses. The third phase resulted in 83-90% of rats developing severe abnormal involuntary movements (AIMs) which included limb and locomotive dyskinesia, axial dystonia and orolingual dyskinesia. Reproducibility of the model, criteria of strict blinding, placebo-controlled design, randomization of study subjects and pretrial determination of sample size were used to measure efficacy of amantadine and istradefylline and to validate the protocol design. Acute or subchronic post-treatment with amantadine reduced the severity of dyskinesia while istradefylline punctually attenuated AIMs. Our experimental conditions using gradual development of dyskinesia induced by increasing doses of L-DOPA resulted in a reliable model of L-DOPA-induced dyskinesia with a high rate of dyskinetic rats.

  7. Phloroglucinol Attenuates Motor Functional Deficits in an Animal Model of Parkinson's Disease by Enhancing Nrf2 Activity

    PubMed Central

    Hong, Bo-Hyun; Yang, Eun-Jung; Kang, Kyoung Ah; Choi, Moonseok; Kim, Ki Cheon; Noh, Su-Jin; Kim, Hee Soo; Lee, Nam-Ho; Hyun, Jin Won; Kim, Hye-Sun

    2013-01-01

    In this study, we investigated whether phloroglucinol (1, 3, 5 - trihydroxybenzene) has therapeutic effects in cellular and animal model of Parkinson's disease (PD). PD is the second most common, chronic and progressive neurodegenerative disease, and is clinically characterized with motor dysfunctions such as bradykinesia, rigidity, postural instability, gait impairment, and resting tremor. In the brains of PD patients, dopaminergic neuronal loss is observed in the Substantia nigra. Although the exact mechanisms underlying PD are largely unknown, mitochondrial dysfunction and oxidative stress are thought to be critical factors that induce the onset of the disease. Here, phloroglucinol administration was shown to attenuate motor functional deficits evaluated with rota-rod and apomorphine-induced rotation tests in 6-hydroxydopamine (6-OHDA)-induced PD animal models. Moreover, phloroglucinol ameliorated the loss of synapses as assessed with protein levels and immunoreactivity against synaptophysin in the midbrain region of the 6-OHDA-lesioned rats. In addition, in SH-SY5Y cultures, the cytotoxicity of 6-OHDA was reduced by pre-treatment with phloroglucinol. The increase in the reactive oxygen species, lipid peroxidation, protein carbonyl formation and 8-hydroxyguanine caused by treatment with 6-OHDA was attenuated by phloroglucinol in SH-SY5Y cells. Furthermore, phloroglucinol treatment rescued the reduced levels of nuclear Nrf2, antioxidant enzymes, i.e., catalase and glutathione peroxidase, in 6-OHDA-treated cells. Taken together, phloroglucinol has a therapeutic potential for treatment of PD. PMID:23976995

  8. Phloroglucinol attenuates motor functional deficits in an animal model of Parkinson's disease by enhancing Nrf2 activity.

    PubMed

    Ryu, Junghwa; Zhang, Rui; Hong, Bo-Hyun; Yang, Eun-Jung; Kang, Kyoung Ah; Choi, Moonseok; Kim, Ki Cheon; Noh, Su-Jin; Kim, Hee Soo; Lee, Nam-Ho; Hyun, Jin Won; Kim, Hye-Sun

    2013-01-01

    In this study, we investigated whether phloroglucinol (1,3,5-trihydroxybenzene) has therapeutic effects in cellular and animal model of Parkinson's disease (PD). PD is the second most common, chronic and progressive neurodegenerative disease, and is clinically characterized with motor dysfunctions such as bradykinesia, rigidity, postural instability, gait impairment, and resting tremor. In the brains of PD patients, dopaminergic neuronal loss is observed in the Substantia nigra. Although the exact mechanisms underlying PD are largely unknown, mitochondrial dysfunction and oxidative stress are thought to be critical factors that induce the onset of the disease. Here, phloroglucinol administration was shown to attenuate motor functional deficits evaluated with rota-rod and apomorphine-induced rotation tests in 6-hydroxydopamine (6-OHDA)-induced PD animal models. Moreover, phloroglucinol ameliorated the loss of synapses as assessed with protein levels and immunoreactivity against synaptophysin in the midbrain region of the 6-OHDA-lesioned rats. In addition, in SH-SY5Y cultures, the cytotoxicity of 6-OHDA was reduced by pre-treatment with phloroglucinol. The increase in the reactive oxygen species, lipid peroxidation, protein carbonyl formation and 8-hydroxyguanine caused by treatment with 6-OHDA was attenuated by phloroglucinol in SH-SY5Y cells. Furthermore, phloroglucinol treatment rescued the reduced levels of nuclear Nrf2, antioxidant enzymes, i.e., catalase and glutathione peroxidase, in 6-OHDA-treated cells. Taken together, phloroglucinol has a therapeutic potential for treatment of PD.

  9. New ghrelin agonist, HM01 alleviates constipation and L-dopa-delayed gastric emptying in 6-hydroxydopamine rat model of Parkinson’s disease

    PubMed Central

    Karasawa, H.; Pietra, C.; Giuliano, C.; Garcia-Rubio, S.; Xu, X.; Yakabi, S.; Taché, Y.; Wang, L.

    2015-01-01

    Background Constipation and L-dopa-induced gastric dysmotility are common gastrointestinal (GI) symptoms in Parkinson’s disease (PD). We investigate the novel ghrelin agonist, HM01 influence on GI motor dysfunctions in 6-hydroxydopamine (6-OHDA) rats. Methods HM01 pharmacological profiles were determined in vitro and in vivo in rats. We assessed changes in fecal output and water content, and gastric emptying (GE) in 6-OHDA rats treated or not with orogastric (og) HM01 and L-dopa/carbidopa (LD/CD, 20/2 mg kg−1). Fos immunoreactivity (ir) cells in specific brain and lumbosacral spinal cord were quantified. Key results HM01 displayed a high binding affinity to ghrelin receptor (Ki: 1.42 ± 0.36 nM), 4.3±1.0 h half-life and high brain/plasma ratio. 6-OHDA rats had reduced daily fecal output (22%) and water intake (23%) compared to controls. HM01 (3 and 10 mg kg−1) similarly reversed the decreased 4-h fecal weight and water content in 6-OHDA rats. Basal GE was not modified in 6-OHDA rats, however, LD/CD (once or daily for 8 days) delayed GE in 6-OHDA and control rats that was prevented by HM01 (3 mg kg−1 acute or daily before LD/CD). HM01 increased Fos-ir cell number in the area postrema, arcuate nucleus, nucleus tractus solitarius and lumbosacral intermediolateral column of 6-OHDA rats where 6-OHDA had a lowering effect compared to controls. Conclusions & Inferences 6-OHDA rats display constipation- and adipsia-like features of PD and L-dopa-inhibited GE. The new orally active ghrelin agonist, HM01 crosses the blood brain barrier and alleviates these alterations suggesting a potential benefit for PD with GI disorders. PMID:25327342

  10. Effects of L-DOPA and STN-HFS dyskinesiogenic treatments on NR2B regulation in basal ganglia in the rat model of Parkinson's disease.

    PubMed

    Quintana, Adrien; Sgambato-Faure, Véronique; Savasta, Marc

    2012-12-01

    Dyskinesia is a major side effect of chronic levodopa (L-DOPA) administration, the reference treatment for Parkinson's disease (PD). High-frequency stimulation of the subthalamic nucleus (STN-HFS) alleviates parkinsonian motor symptoms and indirectly improves dyskinesia by decreasing L-DOPA requirement. However, inadequate stimulation can also trigger dyskinetic movements in PD patients and animal models. Here, we investigated the possible association between L-DOPA- and STN-HFS-induced dyskinesia and regulation of the NR2B subunit of NMDA receptors in the rodent model of PD. We subjected 6-OHDA-lesioned rats to HFS for 1h, at an intensity triggering forelimb dyskinesia. Other 6-OHDA-lesioned rats were treated with chronic high doses of L-DOPA for ten days, to induce abnormal involuntary movements. The 6-OHDA lesion regulated NR2B only in the SNr, where the activation of NR2B was observed (as assessed by phosphorylation of the Tyr1472 residue). Both STN-HFS and L-DOPA dyskinesiogenic treatments induced NR2B activation in the STN and EP, but only L-DOPA triggered NR2B hyperphosphorylation in the striatum. Finally, the use of CP-101,606 exacerbated L-DOPA-induced motor behavior and associated NR2B hyperphosphorylation in the striatum, STN and EP. Thus, NR2B activation in basal ganglia structures is correlated with dyskinesia.

  11. Alterations in primary motor cortex neurotransmission and gene expression in hemi-parkinsonian rats with drug-induced dyskinesia.

    PubMed

    Lindenbach, D; Conti, M M; Ostock, C Y; Dupre, K B; Bishop, C

    2015-12-03

    Treatment of Parkinson's disease (PD) with dopamine replacement relieves symptoms of poverty of movement, but often causes drug-induced dyskinesias. Accumulating clinical and pre-clinical evidence suggests that the primary motor cortex (M1) is involved in the pathophysiology of PD and that modulating cortical activity may be a therapeutic target in PD and dyskinesia. However, surprisingly little is known about how M1 neurotransmitter tone or gene expression is altered in PD, dyskinesia or associated animal models. The present study utilized the rat unilateral 6-hydroxydopamine (6-OHDA) model of PD/dyskinesia to characterize structural and functional changes taking place in M1 monoamine innervation and gene expression. 6-OHDA caused dopamine pathology in M1, although the lesion was less severe than in the striatum. Rats with 6-OHDA lesions showed a PD motor impairment and developed dyskinesia when given L-DOPA or the D1 receptor agonist, SKF81297. M1 expression of two immediate-early genes (c-Fos and ARC) was strongly enhanced by either L-DOPA or SKF81297. At the same time, expression of genes specifically involved in glutamate and GABA signaling were either modestly affected or unchanged by lesion and/or treatment. We conclude that M1 neurotransmission and signal transduction in the rat 6-OHDA model of PD/dyskinesia mirror features of human PD, supporting the utility of the model to study M1 dysfunction in PD and the elucidation of novel pathophysiological mechanisms and therapeutic targets.

  12. Alterations in primary motor cortex neurotransmission and gene expression in hemi-Parkinsonian rats with drug-induced dyskinesia

    PubMed Central

    Lindenbach, David; Conti, Melissa M.; Ostock, Corinne Y.; Dupre, Kristin B.; Bishop, Christopher

    2015-01-01

    Treatment of Parkinson’s disease (PD) with dopamine replacement relieves symptoms of poverty of movement, but often causes drug-induced dyskinesias. Accumulating clinical and pre-clinical evidence suggests that the primary motor cortex (M1) is involved in the pathophysiology of PD and that modulating cortical activity may be a therapeutic target in PD and dyskinesia. However, surprisingly little is known about how M1 neurotransmitter tone or gene expression are altered in PD, dyskinesia or associated animal models. The present study utilized the rat unilateral 6-hydroxydopamine (6-OHDA) model of PD / dyskinesia to characterize structural and functional changes taking place in M1 monoamine innervation and gene expression. 6-OHDA caused dopamine pathology in M1, although the lesion was less severe than in the striatum. Rats with 6-OHDA lesions showed a PD motor impairment and developed dyskinesia when given L-DOPA or the D1 receptor agonist, SKF81297. M1 expression of two immediate-early genes (c-Fos and ARC) was strongly enhanced by either L-DOPA or SKF81297. At the same time, expression of genes specifically involved in glutamate and GABA signaling were either modestly affected or unchanged by lesion and/or treatment. We conclude that M1 neurotransmission and signal transduction in the rat 6-OHDA model of PD / dyskinesia mirror features of human PD, supporting the utility of the model to study M1 dysfunction in PD and the elucidation of novel pathophysiological mechanisms and therapeutic targets. PMID:26363150

  13. Monoaminergic PET imaging and histopathological correlation in unilateral and bilateral 6-hydroxydopamine lesioned rat models of Parkinson's disease: a longitudinal in-vivo study.

    PubMed

    Molinet-Dronda, Francisco; Gago, Belén; Quiroga-Varela, Ana; Juri, Carlos; Collantes, María; Delgado, Mercedes; Prieto, Elena; Ecay, Margarita; Iglesias, Elena; Marín, Concepció; Peñuelas, Iván; Obeso, José A

    2015-05-01

    Carbon-11 labeled dihydrotetrabenazine ((11)C-DTBZ) binds to the vesicular monoamine transporter 2 and has been used to assess nigro-striatal integrity in animal models and patients with Parkinson's disease. Here, we applied (11)C-DTBZ positron emission tomography (PET) to obtain longitudinally in-vivo assessment of striatal dopaminergic loss in the classic unilateral and in a novel bilateral 6-hydroxydopamine (6-OHDA) lesion rat model. Forty-four Sprague-Dawley rats were divided into 3 sub-groups: 1. 6-OHDA-induced unilateral lesion in the medial forebrain bundle, 2. bilateral lesion by injection of 6-OHDA in the third ventricle, and 3. vehicle injection in either site. (11)C-DTBZ PET studies were investigated in the same animals successively at baseline, 1, 3 and 6weeks after lesion using an anatomically standardized volumes-of-interest approach. Additionally, 12 rats had PET and Magnetic Resonance Imaging to construct a new (11)C-DTBZ PET template. Behavior was characterized by rotational, catalepsy and limb-use asymmetry tests and dopaminergic striatal denervation was validated post-mortem by immunostaining of the dopamine transporter (DAT). (11)C-DTBZ PET showed a significant decrease of striatal binding (SB) values one week after the unilateral lesion. At this point, there was a 60% reduction in SB in the affected hemisphere compared with baseline values in 6-OHDA unilaterally lesioned animals. A 46% symmetric reduction over baseline SB values was found in bilaterally lesioned rats at the first week after lesion. SB values remained constant in unilaterally lesioned rats whereas animals with bilateral lesions showed a modest (22%) increase in binding values at the 3rd and 6th weeks post-lesion. The degree of striatal dopaminergic denervation was corroborated histologically by DAT immunostaining. Statistical analysis revealed a high correlation between (11)C-DTBZ PET SB and striatal DAT immunostaining values (r=0.95, p<0.001). The data presented here indicate

  14. Neuroprotective potentials of neurotrophin rich olfactory ensheathing cell's conditioned media against 6OHDA-induced oxidative damage.

    PubMed

    Shukla, A; Mohapatra, T M; Parmar, D; Seth, K

    2014-05-01

    On the basis of recent reports, we propose that impaired neurotrophin signaling (PI3k/Akt), low antioxidant levels, and generation of reactive oxygen species (ROS) conjointly participate in the progressive events responsible for the dopaminergic cell loss in Parkinson's disease (PD). In the present study we tried to target these deficits collectively through multiple neurotrophic factors (NTFs) support in the form of Olfactory Ensheathing Cell's Conditioned Media (OEC CM) using human SH-SY5Y neuroblastoma cell line exposed to 6 hydroxydopamine (6OHDA). 6OHDA exposure induced, oxidative stress-mediated apoptotic cell death viz. enhanced ROS generation, diffused cytosolic cytochrome c (cyt c), impaired Bcl-2: Bax levels along with decrease in GSH content. These changes were accompanied by loss in Akt phosphorylation and TH levels in SH-SY5Y cells. OEC CM significantly checked apoptotic cell death by preserving pAkt levels which coincided with enhanced GSH and suppressed oxidative injury. Functional integrity of OEC CM supported cells was evident by maintained tyrosine hydroxylase (TH) expression. Intercepting Akt signaling by specific inhibitor LY294002 blocked the protective effect. Taken together our findings provide important evidence that the key to protective effect of multiple NTF support via OEC CM is enhanced Akt survival signaling which promotes antioxidant defense leading to suppression of oxidative damage.

  15. Methodology and effects of repeated intranasal delivery of DNSP-11 in a rat model of Parkinson’s disease

    PubMed Central

    Stenslik, Mallory J.; Potts, Lisa F.; Sonne, James W.H.; Cass, Wayne A.; Turchan-Cholewo, Jadwiga; Pomerleau, Francois; Huettl, Peter; Ai, Yi; Gash, Don M.; Gerhardt, Greg A.; Bradley, Luke H.

    2015-01-01

    Background To circumvent the challenges associated with delivering large compounds directly to the brain for the treatment of Parkinson’s disease (PD), non-invasive procedures utilizing smaller molecules with protective and/or restorative actions on dopaminergic neurons are needed. New Method We developed a methodology for evaluating the effects of a synthetic neuroactive peptide, DNSP-11, on the nigrostriatal system using repeated intranasal delivery in both normal and a unilateral 6-hydroxydopamine (6-OHDA) lesion rat model of PD. Results Normal rats repeatedly administered varying doses of DNSP-11 intranasally for 3 weeks exhibited a significant increase in dopamine (DA) turnover in both the striatum and substantia nigra (SN) at 300 μg, suggestive of a stimulative effect of the dopaminergic system. Additionally, a protective effect was observed following repeated intranasal administration in 6-OHDA lesioned rats, as suggested by: a significant decrease in d-amphetamine-induced rotation at 2 weeks; a decrease in DA turnover in the lesioned striatum; and an increased sparing of tyrosine hydroxylase (TH) positive neurons in a specific sub-region of the lesioned substantia nigra pars compacta. Finally, tracer studies showed 125I-DNSP-11 distributed diffusely throughout the brain, including the striatum and SN, as quickly as 30 minutes after a single intranasal dose. Comparison with Existing Methods The results of bilateral intranasal administration of DNSP-11 are compared to our unilateral single infusion studies to the brain in rats. Conclusions These studies support that DNSP-11 can be delivered intranasally and maintain its neuroactive properties in both normal rats and in a unilateral 6-OHDA rat model of PD. PMID:25999268

  16. Pharmacological validation of behavioural measures of akinesia and dyskinesia in a rat model of Parkinson's disease.

    PubMed

    Lundblad, M; Andersson, M; Winkler, C; Kirik, D; Wierup, N; Cenci, M Angela

    2002-01-01

    In an attempt to define clinically relevant models of akinesia and dyskinesia in 6-hydroxydopamine (6-OHDA)-lesioned rats, we have examined the effects of drugs with high (L-DOPA) vs. low (bromocriptine) dyskinesiogenic potential in Parkinson's disease on three types of motor performance, namely: (i) abnormal involuntary movements (AIMs) (ii) rotational behaviour, and (iii) spontaneous forelimb use (cylinder test). Rats with unilateral 6-OHDA lesions received single daily i.p. injections of L-DOPA or bromocriptine at therapeutic doses. During 3 weeks of treatment, L-DOPA but not bromocriptine induced increasingly severe AIMs affecting the limb, trunk and orofacial region. Rotational behaviour was induced to a much higher extent by bromocriptine than L-DOPA. In the cylinder test, the two drugs initially improved the performance of the parkinsonian limb to a similar extent. However, L-DOPA-treated animals showed declining levels of performance in this test because the drug-induced AIMs interfered with physiological limb use, and gradually replaced all normal motor activities. L-DOPA-induced axial, limb and orolingual AIM scores were significantly reduced by the acute administration of compounds that have antidyskinetic efficacy in parkinsonian patients and/or nonhuman primates (-91%, yohimbine 10 mg/kg; -19%, naloxone 4-8 mg/kg; -37%, 5-methoxy 5-N,N-dimethyl-tryptamine 2 mg/kg; -30%, clozapine 8 mg/kg; -50%, amantadine 40 mg/kg). L-DOPA-induced rotation was, however, not affected. The present results demonstrate that 6-OHDA-lesioned rats do exhibit motor deficits that share essential functional similarities with parkinsonian akinesia or dyskinesia. Such deficits can be quantified using novel and relatively simple testing procedures, whereas rotometry cannot discriminate between dyskinetic and antiakinetic effects of antiparkinsonian treatments.

  17. Neuroprotective Effect of the Marine-Derived Compound 11-Dehydrosinulariolide through DJ-1-Related Pathway in In Vitro and In Vivo Models of Parkinson’s Disease

    PubMed Central

    Feng, Chien-Wei; Hung, Han-Chun; Huang, Shi-Ying; Chen, Chun-Hong; Chen, Yun-Ru; Chen, Chun-Yu; Yang, San-Nan; Wang, Hui-Min David; Sung, Ping-Jyun; Sheu, Jyh-Horng; Tsui, Kuan-Hao; Chen, Wu-Fu; Wen, Zhi-Hong

    2016-01-01

    Parkinson’s disease (PD) is a neurodegenerative disorder characterized by tremor, rigidity, bradykinesia, and gait impairment. In a previous study, we found that the marine-derived compound 11-dehydrosinulariolide (11-de) upregulates the Akt/PI3K pathway to protect cells against 6-hydroxydopamine (6-OHDA)-mediated damage. In the present study, SH-SY5Y, zebrafish and rats were used to examine the therapeutic effect of 11-de. The results revealed the mechanism by which 11-de exerts its therapeutic effect: the compound increases cytosolic or mitochondrial DJ-1 expression, and then activates the downstream Akt/PI3K, p-CREB, and Nrf2/HO-1 pathways. Additionally, we found that 11-de could reverse the 6-OHDA-induced downregulation of total swimming distance in a zebrafish model of PD. Using a rat model of PD, we showed that a 6-OHDA-induced increase in the number of turns, and increased time spent by rats on the beam, could be reversed by 11-de treatment. Lastly, we showed that 6-OHDA-induced attenuation in tyrosine hydroxylase (TH), a dopaminergic neuronal marker, in zebrafish and rat models of PD could also be reversed by treatment with 11-de. Moreover, the patterns of DJ-1 expression observed in this study in the zebrafish and rat models of PD corroborated the trend noted in previous in vitro studies. PMID:27763504

  18. Cell Fate Analysis of Embryonic Ventral Mesencephalic Grafts in the 6-OHDA Model of Parkinson's Disease

    PubMed Central

    Puschban, Zoe; Stefanova, Nadia; Nat, Roxana; Dechant, Georg; Wenning, Gregor K.

    2012-01-01

    Evidence from carefully conducted open label clinical trials suggested that therapeutic benefit can be achieved by grafting fetal dopaminergic (DAergic) neurons derived from ventral mesencephalon (VM) into the denervated striatum of Parkinson's disease (PD) patients. However, two double-blind trials generated negative results reporting deleterious side effects such as prominent dyskinesias. Heterogeneous composition of VM grafts is likely to account for suboptimal clinical efficacy. We consider that gene expression patterns of the VM tissue needs to be better understood by comparing the genetic signature of the surviving and functioning grafts with the cell suspensions used for transplantation. In addition, it is crucial to assess whether the grafted cells exhibit the DAergic phenotype of adult substantia nigra pars compacta (SNpc). To investigate this further, we used a GFP reporter mouse as source of VM tissue that enabled the detection and dissection of the grafts 6 weeks post implantation. A comparative gene expression analysis of the VM cell suspension and grafts revealed that VM grafts continue to differentiate post-implantation. In addition, implanted grafts showed a mature SNpc-like molecular DAergic phenotype with similar expression levels of TH, Vmat2 and Dat. However, by comparing gene expression of the adult SNpc with dissected grafts we detected a higher expression of progenitor markers in the grafts. Finally, when compared to the VM cell suspension, post-grafting there was a higher expression of markers inherent to glia and other neuronal populations. In summary, our data highlight the dynamic development of distinctive DAergic and non-DAergic gene expression markers associated with the maturation of VM grafts in vivo. The molecular signature of VM grafts and its functional relevance should be further explored in future studies aimed at the optimization of DAergic cell therapy approaches in PD. PMID:23209667

  19. Involvement of activation of the Nrf2/ARE pathway in protection against 6-OHDA-induced SH-SY5Y cell death by α-iso-cubebenol.

    PubMed

    Park, Sun Young; Kim, Do Yeon; Kang, Jong-Koo; Park, Geuntae; Choi, Young-Whan

    2014-09-01

    Free radical-mediated neurodegeneration is one of the many causes of Parkinson's disease (PD). As part of our ongoing studies on the identification of biologically active Schisandra chinensis components, we have isolated and structurally elucidated α-iso-cubebenol. This study was carried out in an attempt to clarify the neuroprotective effect of α-iso-cubebenol on toxin-insulted dopaminergic neuronal death using 6-hydroxy-dopamine (6-OHDA)-induced dopaminergic SH-SY5Y cells. α-iso-cubebenol significantly attenuated the loss of mitochondrial function (MTT assay) and membrane integrity (lactate dehydrogenase assay) associated with 6-OHDA-induced neurotoxicity. Pretreatment of the cells with α-iso-cubebenol diminished the intracellular accumulation of reactive oxygen species (ROS) and calcium in response to 6-OHDA. Moreover, α-iso-cubebenol protected against 6-OHDA-induced neurotoxicity through inhibition of SH-SY5Y cell apoptosis. In addition, JC-1 staining, which is a well-established measure of mitochondrial damage, was decreased after treatment with α-iso-cubebenol. Notably, α-iso-cubebenol inhibited the release of mitochondrial flavoprotein apoptosis inducing factor (AIF) from the mitochondria to the cytosol and nucleus following 6-OHDA treatment. In addition, α-iso-cubebenol reduced the 6-OHDA-induced phosphorylation of ERK and induced the phosphorylation of PKA, PKB, and CREB in a dose-dependent manner. Moreover, α-iso-cubebenol stimulated the activation of Nrf2, a downstream target of CREB. Furthermore, α-iso-cubebenol stimulated the expression of multiple antioxidant response genes (NQO-1 and HO-1). Finally, CREB and Nrf2 siRNA transfection diminished α-iso-cubebenol-mediated neuroprotection. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. MODELING OPERANT BEHAVIOR IN THE PARKINSONIAN RAT

    PubMed Central

    Avila, Irene; Reilly, Mark P.; Sanabria, Federico; Posadas-Sánchez, Diana; Chavez, Claudia L.; Banerjee, Nikhil; Killeen, Peter; Castañeda, Edward

    2009-01-01

    Mathematical principles of reinforcement (MPR; Killeen, 1994) is a quantitative model of operant behavior that contains 3 parameters representing motor capacity (δ), motivation (a), and short term memory (λ). The present study applied MPR to characterize the effects of bilateral infusions of 6-OHDA into the substantia nigra pars compacta in the rat, a model of Parkinson’s disease. Rats were trained to lever press under a 5-component fixed ratio (5, 15, 30, 60, and 100) schedule of food reinforcement. Rats were tested for 15 days prior to dopamine lesions and again for 15 days post-lesion. To characterize functional loss relative to lesion size, rats were grouped according to the extent and the degree of lateralization of their dopamine loss. Response rates decreased as a function of dopamine depletion, primarily at intermediate ratios. MPR accounted for 98% of variance in pre- and post-lesion response rates. Consistent with reported disruptions in motor behavior induced by dopaminergic lesions, estimates of δ increased when dopamine was severely depleted. There was no support for different estimates of a based on pre- and post-lesion performance of any lesion group, suggesting that dopamine loss has negligible effects on incentive motivation. The present study demonstrates the usefulness of combining operant techniques with a theoretical model to better understand the effects of a neurochemical manipulation. PMID:19073222

  1. Intrastriatal injection of sonic hedgehog reduces behavioral impairment in a rat model of Parkinson's disease.

    PubMed

    Tsuboi, Kyoko; Shults, Clifford W

    2002-01-01

    Sonic hedgehog (Shh), a member of hedgehog (hh) family of signaling molecules, is necessary for normal axial patterning and cellular differentiation in the developing central nervous system. Shh also promotes the survival of fetal dopaminergic neurons and protects cultures of fetal midbrain dopaminergic neurons from the toxic effects of N-methyl-4-phenylpyridinium (MPP(+)), a neurotoxin that selectively injures nigral dopaminergic neurons. The mRNA expression of Shh and its putative receptor in the adult brain indicates an important role of Shh in the mature nervous system in addition to its roles during embryogenesis. In this study we examined the behavioral and anatomical effects of intrastriatal injection of singly myristoylated wild-type human Sonic hedgehog N-terminal fragment (Shh-M) in a rat model of Parkinson's disease (PD). Five groups of rats received a series of four intrastriatal injections of Shh-M (180 ng, 540 ng, or 4.275 microg per injection), glial cell line-derived neurotrophic factor (GDNF) (1 microg/injection), or vehicle on days 1, 3, 5, and 8. On day 4, the animals received an intrastriatal injection of 15 microg 6-hydroxydopamine (6-OHDA) free base. Intrastriatal administration of Shh (180 ng/injection) twice before and after a single intrastriatal injection of 6-OHDA reduced apomorphine- and amphetamine-induced rotation and forelimb akinesia and partially preserved dopaminergic axons in the striatum. This is the first demonstration in vivo that Shh reduces behavioral deficits induced by intrastriatal 6-OHDA lesion and suggests that Shh may be useful in the treatment of disorders that affect the nigrostriatal system, such as PD.

  2. Adaptive down-regulation of the serotonin transporter in the 6-hydroxydopamine-induced rat model of preclinical stages of Parkinson's disease and after chronic pramipexole treatment.

    PubMed

    Berghauzen-Maciejewska, K; Wardas, J; Kosmowska, B; Domin, H; Śmiałowska, M; Głowacka, U; Ossowska, K

    2016-02-09

    Our recent study has indicated that a moderate lesion induced by bilateral 6-hydroxydopamine (6-OHDA) injections into the ventrolateral region of the caudate-putamen (CP) in rats, modeling preclinical stages of Parkinson's disease, induces a "depressive-like" behavior which is reversed by chronic treatment with pramipexole (PRA). The aim of the present study was to examine the influence of the above lesion and chronic PRA treatment on binding to the serotonin transporter (SERT) in different brain regions. As before, 6-OHDA (15 μg/2.5 μl) was administered bilaterally into the CP. PRA (1mg/kg) was injected subcutaneously twice a day for 2 weeks. Serotonergic and dopaminergic neurons of the dorsal raphe (DR) were immunostained for tryptophan hydroxylase and tyrosine hydroxylase, respectively, and were counted stereologically. Binding of [(3)H]GBR 12,935 to the dopamine transporter (DAT) and [(3)H]citalopram to SERT was analyzed autoradiographically. Intrastriatal 6-OHDA injections decreased the number of dopaminergic, but not serotonergic neurons in the DR. 6-OHDA reduced the DAT binding in the CP, and SERT binding in the nigrostriatal system (CP, substantia nigra (SN)), limbic system (ventral tegmental area (VTA), nucleus accumbens (NAC), amygdala, prefrontal cortex (PFCX), habenula, hippocampus) and DR. A significant positive correlation was found between DAT and SERT binding in the CP. Chronic PRA did not influence DAT binding but reduced SERT binding in the above structures, and deepened the lesion-induced losses in the core region of the NAC, SN, VTA and PFCX. The present study indicates that both the lesion of dopaminergic neurons and chronic PRA administration induce adaptive down-regulation of SERT binding. Moreover, although involvement of stimulation of dopaminergic transmission by chronic PRA in its "antidepressant" effect seems to be prevalent, additional contribution of SERT inhibition cannot be excluded. Copyright © 2015 IBRO. Published by Elsevier

  3. Polylysine-modified polyethylenimine (PEI-PLL) mediated VEGF gene delivery protects dopaminergic neurons in cell culture and in rat models of Parkinson's Disease (PD).

    PubMed

    Sheikh, Muhammad Abid; Malik, Yousra Saeed; Xing, Zhenkai; Guo, Zhaopei; Tian, Huayu; Zhu, Xiaojuan; Chen, Xuesi

    2017-05-01

    Parkinson's Disease (PD) is a chronic neurodegenerative disorder characterized by motor deficits which result from the progressive loss of dopaminergic neurons. Gene therapy using growth factors such as VEGF seems to be a viable approach for potential therapeutic treatment of PD. In this study, we utilized a novel non-viral gene carrier designated as PEI-PLL synthesized by our laboratory to deliver VEGF gene to study its effect by using both cell culture as well as animal models of PD. For cell culture experiments, we utilized 6-hydroxydopamine (6-OHDA) mediated cell death model of MN9D cells following transfection with either a control plasmid or VEGF expressing plasmid. As compared to control transfected cells, PEI-PLL mediated VEGF gene delivery to MN9D cells resulted in increased cell viability, increase in the number of Tyrosine hydroxylase (TH) positive cells and decreased apoptosis following 6-OHDA insult. Next, we studied the therapeutic potential of PEI-PLL mediated VEGF gene delivery in SNPc by using unilateral 6-OHDA Medial forebrain bundle (MFB) lesion model of PD in rats. VEGF administration prevented the loss of motor functions induced by 6-OHDA as determined by behavior analysis. Similarly, VEGF inhibited the 6-OHDA mediated loss of DA neurons in Substantia Nigra Pars Compacta (SNPc) as well as DA nerve fibers in striatum as determined by TH immunostaining. In addition, PEI-PLL mediated VEGF gene delivery also prevented apoptosis and microglial activation in PD rat models. Together, these results clearly demonstrated the beneficial effects of PEI-PLL mediated VEGF gene delivery on dopaminergic system in both cell culture and animal models of PD. In this report, we exploited the potential of PEI-PLL to deliver VEGF gene for the potential therapeutic treatment of PD by using both cell culture and animal models of PD. To the best of our knowledge, this is the first report describing the use of novel polymeric gene carriers for the delivery of VEGF gene

  4. Modulation of Corpus Striatal Neurochemistry by Astrocytes and Vasoactive Intestinal Peptide (VIP) in Parkinsonian Rats.

    PubMed

    Yelkenli, İbrahim Halil; Ulupinar, Emel; Korkmaz, Orhan Tansel; Şener, Erol; Kuş, Gökhan; Filiz, Zeynep; Tunçel, Neşe

    2016-06-01

    The neurotoxin 6-hydroxydopamine (6-OHDA) is widely used in animal models of Parkinson's disease. In various neurodegenerative diseases, astrocytes play direct, active, and critical roles in mediating neuronal survival and functions. Vasoactive intestinal peptide (VIP) has neurotrophic actions and modulates a number of astrocytic activities. In this study, the effects of VIP on the striatal neurochemistry were investigated in parkinsonian rats. Adult Sprague-Dawley rats were divided into sham-operated, unilaterally 6-OHDA-lesioned, and lesioned + VIP-administered (25 ng/kg i.p.) groups. VIP was first injected 1 h after the intrastriatal 6-OHDA microinjection and then every 2 days throughout 15 days. Extracellular striatal concentration of glutathione (GSH), gamma-aminobutyric acid (GABA), glutamate (GLU), and lactate were measured in microdialysates by high-performance liquid chromatography (HPLC). Quantification of GABA and activity dependent neuroprotective protein (ADNP)-expressing cells were determined by glutamic acid decarboxylase (GAD)/ADNP + glial fibrillary acidic protein (GFAP) double immunohistochemistry. Our results demonstrated that a 6-OHDA lesion significantly increased the density of astrocytes in the striatum and VIP treatment slightly reduced the gliosis. Extracellular concentration of GABA, GLU, and lactate levels did not change, but GSH level significantly increased in the striatum of parkinsonian rats. VIP treatment reduced GSH level comparable to sham-operated groups, but enhanced GABA and GLU levels. Our double labeling results showed that VIP primarily acts on neurons to increase ADNP and GAD expression for protection. These results suggest that, in the 6-OHDA-induced neurodegeneration model, astrocytes were possibly activated for forefront defensiveness by modulating striatal neurochemistry.

  5. Impact of the Chronic Omega-3 Fatty Acids Supplementation in Hemiparkinsonism Model Induced by 6-Hydroxydopamine in Rats.

    PubMed

    Barros, Alexandre Sales; Crispim, Rafael Yuri Gouveia; Uchoa, Juliana Cavalcante; Souza, Ricardo Basto; Lemos, Jonatas Cavalcante; Filho, Gerardo Cristino; Bezerra, Mirna Marques; Pinheiro, Thales Fontenele Moraes; de Vasconcelos, Silvânia Maria Mendes; Macêdo, Danielle Silveira; de Barros Viana, Glauce Socorro; Aguiar, Lissiana Magna Vasconcelos

    2016-11-24

    Parkinson's disease (PD) is characterized by a progressive degeneration of dopaminergic neurons in the substantia nigra. The neuronal degeneration may result from the convergence of a number of different pathogenic factors, including apoptosis, excitotoxicity and oxidative stress. Many studies emphasize the importance of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) in vital processes such as maintenance of the properties of cell membranes and the participation in signal transduction and biodynamic activity of neuronal membranes. In the present study, the protective effect of ω-3 PUFAs administration on the 6-hydroxydopamine (6-OHDA) model of PD in rats was investigated. ω-3 PUFAs (1.5 and 3.0 g/kg) was orally administered by gavage during 28 consecutive days to male Wistar rats. On the 4(th) day, hemiparkinsonism was induced through intrastriatal injection of 6-OHDA. On the 25(th) day, the animals were submitted to behavioural analysis. On the 28(th) day, after euthanasia, the brain areas were collected for neurochemical evaluation. ω-3 PUFAs (1.5 and 3.0 g/kg) restored monoamine and amino acids levels on the striatum from hemiparkinsonian rats, followed by reduction of the number of apomorphine-induced rotations and promotion of a partial locomotor recovery. In addition, ω-3 PUFAs (1.5 and 3.0 g/kg) decreased the lipid peroxidation levels and nitrite levels in the brain areas from hemiparkinsonian rats. Thus, the present study suggests that supplementation with ω-3 PUFAs prevents behavioural and neurochemical disturbances induced by 6-OHDA, presenting a potential neuroprotective action. This article is protected by copyright. All rights reserved.

  6. The majority of newly generated cells in the adult mouse substantia nigra express low levels of Doublecortin, but their proliferation is unaffected by 6-OHDA-induced nigral lesion or Minocycline-mediated inhibition of neuroinflammation.

    PubMed

    Worlitzer, Maik M A; Viel, Thomas; Jacobs, Andreas H; Schwamborn, Jens C

    2013-09-01

    Parkinson's disease is characterized by a selective loss of dopaminergic neurons in the substantia nigra (SN). However, whether regenerative endogenous neurogenesis is taking place in the mammalian SN of parkinsonian and non-parkinsonian brains remains of debate. Here, we tested whether proliferating cells in the SN and their neurogenic potential would be affected by anti-inflammatory treatment under physiological conditions and in the 6-hydroxy-dopamine (6-OHDA) Parkinson's disease mouse model. We report that the majority of newly generated nigral cells are positive for Doublecortin (Dcx), which is an often used marker for neural progenitor cells. Yet, Dcx expression levels in these cells were much lower than in neural progenitor cells of the subventricular zone and the dentate gyrus neural progenitor cells. Furthermore, these newly generated nigral cells are negative for neuronal lineage markers such as TuJ1 and NeuN. Therefore, their neuronal commitment is questionable. Instead, we found evidence for oligodendrogenesis and astrogliosis in the SN. Finally, neither short-term nor long-term inhibition of neuroinflammation by Minocycline- or 6-OHDA-induced lesion affected the numbers of newly generated cells in our disease paradigm. Our findings of adult generated Dcx(+) cells in the SN add important data for understanding the cellular composition and consequently the regenerative capacity of the SN.

  7. c-Fos expression after deep brain stimulation of the pedunculopontine tegmental nucleus in the rat 6-hydroxydopamine Parkinson model.

    PubMed

    Saryyeva, Assel; Nakamura, Makoto; Krauss, Joachim K; Schwabe, Kerstin

    2011-11-01

    Deep brain stimulation (DBS) is used to alleviate motor dysfunction in Parkinson's disease (PD). The pedunculopontine nucleus (PPN) may be a potential target for severe freezing and postural instability with 25 Hz stimulation being considered more effective than 130 Hz stimulation. Here we evaluated the expression of c-Fos after 25 Hz and 130 Hz DBS of the pedunculopontine tegmental nucleus (PPTg, i.e., the rodent equivalent to the human PPN) in the rat 6-hydroxydopamine (6-OHDA) PD model. Anaesthetized male Sprague Dawley rats with unilateral 6-OHDA-induced nigrostriatal lesions were stimulated with 25 Hz, 130 Hz, or 0 Hz sham-stimulation for 4h by electrodes implanted into the ipsilateral PPTg. Thereafter the distribution and number of neurons expressing the immediate early gene c-Fos, a marker for acute neuronal activity, was assessed. DBS of the PPTg induced strong ipsilateral c-Fos expression at the stimulation site, with 25 Hz having a more marked impact than 130 Hz. Additionally, c-Fos was strongly expressed in the central gray. In the dorsal part expression was stronger after 25 Hz stimulation, while in the medial and ventral part there was no difference between 25 Hz and 130 Hz stimulation. Expression in the basal ganglia was negligible. In the rat 6-OHDA PD model stimulation of the PPTg did not affect c-Fos expression in the basal ganglia, but had a strong impact on other functional circuitries. PPN stimulation in humans might therefore also have an impact on other systems than the motor system.

  8. Early toxic effect of 6-hydroxydopamine on extracellular concentrations of neurotransmitters in the rat striatum: an in vivo microdialysis study.

    PubMed

    Tobón-Velasco, Julio César; Silva-Adaya, Daniela; Carmona-Aparicio, Liliana; García, Esperanza; Galván-Arzate, Sonia; Santamaría, Abel

    2010-12-01

    The early effects of 6-OHDA as a Parkinsonian model in rodents are relevant since pharmacological and toxicological points of view, as they can explain the acute and chronic deleterious events occurring in the striatum. In this study, we focused our attention on the neurochemical and motor dysfunction produced after a pulse infusion of 6-OHDA, paying special attention to the capacity of this molecule to induce neurotransmitter release and behavioural alterations. Extracellular levels of dopamine, serotonin, norepinephrine, glutamate, glutamine, aspartate, glycine and GABA were all assessed in striatal dialysates in freely moving rats immediately after exposed to a single pulse of 6-OHDA in dorsal striatum, and major behavioural markers of motor alterations were simultaneously explored. Enhanced release of dopamine, serotonin and norepinephrine was found immediately after 6-OHDA pulse. Delayed glutamate and glycine release were detected and a biphasic effect on GABA was observed. Mostly serotonin and dopamine outflow, followed by glutamate, correlated with wet dog shakes and other behavioural qualitative alterations. Early dopamine release, accompanied by other neurotransmitters, can generate an excitatory environment affecting the striatal neurons with immediate consequences for behavioural performance. In turn, these changes might be accounting for later features of toxicity described in this model.

  9. Deep brain stimulation exacerbates hypokinetic dysarthria in a rat model of Parkinson's disease.

    PubMed

    King, Nathaniel O; Anderson, Collin J; Dorval, Alan D

    2016-02-01

    Motor symptoms of Parkinson's disease (PD) follow the degeneration of dopaminergic neurons in the substantia nigra pars compacta. Deep brain stimulation (DBS) treats some parkinsonian symptoms, such as tremor, rigidity, and bradykinesia, but may worsen certain medial motor symptoms, including hypokinetic dysarthria. The mechanisms by which DBS exacerbates dysarthria while improving other symptoms are unclear and difficult to study in human patients. This study proposes an animal model of DBS-exacerbated dysarthria. We use the unilateral, 6-hydroxydopamine (6-OHDA) rat model of PD to test the hypothesis that DBS exacerbates quantifiable aspects of vocalization. Mating calls were recorded from sexually experienced male rats under healthy and parkinsonian conditions and during DBS of the subthalamic nucleus. Relative to healthy rats, parkinsonian animals made fewer calls with shorter and less complex vocalizations. In the parkinsonian rats, putatively therapeutic DBS further reduced call frequency, duration, and complexity. The individual utterances of parkinsonian rats spanned a greater bandwidth than those of healthy rats, potentially reducing the effectiveness of the vocal signal. This utterance bandwidth was further increased by DBS. We propose that the parkinsonism-associated changes in call frequency, duration, complexity, and dynamic range combine to constitute a rat analog of parkinsonian dysarthria. Because DBS exacerbates the parkinsonism-associated changes in each of these metrics, the subthalamic stimulated 6-OHDA rat is a good model of DBS-induced hypokinetic dysarthria in PD. This model will help researchers examine how DBS alleviates many motor symptoms of PD while exacerbating parkinsonian speech deficits that can greatly diminish patient quality of life.

  10. An NR2B-Dependent Decrease in the Expression of trkB Receptors Precedes the Disappearance of Dopaminergic Cells in Substantia Nigra in a Rat Model of Presymptomatic Parkinson's Disease

    PubMed Central

    Riquelme, Eduardo; Abarca, Jorge; Campusano, Jorge M.; Bustos, Gonzalo

    2012-01-01

    Compensatory changes occurring during presymptomatic stages of Parkinson's disease (PD) would explain that the clinical symptoms of the disease appear late, when the degenerative process is quite advanced. Several data support the proposition that brain-derived neurotrophic factor (BDNF) could play a role in these plastic changes. In the present study, we evaluated the expression of the specific BDNF receptor, trkB, in a rat model of presymptomatic PD generated by intrastriatal injection of the neurotoxin 6-OHDA. Immunohistochemical studies revealed a decrease in trkB expression in SN pars compacta (SNc) seven days after 6-OHDA injection. At this time point, no change in the number of tyrosine hydroxylase (TH) immunoreactive (TH-IR) cells is detected, although a decrease is evident 14 days after neurotoxin injection. The decrease in TH-positive cells and trkB expression in SNc was significantly prevented by systemic administration of Ifenprodil, a specific antagonist of NR2B-containing NMDA receptors. Therefore, an NR2B-NMDA receptor-dependent decrease in trkB expression precedes the disappearance of TH-IR cells in SNc in response to 6-OHDA injection. These results support the idea that a functional coupling between NMDA receptors and BDNF/trkB signalling may be important for the maintenance of the dopaminergic phenotype in SNc during presymptomatic stages of PD. PMID:22720191

  11. Regional distributions of manganese, iron, copper, and zinc in the brains of 6-hydroxydopamine-induced parkinsonian rats.

    PubMed

    Tarohda, Tohru; Ishida, Yasushi; Kawai, Keiichi; Yamamoto, Masayoshi; Amano, Ryohei

    2005-09-01

    Time courses of changes in manganese, iron, copper, and zinc concentrations were examined in regions of the brain of a 6-hydroxydopamine (6-OHDA)-induced rat model of Parkinson's disease using inductively coupled plasma mass spectrometry (ICP-MS). The concentrations were simultaneously determined in brain section at the level of the substantia nigra 1, 3, 7, 10, 14, and 21 days after the 6-OHDA treatment and compared with those of control rats. The distributions of these elements were obtained for 18 regions of the sagittal section (1-mm thick). The ICP-MS results indicated that Mn, Fe, Cu, and Zn levels of the 6-OHDA-induced parkinsonian brain were observed to increase in all regions that lay along the dopaminergic pathway. In the substantia nigra, the increase in Mn level occurred rapidly from 3 to 7 days and preceded those in the other elements, reaching a plateau in the 6-OHDA brain. Iron and Zn levels increased gradually until 7 days and then increased rapidly from 7 to 10 days. The increase in the copper level was slightly delayed. In other regions, such as the globus pallidus, putamen, and amygdala, the levels of Mn, Fe, Cu, and Zn increased with time after 6-OHDA treatment, although the time courses of their changes were region-specific. These findings contribute to our understanding of the roles of Mn and Fe in the induction of neurological symptoms and progressive loss of dopaminergic neurons in the development of Parkinson's disease. Manganese may hold the key to disturbing cellular Fe homeostasis and accelerating Fe levels, which play the most important role in the development of Parkinson's disease.

  12. L-F001, a Multifunction ROCK Inhibitor Prevents 6-OHDA Induced Cell Death Through Activating Akt/GSK-3beta and Nrf2/HO-1 Signaling Pathway in PC12 Cells and Attenuates MPTP-Induced Dopamine Neuron Toxicity in Mice.

    PubMed

    Luo, Liting; Chen, Jingkao; Su, Dan; Chen, Meihui; Luo, Bingling; Pi, Rongbiao; Wang, Lan; Shen, Wei; Wang, Rikang

    2017-02-01

    Amounting evidences demonstrated that Rho/Rho-associated kinase (ROCK) might be a novel target for the therapy of Parkinson's disease (PD). Recently, we synthesized L-F001 and revealed it was a potent ROCK inhibitor with multifunctional effects. Here we investigated the effects of L-F001 in PD models. We found that L-F001 potently attenuated 6-OHDA-induced cytotoxicity in PC12 cells and significantly decreased intracellular reactive oxygen species (ROS), prevented the 6-OHDA-induced decline of mitochondrial membrane potential and intracellular GSH levels. In addition, L-F001 increased Akt and GSK-3beta phosphorylation and induced the nuclear Nrf2 and HO-1 expression in a time- and concentration-dependent manner. Moreover, L-F001 restored the levels of p-Akt and p-GSK-3beta (Ser9) as well as HO-1 expression reduced by 6-OHDA. Those effects were blocked by the specific PI3K inhibitor, LY294002, indicating the involvement of Akt/GSK-3beta pathway in the neuroprotective effect of L-F001. In addition, L-F001 significantly attenuated the tyrosinehydroxylase immunoreactive cell loss in 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine (MPTP)-induced mice PD model. Together, our findings suggest that L-F001 prevents 6-OHDA-induced cell death through activating Akt/GSK-3beta and Nrf2/HO-1 signaling pathway and attenuates MPTP-induced dopaminergic neuron toxicity in mice. L-F001 might be a promising drug candidate for PD.

  13. Calcitriol promotes augmented dopamine release in the lesioned striatum of 6-hydroxydopamine treated rats

    PubMed Central

    Cass, Wayne A.; Peters, Laura E.; Fletcher, Anita M.; Yurek, David M.

    2014-01-01

    Current therapies for Parkinson's disease (PD) offer symptomatic relief but do not provide a cure or slow the disease process. Treatments that could halt progression of the disease or help restore function to damaged neurons would be of substantial benefit. Calcitriol, the active metabolite of vitamin D, has been shown to have significant effects on the brain. These effects include upregulating trophic factor levels, and reducing the severity of some central nervous system lesions. While previous studies have shown that calcitriol can be neuroprotective in 6-hydroxydopamine (6-OHDA) rodent models of PD, the present experiments were designed to examine the ability of calcitriol to promote restoration of extracellular DA levels and tissue content of DA in animals previously lesioned with 6-OHDA. Male Fischer-344 rats were given a single injection of 12 µg 6-OHDA into the right striatum. Four weeks later the animals were administered vehicle or calcitriol (0.3 or 1.0 µg/kg, s.c.) once a day for eight consecutive days. Three weeks after the calcitriol treatments in vivo microdialysis experiments were conducted to measure potassium and amphetamine evoked overflow of DA from both the left and right striata. In control animals treated with 6-OHDA and vehicle there were significant reductions in both potassium and amphetamine evoked overflow of DA on the lesioned side of the brain compared to the contralateral side. In animals treated with 6-OHDA followed by calcitriol there was significantly greater potassium and amphetamine evoked overflow of DA from the lesioned striatum compared to that from the control animals. The calcitriol treatments also led to increases in postmortem tissue levels of DA in the striatum and substantia nigra. These results suggest that calcitriol may help promote recovery of dopaminergic functioning in injured nigrostriatal neurons. PMID:24858239

  14. Exposure to Early Life Stress Results in Epigenetic Changes in Neurotrophic Factor Gene Expression in a Parkinsonian Rat Model

    PubMed Central

    Mpofana, Thabisile; Daniels, Willie M. U.; Mabandla, Musa V.

    2016-01-01

    Early life adversity increases the risk of mental disorders later in life. Chronic early life stress may alter neurotrophic factor gene expression including those for brain derived neurotrophic factor (BDNF) and glial cell derived neurotrophic factor (GDNF) that are important in neuronal growth, survival, and maintenance. Maternal separation was used in this study to model early life stress. Following unilateral injection of a mild dose of 6-hydroxydopamine (6-OHDA), we measured corticosterone (CORT) in the blood and striatum of stressed and nonstressed rats; we also measured DNA methylation and BDNF and GDNF gene expression in the striatum using real time PCR. In the presence of stress, we found that there was increased corticosterone concentration in both blood and striatal tissue. Further to this, we found higher DNA methylation and decreased neurotrophic factor gene expression. 6-OHDA lesion increased neurotrophic factor gene expression in both stressed and nonstressed rats but this increase was higher in the nonstressed rats. Our results suggest that exposure to early postnatal stress increases corticosterone concentration which leads to increased DNA methylation. This effect results in decreased BDNF and GDNF gene expression in the striatum leading to decreased protection against subsequent insults later in life. PMID:26881180

  15. Antioxidant and neuroprotector effect of Lepidium meyenii (maca) methanol leaf extract against 6-hydroxy dopamine (6-OHDA)-induced toxicity in PC12 cells.

    PubMed

    Rodríguez-Huamán, Ángel; Casimiro-Gonzales, Sandra; Chávez-Pérez, Jorge Antonio; Gonzales-Arimborgo, Carla; Cisneros-Fernández, Richard; Aguilar-Mendoza, Luis Ángel; Gonzales, Gustavo F

    2017-01-08

    Reactive oxygen species (ROS) are normally produced during cell metabolism, there is strong evidence to suggest that ROS produced in excess impair the cell and may be etiologically related to various neurodegenerative diseases. This study was undertaken to examine the effects of Lepidium meyenii (MACA) methanol leaf extract on neurotoxicity in PC12 cell exposed to 6-hydroxydopamine (6-OHDA). Fresh samples of "maca" leaves were processed in order to obtain foliar extracts and to evaluate the neurobiological activity on PC12 cells, subjected to the cytotoxic effect of 6-OHDA through the determination of the capacity antioxidant, cell viability and cytotoxicity assays on PC12 cells. The results of the tests of antioxidant activity, showed maximum values of 2262.37 and 1305.36 expressed in Trolox equivalents (TEAC), for the methanolic and aqueous fractions respectively. Cell viability assays at a dose of 10 μg extract showed an increase of 31% and 60% at 6 and 12 h of pretreatment, respectively. Cytotoxicity assays at the same dose and exposure time showed a 31.4% and 47.8% reduction in lactate dehydrogenase (LDH) activity and an increase in superoxide dismutase (SOD) activity. The results allow us to affirm that the methanolic foliar extract of "maca" presents in vitro neurobiological activity of antioxidant protection, increase in cell viability and reduction of cytotoxicity against oxidative stress generated by 6-OHDA. In conclusion, the present study shows a protective role for Lepidium meyenii leaf extract on 6-OHDA-induced toxicity by an antioxidant effect.

  16. Neurocytoprotective effects of the bioactive constituents of Pueraria thomsonii in 6-hydroxydopamine (6-OHDA)-treated nerve growth factor (NGF)-differentiated PC12 cells.

    PubMed

    Lin, Chien-Min; Lin, Rong-Dih; Chen, Shui-Tein; Lin, Yi-Pei; Chiu, Wen-Ta; Lin, Jia-Wei; Hsu, Feng-Lin; Lee, Mei-Hsien

    2010-12-01

    Chronic neurodegenerative disorders are having an increasing impact on public health as human longevity increases. Parkinson's disease (PD) is a degenerative disorder of the central nervous system and is characterized by motor system disorders resulting in loss of dopamine-producing brain cells. Pueraria thomsonii Benth. (Fabaceae) is an herbal medicine that has traditionally been used as an antipyretic agent. In the present study, the active constituents, daidzein and genistein, were isolated from P. thomsonii. Both compounds exhibited neurocytoprotective effects against 6-hydroxydopamine (6-OHDA)-induced cytotoxicity in nerve growth factor (NGF)-differentiated PC12 cells. Neither daidzein nor genistein affected 6-OHDA-induced cellular reactive oxygen species (ROS) generation according to flow cytometric analysis. Rather, they inhibited caspase-8 and partially inhibited caspase-3 activation, providing a protective mechanism against 6-OHDA-induced cytotoxicity in NGF-differentiated PC12 cells. The present results imply that daidzein and genistein may be useful in the development of future strategies for the treatment of PD. Copyright © 2010 Elsevier Ltd. All rights reserved.

  17. Adenosine A2A Receptor Gene Knockout Prevents l-3,4-Dihydroxyphenylalanine-Induced Dyskinesia by Downregulation of Striatal GAD67 in 6-OHDA-Lesioned Parkinson’s Mice

    PubMed Central

    Yin, Su-bing; Zhang, Xiao-guang; Chen, Shuang; Yang, Wen-ting; Zheng, Xia-wei; Zheng, Guo-qing

    2017-01-01

    l-3,4-Dihydroxyphenylalanine (l-DOPA) remains the primary pharmacological agent for the symptomatic treatment of Parkinson’s disease (PD). However, the development of l-DOPA-induced dyskinesia (LID) limits the long-term use of l-DOPA for PD patients. Some data have reported that adenosine A2A receptor (A2AR) antagonists prevented LID in animal model of PD. However, the mechanism in which adenosine A2AR blockade alleviates the symptoms of LID has not been fully clarified. Here, we determined to knock out (KO) the gene of A2AR and explored the possible underlying mechanisms implicated in development of LID in a mouse model of PD. A2AR gene KO mice were unilaterally injected into the striatum with 6-hydroxydopamine (6-OHDA) in order to damage dopamine neurons on one side of the brain. 6-OHDA-lesioned mice were then injected once daily for 21 days with l-DOPA. Abnormal involuntary movements (AIMs) were evaluated on days 3, 8, 13, and 18 after l-DOPA administration, and real-time polymerase chain reaction and immunohistochemistry for glutamic acid decarboxylase (GAD) 65 and GAD67 were performed. We found that A2AR gene KO was effective in reducing AIM scores and accompanied with decrease of striatal GAD67, rather than GAD65. These results demonstrated that the possible mechanism involved in alleviation of AIM symptoms by A2AR gene KO might be through reducing the expression of striatal GAD67. PMID:28377741

  18. PI3 kinase/Akt activation mediates estrogen and IGF-1 nigral DA neuronal neuroprotection against a unilateral rat model of Parkinson's disease.

    PubMed

    Quesada, Arnulfo; Lee, Becky Y; Micevych, Paul E

    2008-04-01

    Recently, using the medial forebrain bundle (MFB) 6-hydroxydopmaine (6-OHDA) lesion rat model of Parkinson's disease (PD), we have demonstrated that blockade of central IGF-1 receptors (IGF-1R) attenuated estrogen neuroprotection of substantia nigra pars compacta (SNpc) DA neurons, but exacerbated 6-OHDA lesions in IGF-1 only treated rats (Quesada and Micevych [2004]: J Neurosci Res 75:107-116). This suggested that the IGF-1 system is a central mechanism through which estrogen acts to protect the nigrostriatal DA system. Moreover, these results also suggest that IGF-1R-induced intracellular signaling pathways are involved in the estrogen mechanism that promotes neuronal survival. In vitro, two convergent intracellular signaling pathways used by estrogen and IGF-1, the mitogen-activated protein kinase (MAPK/ERK), and phosphatidyl-inositol-3-kinase/Akt (PI3K/Akt), have been demonstrated to be neuroprotective. Continuous central infusions of MAPK/ERK and PI3K/Akt inhibitors were used to test the hypothesis that one or both of these signal transduction pathways mediates estrogen and/or IGF-1 neuroprotection of SNpc DA neurons after a unilateral administration of 6-OHDA into the MFB of rats. Motor behavior tests and tyrosine hydroxylase immunoreactivity revealed that the inhibitor of the PI3K/Akt pathway (LY294002) blocked the survival effects of both estrogen and IGF-1, while an inhibitor of the MAPK/ERK signaling (PD98059) was ineffective. Western blot analyses showed that estrogen and IGF-1 treatments increased PI3K/Akt activation in the SN; however, MAPK/ERK activation was decreased in the SN. Indeed, continuous infusions of inhibitors blocked phosphorylation of PI3K/Akt and MAPK/ERK. These findings indicate that estrogen and IGF-1-mediated SNpc DA neuronal protection is dependent on PI3K/Akt signaling, but not on the MAPK/ERK pathway.

  19. Application of Fluoro-Jade C in acute and chronic neurodegeneration models: utilities and staining differences.

    PubMed

    Ehara, Ayuka; Ueda, Shuichi

    2009-12-29

    Recent neuropathological studies have shown that Fluoro-Jade C (FJC), an anionic fluorescent dye, is a good marker of degenerating neurons. However, those studies have mostly examined acute rather than chronic models of neurodegeneration. We therefore compared FJC staining using the intrastriatal 6-hydroxydopamine (6-OHDA)-injected rat as an acute model and the zitter rat as a chronic model, as both show dopaminergic (DA) neurodegeneration. In the 6-OHDA-injected rat, FJC-positive neurons were found in the substantia nigra pars compacta (SNc) before the loss of tyrosine hydroxylase (TH)-positive DA neurons. In the zitter rat, FJC-labeled fibers were first detected at 1 month old (1M) and were considerably increased in the striatum at 4M, whereas FJC-labeled cell bodies were found at 4M, but not at 1M in the SNc. Furthermore, FJC-labeled neurons of the zitter rat showed TH-immunoreactivity in fibers, but little in cell bodies, while those from the 6-OHDA-injected rat showed TH-immunoreactivity even in the cell bodies. These results demonstrate that FJC is a useful tool for detecting chronically degenerating neurons, and suggest that intracellular substances bound to FJC may accumulate in the cell bodies from fibers at a slower rate in the chronic model than in the acute model.

  20. Possible regulatory factors for intra-abdominal fat mass in a rat model of Parkinson's disease.

    PubMed

    Kuranuki, Sachi; Arai, Chie; Terada, Shin; Aoyama, Toshiaki; Nakamura, Teiji

    2011-02-01

    Patients with Parkinson's disease (PD) lose body weight primarily due to decreased body fat mass. The purpose of this study was to elucidate possible factors related to reduction in the intra-abdominal fat mass of 6-hydroxydopamine (6-OHDA)-treated rats, which are frequently used as an animal model for PD. Sham-operated (NPD: n = 4) and unilaterally 6-OHDA-injected (PD: n = 4) 14-wk-old male Sprague-Dawley rats were fed a relatively high-fat diet for 2 wk, during which food intake and body weight were measured. After the 2-wk feeding period, intra-abdominal fat was dissected out and weighed. Carbohydrate and fat absorption-related gene expressions in the jejunum and serum insulin and glucose concentrations were analyzed. Although final body weights did not differ, total intra-abdominal fat weight, expressed relative to body weight, was significantly lower in the PD group than in the NPD group (P < 0.05). There were no significant differences between the two groups in the mRNA expression of carbohydrate and fat digestion/absorption-related genes in the jejunum, or in fat absorption efficacy assessed by fecal fat excretion. However, PD rats showed significantly lower serum insulin and higher glucose concentrations than NPD rats (P < 0.05). PD model rats displayed loss of intra-abdominal fat, similar to the progressive loss of fat in PD patients. Our results provide preliminary evidence that reduced lipogenesis due to lower insulin levels, rather than impaired digestion/absorption, might have been involved in this decrease in intra-abdominal fat mass. Copyright © 2011. Published by Elsevier Inc.

  1. EPO-dependent activation of PI3K/Akt/FoxO3a signalling mediates neuroprotection in in vitro and in vivo models of Parkinson's disease.

    PubMed

    Jia, Yu; Mo, Shi-Jing; Feng, Qi-Qi; Zhan, Ma-Li; OuYang, Li-Si; Chen, Jia-Chang; Ma, Yu-Xin; Wu, Jia-Jia; Lei, Wan-Long

    2014-05-01

    Erythropoietin (EPO) may become a potential therapeutic candidate for the treatment of the neurodegenerative disorder -- Parkinson's disease (PD), since EPO has been found to prevent neuron apoptosis through the activation of cell survival signalling. However, the underlying mechanisms of how EPO exerts its neuroprotective effect are not fully elucidated. Here we investigated the mechanism by which EPO suppressed 6-hydroxydopamine (6-OHDA)-induced neuron death in in vitro and in vivo models of PD. EPO knockdown conferred 6-OHDA-induced cytotoxicity. This effect was reversed by EPO administration. Treatment of PC12 cells with EPO greatly diminished the toxicity induced by 6-OHDA in a dose- and time-dependent manner. EPO effectively reduced apoptosis of striatal neurons and induced a significant improvement on the neurological function score in the rat models of PD. Furthermore, EPO increased the expression of phosphorylated Akt and phosphorylated FoxO3a, and abrogated the 6-OHDA-induced dysregulation of Bcl-2, Bax and Caspase-3 in PC12 cells and in striatal neurons. Meanwhile, the EPO-dependent neuroprotection was notably reversed by pretreatment with LY294002, a specific inhibitor of phosphatidylinositol 3-kinase (PI3K). Our data suggest that PI3K/Akt/FoxO3a signalling pathway may be a possible mechanism involved in the neuroprotective effect of EPO in PD.

  2. Androgens exacerbate motor asymmetry in male rats with unilateral 6-hydroxydopamine lesion.

    PubMed

    Cunningham, Rebecca L; Macheda, Teresa; Watts, Lora Talley; Poteet, Ethan; Singh, Meharvan; Roberts, James L; Giuffrida, Andrea

    2011-11-01

    Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by dopamine neuron loss in the nigrostriatal pathway that shows greater incidence in men than women. The mechanisms underlying this gender bias remain elusive, although one possibility is that androgens may increase dopamine neuronal vulnerability to oxidative stress. Motor impairment can be modeled in rats receiving a unilateral injection of 6-hydroxydopamine (6-OHDA), a neurotoxin producing nigrostriatal degeneration. To investigate the role of androgens in PD, we compared young (2 months) and aged (24 months) male rats receiving gonadectomy (GDX) and their corresponding intact controls. One month after GDX, rats were unilaterally injected with 6-OHDA, and their motor impairment and asymmetry were assessed 2 weeks later using the cylinder test and the amphetamine-induced rotation test. Plasma samples were also collected to assess the concentration of testosterone and advanced oxidation protein products, a product of oxidative stress. GDX decreased lesion-induced asymmetry along with oxidative stress and increased amphetamine-induced rotations. These results show that GDX improves motor behaviors by decreasing motor asymmetry in 6-OHDA-treated rats, an effect that may be ascribed to increased release of striatal dopamine and decreased oxidative stress. Collectively, the data support the hypothesis that androgens may underlie the gender bias observed in PD.

  3. Selective destruction of nigrostriatal dopaminergic neurons does not alter [3H]-ryanodine binding in rat striatum.

    PubMed

    Noël, F; Geurts, M; Maloteaux, J M

    2000-02-01

    Dopamine nigrostriatal neurons are important for motor control and may contain a particularly dense population of ryanodine receptors involved in the control of dopamine release. To test this hypothesis, we used a classical model of unilateral selective lesion of these neurons in rats based on 6-hydroxydopamine (6-OHDA) injection into the substantia nigra. Binding of [3H]-GBR 12935, used as a presynaptic marker since it labels specifically the dopamine uptake complex, was dramatically decreased by 83-100% in striatum homogenates after 6-OHDA lesion. On the contrary, no reduction of [3H]-ryanodine binding was observed. The present data indicate that [3H]-ryanodine binding sites present in rat striatum are not preferentially localized in dopaminergic terminals.

  4. Effects of discontinuing a high-fat diet on mitochondrial proteins and 6-hydroxydopamine-induced dopamine depletion in rats.

    PubMed

    Ma, Delin; Shuler, Jeffrey M; Raider, Kayla D; Rogers, Robert S; Wheatley, Joshua L; Geiger, Paige C; Stanford, John A

    2015-07-10

    Diet-induced obesity can increase the risk for developing age-related neurodegenerative diseases including Parkinson's disease (PD). Increasing evidence suggests that mitochondrial and proteasomal mechanisms are involved in both insulin resistance and PD. The goal of this study was to determine whether diet intervention could influence mitochondrial or proteasomal protein expression and vulnerability to 6-Hydroxydopamine (6-OHDA)-induced nigrostriatal dopamine (DA) depletion in rats' nigrostriatal system. After a 3 month high-fat diet regimen, we switched one group of rats to a low-fat diet for 3 months (HF-LF group), while the other half continued with the high-fat diet (HF group). A chow group was included as a control. Three weeks after unilateral 6-OHDA lesions, HF rats had higher fasting insulin levels and higher Homeostasis model assessment of insulin resistance (HOMA-IR), indicating insulin resistance. HOMA-IR was significantly lower in HF-LF rats than HF rats, indicating that insulin resistance was reversed by switching to a low-fat diet. Compared to the Chow group, the HF group exhibited significantly greater DA depletion in the substantia nigra but not in the striatum. DA depletion did not differ between the HF-LF and HF group. Proteins related to mitochondrial function (such as AMPK, PGC-1α), and to proteasomal function (such as TCF11/Nrf1) were influenced by diet intervention, or by 6-OHDA lesion. Our findings suggest that switching to a low-fat diet reverses the effects of a high-fat diet on systemic insulin resistance, and mitochondrial and proteasomal function in the striatum. Conversely, they suggest that the effects of the high-fat diet on nigrostriatal vulnerability to 6-OHDA-induced DA depletion persist.

  5. Contralateral retinal dopamine decrease and melatonin increase in progression of hemiparkinsonium rat.

    PubMed

    Meng, Tao; Zheng, Zhi-Hong; Liu, Ting-Ting; Lin, Ling

    2012-05-01

    Both dopamine (DA) and melatonin (MLT) are abundant neuromodulators located in vertebrate retina. The retinal DA deficiency and variations in MLT levels have been linked to Parkinson's disease (PD). No studies have investigated the ipsilateral and contralateral DA and MLT in retina and their relationships in 6-hydroxydopamine (6-OHDA) induced hemiparkinsonian rats. We established PD rat model by unilateral injection of 6-OHDA into the right substantia nigra and the right medial forebrain bundle. Eye tissue was collected and the levels of MLT and DA were measured twice daily at 10:00 and 22:00. The concentrations of DA and its metabolites, 3,4-dihydroxyphenylacetic (DOPAC) and homovanillic acid (HVA), as well as MLT were determined by HPLC. The results show that DA levels in the eye contralateral to the side of a unilateral intracerebral 6-OHDA lesion significantly decreased (P < 0.001). Both the ratios of DOPAC/DA and HVA/DA were increased in comparison with the vehicle groups after 3 weeks post-lesion. The concentrations of MLT at 10:00 and 22:00 in both eyes were distinctly increased compared with the vehicle groups (P < 0.05). The change of DA and its metabolites, as well as MLT appeared to correlate well with the rotation behavior of rats. These findings suggest that rats receive a unilateral intracerebral injection of 6-OHDA that mainly causes the contralateral eye destruction of DA-containing neurons. Increased retinal MLT level probably is associated with the progression of PD.

  6. β-asarone and levodopa co-administration protects against 6-hydroxydopamine-induced damage in parkinsonian rat mesencephalon by regulating autophagy: down-expression Beclin-1 and light chain 3B and up-expression P62.

    PubMed

    Huang, Li-Ping; Deng, Min-Zhen; He, Yu-Ping; Fang, Yong-Qi

    2015-03-01

    In this study, we investigated Beclin-1, light chain (LC)3B, and p62 expression in 6-hydroxydopamine (6-OHDA)-induced parkinsonian rats after β-asarone and levodopa (l-dopa) co-administration. Unilateral 6-OHDA injection into the medial forebrain bundle was used to create the models, except in sham-operated rats. Rats were divided into eight groups: sham-operated group; 6-OHDA model group; madopar group (75 mg/kg, per os (p.o.)); l-dopa group (60 mg/kg, p.o.); β-asarone group (15 mg/kg, p.o.); β-asarone + l-dopa co-administered group (15 mg/kg + 60 mg/kg, p.o.); 3-methyladenine group (500 nmol, intraperitoneal injection); and rapamycin group (1 mg/kg, intraperitoneal injection). Then, Beclin-1, LC3B, and p62 expression in the mesencephalon were detected. The mesencephalon was also observed by transmission electron microscope. The results showed that Beclin-1 and LC3B expression decreased and that p62 expression increased significantly in the madopar, l-dopa, β-asarone, and co-administered groups when compared with the 6-OHDA model. Beclin-1 and LC3B expression in the β-asarone and co-administered groups were less than in the madopar or l-dopa groups, whereas p62 expression in the β-asarone and co-administered groups was higher than in the madopar or l-dopa groups. In addition, a significant decrease in autophagosome was exhibited in the β-asarone and co-administered groups when compared with the 6-OHDA group. Our findings indicate that Beclin-1 and LC3B expression decreased, whereas p62 expression increased after co-administration treatment. In sum, all data suggest that the co-administration of β-asarone and l-dopa may contribute to the treatment of 6-OHDA-induced damage in rats by inhibiting autophagy activity.

  7. Effects of discontinuing a high-fat diet on mitochondrial proteins and 6-hydroxydopamine-induced dopamine depletion in rats

    PubMed Central

    Ma, Delin; Shuler, Jeffrey M.; Raider, Kayla D.; Rogers, Robert S.; Wheatley, Joshua L.; Geiger, Paige C.; Stanford, John A.

    2015-01-01

    Diet-induced obesity can increase the risk for developing age-related neurodegenerative diseases including Parkinson’s disease (PD). Increasing evidence suggests that mitochondrial and proteasomal mechanisms are involved in both insulin resistance and PD. The goal of this study was to determine whether diet intervention could influence mitochondrial or proteasomal protein expression and vulnerability to 6-Hydroxydopamine (6-OHDA)-induced nigrostriatal dopamine (DA) depletion in rats’ nigrostriatal system. After a 3 month high-fat diet regimen, we switched one group of rats to a low-fat diet for 3 months (HF-LF group), while the other half continued with the high-fat diet (HF group). A chow group was included as a control. Three weeks after unilateral 6-OHDA lesions, HF rats had higher fasting insulin levels and higher Homeostasis model assessment of insulin resistance (HOMA-IR), indicating insulin resistance. HOMA-IR was significantly lower in HF-LF rats than HF rats, indicating that insulin resistance was reversed by switching to a low-fat diet. Compared to the Chow group, the HF group exhibited significantly greater DA depletion in the substantia nigra but not in the striatum. DA depletion did not differ between the HF-LF and HF group. Proteins related to mitochondrial function (such as AMPK, PGC-1α), and to proteasomal function (such as TCF11/Nrf1) were influenced by diet intervention, or by 6-OHDA lesion. Our findings suggest that switching to a low-fat diet reverses the effects of a high-fat diet on systemic insulin resistance, and mitochondrial and proteasomal function in the striatum. Conversely, they suggest that the effects of the high-fat diet on nigrostriatal vulnerability to 6-OHDA-induced DA depletion persist. PMID:25862572

  8. Protective effect of L-kynurenine and probenecid on 6-hydroxydopamine-induced striatal toxicity in rats: implications of modulating kynurenate as a protective strategy.

    PubMed

    Silva-Adaya, Daniela; Pérez-De La Cruz, Verónica; Villeda-Hernández, Juana; Carrillo-Mora, Paul; González-Herrera, Irma Gabriela; García, Esperanza; Colín-Barenque, Laura; Pedraza-Chaverrí, José; Santamaría, Abel

    2011-01-01

    The neuroactive metabolite at the kynunerine pathway, kynurenic acid (KYNA), is a well-known competitive antagonist at the co-agonist glycine site of the N-methyl-D-aspartate receptor (NMDAr), and also decreases the extracellular levels of glutamate by blocking α7-nicotinic acetylcholine receptor (α7-nAchr) located on glutamatergic terminals. KYNA has been often reported to be neuroprotective in different neurotoxic models. The systemic administration of L-kynurenine (L-KYN)--the precursor of KYNA--together with probenecid (PROB)--an inhibitor of organic acids transport--to rodents increases KYNA levels in the brain in a dose-dependent manner. The striatal infusion of the toxin 6-hydroxydopamine (6-OHDA) to rodents is one of the common models used to simulate Parkinson's disease (PD). Different studies have linked PD alterations with excessive glutamatergic transmission in the striatum since NMDAr antagonists exert beneficial effects in PD models. In this work we investigated the effect that a systemic administration of L-KYN+PROB exerted on the toxic model induced by 6-OHDA in rats. PROB (50 mg/kg, i.p.) + L-KYN (75 mg/kg, i.p.) were given to rats for seven consecutive days. On day two of treatment, the animals were infused with a single injection of 6-OHDA (20 μg/2 μl) into the right striatum. Fourteen days post-lesion, rotation behavior was assessed as a marker of motor impairment. The total levels of dopamine (DA) were also estimated in striatal tissue samples of 6-OHDA-treated animals as a neurochemical marker of damage. In addition, twenty eight days post-lesion, the striatal damage was assessed by hematoxylin/eosin staining and immunohistochemistry against glial fibrillary acidic protein (GFAP) in the same animals. Neurodegeneration was also assessed by Fluoro Jade staining. 6-OHDA infusion increased rotation behavior, striatal reactive gliosis and neurodegeneration, while DA levels were decreased. For all markers evaluated, we observed protective

  9. Circadian distribution of motor-activity in unilaterally 6-hydroxy-dopamine lesioned rats.

    PubMed

    Baier, Paul Christian; Branisa, Pablo; Koch, Reinhard; Schindehütte, Jan; Paulus, Walter; Trenkwalder, Claudia

    2006-02-01

    Sleep abnormalities in idiopathic Parkinson's disease (PD) frequently consist in a reduction of total sleep time and efficacy and subsequent excessive daytime sleepiness. As it remains unclear whether these phenomena are part of the disease itself or result from pharmacological treatment, animal models for investigating the pathophysiology of sleep alterations in PD may add knowledge to this research area. In the present study, we investigate whether changes in circadian motor activity occur in 6-OHDA-lesioning model for PD, and allow a screening for disturbed sleep-waking behaviour. Activity measurements of six male Wistar rats with 6-OHDA-lesions in the medial forebrain bundle and six controls were carried out in two consecutive 12:12 h light-dark (LD) cycles. A computer-based video-analysis system, recording the animals' movement tracks was used. Distance travelled and number of transitions between movement periods and resting periods were determined. Although 6-OHDA-lesioned animals show a reduced locomotor activity compared to non-lesioned rats, the circadian distribution basically remained intact. However, some lesioning effects were more pronounced in the resting phase than in the activity phase, possibly paralleling nocturnal akinesia in PD. In order to further elucidate the described phenomena, it will be necessary to perform studies combining sleep recordings with locomotor activity measurements.

  10. Electroacupuncture Alleviates Depressive-Like Symptoms and Modulates BDNF Signaling in 6-Hydroxydopamine Rats

    PubMed Central

    Sun, Min; Wang, Ke; Yu, Yan; Su, Wen-Ting; Jiang, Xin-Xin

    2016-01-01

    Previous studies have identified the beneficial effects of electroacupuncture (EA) on motor behaviors in Parkinson's disease (PD). However, the role and potential mechanisms of EA in PD-associated depression remain unclear. In the present study, a rat model of PD with unilateral 6-hydroxydopamine (6-OHDA) lesions in the medial forebrain bundle was treated using EA for 4 weeks. We found that 100 Hz EA improved several motor phenotypes. In addition, tyrosine hydroxylase (TH) immunohistochemical analysis showed that EA had a minimal impact on the TH-positive profiles of the ipsilateral ventral tegmental area. Compared with the 6-OHDA group, long-term EA stimulation significantly increased sucrose solution consumption and decreased immobility time in the forced swim test. EA treatment did not alter dopamine, norepinephrine, and serotonin levels in the striatum and hippocampus. Noticeably, EA treatment reversed the 6-OHDA-induced abnormal expression of brain-derived neurotrophic factor (BDNF) and tropomyosin-related kinase B (TrkB) in the midbrain and hippocampus. These results demonstrate that EA at 100-Hz possesses the ability to improve depressive-like symptoms in PD rats, which is, at least in part, due to the distinct effect of EA on the mesostriatal and mesocorticolimbic dopaminergic pathways. Moreover, BDNF seems to participate in the effect of EA in PD. PMID:27525025

  11. Dopaminergic differentiation of stem cells from human deciduous teeth and their therapeutic benefits for Parkinsonian rats.

    PubMed

    Fujii, Hiromi; Matsubara, Kohki; Sakai, Kiyoshi; Ito, Mikako; Ohno, Kinji; Ueda, Minoru; Yamamoto, Akihito

    2015-07-10

    Parkinson's disease (PD) is a progressive neurodegenerative disorder caused by the loss of nigrostriatal dopaminergic (DAergic) neurons and the depletion of striatal dopamine. Here we show that DAergic-neuron-like cells could be efficiently induced from stem cells derived from human exfoliated deciduous teeth (SHEDs), and that these induced cells had therapeutic benefits in a 6-OHDA-induced Parkinsonian rat model. In our protocol, EGF and bFGF signaling activated the SHED's expression of proneural genes, Ngn2 and Mash1, and subsequent treatment with brain-derived neurotrophic factor (BDNF) promoted their maturation into DAergic neuron-like SHEDs (dSHEDs). A hypoxic DAergic differentiation protocol improved cell viability and enhanced the expression of multiple neurotrophic factors, including BDNF, GDNF, NT-3, and HGF. Engrafted dSHEDs survived in the striatum of Parkinsonian rats, improved the DA level more efficiently than engrafted undifferentiated SHEDs, and promoted the recovery from neurological deficits. Our findings further suggested that paracrine effects of dSHEDs contributed to neuroprotection against 6-OHDA-induced neurodegeneration and to nigrostriatal tract restoration. In addition, we found that the conditioned medium derived from dSHEDs protected primary neurons against 6-OHDA toxicity and accelerated neurite outgrowth in vitro. Thus, our data suggest that stem cells derived from dental pulp may have therapeutic benefits for PD. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. The C-terminal domain of the heavy chain of tetanus toxin given by intramuscular injection causes neuroprotection and improves the motor behavior in rats treated with 6-hydroxydopamine.

    PubMed

    Mendieta, Liliana; Bautista, Elizabeth; Sánchez, Alejandra; Guevara, Jorge; Herrando-Grabulosa, Mireia; Moran, José; Martínez, Rebeca; Aguilera, José; Limón, Ilhuicamina Daniel

    2012-10-01

    We have previously shown that the intrastriatal injection of the C-terminal domain of tetanus toxin (Hc-TeTx) protects the nigrostriatal-dopaminergic pathways and improves motor behavior in hemiparkinsonism-rat models caused by MPP(+) (1-methyl-4-phenylpyridinium). Here we have investigated the protective effects of the intramuscular application of the Hc-TeTx on motor asymmetry and neurodegeneration in the striatum of 6-hydroxydopamine (6-OHDA)-treated rats. Adult male rats were intramuscularly injected with the recombinant Hc-TeTx protein (0.1-20μg/kg, daily) 3days before the stereotaxic injection of 6-OHDA into the left striatum. Our results showed that the motor-improvement functions were extended for 4weeks in all Hc-TeTx-treated groups, obtaining the maximum performance with the highest dose of Hc-TeTx (20μg/kg). The improvements found were 97%, 87%, and 70% in the turning behavior, stepping test, and cylinder test, respectively. The striatal levels of dopamine and its metabolites did not vary compared to the control group. Moreover, the peripheral treatment with Hc-TeTx in rats prevents, for 30days, the neurodegeneration in the striatum caused by the toxicity of the 6-OHDA. Our results lead us to believe that the Hc-TeTx could be a potential therapeutic agent in pathologies caused by impairment of dopaminergic innervations such as Parkinson's disease.

  13. Effects of Postnatal Enriched Environment in a Model of Parkinson's Disease in Adult Rats.

    PubMed

    Jungling, Adel; Reglodi, Dora; Karadi, Zsofia Nozomi; Horvath, Gabor; Farkas, Jozsef; Gaszner, Balazs; Tamas, Andrea

    2017-02-14

    Environmental enrichment is a widespread neuroprotective strategy during development and also in the mature nervous system. Several research groups have described that enriched environment in adult rats has an impact on the progression of Parkinson's disease (PD). The aim of our present study was to examine the effects of early, postnatal environmental enrichment after 6-hydroxydopamine-induced (6-OHDA) lesion of the substantia nigra in adulthood. Newborn Wistar rats were divided into control and enriched groups according to their environmental conditions. For environmental enrichment, during the first five postnatal weeks animals were placed in larger cages and exposed to intensive complex stimuli. Dopaminergic cell loss, and hypokinetic and asymmetrical signs were evaluated after inducing PD with unilateral injections of 6-OHDA in three-month-old animals. Treatment with 6-OHDA led to a significant cell loss in the substantia nigra of control animals, however, postnatal enriched circumstances could rescue the dopaminergic cells. Although there was no significant difference in the percentage of surviving cells between 6-OHDA-treated control and enriched groups, the slightly less dopaminergic cell loss in the enriched group compared to control animals resulted in less severe hypokinesia. Our investigation is the first to provide evidence for the neuroprotective effect of postnatal enriched environment in PD later in life.

  14. Effects of Postnatal Enriched Environment in a Model of Parkinson’s Disease in Adult Rats

    PubMed Central

    Jungling, Adel; Reglodi, Dora; Karadi, Zsofia Nozomi; Horvath, Gabor; Farkas, Jozsef; Gaszner, Balazs; Tamas, Andrea

    2017-01-01

    Environmental enrichment is a widespread neuroprotective strategy during development and also in the mature nervous system. Several research groups have described that enriched environment in adult rats has an impact on the progression of Parkinson’s disease (PD). The aim of our present study was to examine the effects of early, postnatal environmental enrichment after 6-hydroxydopamine-induced (6-OHDA) lesion of the substantia nigra in adulthood. Newborn Wistar rats were divided into control and enriched groups according to their environmental conditions. For environmental enrichment, during the first five postnatal weeks animals were placed in larger cages and exposed to intensive complex stimuli. Dopaminergic cell loss, and hypokinetic and asymmetrical signs were evaluated after inducing PD with unilateral injections of 6-OHDA in three-month-old animals. Treatment with 6-OHDA led to a significant cell loss in the substantia nigra of control animals, however, postnatal enriched circumstances could rescue the dopaminergic cells. Although there was no significant difference in the percentage of surviving cells between 6-OHDA-treated control and enriched groups, the slightly less dopaminergic cell loss in the enriched group compared to control animals resulted in less severe hypokinesia. Our investigation is the first to provide evidence for the neuroprotective effect of postnatal enriched environment in PD later in life. PMID:28216584

  15. Human adipose-derived mesenchymal stem cells improve motor functions and are neuroprotective in the 6-hydroxydopamine-rat model for Parkinson's disease when cultured in monolayer cultures but suppress hippocampal neurogenesis and hippocampal memory function when cultured in spheroids.

    PubMed

    Berg, Jürgen; Roch, Manfred; Altschüler, Jennifer; Winter, Christine; Schwerk, Anne; Kurtz, Andreas; Steiner, Barbara

    2015-02-01

    Adult human adipose-derived mesenchymal stem cells (MSC) have been reported to induce neuroprotective effects in models for Parkinson's disease (PD). However, these effects strongly depend on the most optimal application of the transplant. In the present study we compared monolayer-cultured (aMSC) and spheroid (sMSC) MSC following transplantation into the substantia nigra (SN) of 6-OHDA lesioned rats regarding effects on the local microenvironment, degeneration of dopaminergic neurons, neurogenesis in the hippocampal DG as well as motor and memory function in the 6-OHDA-rat model for PD. aMSC transplantation significantly increased tyrosine hydroxylase (TH) and brain-derived neurotrophic factor (BDNF) levels in the SN, increased the levels of the glial fibrillary acidic protein (GFAP) and improved motor functions compared to untreated and sMSC treated animals. In contrast, sMSC grafting induced an increased local microgliosis, decreased TH levels in the SN and reduced numbers of newly generated cells in the dentate gyrus (DG) without yet affecting hippocampal learning and memory function. We conclude that the neuroprotective potential of adipose-derived MSC in the rat model of PD crucially depends on the applied cellular phenotype.

  16. Intermittent L-DOPA treatment differentially alters synaptotagmin 4 and 7 gene expression in the striatum of hemiparkinsonian rats.

    PubMed

    Glavan, Gordana

    2008-10-21

    Long-term use of L-DOPA in Parkinson's disease (PD) is frequently associated with side effects that are reflected in changed neurotransmitter/neuropeptide secretion in basal ganglia. These side effects could be connected with synaptotagmins (syts) because syts are involved in regulation of membrane trafficking. We have previously reported that acute L-DOPA treatment upregulated the expression of Syt 4 and Syt 7 mRNAs in hypersensitive striatum of 6-OHDA rat model for PD. Here we investigate whether intermittent L-DOPA treatment that produces behavior sensitization affects the Syt 1, Syt 2, Syt 4, Syt 7 and Syt 10 mRNAs in striatum of 6-OHDA rats killed 4 and 12 h after the last L-DOPA injection. We verified behavioral sensitization by increased intensity of contralateral turning. 6-OHDA lesion caused Syt 2 mRNA downregulation and Syt 10 mRNA upregulation in striatum, but failed to alter Syt 4, Syt 7 and Syt 1 mRNAs. Acute l-DOPA induced an increase of Syt 4 and Syt 7 mRNAs in the denervated striatum leaving the levels of Syt 1, Syt 2 and Syt 10 mRNAs unaffected. Intermittent L-DOPA treatment did not alter Syt 1, Syt 2 and Syt 10 mRNA striatal levels, suggesting that 6-OHDA-induced Syt 2 and Syt 10 mRNA changes reflect a persistent striatal abnormality caused by dopamine depletion. On contrary, intermittent L-DOPA treatment downregulated Syt 4 mRNA and prolonged the elevation of Syt 7 mRNA in the denervated striatum. We conclude that Syt 4 and Syt 7 might be specifically involved in striatal plasticity caused by repeated L-DOPA administration that accompanies sensitization.

  17. Transient transfection of human CDNF gene reduces the 6-hydroxydopamine-induced neuroinflammation in the rat substantia nigra.

    PubMed

    Nadella, Rasajna; Voutilainen, Merja H; Saarma, Mart; Gonzalez-Barrios, Juan A; Leon-Chavez, Bertha A; Jiménez, Judith M Dueñas; Jiménez, Sergio H Dueñas; Escobedo, Lourdes; Martinez-Fong, Daniel

    2014-12-16

    The anti-inflammatory effect of the cerebral dopamine neurotrophic factor (CDNF) was shown recently in primary glial cell cultures, yet such effect remains unknown both in vivo and in 6-hydroxydopamine (6-OHDA) models of Parkinson's disease (PD). We addressed this issue by performing an intranigral transfection of the human CDNF (hCDNF) gene in the critical period of inflammation after a single intrastriatal 6-OHDA injection in the rat. At day 15 after lesion, the plasmids p3xNBRE-hCDNF or p3xNBRE-EGFP, coding for enhanced green florescent protein (EGFP), were transfected into the rat substantia nigra (SN) using neurotensin (NTS)-polyplex. At day 15 post-transfection, we measured nitrite and lipoperoxide levels in the SN. We used ELISA to quantify the levels of TNF-α, IL-1β, IL-6, endogenous rat CDNF (rCDNF) and hCDNF. We also used qRT-PCR to measure rCDNF and hCDNF transcripts, and immunofluorescence assays to evaluate iNOS, CDNF and glial cells (microglia, astrocytes and Neuron/Glial type 2 (NG2) cells). Intact SNs were additional controls. In the SN, 6-OHDA triggered nitrosative stress, increased inflammatory cytokines levels, and activated the multipotent progenitor NG2 cells, which convert into astrocytes to produce rCDNF. In comparison with the hemiparkinsonian rats that were transfected with the EGFP gene or without transfection, 6-OHDA treatment and p3xNBRE-hCDNF transfection increased the conversion of NG2 cells into astrocytes resulting in 4-fold increase in the rCDNF protein levels. The overexpressed CDNF reduced nitrosative stress, glial markers and IL-6 levels in the SN, but not TNF-α and IL-1β levels. Our results show the anti-inflammatory effect of CDNF in a 6-OHDA rat of Parkinson's disease. Our results also suggest the possible participation of TNF-α, IL-1β and IL-6 in rCDNF production by astrocytes, supporting their anti-inflammatory role.

  18. Comparison of the SERT-selective [18F]FPBM and VMAT2-selective [18F]AV-133 radiotracers in a rat model of Parkinson’s Disease

    PubMed Central

    Wang, Julie L.; Oya, Shunichi; Parhi, Ajit K.; Lieberman, Brian P.; Ploessl, Karl; Hou, Catherine; Kung, Hank F.

    2010-01-01

    Introduction The utility of [18F]FPBM (2-(2′-((dimethylamino)methyl)-4′-(3-[18F]-fluoropropoxy)phenylthio)benzenamine), a selective serotonin transporter (SERT) tracer, and [18F]AV-133 ((+)-2-Hydroxy-3-isobutyl-9-(3-fluoropropoxy)-10-methoxy-1,2,3,4,6,7-hexahydro-11bH-benzo[a]quinolizine), a selective vesicular monoamine transporter 2 (VMAT2) tracer, were tested in the 6-hydroxydopamine (6-OHDA) unilateral lesioned rat model. Methods PET imaging of three 6-OHDA unilateral lesioned male Sprague Dawley rats (rats #1-3) were performed with [18F]FPBM and [18F]AV-133 to examine whether changes in SERT and VMAT2 binding, respectively, could be detected in the brain. The brains of the three rats were then removed and examined by in vitro autoradiography with [18F]FPBM and the dopamine transporter ligand, [125I]IPT, for confirmation. Results PET image analysis showed varying levels of SERT binding reduction (rat #1 = −11%, rat #2 = −4%, rat #3 = −43%; n = 2) and a clear and definitive loss of VMAT2 binding (rat #1 = −87%, rat #2 = −72%, and rat #3 = −91%; n = 1) in the left striatum when compared to the right (non-lesioned side) striatum. The results from PET imaging were corroborated with quantitative in vitro autoradiography. Rats treated with a selective serotonin toxin (PCA, p-chloroamphetamine) showed a significant reduction of uptake in the cortex and hypothalamus regions of the brain. Conclusion The preliminary data suggest that [18F]FPBM and [18F]AV-133 may be useful for the examination of serotonergic and dopaminergic neuron integrity, respectively, in the living brain. PMID:20447560

  19. Continuous and intermittent nicotine treatment reduces L-3,4-dihydroxyphenylalanine (L-DOPA)-induced dyskinesias in a rat model of Parkinson's disease.

    PubMed

    Bordia, Tanuja; Campos, Carla; Huang, Luping; Quik, Maryka

    2008-10-01

    The development of abnormal involuntary movements (AIMs) or dyskinesias is a serious complication of L-DOPA [L-3,4-dihydroxyphenylalanine] therapy for Parkinson's disease. Our previous work had shown that intermittent nicotine dosing reduced L-DOPA-induced dyskinetic-like movements in nonhuman primates. A readily available nicotine formulation is the nicotine patch, which provides a constant source of nicotine. However, constant nicotine administration more readily desensitizes nicotinic receptors, to possibly yield alternate behavioral outcomes. Therefore, we investigated whether constant nicotine administration reduced L-DOPA-induced AIMs in a rat parkinsonian model, with results compared with those with intermittent nicotine dosing. Rats with a unilateral 6-hydroxydopamine (6-OHDA) lesion were exposed to either intermittent (drinking water) or constant (minipump) nicotine for > or = 2 weeks at doses that yielded plasma levels of the nicotine metabolite cotinine similar to those in smokers. The rats were next treated with L-DOPA/benserazide (8 or 12 mg/kg/15 mg/kg) for > or = 3 weeks to allow for the development of AIMs, with nicotine treatment continued. Both modes of nicotine administration resulted in > or = 50% decline in L-DOPA-induced AIMs. Nicotine treatment also significantly reduced AIMs in L-DOPA-primed rats using either dosing regimen, whereas nicotine removal led to an increase in AIMs. There was no effect of nicotine on various measures of motor performance in 6-OHDA-lesioned rats. In summary, nicotine provided either via the drinking water or minipump reduced L-DOPA-induced AIMs in a rat model of Parkinson's disease. These results suggest that either intermittent or constant nicotine treatment may be useful in the treatment of L-DOPA-induced dyskinesias in patients with Parkinson's disease.

  20. Exercise-induced rescue of tongue function without striatal dopamine sparing in a rat neurotoxin model of Parkinson disease.

    PubMed

    Ciucci, Michelle R; Schaser, Allison J; Russell, John A

    2013-09-01

    Unilateral lesions to the medial forebrain bundle with 6-hydroxydopamine (6-OHDA) lead to force and timing deficits during a complex licking task. We hypothesized that training targeting tongue force generation during licking would improve timing and force measures and also lead to striatal dopamine sparing. Nine month-old male Fisher344/Brown Norway rats were used in this experiment. Sixteen rats were in the control condition and received tongue exercise (n=8) or no exercise (n=8). Fourteen rats were in the 6-OHDA lesion condition and underwent tongue exercise (n=7) and or no exercise (n=7). Following 4 weeks of training and post-training measures, all animals underwent bilateral stimulation of the hypoglossal nerves to measure muscle contractile properties and were then transcardially perfused and brain tissues collected for immunohistochemistry to examine striatal dopamine content. Results demonstrated that exercise animals performed better for maximal force, average force, and press rate than their no-exercise counterparts, and the 6-OHDA animals that underwent exercise performed as well as the Control No Exercise group. Interestingly, there were no group differences for tetanic muscle force, despite behavioral recovery of forces. Additionally, behavioral and neurochemical analyses indicate that there were no differences in striatal dopamine. Thus, targeted exercise can improve tongue force and timing deficits related to 6-OHDA lesions and this exercise likely has a central, versus peripheral (muscle strength) mechanism. However, this mechanism is not related to sparing of striatal dopamine content.

  1. Acupuncture prevents 6-hydroxydopamine-induced neuronal death in the nigrostriatal dopaminergic system in the rat Parkinson's disease model.

    PubMed

    Park, Hi-Joon; Lim, Sabina; Joo, Wan-Seok; Yin, Chang-Shik; Lee, Hyang-Sook; Lee, Hye-Jung; Seo, Jung Chul; Leem, Kanghyun; Son, Yang-Sun; Kim, Youn-Jung; Kim, Chang-Ju; Kim, Yong-Sik; Chung, Joo-Ho

    2003-03-01

    Parkinson's disease (PD) is a chronic neurodegenerative disorder, and it has been suggested that treatments promoting survival and functional recovery of affected dopaminergic neurons could have a significant and long-term therapeutic value. In the present study, we investigated the neuroprotective effects of acupuncture on the nigrostriatal system in rat unilaterally lesioned with 6-hydroxydopamine (6-OHDA, 4 microg/microl, intrastriatal injection) using tyrosine hydroxylase (TH) and receptor for brain-derived neurotrophic factor, trkB, immunohistochemistries. Two weeks after the lesions were made, rats presented with asymmetry in rotational behavior (118.3 +/- 17.5 turns/h) following injection with apomorphine, a dopamine receptor agonist (0.5 mg/kg, sc). In contrast, acupunctural treatment at acupoints GB34 and LI3 was shown to significantly reduce this motor deficit (14.6 +/- 13.4 turns/h). Analysis via TH immunohistochemistry revealed a substantial loss of cell bodies in the substantia nigra (SN) (45.7% loss) and their terminals in the dorsolateral striatum ipsilateral to the 6-OHDA-induced lesion. However, acupunctural treatment resulted in the enhanced survival of dopaminergic neurons in the SN (21.4% loss) and their terminals in the dorsolateral striatum. Acupuncture also increased the expression of trkB significantly (35.6% increase) in the ipsilateral SN. In conclusion, we observed that only acupuncturing without the use of any drug has the neuroprotective effects against neuronal death in the rat PD model and these protective properties of acupuncture could be mediated by trkB.

  2. Neural metabolite changes in corpus striatum after rat multipotent mesenchymal stem cells transplanted in hemiparkinsonian rats by magnetic resonance spectroscopy.

    PubMed

    Fu, Wenyu; Zheng, Zhijuan; Zhuang, Wenxin; Chen, Dandan; Wang, Xiaocui; Sun, Xihe; Wang, Xin

    2013-12-01

    To investigate the biochemical changes in striatum after rat bone marrow mesenchymal stem cells (MSCs) were transplanted into hemiparkinsonian rats and to further confirm the therapeutic effects of rat MSCs for Parkinson's disease (PD). 5-bromo-2-deoxyuridine (BrdU)-labeled MSCs were transplanted into the corpus striatum of the 6-hydroxydopamine (6-OHDA)-injected side of six PD model rats. Before and 8 weeks after MSC transplantation, ethological changes in PD rats were assessed. The expression of tyrosine hydroxylase (TH) in substantia nigra (SN) and striatum were measured using immunohistochemical methods. The differentiation of MSCs was detected by double immunofluorescence techniques. The concentrations of neural metabolites of N-acetylaspartate (NAA), choline (Cho) and creatine (Cr) were measured by ¹H-magnetic resonance spectroscopy (MRS). Relative concentrations of NAA/Cr and Cho/Cr were calculated. The behavior of PD rats in rotarod tests improved, and there were statistical differences in TH-positive cells in SN and TH-positive terminals in striatum after the transplantation of BrdU-labeled MSCs. Transplanted MSCs differentiated into MAP-2-positive neurons. Especially compared with pre-MSC transplantation, the neural metabolite NAA/Cr ratio of the 6-OHDA-injected side of the striatum increased (P < 0.05) and the Cho/Cr ratio decreased (P < 0.05). MSCs transplantation apparently improves neuronal function in the striatum of PD rats.

  3. Magnetic resonance imaging as a tool to image neuroinflammation in a rat model of Parkinson's disease--phagocyte influx to the brain is promoted by bilberry-enriched diet.

    PubMed

    Virel, Ana; Rehnmark, Anna; Orädd, Greger; Olmedo-Díaz, Sonia; Faergemann, Erik; Strömberg, Ingrid

    2015-11-01

    Neuroinflammation is a chronic event in neurodegenerative disorders. In the rat model of Parkinson's disease, including a striatal injection of the neurotoxin 6-hydroxydopamine (6-OHDA), antioxidant treatment affects the inflammatory process. Despite a heavy accumulation of microglia early after the injury, dopamine nerve fibre regeneration occurs. It remains unclear why this heavy accumulation of microglia is found early after the lesion in antioxidant-treated animals, or even more, what is the origin of these microglia. In this study magnetic resonance imaging (MRI) was used to elucidate whether the inflammatory response was generated from the blood or from activated brain microglia. Superparamagnetic iron oxide (SPIO) nanoparticles were injected intravenously prior to a striatal 6-OHDA injection to tag phagocytes in the blood. Rats were fed either with bilberry-enriched or control diet. T2*-weighted MRI scans were performed 1 week after the lesion, and hypointense areas were calculated from T2*-weighted images, to monitor the presence of SPIO particles. The results revealed that feeding the animals with bilberries significantly promoted accumulation of blood-derived immune cells. Gadolinium-enhanced MRI demonstrated no difference in leakage of the blood-brain barrier independent of diets. To conclude, bilberry-enriched diet promotes an influx of periphery-derived immune cells to the brain early after injury.

  4. Multicistronic lentiviral vector-mediated striatal gene transfer of aromatic L-amino acid decarboxylase, tyrosine hydroxylase, and GTP cyclohydrolase I induces sustained transgene expression, dopamine production, and functional improvement in a rat model of Parkinson's disease.

    PubMed

    Azzouz, Mimoun; Martin-Rendon, Enca; Barber, Robert D; Mitrophanous, Kyriacos A; Carter, Emma E; Rohll, Jonathan B; Kingsman, Susan M; Kingsman, Alan J; Mazarakis, Nicholas D

    2002-12-01

    Parkinson's disease (PD) is a neurodegenerative disorder characterized by the selective loss of dopaminergic neurons in the substantia nigra. This loss leads to complete dopamine depletion in the striatum and severe motor impairment. It has been demonstrated previously that a lentiviral vector system based on equine infectious anemia virus (EIAV) gives rise to highly efficient and sustained transduction of neurons in the rat brain. Therefore, a dopamine replacement strategy using EIAV has been investigated as a treatment in the 6-hydroxydopamine (6-OHDA) animal model of PD. A self-inactivating EIAV minimal lentiviral vector that expresses tyrosine hydroxylase (TH), aromatic amino acid dopa decarboxylase (AADC), and GTP cyclohydrolase 1 (CH1) in a single transcription unit has been generated. In cultured striatal neurons transduced with this vector, TH, AADC, and CH1 proteins can all be detected. After stereotactic delivery into the dopamine-denervated striatum of the 6-OHDA-lesioned rat, sustained expression of each enzyme and effective production of catecholamines were detected, resulting in significant reduction of apomorphine-induced motor asymmetry compared with control animals (p < 0.003). Expression of each enzyme in the striatum was observed for up to 5 months after injection. These data indicate that the delivery of three catecholaminergic synthetic enzymes by a single lentiviral vector can achieve functional improvement and thus open the potential for the use of this vector for gene therapy of late-stage PD patients.

  5. Naringin treatment induces neuroprotective effects in a mouse model of Parkinson's disease in vivo, but not enough to restore the lesioned dopaminergic system.

    PubMed

    Kim, Heung Deok; Jeong, Kyoung Hoon; Jung, Un Ju; Kim, Sang Ryong

    2016-02-01

    We recently reported that treatment with naringin, a major flavonoid found in grapefruit and citrus fruits, attenuated neurodegeneration in a rat model of Parkinson's disease (PD) in vivo. In order to investigate whether its effects are universally applied to a different model of PD and whether its treatment induces restorative effects on the lesioned nigrostriatal dopaminergic (DA) projection, we observed the effects of pre-treatment or post-treatment with naringin in a mouse model of PD. For neuroprotective effects, 6-hydroxydopamine (6-OHDA) was unilaterally injected into the striatum of mouse brains for a neurotoxin model of PD in the presence or absence of naringin by daily intraperitoneal injection. Our results showed that naringin protected the nigrostriatal DA projection from 6-OHDA-induced neurotoxicity. Moreover, similar to the effects in rat brains, this treatment induced the activation of mammalian target of rapamycin complex 1 (mTORC1), which is well known as an important survival factor for DA neurons, and inhibited microglial activation in the substantia nigra (SN) of mouse brains treated with 6-OHDA. However, there was no significant change of DA phenotypes in the SN and striatum post-treated with naringin compared with 6-OHDA-lesioned mice, despite the treatment being continued for 12 weeks. These results suggest that post-treatment with naringin alone may not be enough to restore the nigrostriatal DA projection in a mouse model of PD. However, our results apparently suggest that naringin is a beneficial natural product to prevent DA degeneration, which is involved in PD.

  6. Morphological Changes in a Severe Model of Parkinson's Disease and Its Suitability to Test the Therapeutic Effects of Microencapsulated Neurotrophic Factors.

    PubMed

    Requejo, C; Ruiz-Ortega, J A; Bengoetxea, H; García-Blanco, A; Herrán, E; Aristieta, A; Igartua, M; Pedraz, J L; Ugedo, L; Hernández, R M; Lafuente, J V

    2016-11-14

    The unilateral 6-hydroxydopamine (6-OHDA) lesion of medial forebrain bundle (MFB) in rats affords us to study the advanced stages of Parkinson's disease (PD). Numerous evidences suggest synergic effects when various neurotrophic factors are administered in experimental models of PD. The aim of the present work was to assess the morphological changes along the rostro-caudal axis of caudo-putamen complex and substantia nigra (SN) in the referred model in order to test the suitability of a severe model to evaluate new neurorestorative therapies. Administration of 6-OHDA into MFB in addition to a remarkable depletion of dopamine in the nigrostriatal system induced an increase of glial fibrillary acidic protein (GFAP)-positive cells in SN and an intense immunoreactivity for OX-42, vascular endothelial growth factor (VEGF), and Lycopersycum esculentum agglutinin (LEA) in striatum and SN. Tyrosine hydroxylase (TH) immunostaining revealed a significant decrease of the TH-immunopositive striatal volume in 6-OHDA group from rostral to caudal one. The loss of TH-immunoreactive (TH-ir) neurons and axodendritic network (ADN) was higher in caudal sections. Morphological recovery after the implantation of microspheres loaded with VEGF and glial cell line-derived neurotrophic factor (GDNF) in parkinsonized rats was related to the preservation of the TH-ir cell number and ADN in the caudal region of the SN. In addition, these findings support the neurorestorative role of VEGF+GDNF in the dopaminergic system and the synergistic effect between both factors. On the other hand, a topological distribution of the dopaminergic system was noticeable in the severe model, showing a selective vulnerability to 6-OHDA and recovering after treatment.

  7. Forelimb akinesia in the rat Parkinson model: differential effects of dopamine agonists and nigral transplants as assessed by a new stepping test.

    PubMed

    Olsson, M; Nikkhah, G; Bentlage, C; Björklund, A

    1995-05-01

    Methods for the assessment of akinesia in the unilateral rat Parkinson model have so far been lacking. The experiments reported here evaluate the usefulness of a new "stepping test" to monitor forelimb akinesia in rats with unilateral 6-hydroxydopamine (6-OHDA) lesions of the mesencephalic dopamine (DA) system, and to assess the ability of DA-receptor agonists and fetal DA neuron transplants to reverse these deficits. The 6-OHDA lesion induced marked and long-lasting impairments in the initiation of stepping movements with the contralateral paw. Systemic injections of low doses (chosen to be subthreshold for induction of rotation) of the mixed D1 and D2 receptor agonist apomorphine, the D1-selective agonist SKF 38393, and to a lesser extent also the D2-selective agonist quinpirole were effective in reversing these deficits. Similar effects was seen after a subrotational dose of L-dopa, whereas amphetamine had no effect. Fetal nigral transplants, implanted as multiple deposits in the ipsilateral caudate-putamen and substantia nigra, restored initiation of stepping to a similar degree as the DA agonists. Nigral grafts placed in substantia nigra alone were also effective, although the improvement was less pronounced. Apomorphine, at a dose effective in the lesion-only animals, had no additive effect in the grafted rats, whereas amphetamine appeared to further improve stepping in the rats with intranigral transplants. Identical experiments were performed on skilled forelimb use in the so-called staircase test. Interestingly, neither the DA agonist drugs nor the nigral transplants had any effects on the lesion induced deficits in this more complex task. The results show that forelimb stepping is a highly useful test to monitor lesion-/and transplant-induced changes in forelimb akinesia, a behavioral parameter that may be analogous to limb akinesia and gait problems seen in patients with Parkinson's disease.

  8. Novel Food Supplement "CP1" Improves Motor Deficit, Cognitive Function, and Neurodegeneration in Animal Model of Parkinson's Disease.

    PubMed

    Wattanathorn, Jintanaporn; Sutalangka, Chatchada

    2016-08-01

    Based on pivotal roles of oxidative stress, dopaminergic and cholinergic systems on the pathophysiology of Parkinson's disease (PD), the searching for functional food for patients attacked with PD from Cyperus rotundus and Zingiber officinale, the substances possessing antioxidant activity, and the suppression effects on monoamine oxidase B (MAO-B) and acetylcholinesterase (AChE) have been considered. In this study, we aimed to determine the effect of the combined extract of C. rotundus and Z. officinale (CP1) to improve motor and memory deficits, neurodegeneration, oxidative stress, and functions of both cholinergic and dopaminergic systems in the animal model of PD induced by 6-hydroxydopamine hydrochloride (6-OHDA). Male Wistar rats, weighing 180-220 g, were induced unilateral lesion at right substantia nigra by 6-OHDA and were orally given CP1 at doses of 100, 200, and 300 mg/kg body weight for 14 days after 6-OHDA injection. The results showed that the 6-OHDA rats treated with CP1 increased spatial memory, but decreased neurodegeneration, malondialdehyde level, and AChE activity in hippocampus. The decreased motor disorder and neurodegeneration in substantia nigra together with the enhanced catalase activity, but decreased MAO-B activity in striatum, were also observed. The memory enhancing effect of CP1 might occur through the improved oxidative stress and the enhanced cholinergic function, whereas the effect to improve motor disorder of CP1 might occur through the enhanced dopaminergic function in striatum by decreasing the degeneration of dopaminergic neurons and the suppression of MAO-B. Therefore, CP1 is the potential functional food against PD. However, further researches in clinical trial and drug interactions are essential.

  9. Changes in activity and structure of jaw muscles in Parkinson's disease model rats.

    PubMed

    Nakamura, S; Kawai, N; Ohnuki, Y; Saeki, Y; Korfage, J A M; Langenbach, G E J; Kitayama, T; Watanabe, M; Sano, R; Tanne, K; Tanaka, E

    2013-03-01

    Parkinson's disease (PD), a major neurological disease, is characterised by a marked loss of dopaminergic neurons in the substantia nigra. Patients with PD frequently show chewing and swallowing dysfunctions, but little is known about the characteristics of their stomatognathic functions. The purpose of this study was to evaluate the influence of PD on jaw muscle fibre and functions. PD model rats were made by means of the injection of 6-hydroxydopamine (6-OHDA) into the striatum of 8-week-old Sprague-Dawley male rats. Five weeks after the injection, a radio-telemetric device was implanted to record muscle activity continuously from the superficial masseter and anterior belly of digastric muscles. Muscle activity was recorded for 3 days and was evaluated by the total duration of muscle activity per day (duty time). After recording the muscle activities, jaw muscles were isolated for immunohistochemical and PCR analyses. In PD model rats, the following findings of the digastrics muscles verify that compared to the control group: (i) the higher duty time exceeding 5% of the peak activity level, (ii) the higher expression of the mRNA of myosin heavy chain type I, and (iii) the tendency for fast to slow fibre-type transition. With respect to the masseter muscle, there were no significant differences in all analyses. In conclusion, PD leads to the changes in the jaw behaviours, resulting in a PD-specific chewing and swallowing dysfunctions.

  10. Neurocytoprotective Effects of Aliphatic Hydroxamates from Lovastatin, a Secondary Metabolite from Monascus-Fermented Red Mold Rice, in 6-Hydroxydopamine (6-OHDA)-Treated Nerve Growth Factor (NGF)-Differentiated PC12 Cells.

    PubMed

    Lin, Chien-Min; Lin, Yi-Tzu; Lin, Rong-Dih; Huang, Wei-Jan; Lee, Mei-Hsien

    2015-05-20

    Lovastatin, a secondary metabolite isolated from Monascus-fermented red rice mold, has neuroprotective activity and permeates the blood-brain barrier. The aim of this study was to enhance the activity of lovastatin for potential use as a treatment for neuronal degeneration in Parkinson's disease. Six lovastatin-derived compounds were semisynthesized and screened for neurocytoprotective activity against 6-hydroxydopamine (6-OHDA)-induced toxicity in human neuroblastoma PC12 cells. Four compounds, designated as 3a, 3d, 3e, and 3f, significantly enhanced cell viability. In particular, compound 3f showed excellent neurocytoprotective activity (97.0 ± 2.7%). Annexin V-FITC and propidium iodide double staining and 4',6-diamidino-2-phenylindole staining indicated that compound 3f reduced 6-OHDA-induced apoptosis in PC12 cells. Compound 3f also reduced caspase-3, -8, and -9 activities, and intracellular calcium concentrations elevated by 6-OHDA in a concentration-dependent manner, without inhibiting reactive oxygen species generation. JC-1 staining indicated that compound 3f also stabilized mitochondrial membrane potential. Thus, compound 3f may be used as a neurocytoprotective agent. Future studies should investigate its potential application as a treatment for Parkinson's disease.

  11. Trans-blood brain barrier delivery of dopamine-loaded nanoparticles reverses functional deficits in parkinsonian rats.

    PubMed

    Pahuja, Richa; Seth, Kavita; Shukla, Anshi; Shukla, Rajendra Kumar; Bhatnagar, Priyanka; Chauhan, Lalit Kumar Singh; Saxena, Prem Narain; Arun, Jharna; Chaudhari, Bhushan Pradosh; Patel, Devendra Kumar; Singh, Sheelendra Pratap; Shukla, Rakesh; Khanna, Vinay Kumar; Kumar, Pradeep; Chaturvedi, Rajnish Kumar; Gupta, Kailash Chand

    2015-05-26

    Sustained and safe delivery of dopamine across the blood brain barrier (BBB) is a major hurdle for successful therapy in Parkinson's disease (PD), a neurodegenerative disorder. Therefore, in the present study we designed neurotransmitter dopamine-loaded PLGA nanoparticles (DA NPs) to deliver dopamine to the brain. These nanoparticles slowly and constantly released dopamine, showed reduced clearance of dopamine in plasma, reduced quinone adduct formation, and decreased dopamine autoxidation. DA NPs were internalized in dopaminergic SH-SY5Y cells and dopaminergic neurons in the substantia nigra and striatum, regions affected in PD. Treatment with DA NPs did not cause reduction in cell viability and morphological deterioration in SH-SY5Y, as compared to bulk dopamine-treated cells, which showed reduced viability. Herein, we report that these NPs were able to cross the BBB and capillary endothelium in the striatum and substantia nigra in a 6-hydroxydopamine (6-OHDA)-induced rat model of PD. Systemic intravenous administration of DA NPs caused significantly increased levels of dopamine and its metabolites and reduced dopamine-D2 receptor supersensitivity in the striatum of parkinsonian rats. Further, DA NPs significantly recovered neurobehavioral abnormalities in 6-OHDA-induced parkinsonian rats. Dopamine delivered through NPs did not cause additional generation of ROS, dopaminergic neuron degeneration, and ultrastructural changes in the striatum and substantia nigra as compared to 6-OHDA-lesioned rats. Interestingly, dopamine delivery through nanoformulation neither caused alterations in the heart rate and blood pressure nor showed any abrupt pathological change in the brain and other peripheral organs. These results suggest that NPs delivered dopamine into the brain, reduced dopamine autoxidation-mediated toxicity, and ultimately reversed neurochemical and neurobehavioral deficits in parkinsonian rats.

  12. Reduced ability of calcitriol to promote augmented dopamine release in the lesioned striatum of aged rats.

    PubMed

    Cass, Wayne A; Peters, Laura E

    2017-04-05

    Parkinson's disease (PD) is a progressive and debilitating neurodegenerative disorder that affects over one million people in the United States. Previous studies, carried out in young adult rats, have shown that calcitriol, the active metabolite of vitamin D, can be neuroprotective in 6-hydroxydopamine (6-OHDA) models of PD. However, as PD usually affects older individuals, the ability of calcitriol to promote dopaminergic recovery was examined in lesioned young adult (4 month old), middle-aged (14 month old) and aged (22 month old) rats. Animals were given a single injection of 12 μg 6-OHDA into the right striatum. Four weeks later they were administered vehicle or calcitriol (1.0 μg/kg, s.c.) once a day for eight consecutive days. In vivo microdialysis experiments were carried out three weeks after the calcitriol or vehicle treatments to measure potassium and amphetamine evoked overflow of DA from both the left and right striata. In control animals treated with 6-OHDA and vehicle there were significant reductions in evoked overflow of DA on the lesioned side of the brain compared to the contralateral side. The calcitriol treatments significantly increased evoked overflow of DA from the lesioned striatum in both the young adult and middle-aged rats. However, the calcitriol treatments did not significantly augment DA overflow in the aged rats. Postmortem tissue levels of striatal DA were also increased in the young and middle-aged animals, but not in the aged animals. In the substantia nigra, the calcitriol treatments led to increased levels of DA in all three age groups. Thus, the effects of calcitriol were similar in the young adult and middle-aged animals, but in the aged animals the effects of calcitriol were diminished. These results suggest that calcitriol may help promote recovery of dopaminergic functioning in injured nigrostriatal neurons; however, the effectiveness of calcitriol may be reduced in aging.

  13. The Vermicelli Handling Test: A Simple Quantitative Measure of Dexterous Forepaw Function in Rats

    PubMed Central

    Allred, Rachel P.; Adkins, DeAnna L.; Woodlee, Martin T.; Husbands, Lincoln C.; Maldonado, Mónica A.; Kane, Jacqueline R.; Schallert, Timothy; Jones, Theresa A.

    2008-01-01

    Loss of function in the hands occurs with many brain disorders, but there are few measures of skillful forepaw use in rats available to model these impairments that are both sensitive and simple to administer. Whishaw and Coles (1996) previously described the dexterous manner in which rats manipulate food items with their paws, including thin pieces of pasta. We set out to develop a measure of this food handling behavior that would be quantitative, easy to administer, sensitive to the effects of damage to sensory and motor systems of the CNS and useful for identifying the side of lateralized impairments. When rats handle 7 cm lengths of vermicelli, they manipulate the pasta by repeatedly adjusting the forepaw hold on the pasta piece. As operationally defined, these adjustments can be easily identified and counted by an experimenter without specialized equipment. After unilateral sensorimotor cortex (SMC) lesions, transient middle cerebral artery occlusion (MCAO) and striatal dopamine depleting (6-hydroxydopamine, 6-OHDA) lesions in adult rats, there were enduring reductions in adjustments made with the contralateral forepaw. Additional pasta handling characteristics distinguished between the lesion types. MCAO and 6-OHDA lesions increased the frequency of several identified atypical handling patterns. Severe dopamine depletion increased eating time and adjustments made with the ipsilateral forepaw. However, contralateral forepaw adjustment number most sensitively detected enduring impairments across lesion types. Because of its ease of administration and sensitivity to lateralized impairments in skilled forepaw use, this measure may be useful in rat models of upper extremity impairment. PMID:18325597

  14. Neuroprotective effect of hydroxysafflor yellow A on 6-hydroxydopamine-induced Parkinson's disease in rats.

    PubMed

    Han, Bing; Hu, Jia; Shen, Jingyu; Gao, Yonglin; Lu, Yan; Wang, Tian

    2013-08-15

    Parkinson's disease (PD) is a progressive neurodegenerative disorder affecting predominantly the dopaminergic mesotelencephalic system. Enormous progress has been made in the treatment of PD. Our previous study has shown that hydroxysafflor yellow A (HSYA) could attenuate the neurotoxicity induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine in mice. In the present work, we examined whether HSYA had the neuroprotective effect on dopaminergic neurons of substantia nigra in a rat model of PD. Adult Sprague-Dawley rats were unilaterally injected with 6-hydroxydopamine (6-OHDA) into the medial forebrain bundle. The PD rats were treated with HSYA (2 or 8 mg/kg) via caudal vein injection daily for 4 weeks. Rotational tests showed that HSYA significantly attenuated apomorphine-induced turns in 6-OHDA-induced PD rats. HSYA treatment resulted in a significant protection against the loss of tyrosine hydroxylase-positive cells. Our data showed that HSYA also increased the levels of dopamine and its metabolites, glial cell line-derived neurotrophic factor and brain-derived neurotrophic factor in striatum of PD rats. In conclusion, these results supported a role for HSYA in preserving dopamine neuron integrity and motor function in a rodent model of PD, and implied a potential neuroprotective role for HSYA in this disease.

  15. Assessment of the Protection of Dopaminergic Neurons by an α7 Nicotinic Receptor Agonist, PHA 543613 Using [(18)F]LBT-999 in a Parkinson's Disease Rat Model.

    PubMed

    Sérrière, Sophie; Doméné, Aurélie; Vercouillie, Johnny; Mothes, Céline; Bodard, Sylvie; Rodrigues, Nuno; Guilloteau, Denis; Routier, Sylvain; Page, Guylène; Chalon, Sylvie

    2015-01-01

    The inverse association between nicotine intake and Parkinson's disease (PD) is well established and suggests that this molecule could be neuroprotective through anti-inflammatory action mediated by nicotinic receptors, including the α7-subtype (α7R). The objective of this study was to evaluate the effects of an agonist of α7R, PHA 543613, on striatal dopaminergic neurodegeneration and neuroinflammation in a rat model of PD induced by 6-hydroxydopamine (6-OHDA) lesion. Adult male Wistar rats were lesioned in the right striatum and assigned to either the PHA group (n = 7) or the Sham group (n = 5). PHA 543613 hydrochloride at the concentration of 6 mg/kg (PHA group) or vehicle (Sham group) was intra-peritoneally injected 2 h before 6-OHDA lesioning and then at days 2, 4, and 6 post-lesion. Positron emission tomography (PET) imaging was performed at 7 days post-lesion using [(18)F]LBT-999 to quantify the striatal dopamine transporter (DAT). After PET imaging, neuroinflammation was evaluated in same animals in vitro through the measurement of the microglial activation marker 18 kDa translocator protein (TSPO) by quantitative autoradiography with [(3)H]PK-11195. The DAT density reflecting the integrity of dopaminergic neurons was significantly decreased while the intensity of neuroinflammation measured by TSPO density was significantly increased in the lesioned compared to intact striatum in both groups. However, these both modifications were partially reversed in the PHA group compared to Sham. In addition, a significant positive correlation between the degree of lesion and the intensity of neuroinflammation was evidenced. These findings indicate that PHA 543613 exerts neuroprotective effects on the striatal dopaminergic neurons associated with a reduction in microglial activation in this model of PD. This reinforces the hypothesis that an α7R agonist could provide beneficial effects for the treatment of PD.

  16. Noradrenaline neuron degeneration contributes to motor impairments and development of L-DOPA-induced dyskinesia in a rat model of Parkinson's disease.

    PubMed

    Shin, Eunju; Rogers, James T; Devoto, Paola; Björklund, Anders; Carta, Manolo

    2014-07-01

    Parkinson's disease (PD) is characterized by progressive loss of dopaminergic (DA) neurons in the substantia nigra. However, studies of post-mortem PD brains have shown that not only DA neurons but also the noradrenergic (NA) neurons in the locus coeruleus degenerate, and that the NA neurodegeneration may be as profound, and also precede degeneration of the midbrain DA neurons. Previous studies in animal models of PD have suggested that loss of forebrain NA will add to the development of motor symptoms in animals with lesions of the nigrostriatal DA neurons, but the results obtained in rodents have been inconclusive due to the shortcomings of the toxin, DSP-4, used to lesion the NA projections. Here, we have developed an alternative double-lesion paradigm using injections of 6-OHDA into striatum in combination with intraventricular injections of a powerful NA immunotoxin, anti-DBH-Saporin, to eliminate the NA neurons in the locus coeruleus, and associated pontine nuclei. Animals with combined DA and NA lesions were more prone to develop L-DOPA-induced dyskinesia, even at low L-DOPA doses, and they performed significantly worse in tests of reflexive and skilled paw use, the stepping and staircase tests, compared to DA-only lesioned rats. Post-mortem analysis revealed that NA depletion did not affect the degree of DA depletion, or the loss of tyrosine hydroxylase-positive innervation in the striatum. Cell loss in the substantia nigra was similar in both single and double lesioned animals, showing that the worsening effect was not due to increased loss of nigral DA neurons. The results show that damage to brainstem NA neurons, contributes to the development of motor impairments and the appearance of L-DOPA-induced dyskinesia in 6-OHDA lesioned rats, and provide support for the view that the development of motor symptoms and dyskinetic side effects in PD patients reflects the combined loss of midbrain DA neurons and NA neurons. Copyright © 2014 Elsevier Inc. All

  17. Chronic L-DOPA treatment attenuates behavioral and biochemical deficits induced by unilateral lactacystin administration into the rat substantia nigra.

    PubMed

    Konieczny, Jolanta; Czarnecka, Anna; Lenda, Tomasz; Kamińska, Kinga; Lorenc-Koci, Elżbieta

    2014-03-15

    The aim of the study was to determine whether the dopamine (DA) precursor l-DOPA attenuates parkinsonian-like symptoms produced by the ubiquitin-proteasome system inhibitor lactacystin. Wistar rats were injected unilaterally with lactacystin (2.5 μg/2 μl) or 6-OHDA (8 μg/2 μl) into the substantia nigra (SN) pars compacta. Four weeks after the lesion, the animals were treated chronically with l-DOPA (25 or 50 mg/kg) for two weeks. During l-DOPA treatment, the lactacystin-treated rats were tested for catalepsy and forelimb asymmetry. Rotational behavior was evaluated after apomorphine (0.25 mg/kg) and l-DOPA in both PD models. After completion of experiments, the animals were killed and the levels of DA and its metabolites in the striatum and SN were assayed. We found that acute l-DOPA administration effectively decreased catalepsy and increased the use of the compromised forelimb in the cylinder test. However, the lactacystin group did not respond to apomorphine or acute l-DOPA administration in the rotational test. Repeated l-DOPA treatment produced contralateral rotations in both PD models, but the number of rotations was much greater in the 6-OHDA-lesioned rats. Both toxins markedly (>90%) reduced the levels of DA and its metabolites in the striatum and SN, while l-DOPA diminished these decreases, especially in the SN. By demonstrating the efficacy of l-DOPA in several behavioral tests, our study confirms the usefulness of the lactacystin lesion as a model of PD. However, marked differences in the rotational response to apomorphine and l-DOPA suggest different mechanisms of neurodegeneration evoked by lactacystin and 6-OHDA.

  18. Central effects of 6-hydroxydopamine on the body temperature of the rat

    PubMed Central

    Simmonds, M. A.; Uretsky, N. J.

    1970-01-01

    1. Rats which had been pretreated with intraventricular injections of 6-hydroxydopamine (6-OHDA) to cause a selective depletion of brain noradrenaline (NA) to 20·7% of control brain NA and brain dopamine (DA) to 34·6% of control brain DA retained an unimpaired ability to regulate their body temperatures on exposure to heat or cold. This is discussed in relation to the possible role of brain NA in the central control of body temperature. 2. Intraventricular injections of 6-OHDA in normal rats at room temperature caused an acute, dose dependent hypothermia of up to 4·5° C which lasted for 4-5 hours. Depletion of brain NA and DA by prior treatment with 6-OHDA markedly reduced the hypothermic response to a subsequent dose of 6-OHDA. Selective depletion of brain NA without affecting brain DA did not reduce the response to 6-OHDA. The acute hypothermic response to 6-OHDA, may therefore, be related to a release of DA in the brain. PMID:5495172

  19. Enhancing effect of taurine in the rat caudate spindle. II. Effect of bilateral 6-hydroxydopamine lesions of the nigro-striatal dopamine system.

    PubMed

    Hashimoto-Kitsukawa, S; Okuyama, S; Aihara, H

    1988-10-01

    Bilateral injections of 6-hydroxydopamine (6-OHDA) into the medial forebrain bundle of rats resulted in destruction of dopamine (DA) nerve terminals in the striatum. DA contents decreased to 16.8, 15.0 and 13.7% of control values on 3, 5 and 7 days after the lesions, respectively. The time course of the effect of 6-OHDA lesions on apomorphine (0.5 mg/kg, IV)-induced stereotypy was investigated as the index of the development of supersensitivity. Stereotypy was unchanged on 3 days, but was enhanced 5 and 7 days after 6-OHDA lesions. Therefore, the sensitivity of postsynaptic DA receptors for apomorphine did not change 3 days after 6-OHDA lesions, although the striatal DA was depleted. The effects of bilateral injections of taurine into the striatum on the rat caudate spindle were determined 3 days after 6-OHDA lesions. Taurine, at a dose of 30 micrograms, enhanced the spindle in sham-operated rats, but this enhancement was not seen after 6-OHDA lesions. Intravenous administration of apomorphine (0.5 mg/kg) to lesioned rats suppressed the spindle, and this effect was prevented by a lower dose (3 micrograms) of taurine. These results provide further evidence that taurine enhances the spindle, possibly by decreasing the activity of the nigro-striatal DA system at the pre- and postsynaptic sites.

  20. 5-Hydroxy-tryptophan for the treatment of L-DOPA-induced dyskinesia in the rat Parkinson's disease model.

    PubMed

    Tronci, Elisabetta; Lisci, Carlo; Stancampiano, Roberto; Fidalgo, Camino; Collu, Maria; Devoto, Paola; Carta, Manolo

    2013-12-01

    The serotonin system has recently emerged as an important player in the appearance of L-DOPA-induced dyskinesia (LID) in experimental models of Parkinson's disease, as it provides an unregulated source of L-DOPA-derived dopamine release in the dopamine-depleted striatum. Accordingly, toxin lesion or pharmacological silencing of serotonin neurons suppressed LID in the rat and monkey models of Parkinson's disease. However, 5-HT1 receptor agonists were also found to partially reduce the therapeutic effect of L-DOPA. In this study, we evaluated whether enhancement of the serotonin tone induced by the administration of the serotonin precursor 5-hydroxy-tryptophan (5-HTP) could affect induction and expression of LID, as well as the therapeutic effect of L-DOPA, in 6-OHDA-lesioned rats. Drug naïve and L-DOPA-primed 6-OHDA-lesioned rats were chronically treated with a daily injection of L-DOPA (6 mg/kg plus benserazide, s.c.) alone, or in combination with 5-HTP (24-48 mg/kg, i.p.). The abnormal involuntary movements (AIMs) test, as well as the stepping and the motor activity tests, were performed during the chronic treatments. Results showed that 5-HTP reduced the appearance of LID of about 50% at both tested doses. A partial reduction of the therapeutic effect of L-DOPA was seen with the higher but not with the lower dose of 5-HTP. 5-HTP 24 mg/kg was also able to reduce the expression of dyskinesia in L-DOPA-primed dyskinetic rats, to a similar extent than in L-DOPA-primed rats. Importantly, the antidyskinetic effect of 5-HTP 24 mg/kg does not appear to be due to a competition with L-DOPA for crossing the blood-brain barrier; in fact, similar L-DOPA striatal levels were found in L-DOPA only and L-DOPA plus 5-HTP 24 mg/kg treated animals. These data further confirm the involvement of the serotonin system in the appearance of LID, and suggest that 5-HTP may be useful to counteract the appearance of dyskinesia in Parkinson's disease patients.

  1. Comparative assessment of 6-[(18) F]fluoro-L-m-tyrosine and 6-[(18) F]fluoro-L-dopa to evaluate dopaminergic presynaptic integrity in a Parkinson's disease rat model.

    PubMed

    Becker, Guillaume; Bahri, Mohamed Ali; Michel, Anne; Hustadt, Fabian; Garraux, Gaëtan; Luxen, André; Lemaire, Christian; Plenevaux, Alain

    2017-03-10

    Because of the progressive loss of nigro-striatal dopaminergic terminals in Parkinson's disease (PD), in vivo quantitative imaging of dopamine (DA) containing neurons in animal models of PD is of critical importance in the preclinical evaluation of highly awaited disease-modifying therapies. Among existing methods, the high sensitivity of positron emission tomography (PET) is attractive to achieve that goal. The aim of this study was to perform a quantitative comparison of brain images obtained in 6-hydroxydopamine (6-OHDA) lesioned rats using two dopaminergic PET radiotracers, namely [(18) F]fluoro-3,4-dihydroxyphenyl-L-alanine ([(18) F]FDOPA) and 6-[(18) F]fluoro-L-m-tyrosine ([(18) F]FMT). Because the imaging signal is theoretically less contaminated by metabolites, we hypothesized that the latter would show stronger relationship with behavioural and post-mortem measures of striatal dopaminergic deficiency. We used a within-subject design to measure striatal [(18) F]FMT and [(18) F]FDOPA uptake in eight partially lesioned, eight fully lesioned and ten sham-treated rats. Animals were pretreated with an L-aromatic amino acid decarboxylase inhibitor. A catechol-O-methyl transferase inhibitor was also given before [(18) F]FDOPA PET. Quantitative estimates of striatal uptake were computed using conventional graphical Patlak method. Striatal dopaminergic deficiencies were measured with apomorphine-induced rotations and post-mortem striatal DA content. We observed a strong relationship between [(18) F]FMT and [(18) F]FDOPA estimates of decreased uptake in the denervated striatum using the tissue-derived uptake rate constant Kc . However, only [(18) F]FMT Kc succeeded to discriminate between the partial and the full 6-OHDA lesion and correlated well with the post-mortem striatal DA content. This study indicates that the [(18) F]FMT could be more sensitive, with respect of [(18) F]FDOPA, to investigate DA terminals loss in 6-OHDA rats, and open the way to in vivo L

  2. Neuroprotective Activity of Peripherally Administered Liver Growth Factor in a Rat Model of Parkinson’s Disease

    PubMed Central

    Gonzalo-Gobernado, Rafael; Calatrava-Ferreras, Lucía; Reimers, Diana; Herranz, Antonio Sánchez; Rodríguez-Serrano, Macarena; Miranda, Cristina; Jiménez-Escrig, Adriano; Díaz-Gil, Juan José; Bazán, Eulalia

    2013-01-01

    Liver growth factor (LGF) is a hepatic mitogen purified some years ago that promotes proliferation of different cell types and the regeneration of damaged tissues, including brain tissue. Considering the possibility that LGF could be used as a therapeutic agent in Parkinson’s disease, we analyzed its potential neuroregenerative and/or neuroprotective activity when peripherally administered to unilaterally 6-hydroxydopamine (6-OHDA)-lesioned rats. For these studies, rats subjected to nigrostriatal lesions were treated intraperitoneally twice a week with LGF (5 microg/rat) for 3 weeks. Animals were sacrificed 4 weeks after the last LGF treatment. The results show that LGF stimulates sprouting of tyrosine hydroxylase-positive terminals and increases tyrosine hydroxylase and dopamine transporter expression, as well as dopamine levels in the denervated striatum of 6-OHDA-lesioned rats. In this structure, LGF activates microglia and raises tumor necrosis factor-alpha protein levels, which have been reported to have a role in neuroregeneration and neuroprotection. Besides, LGF stimulates the phosphorylation of MAPK/ERK1/2 and CREB, and regulates the expression of proteins which are critical for cell survival such as Bcl2 and Akt. Because LGF partially protects dopamine neurons from 6-OHDA neurotoxicity in the substantia nigra, and reduces motor deficits in these animals, we propose LGF as a novel factor that may be useful in the treatment of Parkinson’s disease. PMID:23861803

  3. Long-term protective effects of AAV9-mesencephalic astrocyte-derived neurotrophic factor gene transfer in parkinsonian rats.

    PubMed

    Hao, Fei; Yang, Chun; Chen, Sha-Sha; Wang, Yan-Yan; Zhou, Wei; Hao, Qiang; Lu, Tao; Hoffer, Barry; Zhao, Li-Ru; Duan, Wei-Ming; Xu, Qun-Yuan

    2017-05-01

    Intrastriatal injection of mesencephalic astrocyte-derived neurotrophic factor (MANF) protein has been shown to provide neuroprotective and neurorestorative effects in a 6-hydroxydopamine (6-OHDA) - lesioned rat model of Parkinson's disease. Here, we used an adeno-associated virus serotype 9 (AAV9) vector to deliver the human MANF (hMANF) gene into the rat striatum 10days after a 6-OHDA lesion to examine long-term effects of hMANF on nigral dopaminergic neurons and mechanisms underlying MANF neuroprotection. Intrastriatal injection of AAV9-hMANF vectors led to a robust and widespread expression of the hMANF gene in the injected striatum up to 24weeks. Increased levels of hMANF protein were also detected in the ipsilateral substantia nigra. The hMANF gene transfer promoted the survival of nigral dopaminergic neurons, regeneration of striatal dopaminergic fibers and an upregulation of striatal dopamine levels, resulting in a long-term improvement of rotational behavior up to 16weeks after viral injections. By using SH-SY5Y cells, we found that intra- and extracellular application of MANF protected cells against 6-OHDA-induced toxicity via inhibiting the endoplasmic reticulum stress and activating the PI3K/Akt/mTOR pathway. Our results suggest that AAV9-mediated hMANF gene delivery into the striatum exerts long-term neuroprotective and neuroregenerative effects on the nigrostriatal dopaminergic system in parkinsonian rats, and provide insights into mechanisms responsible for MANF neuroprotection. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Anodal transcranial direct current stimulation relieves the unilateral bias of a rat model of Parkinson's disease.

    PubMed

    Li, Yiyan; Tian, Xulong; Qian, Long; Yu, Xuehong; Jiang, Weiwei

    2011-01-01

    The unilaterally lesioned rat model of Parkinson's disease which fails to orient to the food stimuli presented on the contralateral side of its preferential side of body could be induced by the injection of 6-hydroxydopamine (6-OHDA) into the medial forebrain bundle (MFB). We employed transcranial direct current stimulation (tDCS, current intensity: 80 μA, and 40 μA; anodal electrode area: 3.14 mm(2); stimulation time: 30 minutes) over the M1 area to relieve the ipsilateral bias in the rat model. A corridor test was set to count the ipsilateral bias of the rats. In this experiment, 30 Sprague-Dawley rats (80 μA: n = 8, 40 μA: n = 8, sham: n = 7, healthy control: n = 7) were chosen for the corridor test and the tDCS session. The lesioned rats exhibited increased ipsilateral bias 4 weeks after the lesion surgery (P < 0.01), and the anodal tDCS with the active electrode on the lesioned side relieved the ipsilateral bias significantly (P < 0.01) immediately after the surgery and the improvement lasted for nearly 1 day. The rats in the group of 80 μA exhibited more significant changes than the 40 μA group after one day. After all the experiments, the histological process showed no neurotrauma led by the tDCS. In conclusion, the modulatory function of the cortical excitability of the tDCS may awaken the compensatory mechanisms and the response mechanisms which modulate the loss of the brain function. Further studies should be done to provide more evidence about the assumption.

  5. [The alterations of apoptosis factor Bcl-2/Bax in the early Parkinson's disease rats and the protective effect of scorpion venom derived activity peptide].

    PubMed

    Xu, Hong; An, Dong; Yin, Sheng-ming; Chen, Wei; Zhao, Dan; Meng, Xu; Yu, De-qin; Sun, Yi-ping; Zhao, Jie; Zhang, Wan-qin

    2015-05-01

    To explore the alterations of apoptosis factor Bcl-2/Bax in the early Parkinson's disease (PD) rats and the protective effect of scorpion venom derived bioactive peptide. Healthy male SD rats (180-220 g) were randomly divided into 4 groups (n = 10): early PD model group, sham operation group, scorpion venom derived bioactive peptide control group, scorpion venom derived bioactive peptide therapy group. 6-hydroxydopamine (6-OHDA) was used to prepare the early PD rat model. The immunohistochemistry was used to detect the expression of Bax and Bcl-2 and further explore the mechanism of anti-apoptosis regarding the neuroprotective effect of scorpion venom derived bioactive peptide. The results indicated that compared with the control rats, the immunostaining of Bax in the brain increased significantly while that of Bcl-2 decreased significantly in the lesion side of 6-OHDA treated rats. Interestingly, scorpion venom derived bioactive peptide could attenuate the above abnormal changes. Up-regulation of Bax and down-regulation of Bcl-2 could participate in the early stage of PD and the anti-apoptotic mechanism could be involved in the neuroprotective effect exerted by scorpion venom derived activity peptide regarding the dopaminergic neuron in the early stage.

  6. Overhauser-enhanced magnetic resonance imaging characterization of mitochondria functional changes in the 6-hydroxydopamine rat model.

    PubMed

    Yamato, Mayumi; Shiba, Takeshi; Naganuma, Tatsuya; Ichikawa, Kazuhiro; Utsumi, Hideo; Yamada, Ken-ichi

    2011-11-01

    Oxidative stress may be involved in the dopaminergic neurodegenerations seen in 6-OHDA-lesioned rats through its production of free radicals and through mitochondrial dysfunction. In this study, we noninvasively demonstrate brain redox alterations in 6-OHDA-lesioned rats using Overhauser-enhanced magnetic resonance imaging (OMRI). The reduction rate of 3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine-l-oxyl (methoxycarbonyl-PROXYL), a redox-sensitive contrast agent, was used as an index of the redox status in vivo. The methoxycarbonyl-PROXYL reduction rate, calculated from continuous images, decreased significantly in lesioned hemispheres compared to their corresponding contralateral hemispheres. The reduction rates in cellular fractions obtained from the striatum were estimated by X-band electron spin resonance (ESR) and calculated by assuming first-order kinetics for their time-dependent decreases. When methoxycarbonyl-PROXYL was mixed with cytoplasm fractions, the reduction rates were the same in both hemispheres. However, the ESR signal of methoxycarbonyl-PROXYL in the mitochondrial fraction of the lesioned hemispheres decayed more slowly than that of the corresponding contralateral hemispheres. Concordantly, biochemical assays showed that the activity of mitochondrial complex I also decreased more slowly in lesioned hemispheres. Thus, this method of noninvasively imaging brain redox alterations faithfully reflects changes in mitochondrial complex I activity in 6-OHDA-lesioned rats. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. [High-frequency electro-acupuncture stimulation modulates intracerebral γ-aminobutyric acid content in rat model of Parkinson's disease].

    PubMed

    Du, Jing; Sun, Zuo-Li; Jia, Jun; Wang, Xuan; Wang, Xiao-Min

    2011-08-25

    The purpose of the present study is to observe the effect of electro-acupuncture (EA) stimulation on intracerebral neurotransmitters in a rat model of Parkinson's disease (PD), and explore the possible mechanism. We used 6-hydroxydopamine (6-OHDA) injection in medial forebrain bundle (MFB) in the right brain of Sprague Dawley (SD) rat to establish the parkinsonian rat model, and randomly divided the PD rats into model and 100 Hz EA stimulation groups (n =10 in each group). EA stimulation group received 4 courses of EA stimulation on Baihui (GV-20) and Dazhui (GV-14) acupuncture points. Moreover, ten rats were randomly selected as sham operation group, only receiving normal saline (NS) injection in MFB. Then apomorphine (APO)-induced rotational behavior in different groups was recorded, and the contents of γ-aminobutyric acid (GABA) in the brain were analyzed with high pressure/performance liquid chromatography-electrochemical detection (HPLC-ECD). The results showed that model group exhibited abnormal rotational behavior with APO treatment, suggesting the successful establishment of PD model. Compared with sham operation group, model group showed increased GABA contents in cortex and striatum, as well as decreased GABA content in ventral midbrain, on the lesioned side. EA stimulation could effectively ameliorate the abnormal rotational behavior of PD rat. Compared with the model group, EA stimulation decreased the ratio of GABA content on the lesioned side to that on unlesioned side in the cortex, while increased the ratios in the striatum and cerebellum. However, there was no difference of the ratio in the ventral midbrain among three groups. These results suggest high-frequency EA stimulation significantly improves the abnormal behavior of PD rats, which may exert through enhancing the inhibitory effect of cerebellum-basal ganglia-cortical loop on motor center.

  8. Phenylalanine derivatives with modulating effects on human α1-glycine receptors and anticonvulsant activity in strychnine-induced seizure model in male adult rats.

    PubMed

    Sadek, Bassem; Oz, Murat; Nurulain, Syed M; Jayaprakash, Petrilla; Latacz, Gniewomir; Kieć-Kononowicz, Katarzyna; Szymańska, Ewa

    2017-05-26

    The critical role of α1-glycine receptor (α1-GLYRs) in pathological conditions such as epilepsy is well known. In the present study, structure-activity relations for a series of phenylalanine derivatives carrying selected hydrogen bond acceptors were investigated on the functional properties of human α1-GLYR expressed in Xenopus oocytes. The results indicate that one particular substitution position appeared to be of special importance for control of ligand activity. Among tested ligands (1-8), the biphenyl derivative (2) provided the most promising antagonistic effect on α1-GLYRs, while its phenylbenzyl analogue (5) exhibited the highest potentiation effect. Moreover, ligand 5 with most promising potentiating effect showed in-vivo moderate protection when tested in strychnine (STR)-induced seizure model in male adult rats, whereas ligand 2 with highest antagonistic effect failed to provide appreciable anti(pro)convulsant effect. Furthermore, ligands 2 and 5 with the most promising effects on human α1-GLYRs were examined for their toxicity and potential neuroprotective effect against neurotoxin 6-hydroxydopamine (6-OHDA). The results show that ligands 2 and 5 possessed neither significant antiproliferative effects, nor necrotic and mitochondrial toxicity (up to concentration of 50μM). Moreover, ligand 2 showed weak neuroprotective effect at the 50μM against 100μM toxic dose of 6-OHDA. Our results indicate that modulatory effects of ligands 2 and 5 on human α1-GLYRs as well as on STR-induced convulsion can provide further insights for the design of therapeutic agents in treatment of epilepsy and other pathological conditions requiring enhanced activity of inhibitory glycine receptors. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Noisy Galvanic Vestibular Stimulation Promotes GABA Release in the Substantia Nigra and Improves Locomotion in Hemiparkinsonian Rats

    PubMed Central

    Samoudi, Ghazaleh; Nissbrandt, Hans; Dutia, Mayank B.; Bergquist, Filip

    2012-01-01

    Background The vestibular system is connected to spinal, cerebellar and cerebral motor control structures and can be selectively activated with external electrodes. The resulting sensation of disturbed balance can be avoided by using stochastic stimulation patterns. Adding noise to the nervous system sometimes improves function. Small clinical trials suggest that stochastic vestibular stimulation (SVS) may improve symptoms in Parkinson's disease. We have investigated this claim and possible mechanisms using the 6-hydroxydopamine (6-OHDA) hemilesion model of Parkinson's disease. Methodology/Principal Findings Animals were tested in the accelerating rod test and the Montoya staircase test of skilled forelimb use. In 6-OHDA hemilesioned animals, SVS improved rod performance by 56±11 s. At group level L-DOPA treatment had no effect, but positive responders improved time on rod by 60±19 s. Skilled forelimb use was not altered by SVS. To investigate how SVS may influence basal ganglia network activity, intracerebral microdialysis was employed in four regions of interest during and after SVS. In presence of the γ-amino buturic acid (GABA) transporter inhibitor NNC 711, SVS induced an increase in GABA to 150±15% of baseline in the substantia nigra (SN) of unlesioned animals, but had no effect in the pedunculopontine nucleus (PPN), the striatum or the ventromedial thalamus (VM). Dopamine release remained stable in all areas, as did GABA and amine concentrations in the SN of unstimulated controls. Following SVS, a sustained increase in GABA concentrations was observed in the ipsilesional, but not in the contralesional SN of 6-OHDA hemilesioned rats. In contrast, L-DOPA treatment produced a similar increase of GABA in the ipsi- and contra-lesional SN. Conclusions/Significance SVS improves rod performance in a rat model of Parkinson's disease, possibly by increasing nigral GABA release in a dopamine independent way. We propose that SVS could be useful for treating symptoms

  10. Decreased response of interneurons in the medial prefrontal cortex to 5-HT₁A receptor activation in the rat 6-hydroxydopamine Parkinson model.

    PubMed

    Zhang, Qiaojun; Wang, Shuang; Zhang, Lina; Zhang, Huan; Qiao, Hongfei; Niu, Xiaolin; Liu, Jian

    2014-08-01

    This study examined the response of interneurons in the medial prefrontal cortex (mPFC) to 5-HT1A receptor agonist 8-OH-DPAT and change in expression of 5-HT1A receptor on glutamate decarboxylase 67 (GAD67)-positive neurons in rats with 6-hydroxydopamine (6-OHDA) lesions of the substantia nigra pars compacta (SNc). Systemic administration of 5-HT1A receptor agonist 8-OH-DPAT dose-dependently inhibited the firing rate of the interneurons at all doses tested in sham-operated rats. In 6-OHDA-lesioned rats, 8-OH-DPAT, at the same doses, also inhibited the firing rate of the interneurons, whereas the inhibition was significant only at a high cumulative dose. Furthermore, injection of 8-OH-DPAT into the mPFC inhibited the interneurons in sham-operated rats, while having no effect on firing rate of the interneurons in 6-OHDA-lesioned rats. In contrast to sham-operated rats, SNc lesion reduced the expression of 5-HT1A receptor on GAD67-positive neurons in the prelimbic cortex, a sub-region of the mPFC. Our results indicate that degeneration of the nigrostriatal pathway leads to decreased response of mPFC interneurons to 5-HT1A receptor activation, which attributes to the down-regulation of 5-HT1A receptor expression in these interneurons.

  11. CART modulates the effects of levodopa in rat model of Parkinson's disease.

    PubMed

    Upadhya, Manoj A; Shelkar, Gajanan P; Subhedar, Nishikant K; Kokare, Dadasaheb M

    2016-03-15

    Parkinson's disease (PD) is an age-related disorder characterized by a progressive degeneration of dopaminergic neurons of substantia nigra (SN). The neuropeptide cocaine- and amphetamine-regulated transcript (CART) is known to closely interact with the dopamine system and regulate psychomotor activity. We screened the effectiveness of CART in reversing the symptoms of PD in a rat model. PD like condition was induced by administering 6-hydroxydopamine (6-OHDA) directly in the SN of the right side. Fifteen days later, intraperitoneal (IP) treatment with apomorphine hydrochloride to these rats, resulted in contralateral rotations in the rotation test chamber suggesting induction of PD-like symptoms. This action of apomorphine was significantly attenuated by intracerebroventricular (ICV) treatment with CART and potentiated by CART antibody. IP treatment with levodopa also produced contralateral rotation in PD induced rats, and showed anti-Parkinson-like action. Prior treatment with CART via ICV route potentiated the anti-Parkinsonian effects of levodopa, while CART antibody produced opposite effects. CART treatment per se, to PD induced rats produced ipsilateral rotations, suggesting that the peptide may promote the endogenous release of dopamine from intact neurons. While CART-immunoreactivity in arcuate nucleus, paraventricular nucleus, striatum, substantia nigra, ventral tegmental area and locus coeruleus was reduced in the PD induced rats, levodopa treatment restored the expression of CART-immunoreactivity in these nuclei. These results suggest that endogenous CART might closely interact with the dopamine containing SN-striatal pathway which is known to profoundly influence the motor system. The study underscores the importance of CART as a potential therapeutic agent in the treatment of PD.

  12. Effect of Central Catecholamine Depletion on the Osmotic and Nonosmotic Stimulation of Vasopressin (Antidiuretic Hormone) in the Rat

    PubMed Central

    Miller, Thomas R.; Handelman, William A.; Arnold, Patricia E.; McDonald, Keith M.; Molinoff, Perry B.; Schrier, Robert W.

    1979-01-01

    The central nervous system (CNS) mechanism(s) for the release of antidiuretic hormone (ADH) by various stimuli is unknown. In this study, the role of CNS catecholamines in effecting ADH release was examined in conscious rats 10-14 d after the cerebroventricular injection of 6-hydroxydopamine (6-OHDA). This dose of 6-OHDA caused a 67% depletion of brain tissue norepinephrine and only 3% depletion of heart norepinephrine, as compared with controls, which were injected with the vehicle buffer alone. Either intravenous 3% saline (osmotic stimulus) or intraperitoneal hyperoncotic dextran (nonosmotic stimulus) was administered to water-diuresing rats through indwelling catheters. Neither of these maneuvers changed arterial pressure, pulse, or inulin clearance in control or 6-OHDA rats. The 3% saline caused similar increases in plasma osmolality (15 mosmol/kg H2O) in control and 6-OHDA rats. The control rats, however, increased urinary osmolality (Uosm) to 586 mosmol/kg H2O, whereas 6-OHDA rats increased Uosm only to 335 mosmol/kg H2O (P < 0.005). These changes in Uosm were accompanied by an increase in plasma ADH to 7.6 μIU/ml in control animals vs. 2.9 μIU/ml in 6-OHDA rats (P < 0.005). All waterdiuresing animals had undetectable plasma ADH levels. Dextran-induced hypovolemia caused similar decrements (− 10%) in blood volume in both control and 6-OHDA animals, neither of which had significant changes in plasma osmolality. This nonosmotic hypovolemic stimulus caused an increase in Uosm to 753 mosmol/kg H2O in control rats, whereas Uosm in 6-OHDA rats increased to only 358 mosmol/kg H2O (P < 0.001). At the same time, ADH levels also were significantly greater in Cont rats (2.4 μIU/ml) than in the 6-OHDA animals (0.69 μIU/ml; P < 0.05). These results therefore suggest that CNS catecholamines may play an important role in mediating ADH release in response to both osmotic and nonosmotic (hypovolemic) stimuli. PMID:500827

  13. Characterizing effects of subthalamic nucleus deep brain stimulation on methamphetamine-induced circling behavior in hemi-Parkinsonian rats.

    PubMed

    So, Rosa Q; McConnell, George C; August, Auriel T; Grill, Warren M

    2012-09-01

    The unilateral 6-hydroxydopamine (6-OHDA) lesioned rat model is frequently used to study the effects of subthalamic nucleus (STN) deep brain stimulation (DBS) for the treatment of Parkinson's disease. However, systematic knowledge of the effects of DBS parameters on behavior in this animal model is lacking. The goal of this study was to characterize the effects of DBS on methamphetamine-induced circling in the unilateral 6-OHDA lesioned rat. DBS parameters tested include stimulation amplitude, stimulation frequency, methamphetamine dose, stimulation polarity, and anatomical location of the electrode. When an appropriate stimulation amplitude and dose of methamphetamine were applied, high-frequency stimulation (> 130 Hz), but not low frequency stimulation (< 10 Hz), reversed the bias in ipsilateral circling without inhibiting movement. This characteristic frequency tuning profile was only generated when at least one electrode used during bipolar stimulation was located within the STN. No difference was found between bipolar stimulation and monopolar stimulation when the most effective electrode contact was selected, indicating that monopolar stimulation could be used in future experiments. Methamphetamine-induced circling is a simple, reliable, and sensitive behavioral test and holds potential for high-throughput study of the effects of STN DBS in unilaterally lesioned rats.

  14. Characterizing Effects of Subthalamic Nucleus Deep Brain Stimulation on Methamphetamine-Induced Circling Behavior in Hemiparkinsonian Rats

    PubMed Central

    So, Rosa Q.; McConnell, George C.; August, Auriel T.; Grill, Warren M.

    2013-01-01

    The unilateral 6-hydroxydopamine (6-OHDA) lesioned rat model is frequently used to study the effects of subthalamic nucleus (STN) deep brain stimulation (DBS) for the treatment of Parkinson’s disease. However, systematic knowledge of the effects of DBS parameters on behavior in this animal model is lacking. The goal of this study was to characterize the effects of DBS on methamphetamine-induced circling in the unilateral 6-OHDA lesioned rat. DBS parameters tested include stimulation amplitude, stimulation frequency, methamphetamine dose, stimulation polarity, and anatomical location of the electrode. When an appropriate stimulation amplitude and dose of methamphetamine were applied, high frequency stimulation (> 130 Hz), but not low frequency stimulation (< 10 Hz), reversed the bias in ipsilateral circling without inhibiting movement. This characteristic frequency tuning profile was only generated when at least one electrode used during bipolar stimulation was located within the STN. No difference was found between bipolar stimulation and monopolar stimulation when the most effective electrode contact was selected, indicating that monopolar stimulation could be used in future experiments. Methamphetamine-induced circling is a simple, reliable, and sensitive behavioral test and holds potential for high-throughput study of the effects of STN DBS in unilaterally lesioned rats. PMID:22692937

  15. Assessment of the Protection of Dopaminergic Neurons by an α7 Nicotinic Receptor Agonist, PHA 543613 Using [18F]LBT-999 in a Parkinson’s Disease Rat Model

    PubMed Central

    Sérrière, Sophie; Doméné, Aurélie; Vercouillie, Johnny; Mothes, Céline; Bodard, Sylvie; Rodrigues, Nuno; Guilloteau, Denis; Routier, Sylvain; Page, Guylène; Chalon, Sylvie

    2015-01-01

    The inverse association between nicotine intake and Parkinson’s disease (PD) is well established and suggests that this molecule could be neuroprotective through anti-inflammatory action mediated by nicotinic receptors, including the α7-subtype (α7R). The objective of this study was to evaluate the effects of an agonist of α7R, PHA 543613, on striatal dopaminergic neurodegeneration and neuroinflammation in a rat model of PD induced by 6-hydroxydopamine (6-OHDA) lesion. Adult male Wistar rats were lesioned in the right striatum and assigned to either the PHA group (n = 7) or the Sham group (n = 5). PHA 543613 hydrochloride at the concentration of 6 mg/kg (PHA group) or vehicle (Sham group) was intra-peritoneally injected 2 h before 6-OHDA lesioning and then at days 2, 4, and 6 post-lesion. Positron emission tomography (PET) imaging was performed at 7 days post-lesion using [18F]LBT-999 to quantify the striatal dopamine transporter (DAT). After PET imaging, neuroinflammation was evaluated in same animals in vitro through the measurement of the microglial activation marker 18 kDa translocator protein (TSPO) by quantitative autoradiography with [3H]PK-11195. The DAT density reflecting the integrity of dopaminergic neurons was significantly decreased while the intensity of neuroinflammation measured by TSPO density was significantly increased in the lesioned compared to intact striatum in both groups. However, these both modifications were partially reversed in the PHA group compared to Sham. In addition, a significant positive correlation between the degree of lesion and the intensity of neuroinflammation was evidenced. These findings indicate that PHA 543613 exerts neuroprotective effects on the striatal dopaminergic neurons associated with a reduction in microglial activation in this model of PD. This reinforces the hypothesis that an α7R agonist could provide beneficial effects for the treatment of PD. PMID:26389120

  16. PEGylated rhFGF-2 conveys long-term neuroprotection and improves neuronal function in a rat model of Parkinson's disease.

    PubMed

    Zhu, Guanghui; Chen, Ganping; Shi, Lu; Feng, Jenny; Wang, Yan; Ye, Chaohui; Feng, Wenke; Niu, Jianlou; Huang, Zhifeng

    2015-02-01

    Fibroblast growth factor 2 (FGF-2) has a neurotrophic effect on dopaminergic neurons in vitro and in vivo, and exhibits beneficial effects in animal models of neurodegenerative disorders such as Parkinson's disease (PD). The poor stability and short half-life of FGF-2, however, have hampered its clinical use for neurological diseases. In the present study, we modified native recombinant human FGF-2 (rhFGF-2) by covalently attaching polyethylene glycol (PEG) polymers, named PEGylation, to enhance its neuroprotection efficacy in 6-hydroxydopamine (6-OHDA)-induced model of PD. In vitro, PEG-rhFGF-2 performed better biostability in 6-OHDA-induced PC-12 cells than native rhFGF-2. The in vivo data showed that, compared with native rhFGF-2, PEGylated rhFGF-2 was more efficacious in preventing 6-OHDA-induced lesion upon tyrosine hydroxylase-positive neurons in the substantia nigra (SN), improving the apomorphine-induced rotational behavior and the 6-OHDA-induced decline in tissue concentration of dopamine (DA) and its metabolites. Importantly, our data showed that the superior pharmacological activity of PEGylated rhFGF-2 is probably due to its greater permeability through the blood-brain barrier and better in vivo stability compared to native rhFGF-2. The enhanced stability and bioavailability of PEGylated rhFGF-2 make this molecule a great therapeutic candidate for neurodegenerative diseases such as PD and mood disorders.

  17. Intranigral administration of substance P receptor antagonist attenuated levodopa-induced dyskinesia in a rat model of Parkinson's disease.

    PubMed

    Yang, Xinxin; Zhao, Hui; Shi, Hongjuan; Wang, Xiaoying; Zhang, Shenyang; Zhang, Zunsheng; Zu, Jie; Zhang, Wei; Shen, Xia; Cui, Guiyun; Hua, Fang

    2015-09-01

    Levodopa (L-dopa) remains the most effective drug in the treatment of Parkinson's disease (PD). However, L-dopa-induced dyskinesia (LID) has hindered its use for PD patients. The mechanisms of LID are not fully understood. Substance P (SP) receptor antagonist has been shown to reduce parkinsonism in animal models of PD, and ameliorate LID in PD rats. But the concrete mechanism is not fully understood. To address this issue, we produced a rat model of PD using 6-hydroxydompamine (6-OHDA) injections, and valid PD rats were intranigrally administrated with different doses of SP receptor antagonist LY303870 (5 nmol/day, 10 nmol/day and 20 nmol/day) following L-dopa (6 mg/kg/day, i.p.) plus benserazide (12 mg/kg/day, i.p.) for 23 days. We found that nigral SP levels were increased on days 3, 7 and 14 and decreased on day 21 after 6-hydroxydompamine lesions. But nigral SP levels kept increasing after repeated L-dopa administration in PD rats. Intranigral administration of low and moderate LY303870 reduced abnormal involuntary movements (AIMs) while improving motor deficits in PD rats treated with L-dopa plus benserazide. Microdialysis revealed that LY303870 (10 nmol/day) treatment attenuated the increase of striatal dopamine and the reduction of γ-aminobutyric acid in ventromedial thalamus of PD rats primed with L-dopa. Additionally, LY303870 (10 nmol/day) treatment prior to L-dopa administration reduced the phosphorylated levels of dopamine- and cyclic adenosine monophosphate-regulated phosphoprotein of 32 kDa at Thr 34 and extracellular signal-regulated kinases 1/2 as well as the levels of activity-regulated cytoskeleton-associated protein and Penk in L-dopa-primed PD rats. Taken together, these data showed that low and moderate SP receptor antagonists LY303870 could ameliorate LID via neurokinin 1 receptor without affecting therapeutic effect of L-dopa.

  18. Lesioning of the Striatum Reverses Motor Asymmetry in the 6-Hydroxydopamine Rodent Model of Parkinsonism

    PubMed Central

    Friehs, G. M.; Parker, R. G.; He, L. S.; Haines, S. J.; Turner, D. A.; Ebner, T. J.

    1991-01-01

    In the rat several paradigms of grafting of adrenal medulla into the striatum were studied following the induction of a parkinsonian model, using a unilateral 6-hydroxydopamine (6-OHDA) lesion of the substantia nigra . Direct autologous grafting of adrenal medulla into the caudate-putamen complex, a radiofrequency lesion of the striatum alone, and a radiofrequency lesion followed by delayed grafting of adrenal medulla were compared by analyzing rotational behavior. Direct grafting of adrenal medulla produced an overall reduction in apomorphine induced turning behavior by 43.5% when compared with controls. Radiofrequency lesioning of the striatum without graft showed the best improvement over control animals with a 92% reduction in the total number of rotations induced by apomorphine. Delayed grafting into the caudate lesion cavity also produced a dramatic reduction in motor asymmetry but did not improve the behavioral outcome over that of the lesion alone. Animals receiving only radiofrequency lesions exhibited a band of increased tyrosine hydroxylase like immunoreactivity bordering the lesion cavity. Graft survival was limited in the nonlesioned animals but appeared enhanced in the animals whose striatum was previously lesioned. Lesion location within the striatum influenced the behavioral outcome. Large reductions in apomorphine-induced rotations could result from small lesions of the dorso-lateral striatum. These findings indicate that selective destruction of the caudate-putamen complex without tissue transplantation produces a dramatic reduction in the motor asymmetry of 6-OHDA treated rats. Suggested explanations for the decrease in induced rotational behavior with radiofrequency lesions include a decrease in the number of striatal dopamine receptors following cell destruction and lesioninduced recovery of host dopaminergic afferents. Striatal damage in critical areas can reverse some of the motor behavior associated with the 6-OHDA model and needs to be

  19. Neuron-derived IgG protects dopaminergic neurons from insult by 6-OHDA and activates microglia through the FcγR I and TLR4 pathways.

    PubMed

    Zhang, Jie; Niu, Na; Wang, Mingyu; McNutt, Michael A; Zhang, Donghong; Zhang, Baogang; Lu, Shijun; Liu, Yuqing; Liu, Zhihui

    2013-08-01

    Oxidative and immune attacks from the environment or microglia have been implicated in the loss of dopaminergic neurons of Parkinson's disease. The role of IgG which is an important immunologic molecule in the process of Parkinson's disease has been unclear. Evidence suggests that IgG can be produced by neurons in addition to its traditionally recognized source B lymphocytes, but its function in neurons is poorly understood. In this study, extensive expression of neuron-derived IgG was demonstrated in dopaminergic neurons of human and rat mesencephalon. With an in vitro Parkinson's disease model, we found that neuron-derived IgG can improve the survival and reduce apoptosis of dopaminergic neurons induced by 6-hydroxydopamine toxicity, and also depress the release of NO from microglia triggered by 6-hydroxydopamine. Expression of TNF-α and IL-10 in microglia was elevated to protective levels by neuron-derived IgG at a physiologic level via the FcγR I and TLR4 pathways and microglial activation could be attenuated by IgG blocking. All these data suggested that neuron-derived IgG may exert a self-protective function by activating microglia properly, and IgG may be involved in maintaining immunity homeostasis in the central nervous system and serve as an active factor under pathological conditions such as Parkinson's disease.

  20. Topographical Distribution of Morphological Changes in a Partial Model of Parkinson's Disease--Effects of Nanoencapsulated Neurotrophic Factors Administration.

    PubMed

    Requejo, C; Ruiz-Ortega, J A; Bengoetxea, H; Garcia-Blanco, A; Herrán, E; Aristieta, A; Igartua, M; Ugedo, L; Pedraz, J L; Hernández, R M; Lafuente, J V

    2015-10-01

    Administration of various neurotrophic factors is a promising strategy against Parkinson's disease (PD). An intrastriatal infusion of 6-hydroxidopamine (6-OHDA) in rats is a suitable model to study PD. This work aims to describe stereological parameters regarding rostro-caudal gradient, in order to characterize the model and verify its suitability for elucidating the benefits of therapeutic strategies. Administration of 6-OHDA induced a reduction in tyrosine hidroxylase (TH) reactivity in the dorsolateral part of the striatum, being higher in the caudal section than in the rostral one. Loss of TH-positive neurons and axodendritic network was highly significant in the external third of substantia nigra (e-SN) in the 6-OHDA group versus the saline one. After the administration of nanospheres loaded with neurotrophic factors (NTF: vascular endothelial growth factor (VEGF) + glial cell line-derived neurotrophic factor (GDNF)), parkinsonized rats showed more TH-positive fibers than those of control groups; this recovery taking place chiefly in the rostral sections. Neuronal density and axodendritic network in e-SN was more significant than in the entire SN; the topographical analysis showed that the highest difference between NTF versus control group was attained in the middle section. A high number of bromodeoxyuridine (BrdU)-positive cells were found in sub- and periventricular areas in the group receiving NTF, where most of them co-expressed doublecortin. Measurements on the e-SN achieved more specific and significant results than in the entire SN. This difference in rostro-caudal gradients underpins the usefulness of a topological approach to the assessment of the lesion and therapeutic strategies. Findings confirmed the neurorestorative, neurogenic, and synergistic effects of VEGF+GDNF administration.

  1. Motor disturbances and thalamic electrical power of frequency bands' improve by grape seed extract in animal model of Parkinson's disease

    PubMed Central

    Sarkaki, Alireza; Eidypour, Zainab; Motamedi, Freshteh; keramati, keivan; Farbood, Yaghoub

    2012-01-01

    Objective: Previous studies showed that grape seed extract (GSE) is an excellent natural substance with potent antioxidant effect and free radical scavenger. This study aimed to evaluate the effect of GSE on motor dysfunctions and thalamic local Electroencephalography (EEG) frequency bands' powers in rats with Parkinson's disease (PD). Materials and Methods: In this study 8 µg 6-hydroxydopamine (6-OHDA) dissolved in 2 µl normal saline containing 0.01% ascorbic acid was infused into right medial forebrain bundle (MFB) to make an animal model of PD. Rats with PD received four weeks GSE (100 mg/kg, p.o.) after apomorphine-induced rotation test. Spontaneous motor tests and also thalamic ventroanterior nucleus (AV) local EEG recording were done in freely moving rats in all groups. Results: Chronic treatment of PD rats with GSE could influence potentially frequency bands' powers of thalamic VA and improve post-lesion motor dysfunctions significantly (p<0.05 and p<0.01, respectively). Conclusion: Our findings suggest that GSE modulates the CNS function and has beneficial effects on the direct and indirect striato-thalamo-cortical pathways in PD. GSE acts as a new and potent natural free radical scavenger which removes oxidants produced by neurotoxin 6-OHDA in brain. Therefore, it reinforces electrical power of remained thalamic VA neurons and thereby improves post-lesion motor disorders. PMID:25050252

  2. Effects of age, gender, and gonadectomy on neurochemistry and behavior in animal models of Parkinson's disease.

    PubMed

    Tamás, Andrea; Lubics, Andrea; Lengvári, István; Reglodi, Dóra

    2006-04-01

    The effects of aging and gender on the neurochemistry of the dopaminergic system have been studied extensively; however, data on comparative behavioral consequences of lesions of the dopaminergic system in aging and in female animals are limited. This study presents experimental results on the behavioral and morphological outcome in young, aging, and gonadectomized male and female rats in the 6-OHDA model of Parkinson's disease. Both young and aging male animals were more susceptible to 6-OHDA than females: female rats had significantly less dopaminergic cell loss and showed a higher degree of behavioral recovery. Although the dopaminergic cell loss was only slightly more in the aging rats of the same sex, they showed more severe behavioral deficits in both gender groups. Ovariectomy did not significantly influence the dopaminergic cell loss, but behavioral recovery was worse when compared to non-ovariectomized females. In contrast, castrated males had significantly less dopaminergic cell loss than non-castrated males, but the behavioral recovery was not significantly better. The obtained results are discussed in light of the available literature on the age and gender differences in animals models of Parkinson's disease.

  3. Chronic treatment with the mGlu5R antagonist MPEP reduces the functional effects of the mGlu5R agonist CHPG in the striatum of 6-hydroxydopamine-lesioned rats: possible relevance to the effects of mGlu5R blockade in Parkinson's disease.

    PubMed

    Domenici, Maria Rosaria; Potenza, Rosa Luisa; Martire, Alberto; Coccurello, Roberto; Pèzzola, Antonella; Reggio, Rosaria; Tebano, Maria Teresa; Popoli, Patrizia

    2005-06-01

    This study was designed to test whether chronic treatment with the metabotropic glutamate receptor 5 (mGlu5R) antagonist MPEP showed antiparkinsonian effects in rats unilaterally lesioned with 6-hydroxydopamine (6-OHDA) (a "classic" model of Parkinson's disease, PD), and to evaluate whether chronic MPEP influenced the functional properties and/or the expression of striatal mGlu5Rs. Wistar rats were lesioned with 6-OHDA and then treated with MPEP (3 mg/kg/day, i.p.) or its vehicle over 2 weeks. Chronic MPEP did not induce measurable antiparkinsonian effects, since no differences were found between MPEP- and vehicle-treated animals in the pattern of L-DOPA-induced contralateral rotations. In corticostriatal slices taken from animals chronically treated with MPEP, the functional effects of the mGlu5R agonist CHPG were significantly reduced in the lesioned vs. the intact side, while no changes were found in slices taken from vehicle-treated rats. The binding of [3H]MPEP to striatal membranes showed that neither the maximal number of binding sites (Bmax) nor the dissociation constant (Kd) were changed by the lesion and/or by chronic MPEP. While chronic MPEP did not potentiate L-DOPA-induced turning in a classical model of PD, its ability to reduce mGlu5R-associated signal could help to explain the neuroprotective/antiparkinsonian effects observed in other models of PD.

  4. Participation of locus coeruleus in breathing control in female rats.

    PubMed

    de Carvalho, Débora; Patrone, Luis Gustavo A; Marques, Danuzia A; Vicente, Mariane C; Szawka, Raphael E; Anselmo-Franci, Janete A; Bícego, Kênia C; Gargaglioni, Luciane H

    2017-07-04

    Several evidences indicate that the locus coeruleus (LC) is involved in central chemoreception responding to CO2/pH and displaying a high percentage of chemosensitive neurons (>80%). However, there are no studies about the LC-mediated hypercapnic ventilation performed in females. Therefore, we assessed the role of noradrenergic LC neurons in non-ovariectomized (NOVX), ovariectomized (OVX) and estradiol (E2)-treated ovariectomized (OVX+E2) rats in respiratory response to hypercapnia, using a 6-hydroxydopamine (6-OHDA) - lesion model. A reduction in the number of tyrosine hydroxylase (TH) immunoreactive neurons (51-90% in 3 animals of NOVX group, 20-42% of lesion in 5 animals of NOVX females, 61.3% for OVX and 62.6% for OVX+E2 group) was observed seven days after microinjection of 6-OHDA in the LC. The chemical lesion of the LC resulted in decreased respiratory frequency under normocapnic conditions in OVX and OVX+E2 group. Hypercapnia increased ventilation in all groups as consequence of increases in respiratory frequency (fR) and tidal volume (VT). Nevertheless, the hypercapnic ventilatory response was significantly decreased in 6-OHDA-NOVX>50% rats compared with SHAM-NOVX group and with females that had 20-42% of LC lesion. In OVX and OVX+E2 lesioned groups, no difference in CO2 ventilatory response was observed when compared to SHAM-OVX and SHAM-OVX+E2 groups, respectively. Neither basal body temperature (Tb) nor Tb reduction in response to hypercapnia were affected by E2 treatment, ovariectomy or LC lesion. Thus, our data show that LC noradrenergic neurons seem to exert an excitatory role on the hypercapnic ventilatory response in female rats, as evidenced by the results in NOVX animals with LC lesioned more than 50%; however, this modulation is not observed in OVX and OVX+E2 rats. In addition, LC noradrenergic neurons of OVX females seem to provide a tonic excitatory drive to maintain breathing frequency in normocapnia, and this response may not to be

  5. Therapeutic efficacy of intranasally delivered mesenchymal stem cells in a rat model of Parkinson disease.

    PubMed

    Danielyan, Lusine; Schäfer, Richard; von Ameln-Mayerhofer, Andreas; Bernhard, Felix; Verleysdonk, Stephan; Buadze, Marine; Lourhmati, Ali; Klopfer, Tim; Schaumann, Felix; Schmid, Barbara; Koehle, Christoph; Proksch, Barbara; Weissert, Robert; Reichardt, Holger M; van den Brandt, Jens; Buniatian, Gayane H; Schwab, Matthias; Gleiter, Christoph H; Frey, William H

    2011-02-01

    Safe and effective cell delivery remains one of the main challenges in cell-based therapy of neurodegenerative disorders. Graft survival, sufficient enrichment of therapeutic cells in the brain, and avoidance of their distribution throughout the peripheral organs are greatly influenced by the method of delivery. Here we demonstrate for the first time noninvasive intranasal (IN) delivery of mesenchymal stem cells (MSCs) to the brains of unilaterally 6-hydroxydopamine (6-OHDA)-lesioned rats. IN application (INA) of MSCs resulted in the appearance of cells in the olfactory bulb, cortex, hippocampus, striatum, cerebellum, brainstem, and spinal cord. Out of 1 × 10⁶ MSCs applied intranasally, 24% survived for at least 4.5 months in the brains of 6-OHDA rats as assessed by quantification of enhanced green fluorescent protein (EGFP) DNA. Quantification of proliferating cell nuclear antigen-positive EGFP-MSCs showed that 3% of applied MSCs were proliferative 4.5 months after application. INA of MSCs increased the tyrosine hydroxylase level in the lesioned ipsilateral striatum and substantia nigra, and completely eliminated the 6-OHDA-induced increase in terminal deoxynucleotidyl transferase (TdT)-mediated 2'-deoxyuridine, 5'-triphosphate (dUTP)-biotin nick end labeling (TUNEL) staining of these areas. INA of EGFP-labeled MSCs prevented any decrease in the dopamine level in the lesioned hemisphere, whereas the lesioned side of the control animals revealed significantly lower levels of dopamine 4.5 months after 6-OHDA treatment. Behavioral analyses revealed significant and substantial improvement of motor function of the Parkinsonian forepaw to up to 68% of the normal value 40-110 days after INA of 1 × 10⁶ cells. MSC-INA decreased the concentrations of inflammatory cytokines-interleukin-1β (IL-1β), IL-2, -6, -12, tumor necrosis factor (TNF), interferon-γ (IFN-γ, and granulocyte-macrophage colony-stimulating factor (GM-CSF)-in the lesioned side to their

  6. Protective effect of tetrahydroxystilbene glucoside on 6-OHDA-induced apoptosis in PC12 cells through the ROS-NO pathway.

    PubMed

    Tao, Lizhen; Li, Xiaofeng; Zhang, Lingling; Tian, Jiyu; Li, Xiaobing; Sun, Xin; Li, Xuefen; Jiang, Lin; Zhang, Xiaojun; Chen, Jianzong

    2011-01-01

    Oxidative stress plays an important role in the pathogenesis of neurodegenerative diseases, such as Parkinson's disease. The molecule, 2,3,5,4'-tetrahydr- oxystilbene-2-O-β-D-glucoside (TSG), is a potent antioxidant derived from the Chinese herb, Polygonum multiflorum Thunb. In this study, we investigated the protective effect of TSG against 6-hydroxydopamine-induced apoptosis in rat adrenal pheochromocytoma PC12 cells and the possible mechanisms. Our data demonstrated that TSG significantly reversed the 6-hydroxydopamine-induced decrease in cell viability, prevented 6-hydroxydopamine-induced changes in condensed nuclei and decreased the percentage of apoptotic cells in a dose-dependent manner. In addition, TSG slowed the accumulation of intracellular reactive oxygen species and nitric oxide, counteracted the overexpression of inducible nitric oxide syntheses as well as neuronal nitric oxide syntheses, and also reduced the level of protein-bound 3-nitrotyrosine. These results demonstrate that the protective effects of TSG on rat adrenal pheochromocytoma PC12 cells are mediated, at least in part, by the ROS-NO pathway. Our results indicate that TSG may be effective in providing protection against neurodegenerative diseases associated with oxidative stress.

  7. Roles of dopaminergic innervation of nucleus accumbens shell and dorsolateral caudate-putamen in cue-induced morphine seeking after prolonged abstinence and the underlying D1- and D2-like receptor mechanisms in rats

    PubMed Central

    Gao, Jun; Li, Yonghui; Zhu, Ning; Brimijoin, Stephen; Sui, Nan

    2013-01-01

    Drug-associated cues can elicit relapse to drug seeking after abstinence. Studies with extinction–reinstatement models implicate dopamine (DA) in the nucleus accumbens shell (NAshell) and dorsolateral caudate-putamen (dlCPu) in cocaine seeking. However, less is known about their roles in cue-induced opiate seeking after prolonged abstinence. Using a morphine self-administration and abstinence–relapse model, we explored the roles of NAshell and dlCPu DA and the D1/D2-like receptor mechanisms underlying morphine rewarding and/or seeking. Acquisition of morphine self-administration was examined following 6-Hydroxydopamine hydrobromide (6-OHDA) lesions of the NAshell and dlCPu. For morphine seeking, rats underwent 3 weeks’ morphine self-administration followed by 3 weeks’ abstinence from morphine and the training environment. Prior to testing, 6-OHDA, D1 antagonist SCH23390, or D2 antagonist eticlopride was locally injected; then rats were exposed to morphine-associated contextual and discrete cues. Results show that acquisition of morphine self-administration was inhibited by NAshell (not dlCPu) lesions, while morphine seeking was attenuated by lesions of either region, by D1 (not D2) receptor blockade in NAshell, or by blockade of either D1 or D2 receptors in dlCPu. These data indicate a critical role of dopaminergic transmission in the NAshell (via D1-like receptors) and dlCPu (via D1- and D2-like receptors) in morphine seeking after prolonged abstinence. PMID:23151613

  8. The Treadmill Exercise Protects against Dopaminergic Neuron Loss and Brain Oxidative Stress in Parkinsonian Rats.

    PubMed

    da Costa, Roberta Oliveira; Gadelha-Filho, Carlos Vinicius Jataí; da Costa, Ayane Edwiges Moura; Feitosa, Mariana Lima; de Araújo, Dayane Pessoa; de Lucena, Jalles Dantas; de Aquino, Pedro Everson Alexandre; Lima, Francisco Arnaldo Viana; Neves, Kelly Rose Tavares; de Barros Viana, Glauce Socorro

    2017-01-01

    Parkinson's disease (PD), a progressive neurological pathology, presents motor and nonmotor impairments. The objectives were to support data on exercise benefits to PD. Male Wistar rats were distributed into sham-operated (SO) and 6-OHDA-lesioned, both groups without and with exercise. The animals were subjected to treadmill exercises (14 days), 24 h after the stereotaxic surgery and striatal 6-OHDA injection. Those from no-exercise groups stayed on the treadmill for the same period and, afterwards, were subjected to behavioral tests and euthanized for neurochemical and immunohistochemical assays. The data, analyzed by ANOVA and Tukey post hoc test, were considered significant for p < 0.05. The results showed behavioral change improvements in the 6-OHDA group, after the treadmill exercise, evaluated by apomorphine rotational behavior, open field, and rota rod tests. The exercise reduced striatal dopaminergic neuronal loss and decreased the oxidative stress. In addition, significant increases in BDNF contents and in immunoreactive cells to TH and DAT were also observed, in striata of the 6-OHDA group with exercise, relatively to those with no exercise. We conclude that exercise improves behavior and dopaminergic neurotransmission in 6-OHDA-lesioned animals. The increased oxidative stress and decreased BDNF contents were also reversed, emphasizing the importance of exercise for the PD management.

  9. Intracarotid Infusion of Mesenchymal Stem Cells in an Animal Model of Parkinson’s Disease, Focusing on Cell Distribution and Neuroprotective and Behavioral Effects

    PubMed Central

    Cerri, Silvia; Greco, Rosaria; Levandis, Giovanna; Ghezzi, Cristina; Mangione, Antonina Stefania; Fuzzati-Armentero, Marie-Therese; Bonizzi, Arianna; Avanzini, Maria Antonietta; Maccario, Rita

    2015-01-01

    Mesenchymal stem cells (MSCs) have been proposed as a potential therapeutic tool for Parkinson’s disease (PD) and systemic administration of these cells has been tested in preclinical and clinical studies. However, no information on survival and actual capacity of MSCs to reach the brain has been provided. In this study, we evaluated homing of intraarterially infused rat MSCs (rMSCs) in the brain of rats bearing a 6-hydroxydopamine (6-OHDA)-induced lesion of the nigrostriatal tract, to establish whether the toxin-induced damage is sufficient to grant MSC passage across the blood-brain barrier (BBB) or if a transient BBB disruption is necessary. The rMSC distribution in peripheral organs and the effects of cell infusion on neurodegenerative process and motor deficits were also investigated. rMSCs were infused 14 days after 6-OHDA injection. A hyperosmolar solution of mannitol was used to transiently permeabilize the BBB. Behavioral impairment was assessed by adjusting step test and response to apomorphine. Animals were sacrificed 7 and 28 days after cell infusion. Our work shows that appreciable delivery of rMSCs to the brain of 6-OHDA-lesioned animals can be obtained only after mannitol pretreatment. A notable percentage of infused cells accumulated in peripheral organs. Infusion of rMSCs did not modify the progression of 6-OHDA-induced damage or the motor impairment at the stepping test, but induced progressive normalization of the pathological response (contralateral turning) to apomorphine administration. These findings suggest that many aspects should be further investigated before considering any translation of MSC systemic administration into the clinical setting for PD treatment. Significance This study demonstrates that mesenchymal stem cells infused through the carotid artery do not efficiently cross the blood-brain barrier in rats with a Parkinson’s disease-like degeneration of nigrostriatal neurons, unless a permeabilizing agent (e.g., mannitol) is

  10. Intracarotid Infusion of Mesenchymal Stem Cells in an Animal Model of Parkinson's Disease, Focusing on Cell Distribution and Neuroprotective and Behavioral Effects.

    PubMed

    Cerri, Silvia; Greco, Rosaria; Levandis, Giovanna; Ghezzi, Cristina; Mangione, Antonina Stefania; Fuzzati-Armentero, Marie-Therese; Bonizzi, Arianna; Avanzini, Maria Antonietta; Maccario, Rita; Blandini, Fabio

    2015-09-01

    Mesenchymal stem cells (MSCs) have been proposed as a potential therapeutic tool for Parkinson's disease (PD) and systemic administration of these cells has been tested in preclinical and clinical studies. However, no information on survival and actual capacity of MSCs to reach the brain has been provided. In this study, we evaluated homing of intraarterially infused rat MSCs (rMSCs) in the brain of rats bearing a 6-hydroxydopamine (6-OHDA)-induced lesion of the nigrostriatal tract, to establish whether the toxin-induced damage is sufficient to grant MSC passage across the blood-brain barrier (BBB) or if a transient BBB disruption is necessary. The rMSC distribution in peripheral organs and the effects of cell infusion on neurodegenerative process and motor deficits were also investigated. rMSCs were infused 14 days after 6-OHDA injection. A hyperosmolar solution of mannitol was used to transiently permeabilize the BBB. Behavioral impairment was assessed by adjusting step test and response to apomorphine. Animals were sacrificed 7 and 28 days after cell infusion. Our work shows that appreciable delivery of rMSCs to the brain of 6-OHDA-lesioned animals can be obtained only after mannitol pretreatment. A notable percentage of infused cells accumulated in peripheral organs. Infusion of rMSCs did not modify the progression of 6-OHDA-induced damage or the motor impairment at the stepping test, but induced progressive normalization of the pathological response (contralateral turning) to apomorphine administration. These findings suggest that many aspects should be further investigated before considering any translation of MSC systemic administration into the clinical setting for PD treatment. This study demonstrates that mesenchymal stem cells infused through the carotid artery do not efficiently cross the blood-brain barrier in rats with a Parkinson's disease-like degeneration of nigrostriatal neurons, unless a permeabilizing agent (e.g., mannitol) is used. The infusion

  11. Exercise partly reverses the effect of maternal separation on hippocampal proteins in 6-hydroxydopamine-lesioned rat brain.

    PubMed

    Dimatelis, J J; Hendricks, S; Hsieh, J; Vlok, N M; Bugarith, K; Daniels, W M U; Russell, V A

    2013-01-01

    Animals subjected to maternal separation stress during the early stages of development display behavioural, endocrine and growth factor abnormalities that mirror the clinical findings in anxiety/depression. In addition, maternal separation has been shown to exacerbate the behavioural deficits induced by 6-hydroxydopamine (6-OHDA) in a rat model of Parkinson's disease. In contrast, voluntary exercise reduced the detrimental effects of 6-OHDA in the rat model. The beneficial effects of exercise appeared to be largely due to compensation in the non-lesioned hemisphere. The aim of the present study was to investigate whether voluntary exercise for 3 weeks could reverse the effects of maternal separation in rats challenged with the neurotoxin 6-OHDA infused into the medial forebrain bundle after 1 week of exercise, at postnatal day 60. The rats were killed 2 weeks later, at postnatal day 74. Their brains were dissected and the hippocampus rapidly removed for proteomic analysis by isobaric tagging (iTRAQ) and quantification of peptides by matrix-assisted laser desorption/ionization tandem mass spectrometry (MALDI-MS/MS). Maternal separation upregulated hippocampal proteins functionally involved in energy metabolism (nucleoside diphosphate kinase B, enolase and triosephosphate isomerase) and synaptic plasticity (α-synuclein, tenascin-R, Ba1-667, brevican and neurocan core protein) in the non-lesioned hemisphere. Exercise reversed many of these changes by downregulating the levels of hippocampal proteins functionally associated with energy metabolism (nucleoside diphosphate kinase B, enolase and triosephosphate isomerase) and synaptic plasticity (α-synuclein, tenascin-R, Ba1-667, brevican and neurocan core protein) in the non-lesioned hemisphere of rats subjected to maternal separation. Exercise and maternal separation therefore appeared to have opposing effects on the hippocampus in the non-lesioned hemisphere of the rat brain. Exercise seemed partly to reverse the

  12. Delayed dominant-negative TNF gene therapy halts progressive loss of nigral dopaminergic neurons in a rat model of Parkinson's disease.

    PubMed

    Harms, Ashley S; Barnum, Christopher J; Ruhn, Kelly A; Varghese, Steve; Treviño, Isaac; Blesch, Armin; Tansey, Malú G

    2011-01-01

    Parkinson's disease (PD) is a progressive neurodegenerative disorder typified by the loss of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNpc). Recent evidence indicates that neuroinflammation may play a critical role in the pathogenesis of PD, particularly tumor necrosis factor (TNF). We have previously shown that soluble TNF (solTNF) is required to mediate robust degeneration induced by 6-hydroxydopamine (6-OHDA) or lipopolysaccharide. What remains unknown is whether TNF inhibition can attenuate the delayed and progressive phase of neurodegeneration. To test this, rats were injected in the SNpc with lentivirus encoding dominant-negative TNF (lenti-DN-TNF) 2 weeks after receiving a 6-OHDA lesion. Remarkably, when examined 5 weeks after the initial 6-OHDA lesion, no further loss of nigral DA neurons was observed. Lenti-DN-TNF also attenuated microglial activation. Together, these data suggest that TNF is likely a critical mediator of nigral DA neuron death during the delayed and progressive phase of neurodegeneration, and that microglia may be the principal cell type involved. These promising findings provide compelling reasons to perform DN-TNF gene transfer studies in nonhuman primates with the long-term goal of using it in the clinic to prevent the delayed and progressive degeneration of DA neurons that gives rise to motor symptoms in PD.

  13. Delayed Dominant-Negative TNF Gene Therapy Halts Progressive Loss of Nigral Dopaminergic Neurons in a Rat Model of Parkinson's Disease

    PubMed Central

    Harms, Ashley S; Barnum, Christopher J; Ruhn, Kelly A; Varghese, Steve; Treviño, Isaac; Blesch, Armin; Tansey, Malú G

    2011-01-01

    Parkinson's disease (PD) is a progressive neurodegenerative disorder typified by the loss of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNpc). Recent evidence indicates that neuroinflammation may play a critical role in the pathogenesis of PD, particularly tumor necrosis factor (TNF). We have previously shown that soluble TNF (solTNF) is required to mediate robust degeneration induced by 6-hydroxydopamine (6-OHDA) or lipopolysaccharide. What remains unknown is whether TNF inhibition can attenuate the delayed and progressive phase of neurodegeneration. To test this, rats were injected in the SNpc with lentivirus encoding dominant-negative TNF (lenti-DN-TNF) 2 weeks after receiving a 6-OHDA lesion. Remarkably, when examined 5 weeks after the initial 6-OHDA lesion, no further loss of nigral DA neurons was observed. Lenti-DN-TNF also attenuated microglial activation. Together, these data suggest that TNF is likely a critical mediator of nigral DA neuron death during the delayed and progressive phase of neurodegeneration, and that microglia may be the principal cell type involved. These promising findings provide compelling reasons to perform DN-TNF gene transfer studies in nonhuman primates with the long-term goal of using it in the clinic to prevent the delayed and progressive degeneration of DA neurons that gives rise to motor symptoms in PD. PMID:20959812

  14. Treadmill exercise alleviates short-term memory impairment in 6-hydroxydopamine-induced Parkinson’s rats

    PubMed Central

    Cho, Han-Sam; Shin, Mal-Soon; Song, Wook; Jun, Tae-Won; Lim, Baek-Vin; Kim, Young-Pyo; Kim, Chang-Ju

    2013-01-01

    Progressive loss of dopaminergic neurons in substantia nigra is a key pathogenesis of Parkinson’s disease. In the present study, we investigated the effects of treadmill exercise on short-term memory, apoptotic dopaminergic neuronal cell death and fiber loss in the nigrostriatum, and cell proliferation in the hippocampal dentate gyrus of Parkinson’s rats. Parkinson’s rats were made by injection of 6-hydroxydopamine (6-OHDA) into the striatum using stereotaxic instrument. Four weeks after 6-OHDA injection, the rats in the 6-OHDA-injection group exhibited significant rotational asymmetry following apomorphine challenge. The rats in the exercise groups were put on the treadmill to run for 30 min once a day for 14 consecutive days starting 4 weeks after 6-OHDA injection. In the present results, extensive degeneration of the dopaminergic neurons in the substantia nigra with loss of dopaminergic fibers in the striatum were produced in the rats without treadmill running, which resulted in short-term memory impairment. However, the rats performing treadmill running for 2 weeks alleviated nigrostriatal dopaminergic cell loss and alleviated short-term memory impairment with increasing cell proliferation in the hippocampal dentate gyrus of Parkinson’s rats. The present results show that treadmill exercise may provide therapeutic value for the Parkinson’s disease. PMID:24278884

  15. The 5-alpha reductase inhibitor finasteride reduces dyskinesia in a rat model of Parkinson's disease.

    PubMed

    Frau, Roberto; Savoia, Paola; Fanni, Silvia; Fiorentini, Chiara; Fidalgo, Camino; Tronci, Elisabetta; Stancampiano, Roberto; Meloni, Mario; Cannas, Antonino; Marrosu, Francesco; Bortolato, Marco; Devoto, Paola; Missale, Cristina; Carta, Manolo

    2017-05-01

    Levodopa-induced dyskinesia (LID) is a disabling motor complication occurring in Parkinson's disease patients (PD) after long-term l-DOPA treatment. Although its etiology remains unclear, there is accumulating evidence that LID relies on an excessive dopamine receptor transmission, particularly at the downstream signaling of D1 receptors. We previously reported that the pharmacological blockade of 5-alpha reductase (5AR), the rate limiting enzyme in neurosteroids synthesis, rescued a number of behavioral aberrations induced by D1 receptor-selective and non-selective agonists, without inducing extrapyramidal symptoms. Thus, the present study was designed to verify whether the 5AR inhibitor finasteride (FIN) may counteract the dyskinesias induced by dopaminergic agonists in 6-hydroxydopamine (6-OHDA)-lesioned rats. First, we assessed the acute and chronic effect of different doses of FIN (30-60mg/kg) on LID, in male 6-OHDA-lesioned dyskinetic rats. Thereafter, to fully characterize the therapeutic potential of FIN on LID and its impact on l-DOPA efficacy, we assessed abnormal involuntary movements and forelimb use in hemiparkinsonian male rats chronically injected with FIN (30-60mg/kg/24days) either prior to- or concomitant with l-DOPA administration. In addition, to investigate whether the impact of FIN on LID may be ascribed to a modulation of the D1- or D2/D3-receptor function, dyskinesias were assessed in l-DOPA-primed 6-OHDA-lesioned rats that received FIN in combination with selective direct dopaminergic agonists. Finally, we set to investigate whether FIN may produce similar effect in female hemiparkinsonian rats, as seen in males. The results indicated that FIN administrations significantly dampened LID in all tested treatment regimens, without interfering with the ability of l-DOPA to ameliorate forelimb use in the stepping test. The antidyskinetic effect appears to be due to modulation of both D1- and D2/D3-receptor function, as FIN also reduced abnormal

  16. Regional, kinetic [18F]FDG PET imaging of a unilateral Parkinsonian animal model

    PubMed Central

    Silva, Matthew D; Glaus, Charles; Hesterman, Jacob Y; Hoppin, Jack; Puppa, Geraldine Hill della; Kazules, Timothy; Orcutt, Kelly M; Germino, Mary; Immke, David; Miller, Silke

    2013-01-01

    Positron emission tomography (PET) imaging with the glucose analog 2-deoxy-2-[18F]fluoro-D-glucose ([18F] FDG) has demonstrated clinical utility for the monitoring of brain glucose metabolism alteration in progressive neurodegenerative diseases. We examined dynamic [18F]FDG PET imaging and kinetic modeling of atlas-based regions to evaluate regional changes in the cerebral metabolic rate of glucose in the widely-used 6-hydroxydopamine (6-OHDA) rat model of Parkinson’s disease. Following a bolus injection of 18.5 ± 1 MBq [18F]FDG and a 60-minute PET scan, image-derived input functions from the vena cava and left ventricle were used with three models, including Patlak graphical analysis, to estimate the influx constant and the metabolic rate in ten brain regions. We observed statistically significant changes in [18F]FDG uptake ipsilateral to the 6-OHDA injection in the basal ganglia, olfactory bulb, and amygdala regions; and these changes are of biological relevance to the disease. These experiments provide further validation for the use of [18F]FDG PET imaging in this model for drug discovery and development. PMID:23526185

  17. Laser Acupuncture at HT7 Acupoint Improves Cognitive Deficit, Neuronal Loss, Oxidative Stress, and Functions of Cholinergic and Dopaminergic Systems in Animal Model of Parkinson's Disease.

    PubMed

    Wattanathorn, Jintanaporn; Sutalangka, Chatchada

    2014-01-01

    To date, the therapeutic strategy against cognitive impairment in Parkinson's disease (PD) is still not in satisfaction level and requires novel effective intervention. Based the oxidative stress reduction and cognitive enhancement induced by laser acupuncture at HT7, the beneficial effect of laser acupuncture at HT7 against cognitive impairment in PD has been focused. In this study, we aimed to determine the effect of laser acupuncture at HT7 on memory impairment, oxidative stress status, and the functions of both cholinergic and dopaminergic systems in hippocampus of animal model of PD. Male Wistar rats, weighing 180-220 g, were induced unilateral lesion at right substantianigra by 6-OHDA and were treated with laser acupuncture continuously at a period of 14 days. The results showed that laser acupuncture at HT7 enhanced memory and neuron density in CA3 and dentate gyrus. The decreased AChE, MAO-B, and MDA together with increased GSH-Px in hippocampus of a 6-OHDA lesion rats were also observed. In conclusion, laser acupuncture at HT7 can improve neuron degeneration and memory impairment in animal model of PD partly via the decreased oxidative stress and the improved cholinergic and dopaminergic functions. More researches concerning effect of treatment duration are still required.

  18. Effects of early and delayed treatment with an mGluR5 antagonist on motor impairment, nigrostriatal damage and neuroinflammation in a rodent model of Parkinson's disease.

    PubMed

    Ambrosi, G; Armentero, M-T; Levandis, G; Bramanti, P; Nappi, G; Blandini, F

    2010-04-29

    The loss of nigrostriatal dopaminergic neurons that characterizes Parkinson's disease (PD) causes complex functional alterations in the basal ganglia circuit. Increased glutamatergic activity at crucial points of the circuit may be central to these alterations, thereby contributing to the onset of PD motor symptoms. Signs of neuroinflammation accompanying the neuronal loss have also been observed; also in this case, glutamate-mediated mechanisms may be involved. Glutamate may therefore intervene at multiple levels in PD pathophysiology, possibly through the modulation of metabotropic receptors. To address this issue, we evaluated the effects of systemic treatment with MPEP (2-methyl-6-(phenylethynyl)-pyridine), an antagonist of metabotropic receptor mGluR5, in a rodent model of progressive nigrostriatal degeneration based on the intrastriatal injection of 6-hydroxydopamine (6-OHDA). Following 6-OHDA injection, Sprague-Dawley rats underwent a 4-week, daily treatment with MPEP (1.5mg/kg, i.p.). To investigate whether the effects varied with the progression of the lesion, subgroups of lesioned animals started the treatment at different time-points: (1) immediately, (2) 1 week, or (3) 4 weeks after the neurotoxin injection. Akinesia, dopaminergic nigrostriatal damage and neuroinflammatory response (microglial and astroglial activation) were investigated. MPEP prompted immediate amelioration of 6-OHDA-induced akinesia, as measured by the Adjusting step test, in all subgroups, regardless of the degree of nigrostriatal damage. Conversely, MPEP did not modify neuronal survival or neuroinflammatory response in the nigrostriatal pathway. In conclusion, chronic treatment with MPEP exerted a pure symptomatic effect, further supporting that mGluR5 modulation may be a viable strategy to counteract the basal ganglia functional modifications underlying PD motor symptoms. Copyright 2010 Elsevier Inc. All rights reserved.

  19. Drinking hydrogen water and intermittent hydrogen gas exposure, but not lactulose or continuous hydrogen gas exposure, prevent 6-hydorxydopamine-induced Parkinson’s disease in rats

    PubMed Central

    2012-01-01

    Background Lactulose is a synthetic disaccharide that can be catalyzed only by intestinal bacteria in humans and rodents, and a large amount of hydrogen is produced by bacterial catalysis of lactulose. We previously reported marked effects of ad libitum administration of hydrogen water on prevention of a rat model of Parkinson’s disease (PD). Methods End-alveolar breath hydrogen concentrations were measured in 28 healthy subjects and 37 PD patients, as well as in 9 rats after taking hydrogen water or lactulose. Six-hydroxydopamine (6-OHDA)-induced hemi-PD model was stereotactically generated in rats. We compared effects of hydrogen water and lactulose on prevention of PD. We also analyzed effects of continuous and intermittent administration of 2% hydrogen gas. Results Hydrogen water increased breath hydrogen concentrations from 8.6 ± 2.1 to 32.6 ± 3.3 ppm (mean and SEM, n = 8) in 10 min in healthy subjects. Lactulose increased breath hydrogen concentrations in 86% of healthy subjects and 59% of PD patients. Compared to monophasic hydrogen increases in 71% of healthy subjects, 32% and 41% of PD patients showed biphasic and no increases, respectively. Lactulose also increased breath hydrogen levels monophasically in 9 rats. Lactulose, however, marginally ameliorated 6-OHDA-induced PD in rats. Continuous administration of 2% hydrogen gas similarly had marginal effects. On the other hand, intermittent administration of 2% hydrogen gas prevented PD in 4 of 6 rats. Conclusions Lack of dose responses of hydrogen and the presence of favorable effects with hydrogen water and intermittent hydrogen gas suggest that signal modulating activities of hydrogen are likely to be instrumental in exerting a protective effect against PD. PMID:22608009

  20. Decreased forelimb ability in mice intracerebroventricularly injected with low dose 6-hydroxidopamine: A model on the dissociation of bradykinesia from hypokinesia.

    PubMed

    Ribeiro, Renata Pietsch; Santos, Danúbia Bonfanti; Colle, Dirleise; Naime, Aline Aita; Gonçalves, Cinara Ludvig; Ghizoni, Heloisa; Hort, Mariana Appel; Godoi, Marcelo; Dias, Paulo Fernando; Braga, Antonio Luiz; Farina, Marcelo

    2016-05-15

    Bradykinesia and hypokinesia represent well-known motor symptoms of Parkinson's disease (PD). While bradykinesia (slow execution of movements) is present in less affected PD patients and aggravates as the disease severity increases, hypokinesia (reduction of movement) seems to emerge prominently only in the more affected patients. Here we developed a model based on the central infusion of low dose (40μg) 6-hydroxydopamine (6-OHDA) in mice in an attempt to discriminate bradykinesia (accessed through forelimb inability) from hypokinesia (accessed through locomotor and exploratory activities). The potential beneficial effects of succinobucol against 6-OHDA-induced forelimb inability were also evaluated. One week after the beginning of treatment with succinobucol (i.p. injections, 10mg/kg/day), mice received a single i.c.v. infusion of 6-OHDA (40μg/site). One week after 6-OHDA infusion, general locomotor/exploratory activities (open field test), muscle strength (grid test), forelimb skill (single pellet task), as well as striatal biochemical parameters related to oxidative stress and cellular homeostasis (glutathione peroxidase, glutathione reductase and NADH dehydrogenases activities, lipid peroxidation and TH levels), were evaluated. 6-OHDA infusions did not change locomotor/exploratory activities and muscle strength, as well as the evaluated striatal biochemical parameters. However, 6-OHDA infusions caused significant reductions (50%) in the single pellet reaching task performance, which detects forelimb skill inability and can be used to experimentally identify bradykinesia. Succinobucol partially protected against 6-OHDA-induced forelimb inability. The decreased forelimb ability with no changes in locomotor/exploratory behavior indicates that our 6-OHDA-based protocol represents a useful tool to mechanistically study the dissociation of bradykinesia and hypokinesia in PD.

  1. Neuronal activity in the medial associative-limbic and lateral motor part of the rat subthalamic nucleus and the effect of 6-hydroxydopamine-induced lesions of the dorsolateral striatum.

    PubMed

    Lindemann, Christoph; Alam, Mesbah; Krauss, Joachim K; Schwabe, Kerstin

    2013-10-01

    Lesions of the rat nigrostriatal dopamine system by injection of 6-hydroxydopamine (6-OHDA) lead to abnormal neuronal activity in the basal ganglia (BG) motor loop similar to that found in Parkinson's disease (PD). In the BG motor loop the subthalamic nucleus (STN) represents an important structure, which, however, also comprises areas of the BG associative and limbic loops. We were interested whether neuronal activity would differ between the STN medial associative-limbic and lateral motor part, and whether selective 6-OHDA-induced lesions of the dorsolateral striatum, the entrance region of the BG motor loop, would differently affect these subregions. In male Sprague-Dawley rats 6-OHDA (n = 12) or vehicle (n = 10) was bilaterally injected in the dorsolateral striatum. Four weeks later extracellular single-unit activity and local field potentials were recorded in medial and lateral STN neurons of urethane-anesthetized rats. In sham-lesioned rats the discharge rate and burst activity were higher in the lateral compared to the medial STN. Similar differences were found for other neuronal activity measures (coefficient of variation of interspike interval, skewness, kurtosis, approximate entropy). After 6-OHDA injection neuronal burst activity was enhanced, while the discharge rate was not affected. In addition, in 6-OHDA-lesioned rats β-band oscillatory activity was enhanced, with no difference between STN subregions. We found important differences of neuronal activity between STN subregions, indicating functional segregation. However, selective 6-OHDA lesions of the dorsolateral striatum also had a pronounced effect on the medial STN subregion, indicating interaction between BG loops. © 2013 Wiley Periodicals, Inc.

  2. Alterations of BDNF and trkB mRNA Expression in the 6-Hydroxydopamine-Induced Model of Preclinical Stages of Parkinson’s Disease: An Influence of Chronic Pramipexole in Rats

    PubMed Central

    Berghauzen-Maciejewska, Klemencja; Wardas, Jadwiga; Kosmowska, Barbara; Głowacka, Urszula; Kuter, Katarzyna; Ossowska, Krystyna

    2015-01-01

    Our recent study has indicated that a moderate lesion of the mesostriatal and mesolimbic pathways in rats, modelling preclinical stages of Parkinson’s disease, induces a depressive-like behaviour which is reversed by chronic treatment with pramipexole. The purpose of the present study was to examine the role of brain derived neurotrophic factor (BDNF) signalling in the aforementioned model of depression. Therefore, we investigated the influence of 6-hydoxydopamine (6-OHDA) administration into the ventral region of the caudate-putamen on mRNA levels of BDNF and tropomyosin-related kinase B (trkB) receptor. The BDNF and trkB mRNA levels were determined in the nigrostriatal and limbic structures by in situ hybridization 2 weeks after the operation. Pramipexole (1 mg/kg sc twice a day) and imipramine (10 mg/kg ip once a day) were injected for 2 weeks. The lesion lowered the BDNF and trkB mRNA levels in the hippocampus [CA1, CA3 and dentate gyrus (DG)] and amygdala (basolateral/lateral) as well as the BDNF mRNA content in the habenula (medial/lateral). The lesion did not influence BDNF and trkB expression in the caudate-putamen, substantia nigra, nucleus accumbens (shell and core) and ventral tegmental area (VTA). Chronic imipramine reversed the lesion-induced decreases in BDNF mRNA in the DG. Chronic pramipexole increased BDNF mRNA, but decreased trkB mRNA in the VTA in lesioned rats. Furthermore, it reduced BDNF and trkB mRNA expression in the shell and core of the nucleus accumbens, BDNF mRNA in the amygdala and trkB mRNA in the caudate-putamen in these animals. The present study indicates that both the 6-OHDA-induced dopaminergic lesion and chronic pramipexole influence BDNF signalling in limbic structures, which may be related to their pro-depressive and antidepressant activity in rats, respectively. PMID:25739024

  3. Alterations of BDNF and trkB mRNA expression in the 6-hydroxydopamine-induced model of preclinical stages of Parkinson's disease: an influence of chronic pramipexole in rats.

    PubMed

    Berghauzen-Maciejewska, Klemencja; Wardas, Jadwiga; Kosmowska, Barbara; Głowacka, Urszula; Kuter, Katarzyna; Ossowska, Krystyna

    2015-01-01

    Our recent study has indicated that a moderate lesion of the mesostriatal and mesolimbic pathways in rats, modelling preclinical stages of Parkinson's disease, induces a depressive-like behaviour which is reversed by chronic treatment with pramipexole. The purpose of the present study was to examine the role of brain derived neurotrophic factor (BDNF) signalling in the aforementioned model of depression. Therefore, we investigated the influence of 6-hydoxydopamine (6-OHDA) administration into the ventral region of the caudate-putamen on mRNA levels of BDNF and tropomyosin-related kinase B (trkB) receptor. The BDNF and trkB mRNA levels were determined in the nigrostriatal and limbic structures by in situ hybridization 2 weeks after the operation. Pramipexole (1 mg/kg sc twice a day) and imipramine (10 mg/kg ip once a day) were injected for 2 weeks. The lesion lowered the BDNF and trkB mRNA levels in the hippocampus [CA1, CA3 and dentate gyrus (DG)] and amygdala (basolateral/lateral) as well as the BDNF mRNA content in the habenula (medial/lateral). The lesion did not influence BDNF and trkB expression in the caudate-putamen, substantia nigra, nucleus accumbens (shell and core) and ventral tegmental area (VTA). Chronic imipramine reversed the lesion-induced decreases in BDNF mRNA in the DG. Chronic pramipexole increased BDNF mRNA, but decreased trkB mRNA in the VTA in lesioned rats. Furthermore, it reduced BDNF and trkB mRNA expression in the shell and core of the nucleus accumbens, BDNF mRNA in the amygdala and trkB mRNA in the caudate-putamen in these animals. The present study indicates that both the 6-OHDA-induced dopaminergic lesion and chronic pramipexole influence BDNF signalling in limbic structures, which may be related to their pro-depressive and antidepressant activity in rats, respectively.

  4. An In Vivo Microdialysis Study of FLZ Penetration through the Blood-Brain Barrier in Normal and 6-Hydroxydopamine Induced Parkinson's Disease Model Rats

    PubMed Central

    Hou, Jinfeng; Liu, Qian; Li, Yingfei; Sun, Hua; Zhang, Jinlan

    2014-01-01

    FLZ (N-[2-(4-hydroxy-phenyl)-ethyl]-2-(2,5-dimethoxy-phenyl)-3-(3-methoxy-4-hydroxy-phenyl)-acrylamide) is a novel synthetic squamosamide derivative and a potential anti-Parkinson's disease (PD) agent. The objective of the present study was to investigate the penetration of free FLZ across the BBB and the effects of P-gp inhibition on FLZ transport in normal and 6-hydroxydopamine (6-OHDA) induced PD model rats. In vivo microdialysis was used to collect FLZ containing brain and blood dialysates following intravenous (i.v.) drug administration either with or without pretreatment with the specific P-gp inhibitor, zosuquidar trihydrochloride (zosuquidar·3HCl). A sensitive, rapid, and reliable ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) technique was developed and validated to quantitate free FLZ levels in the dialysates. No significant differences were observed in the brain/blood FLZ area under the concentration-time curve (AUC) ratio between normal and PD model rats. However, pretreatment with zosuquidar·3HCl markedly increased the AUC ratio in both rat models. In addition, FLZ penetration was similar in zosuquidar·3HCl-pretreated normal and PD rats. These results suggest that P-gp inhibition increases BBB permeability to FLZ, thereby supporting the hypothesis that P-gp normally restricts FLZ transfer to the brain. These findings could provide reference data for future clinical trials and may aid investigation of the BBB permeability of other CNS-active substances. PMID:25045708

  5. An in vivo microdialysis study of FLZ penetration through the blood-brain barrier in normal and 6-hydroxydopamine induced Parkinson's disease model rats.

    PubMed

    Hou, Jinfeng; Liu, Qian; Li, Yingfei; Sun, Hua; Zhang, Jinlan

    2014-01-01

    FLZ (N-[2-(4-hydroxy-phenyl)-ethyl]-2-(2,5-dimethoxy-phenyl)-3-(3-methoxy-4-hydroxy-phenyl)-acrylamide) is a novel synthetic squamosamide derivative and a potential anti-Parkinson's disease (PD) agent. The objective of the present study was to investigate the penetration of free FLZ across the BBB and the effects of P-gp inhibition on FLZ transport in normal and 6-hydroxydopamine (6-OHDA) induced PD model rats. In vivo microdialysis was used to collect FLZ containing brain and blood dialysates following intravenous (i.v.) drug administration either with or without pretreatment with the specific P-gp inhibitor, zosuquidar trihydrochloride (zosuquidar·3HCl). A sensitive, rapid, and reliable ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) technique was developed and validated to quantitate free FLZ levels in the dialysates. No significant differences were observed in the brain/blood FLZ area under the concentration-time curve (AUC) ratio between normal and PD model rats. However, pretreatment with zosuquidar·3HCl markedly increased the AUC ratio in both rat models. In addition, FLZ penetration was similar in zosuquidar·3HCl-pretreated normal and PD rats. These results suggest that P-gp inhibition increases BBB permeability to FLZ, thereby supporting the hypothesis that P-gp normally restricts FLZ transfer to the brain. These findings could provide reference data for future clinical trials and may aid investigation of the BBB permeability of other CNS-active substances.

  6. Rat Endovascular Perforation Model

    PubMed Central

    Sehba, Fatima A.

    2014-01-01

    Experimental animal models of aneurysmal subarachnoid hemorrhage (SAH) have provided a wealth of information on the mechanisms of brain injury. The Rat endovascular perforation model (EVP) replicates the early pathophysiology of SAH and hence is frequently used to study early brain injury following SAH. This paper presents a brief review of historical development of the EVP model, details the technique used to create SAH and considerations necessary to overcome technical challenges. PMID:25213427

  7. Vocal training, levodopa, and environment effects on ultrasonic vocalizations in a rat neurotoxin model of Parkinson disease.

    PubMed

    Kelm-Nelson, Cynthia A; Brauer, Alexander F L; Ciucci, Michelle R

    2016-07-01

    Levodopa does not improve dysarthria in patients with Parkinson Disease (PD), although vocal exercise therapy, such as "LSVT/LOUD(®)", does improve vocal communication. Most patients receive vocal exercise therapy while concurrently being treated with levodopa, although the interaction between levodopa and vocal exercise therapy on communication in PD is relatively unknown. Further, carryover of vocal exercise therapy to novel situations is critical for successful outcomes, but the influence of novel situations on rehabilitated vocal communication is not well understood. To address the influence of exercise, medications, and environment on vocal communication with precise experimental control, we employed the widely used 6-OHDA rat neurotoxin model of PD (infusion to the medial forebrain bundle), and assessed ultrasonic vocalizations after: vocal exercise, vocal exercise with levodopa, levodopa alone, and control conditions. We tested USVs in the familiar training environment of the home cage and a novel cage. We hypothesized that parkinsonian rats that undergo vocal exercise would demonstrate significant improvement of ultrasonic vocalization (USV) acoustic parameters as compared to the control exercise and levodopa-only treatment groups. We further hypothesized that vocal exercise in combination with levodopa administration, similar to what is common in humans, would lead to improvement in USV outcomes, particularly when tested in a familiar versus a novel environment. We found that the combination of exercise and levodopa lead to some improvement in USV acoustic parameters and these effects were stronger in a familiar vs. a novel environment. Our results suggest that although treatment can improve aspects of communication, environment can influence the benefits of these effects.

  8. Vocal training, levodopa, and environment effects on ultrasonic vocalizations in a rat neurotoxin model of Parkinson disease

    PubMed Central

    Kelm-Nelson, Cynthia A.; Brauer, Alexander F.L.; Ciucci, Michelle R.

    2016-01-01

    Levodopa does not improve dysarthria in patients with Parkinson Disease (PD), although vocal exercise therapy, such as “LSVT/LOUD®”, does improve vocal communication. Most patients receive vocal exercise therapy while concurrently being treated with levodopa, although the interaction between levodopa and vocal exercise therapy on communication in PD is relatively unknown. Further, carryover of vocal exercise therapy to novel situations is critical for successful outcomes, but the influence of novel situations on rehabilitated vocal communication is not well understood. To address the influence of exercise, medications, and environment on vocal communication with precise experimental control, we employed the widely used 6-OHDA rat neurotoxin model of PD (infusion to the medial forebrain bundle), and assessed ultrasonic vocalizations after: vocal exercise, vocal exercise with levodopa, levodopa alone, and control conditions. We tested USVs in the familiar training environment of the home cage and a novel cage. We hypothesized that parkinsonian rats that undergo vocal exercise would demonstrate significant improvement of ultrasonic vocalization (USV) acoustic parameters as compared to the control exercise and levodopa-only treatment groups. We further hypothesized that vocal exercise in combination with levodopa administration, similar to what is common in humans, would lead to improvement in USV outcomes, particularly when tested in a familiar versus a novel environment. We found that the combination of exercise and levodopa lead to some improvement in USV acoustic parameters and these effects were stronger in a familiar vs. a novel environment. Our results suggest that although treatment can improve aspects of communication, environment can influence the benefits of these effects. PMID:27025445

  9. Effects of electroacupuncture on cognitive function in rats with Parkinson’s disease

    PubMed Central

    Shen, Xiang; Xie, Yan-Ying; Chen, Chen; Wang, Xiao-Ping

    2015-01-01

    This study was designed to illustrate the effects of electroacupuncture on cognitive function in rats with Parkinson’s disease (PD). The PD model was established by injecting 6-OHDA into the rat brain. Rats with PD were then subjected to electroacupuncture and levodopa treatment for 2 weeks. The level of choline acetyltransferase (ChAT) activity in rat brain homogenates was assessed, for the cerebral cholinergic system is a major chemical pathway consisting of cognitive functions. Immunohistochemistry was applied to observe ChAT expression in the rat hippocampus and corpus striatum. The effects of electroacupuncture on cognitive function were comprehensively assessed in PD rats using Y-maze test. Compared with model control group, electroacupuncture group were apparently improved in learning & memory abilities, and ChAT activity was elevated, and apoptosis was reduced in the rat hippocampus and corpus striatum. No significant differences in learning & memory abilities and ChAT activity were detected between electroacupuncture and levodopa groups. Electroacupuncture remarkably improved cognition in PD rats, and its mechanisms are possibly associated with protecting cholinergic neurons in the central nervous system and elevating ChAT activity, and also might suitable dosage of levodopa protect physiologically the cognitive function in PD rats. PMID:26823963

  10. Therapeutic effects of repetitive transcranial magnetic stimulation in an animal model of Parkinson's disease.

    PubMed

    Lee, Ji Yong; Kim, Sung Hoon; Ko, Ah-Ra; Lee, Jin Suk; Yu, Ji Hea; Seo, Jung Hwa; Cho, Byung Pil; Cho, Sung-Rae

    2013-11-06

    Repetitive transcranial magnetic stimulation (rTMS) is used to treat neurological diseases such as stroke and Parkinson's disease (PD). Although rTMS has been used clinically, its underlying therapeutic mechanism remains unclear. The objective of the present study was to clarify the neuroprotective effect and therapeutic mechanism of rTMS in an animal model of PD. Adult Sprague-Dawley rats were unilaterally injected with 6-hydroxydopamine (6-OHDA) into the right striatum. Rats with PD were then treated with rTMS (circular coil, 10 Hz, 20 min/day) daily for 4 weeks. Behavioral assessments such as amphetamine-induced rotational test and treadmill locomotion test were performed, and the dopaminergic (DA) neurons of substantia nigra pas compacta (SNc) and striatum were histologically examined. Expression of neurotrophic/growth factors was also investigated by multiplex ELISA, western blotting analysis and immunohistochemistry 4 weeks after rTMS application. Among the results, the number of amphetamine-induced rotations was significantly lower in the rTMS group than in the control group at 4 weeks post-treatment. Treadmill locomotion was also significantly improved in the rTMS-treated rats. Tyrosine hydroxylase-positive DA neurons and DA fibers in rTMS group rats were greater than those in untreated group in both ipsilateral SNc and striatum, respectively. The expression levels of brain-derived neurotrophic factor, glial cell line-derived neurotrophic factor, platelet-derived growth factor, and vascular endothelial growth factor were elevated in both the 6-OHDA-injected hemisphere and the SNc of the rTMS-treated rats. In conclusion, rTMS treatment improved motor functions and survival of DA neurons, suggesting that the neuroprotective effect of rTMS treatment might be induced by upregulation of neurotrophic/growth factors in the PD animal model.

  11. The 6-hydroxydopamine model and parkinsonian pathophysiology: Novel findings in an older model.

    PubMed

    Hernandez-Baltazar, D; Zavala-Flores, L M; Villanueva-Olivo, A

    2017-10-01

    The neurotoxin 6-hydroxydopamine (6-OHDA) is widely used to induce models of Parkinson's disease (PD). We now know that the model induced by 6-OHDA does not include all PD symptoms, although it does reproduce the main cellular processes involved in PD, such as oxidative stress, neurodegeneration, neuroinflammation, and neuronal death by apoptosis. In this review we analyse the factors affecting the vulnerability of dopaminergic neurons as well as the close relationships between neuroinflammation, neurodegeneration, and apoptosis in the 6-OHDA model. Knowledge of the mechanisms involved in neurodegeneration and cell death in this model is the key to identifying potential therapeutic targets for PD. Copyright © 2014 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  12. 6-Hydroxydopamine-lesioning of the nigrostriatal pathway in rats alters basal ganglia mRNA for copper, zinc- and manganese-superoxide dismutase, but not glutathione peroxidase.

    PubMed

    Kunikowska, G; Jenner, P

    2001-12-13

    The effects of nigrostriatal pathway destruction on the mRNA levels of copper, zinc-dependent superoxide dismutase (Cu,Zn-SOD), manganese-dependent superoxide dismutase (Mn-SOD), and glutathione peroxidase in basal ganglia of adult rat were investigated using in situ hybridization histochemistry and oligodeoxynucleotide (single-stranded complementary DNA) probes. The 6-hydroxydopamine (6-OHDA)-induced destruction of the nigrostriatal pathway resulted in contralateral rotation to apomorphine and a marked loss of specific [(3)H]mazindol binding in the striatum (93%; P<0.05) and of tyrosine hydroxylase mRNA in substantia nigra pars compacta (SC) (93%; P<0.05) compared with control rats. Levels of Cu,Zn-SOD mRNA were decreased in the striatum, globus pallidus, and SC on the lesioned side of 6-OHDA-lesioned rats compared with sham-lesioned rats (P<0.05). Levels of Mn-SOD mRNA were increased in the nucleus accumbens (P<0.05), but decreased in the SC (P<0.05) on the lesioned side of 6-OHDA-treated rats compared with sham-lesioned rats. Lesioning with 6-OHDA had no effect on glutathione peroxidase mRNA levels in any region of basal ganglia examined. The significant changes in Cu,Zn-SOD and Mn-SOD mRNA indicate that SOD is primarily expressed by dopaminergic neurons of the nigrostriatal pathway, and that the Mn-SOD gene appears to be inducible in rat basal ganglia in response to both physical and chemical damage 5 weeks after 6-OHDA-lesioning. These findings may clarify the status of antioxidant enzymes, particularly Mn-SOD, in patients with Parkinson's disease and their relevance to disease pathogenesis.

  13. Major Alterations of Phosphatidylcholine and Lysophosphotidylcholine Lipids in the Substantia Nigra Using an Early Stage Model of Parkinson’s Disease

    PubMed Central

    Farmer, Kyle; Smith, Catherine A.; Hayley, Shawn; Smith, Jeffrey

    2015-01-01

    Parkinson’s disease (PD) is a progressive neurodegenerative disease affecting the nigrostriatal pathway, where patients do not manifest motor symptoms until >50% of neurons are lost. Thus, it is of great importance to determine early neuronal changes that may contribute to disease progression. Recent attention has focused on lipids and their role in pro- and anti-apoptotic processes. However, information regarding the lipid alterations in animal models of PD is lacking. In this study, we utilized high performance liquid chromatography electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) and novel HPLC solvent methodology to profile phosphatidylcholines and sphingolipids within the substantia nigra. The ipsilateral substantia nigra pars compacta was collected from rats 21 days after an infusion of 6-hydroxydopamine (6-OHDA), or vehicle into the anterior dorsal striatum. We identified 115 lipid species from their mass/charge ratio using the LMAPS Lipid MS Predict Database. Of these, 19 lipid species (from phosphatidylcholine and lysophosphotidylcholine lipid classes) were significantly altered by 6-OHDA, with most being down-regulated. The two lipid species that were up-regulated were LPC (16:0) and LPC (18:1), which are important for neuroinflammatory signalling. These findings provide a first step in the characterization of lipid changes in early stages of PD-like pathology and could provide novel targets for early interventions in PD. PMID:26274953

  14. Antidyskinetic Effect of 7-Nitroindazole and Sodium Nitroprusside Associated with Amantadine in a Rat Model of Parkinson's Disease.

    PubMed

    Bortolanza, Mariza; Bariotto-Dos-Santos, Keila D; Dos-Santos-Pereira, Maurício; da-Silva, Célia Aparecida; Del-Bel, Elaine

    2016-07-01

    Amantadine is the noncompetitive antagonist of N-methyl-D-aspartate, receptor activated by the excitatory neurotransmitter glutamate. It is the only effective medication used to alleviate dyskinesia induced by L-3,4-dihydroxyphenylalanine (L-DOPA) in Parkinson's disease patients. Unfortunately, adverse effects as abnormal involuntary movements (AIMs) known as L-DOPA-induced dyskinesia limit its clinical utility. Combined effective symptomatic treatment modalities may lessen the liability to undesirable events. Likewise drugs known to interfere with nitrergic system reduce AIMs in animal models of Parkinson's disease. We aimed to analyze an interaction between amantadine, neuronal nitric oxide synthase inhibitor (7-nitroindazole, 7NI), and nitric oxide donor (sodium nitroprusside, SNP) in 6-hydroxydopamine-(6-OHDA)-lesioned rats (microinjection in the medial forebrain bundle) presenting L-DOPA-induced dyskinesia (20 mg/kg, gavage, during 21 days). We confirm that 7NI-30 mg/kg, SNP-2/4 mg/kg and amantadine-40 mg/kg, individually reduced AIMs. Our results revealed that co-administration of sub-effective dose of amantadine (10 mg/kg) plus sub-effective dose of 7NI (20 mg/kg) potentiates the effect of reducing AIMs scores when compared to the effect of the drugs individually. No superior benefit on L-DOPA-induced AIMs was observed with the combination of amantadine and SNP. The results revealed that combination of ineffective doses of amantadine and 7NI represents a new strategy to increase antidyskinetic effect in L-DOPA-induced AIMs. It may provide additional therapeutic benefits to Parkinson's disease patients from these disabling complications at lower and thus safer and more tolerable doses than required when either drug is used alone. To close, we discuss the paradox of both nitric oxide synthase inhibitor and/or donor produced AIMs reduction by targeting nitric oxide synthase.

  15. Co-Transplantation of GDNF-Overexpressing Neural Stem Cells and Fetal Dopaminergic Neurons Mitigates Motor Symptoms in a Rat Model of Parkinson’s Disease

    PubMed Central

    Lu, Hua; Yang, Zhiyong; Liu, Ru’en; Wang, Jinkun; Song, Xiaobin; Long, Jiang; Li, Yu; Lei, Deqiang; Feng, Zhongtang

    2013-01-01

    Striatal transplantation of dopaminergic (DA) neurons or neural stem cells (NSCs) has been reported to improve the symptoms of Parkinson’s disease (PD), but the low rate of cell survival, differentiation, and integration in the host brain limits the therapeutic efficacy. We investigated the therapeutic effects of intracranial co-transplantation of mesencephalic NSCs stably overexpressing human glial-derived neurotrophic factor (GDNF-mNSCs) together with fetal DA neurons in the 6-OHDA rat model of PD. Striatal injection of mNSCs labeled by the contrast enhancer superparamagnetic iron oxide (SPIO) resulted in a hypointense signal in the striatum on T2-weighted magnetic resonance images that lasted for at least 8 weeks post-injection, confirming the long-term survival of injected stem cells in vivo. Co-transplantation of GDNF-mNSCs with fetal DA neurons significantly reduced apomorphine-induced rotation, a behavioral endophenotype of PD, compared to sham-treated controls, rats injected with mNSCs expressing empty vector (control mNSCs) plus fetal DA neurons, or rats injected separately with either control mNSCs, GDNF-mNSCs, or fetal DA neurons. In addition, survival and differentiation of mNSCs into DA neurons was significantly greater following co-transplantation of GDNF-mNSCs plus fetal DA neurons compared to the other treatment groups as indicated by the greater number of cell expressing both the mNSCs lineage tracer enhanced green fluorescent protein (eGFP) and the DA neuron marker tyrosine hydroxylase. The success of cell-based therapies for PD may be greatly improved by co-transplantation of fetal DA neurons with mNSCs genetically modified to overexpress trophic factors such as GDNF that support differentiation into DA cells and their survival in vivo. PMID:24312503

  16. Co-transplantation of GDNF-overexpressing neural stem cells and fetal dopaminergic neurons mitigates motor symptoms in a rat model of Parkinson's disease.

    PubMed

    Deng, Xingli; Liang, Yuanxin; Lu, Hua; Yang, Zhiyong; Liu, Ru'en; Wang, Jinkun; Song, Xiaobin; Long, Jiang; Li, Yu; Lei, Deqiang; Feng, Zhongtang

    2013-01-01

    Striatal transplantation of dopaminergic (DA) neurons or neural stem cells (NSCs) has been reported to improve the symptoms of Parkinson's disease (PD), but the low rate of cell survival, differentiation, and integration in the host brain limits the therapeutic efficacy. We investigated the therapeutic effects of intracranial co-transplantation of mesencephalic NSCs stably overexpressing human glial-derived neurotrophic factor (GDNF-mNSCs) together with fetal DA neurons in the 6-OHDA rat model of PD. Striatal injection of mNSCs labeled by the contrast enhancer superparamagnetic iron oxide (SPIO) resulted in a hypointense signal in the striatum on T2-weighted magnetic resonance images that lasted for at least 8 weeks post-injection, confirming the long-term survival of injected stem cells in vivo. Co-transplantation of GDNF-mNSCs with fetal DA neurons significantly reduced apomorphine-induced rotation, a behavioral endophenotype of PD, compared to sham-treated controls, rats injected with mNSCs expressing empty vector (control mNSCs) plus fetal DA neurons, or rats injected separately with either control mNSCs, GDNF-mNSCs, or fetal DA neurons. In addition, survival and differentiation of mNSCs into DA neurons was significantly greater following co-transplantation of GDNF-mNSCs plus fetal DA neurons compared to the other treatment groups as indicated by the greater number of cell expressing both the mNSCs lineage tracer enhanced green fluorescent protein (eGFP) and the DA neuron marker tyrosine hydroxylase. The success of cell-based therapies for PD may be greatly improved by co-transplantation of fetal DA neurons with mNSCs genetically modified to overexpress trophic factors such as GDNF that support differentiation into DA cells and their survival in vivo.

  17. Hypericum Perforatum Hydroalcoholic Extract Mitigates Motor Dysfunction and is Neuroprotective in Intrastriatal 6-Hydroxydopamine Rat Model of Parkinson's Disease.

    PubMed

    Kiasalari, Zahra; Baluchnejadmojarad, Tourandokht; Roghani, Mehrdad

    2016-05-01

    Parkinson's disease is the second most common neurodegenerative disorder with selective and progressive decline of nigral dopaminergic neurons. Hypericum perforatum L. (H. perforatum, St. John's wort) has been traditionally used for management of different disorders, especially mild-to-moderate depression. This study was conducted to evaluate the effect of H. perforatum extract against unilateral striatal 6-hydroxydopamine (6-OHDA) toxicity and to unmask some involved mechanisms. Intrastriatal 6-OHDA-lesioned rats were treated with H. perforatum hydroalcoholic extract at a dose of 200 mg/kg/day started 1 week pre-surgery for 1 week post-surgery. The extract attenuated apomorphine-induced rotational behavior, decreased the latency to initiate and the total time on the narrow beam task, lowered striatal level of malondialdehyde and enhanced striatal catalase activity and reduced glutathione content, normalized striatal expression of glial fibrillary acidic protein, tumor necrosis factor α with no significant effect on mitogen-activated protein kinase, lowered nigral DNA fragmentation, and prevented damage of nigral dopaminergic neurons with a higher striatal tyrosine hydroxylase immunoreactivity. These findings reveal the beneficial effect of H. perforatum via attenuation of DNA fragmentation, astrogliosis, inflammation, and oxidative stress.

  18. Phytic Acid Protects against 6-Hydroxydopamine-Induced Dopaminergic Neuron Apoptosis in Normal and Iron Excess Conditions in a Cell Culture Model.

    PubMed

    Xu, Qi; Kanthasamy, Anumantha G; Reddy, Manju B

    2011-02-07

    Iron may play an important role in Parkinson's disease (PD) since it can induce oxidative stress-dependent neurodegeneration. The objective of this study was to determine whether the iron chelator, phytic acid (IP6) can protect against 6-hydroxydopamine- (6-OHDA-) induced apoptosis in immortalized rat mesencephalic dopaminergic cells under normal and iron-excess conditions. Caspase-3 activity was increased about 6-fold after 6-OHDA treatment (compared to control; P < .001) and 30 μmol/L IP6 pretreatment decreased it by 38% (P < .05). Similarly, a 63% protection (P < .001) against 6-OHDA induced DNA fragmentation was observed with IP6 pretreatment. Under iron-excess condition, a 6-fold increase in caspase-3 activity (P < .001) and a 42% increase in DNA fragmentation (P < .05) with 6-OHDA treatment were decreased by 41% (P < .01) and 27% (P < .05), respectively, with 30 μmol/L IP6. Together, our data suggest that IP6 protects against 6-OHDA-induced cell apoptosis in both normal and iron-excess conditions, and IP6 may offer neuroprotection in PD.

  19. Phytic Acid Protects against 6-Hydroxydopamine-Induced Dopaminergic Neuron Apoptosis in Normal and Iron Excess Conditions in a Cell Culture Model

    PubMed Central

    Xu, Qi; Kanthasamy, Anumantha G.; Reddy, Manju B.

    2011-01-01

    Iron may play an important role in Parkinson's disease (PD) since it can induce oxidative stress-dependent neurodegeneration. The objective of this study was to determine whether the iron chelator, phytic acid (IP6) can protect against 6-hydroxydopamine- (6-OHDA-) induced apoptosis in immortalized rat mesencephalic dopaminergic cells under normal and iron-excess conditions. Caspase-3 activity was increased about 6-fold after 6-OHDA treatment (compared to control; P < .001) and 30 μmol/L IP6 pretreatment decreased it by 38% (P < .05). Similarly, a 63% protection (P < .001) against 6-OHDA induced DNA fragmentation was observed with IP6 pretreatment. Under iron-excess condition, a 6-fold increase in caspase-3 activity (P < .001) and a 42% increase in DNA fragmentation (P < .05) with 6-OHDA treatment were decreased by 41% (P < .01) and 27% (P < .05), respectively, with 30 μmol/L IP6. Together, our data suggest that IP6 protects against 6-OHDA-induced cell apoptosis in both normal and iron-excess conditions, and IP6 may offer neuroprotection in PD. PMID:21331377

  20. MK-801 (Dizocilpine) Regulates Multiple Steps of Adult Hippocampal Neurogenesis and Alters Psychological Symptoms via Wnt/β-Catenin Signaling in Parkinsonian Rats.

    PubMed

    Singh, Sonu; Mishra, Akanksha; Srivastava, Neha; Shukla, Shubha

    2017-03-15

    Adult hippocampal neurogenesis is directly involved in regulation of stress, anxiety, and depression that are commonly observed nonmotor symptoms in Parkinson's disease (PD). These symptoms do not respond to pharmacological dopamine replacement therapy. Excitotoxic damage to neuronal cells by N-methyl-d-aspartate (NMDA) receptor activation is also a major contributing factor in PD development, but whether it regulates hippocampal neurogenesis and nonmotor symptoms in PD is yet unexplored. Herein, for the first time, we studied the effect of MK-801, an NMDA receptor antagonist, on adult hippocampal neurogenesis and behavioral functions in 6-OHDA (6-hydroxydopamine) induced rat model of PD. MK-801 treatment (0.2 mg/kg, ip) increased neural stem cell (NSC) proliferation, self-renewal capacity, long-term survival, and neuronal differentiation in the hippocampus of rat model of PD. MK-801 potentially enhanced long-term survival, improved dendritic arborization of immature neurons, and reduced 6-OHDA induced neurodegeneration via maintaining the NSC pool in hippocampus, leading to decreased anxiety and depression-like phenotypes in the PD model. MK-801 inhibited glycogen synthase kinase-3β (GSK-3β) through up-regulation of Wnt-3a, which resulted in the activation of Wnt/β-catenin signaling leading to enhanced hippocampal neurogenesis in PD model. Additionally, MK-801 treatment protected the dopaminergic (DAergic) neurons in the nigrostriatal pathway and improved motor functions by increasing the expression of Nurr-1 and Pitx-3 in the PD model. Therefore, MK-801 treatment serves as a valuable tool to enhance hippocampal neurogenesis in PD, but further studies are needed to revisit the role of MK-801 in the neurodegenerative disorder before proposing a potential therapeutic candidate.

  1. Environmental enrichment brings a beneficial effect on beam walking and enhances the migration of doublecortin-positive cells following striatal lesions in rats.

    PubMed

    Urakawa, S; Hida, H; Masuda, T; Misumi, S; Kim, T-S; Nishino, H

    2007-02-09

    Rats raised in an enriched environment (enriched rats) have been reported to show less motor dysfunction following brain lesions, but the neuronal correlates of this improvement have not been well clarified. The present study aimed to elucidate the effect of chemical brain lesions and environmental enrichment on motor function and lesion-induced neurogenesis. Three week-old, recently weaned rats were divided into two groups: one group was raised in an enriched environment and the other group was raised in a standard cage for 5 weeks. Striatal damage was induced at an age of 8 weeks by injection of the neuro-toxins 6-hydroxydopamine (6-OHDA) or quinolinic acid (QA) into the striatum, or by injection of 6-OHDA into the substantia nigra (SN), which depleted nigrostriatal dopaminergic innervation. Enriched rats showed better performance on beam walking compared with those raised in standard conditions, but both groups showed similar forelimb use asymmetry in a cylinder test. The number of bromodeoxyuridine-labeled proliferating cells in the subventricular zone was increased by a severe striatal lesion induced by QA injection 1 week after the lesion, but decreased by injection of 6-OHDA into the SN. Following induction of lesions by striatal injection of 6-OHDA or QA, the number of cells positive for doublecortin (DCX) was strongly increased in the striatum; however, there was no change in the number of DCX-positive cells following 6-OHDA injection into the SN. Environmental enrichment enhanced the increase of DCX-positive cells with migrating morphology in the dorsal striatum. In enriched rats, DCX-positive cells traversed the striatal parenchyma far from the corpus callosum and lateral ventricle. DCX-positive cells co-expressed an immature neuronal marker, polysialylated neural cell adhesion molecule, but were negative for a glial marker. These data suggest that environmental enrichment improves motor performance on beam walking and enhances neuronal migration toward

  2. Effects of electroacupuncture on metabolic changes in motor cortex and striatum of 6-hydroxydopamine-induced Parkinsonian rats.

    PubMed

    Li, Min; Wang, Ke; Su, Wen-Ting; Jia, Jun; Wang, Xiao-Min

    2017-10-06

    To explore the possible underlying mechanism by investigating the effect of electroacupuncture (EA) treatment on the primary motor cortex and striatum in a unilateral 6-hydroxydopamine (6-OHDA) induced rat Parkinson's disease (PD) model. Male Sprague-Dawley rats were randomly divided into sham group (n=16), model group (n=14), and EA group (n=14). EA stimulation at Dazhui (GV 14) and Baihui (GV20) was applied to PD rats in the EA group for 4 weeks. Behavioral tests were conducted to evaluate the effectiveness of EA treatment. Metabolites were detected by 7.0 T proton nuclear magnetic resonance. Following 4 weeks of EA treatment in PD model rats, the abnormal behavioral impairment induced by 6-OHDA was alleviated. In monitoring changes in metabolic activity, ratios of myoinositol/creatine (Cr) and N-acetyl aspartate (NAA)/Cr in the primary motor cortex were significantly lower at the injected side than the non-injected side in PD rats (P=0.024 and 0.020). The ratios of glutamate + glutamine (Glx)/Cr and NAA/Cr in the striatum were higher and lower, respectively, at the injected side than the non-injected side (P=0.046 and 0.008). EA treatment restored the balance of metabolic activity in the primary motor cortex and striatum. In addition, the taurine/Cr ratio and Glx/Cr ratio were elevated in the striatum of PD model rats compared to sham-lesioned rats (P=0.026 and 0.000). EA treatment alleviated the excessive glutamatergic transmission by down-regulating the striatal Glx/Cr ratio (P=0.001). The Glx/Cr ratio was negatively correlated with floor plane spontaneous locomotion in PD rats (P=0.027 and P=0.0007). EA treatment is able to normalize the metabolic balance in the primary motor cortex and striatum of PD rats, which may contribute to its therapeutic effect on motor deficits. The striatal Glx/Cr ratio may serve as a potential indicator of PD and a therapeutic target of EA treatment.

  3. Rat Genome and Model Resources.

    PubMed

    Shimoyama, Mary; Smith, Jennifer R; Bryda, Elizabeth; Kuramoto, Takashi; Saba, Laura; Dwinell, Melinda

    2017-07-01

    Rats remain a major model for studying disease mechanisms and discovery, validation, and testing of new compounds to improve human health. The rat's value continues to grow as indicated by the more than 1.4 million publications (second to human) at PubMed documenting important discoveries using this model. Advanced sequencing technologies, genome modification techniques, and the development of embryonic stem cell protocols ensure the rat remains an important mammalian model for disease studies. The 2004 release of the reference genome has been followed by the production of complete genomes for more than two dozen individual strains utilizing NextGen sequencing technologies; their analyses have identified over 80 million variants. This explosion in genomic data has been accompanied by the ability to selectively edit the rat genome, leading to hundreds of new strains through multiple technologies. A number of resources have been developed to provide investigators with access to precision rat models, comprehensive datasets, and sophisticated software tools necessary for their research. Those profiled here include the Rat Genome Database, PhenoGen, Gene Editing Rat Resource Center, Rat Resource and Research Center, and the National BioResource Project for the Rat in Japan. © The Author 2017. Published by Oxford University Press.

  4. Bee Venom Alleviates Motor Deficits and Modulates the Transfer of Cortical Information through the Basal Ganglia in Rat Models of Parkinson’s Disease

    PubMed Central

    Maurice, Nicolas; Deltheil, Thierry; Melon, Christophe; Degos, Bertrand; Mourre, Christiane

    2015-01-01

    Recent evidence points to a neuroprotective action of bee venom on nigral dopamine neurons in animal models of Parkinson’s disease (PD). Here we examined whether bee venom also displays a symptomatic action by acting on the pathological functioning of the basal ganglia in rat PD models. Bee venom effects were assessed by combining motor behavior analyses and in vivo electrophysiological recordings in the substantia nigra pars reticulata (SNr, basal ganglia output structure) in pharmacological (neuroleptic treatment) and lesional (unilateral intranigral 6-hydroxydopamine injection) PD models. In the hemi-parkinsonian 6-hydroxydopamine lesion model, subchronic bee venom treatment significantly alleviates contralateral forelimb akinesia and apomorphine-induced rotations. Moreover, a single injection of bee venom reverses haloperidol-induced catalepsy, a pharmacological model reminiscent of parkinsonian akinetic deficit. This effect is mimicked by apamin, a blocker of small conductance Ca2+-activated K+ (SK) channels, and blocked by CyPPA, a positive modulator of these channels, suggesting the involvement of SK channels in the bee venom antiparkinsonian action. In vivo electrophysiological recordings in the substantia nigra pars reticulata (basal ganglia output structure) showed no significant effect of BV on the mean neuronal discharge frequency or pathological bursting activity. In contrast, analyses of the neuronal responses evoked by motor cortex stimulation show that bee venom reverses the 6-OHDA- and neuroleptic-induced biases in the influence exerted by the direct inhibitory and indirect excitatory striatonigral circuits. These data provide the first evidence for a beneficial action of bee venom on the pathological functioning of the cortico-basal ganglia circuits underlying motor PD symptoms with potential relevance to the symptomatic treatment of this disease. PMID:26571268

  5. RETRACTED: S-allyl cysteine protects against 6-hydroxydopamine-induced neurotoxicity in the rat striatum: involvement of Nrf2 transcription factor activation and modulation of signaling kinase cascades.

    PubMed

    Tobón-Velasco, Julio César; Vázquez-Victorio, Genaro; Macías-Silva, Marina; Cuevas, Elvis; Ali, Syed F; Maldonado, Perla D; González-Trujano, María Eva; Cuadrado, Antonio; Pedraza-Chaverrí, José; Santamaría, Abel

    2012-09-01

    Pharmacological activation at the basal ganglia of the transcription factor Nrf2, guardian of redox homeostasis, holds a strong promise for the slow progression of Parkinson's disease (PD). However, a potent Nrf2 activator in the brain still must be found. In this study, we have investigated the potential use of the antioxidant compound S-allyl cysteine (SAC) in the activation of Nrf2 in 6-hydoxydopamine (6-OHDA)-intoxicated rats. In the rat striatum, SAC by itself promoted the Nrf2 dissociation of Keap-1, its nuclear translocation, the subsequent association with small MafK protein, and further binding of the Nrf2/MafK complex to ARE sequence, as well as the up-regulation of Nrf2-dependent genes encoding the antioxidant enzymes HO-1, NQO-1, GR, and SOD-1. In vivo and in vitro experiments to identify signaling pathways activated by SAC pointed to Akt as the most likely kinase participating in Nrf2 activation by SAC. In PC12 cells, SAC stimulated the activation of Akt and ERK1/2 and inhibited JNK1/2/3 activation. In the rat striatum, the SAC-induced activation of Nrf2 is likely to contribute to inhibit the toxic effects of 6-OHDA evidenced by phase 2 antioxidant enzymes up-regulation, glutathione recovery, and attenuation of reactive oxygen species (ROS), nitric oxide (NO), and lipid peroxides formation. These early protective effects correlated with the long-term preservation of the cellular redox status, the striatal dopamine (DA) and tyrosine hydroxylase (TH) levels, and the improvement of motor skills. Therefore, this study indicates that, in addition to direct scavenging actions, the activation of Nrf2 by SAC might confer neuroprotective responses through the modulation of kinase signaling pathways in rodent models of PD, and suggests that this antioxidant molecule may have a therapeutic value in this human pathology.

  6. Effect of simvastatin on L-DOPA-induced abnormal involuntary movements of hemiparkinsonian rats.

    PubMed

    Wang, Tan; Cao, Xuebin; Zhang, Tian; Shi, Qingqing; Chen, Zhibin; Tang, Beisha

    2015-08-01

    Chronic L-3,4-dihydroxyphenylalanine (L-DOPA) treatment of Parkinson's disease (PD) often results in debilitating involuntary movements known as L-DOPA-induced dyskinesia (LID), which is the main obstacle in PD. The abnormal involuntary movements (AIMs) are consistently involved with the activation of the Ras-extracellular signal-regulated kinase 1/2 (ERK1/2) mitogen-activated protein kinase (MAPK) signaling pathway. Previous research has also shown that blockade of ERK phosphorylation could reduce the induction of LID. Consequently, inhibitors of MAPK signaling cascade that block the aberrant supersensitive response of direct pathway striatal neurons could provide a novel therapeutic adjunct to L-DOPA in the treatment of PD. Statins, a specific inhibitor of the rate-limiting enzyme in cholesterol biosynthesis, can also inhibit Ras isoprenylation and activity, and the subsequent phosphorylation of ERK1/2 (pERK1/2). Simvastatin, a representative of statins, could reduce L-DOPA-induced AIM incidence and severity in the 6-hydroxydopamine (6-OHDA) rat model of PD by preventing the L-DOPA/benserazide-induced increase in pERK1/2 levels in our study. The simvastatin-L-DOPA/benserazide-treated 6-OHDA animals displayed less severe rotational behavior and a dramatic reduction in AIM severity than the L-DOPA/benserazide-treated ones. This lower AIM severity was related to a decrease in L-DOPA-induced increase in the following: (1) striatal pERK1/2 and (2) FosB levels. These results suggest that simvastatin could represent a treatment option for managing LID in PD.

  7. Cyclosporin promotes neurorestoration and cell replacement therapy in pre-clinical models of Parkinson's disease.

    PubMed

    Tamburrino, Anna; Churchill, Madeline J; Wan, Oi W; Colino-Sanguino, Yolanda; Ippolito, Rossana; Bergstrand, Sofie; Wolf, Daniel A; Herz, Niculin J; Sconce, Michelle D; Björklund, Anders; Meshul, Charles K; Decressac, Mickael

    2015-12-14

    The early clinical trials using fetal ventral mesencephalic (VM) allografts in Parkinson's disease (PD) patients have shown efficacy (albeit not in all cases) and have paved the way for further development of cell replacement therapy strategies in PD. The preclinical work that led to these clinical trials used allografts of fetal VM tissue placed into 6-OHDA lesioned rats, while the patients received similar allografts under cover of immunosuppression in an α-synuclein disease state. Thus developing models that more faithfully replicate the clinical scenario would be a useful tool for the translation of such cell-based therapies to the clinic. Here, we show that while providing functional recovery, transplantation of fetal dopamine neurons into the AAV-α-synuclein rat model of PD resulted in smaller-sized grafts as compared to similar grafts placed into the 6-OHDA-lesioned striatum. Additionally, we found that cyclosporin treatment was able to promote the survival of the transplanted cells in this allografted state and surprisingly also provided therapeutic benefit in sham-operated animals. We demonstrated that delayed cyclosporin treatment afforded neurorestoration in three complementary models of PD including the Thy1-α-synuclein transgenic mouse, a novel AAV-α-synuclein mouse model, and the MPTP mouse model. We then explored the mechanisms for this benefit of cyclosporin and found it was mediated by both cell-autonomous mechanisms and non-cell autonomous mechanisms. This study provides compelling evidence in favor for the use of immunosuppression in all grafted PD patients receiving cell replacement therapy, regardless of the immunological mismatch between donor and host cells, and also suggests that cyclosporine treatment itself may act as a disease-modifying therapy in all PD patients.

  8. The effect of low frequency stimulation of the pedunculopontine tegmental nucleus on basal ganglia in a rat model of Parkinson's disease.

    PubMed

    Park, Eunkyoung; Song, Inho; Jang, Dong Pyo; Kim, In Young

    2014-08-08

    The pedunculopontine nucleus (PPN) has recently been introduced as an alternative target to the subthalamic nucleus (STN) or globus pallidus internus (GPi) for the treatment of advanced Parkinson's disease with severe and medically intractable axial symptoms such as gait and postural impairment. However, it is little known about how electrical stimulation of the PPN affects control of neuronal activities between the PPN and basal ganglia. We examined how low frequency stimulation of the pedunculopontine tegmental nucleus (PPTg) affects control of neuronal activities between the PPN and basal ganglia in 6-OHDA lesioned rats. In order to identify the effect of low frequency stimulation on the PPTg, neuronal activity in both the STN and substantia nigra par reticulata (SNr) were recorded and subjected to quantitative analysis, including analysis of firing rates and firing patterns. In this study, we found that the firing rates of the STN and SNr were suppressed during low frequency stimulation of the PPTg. However, the firing pattern, in contrast to the firing rate, did not exhibit significant changes in either the STN or SNr of 6-OHDA lesioned rats during low frequency stimulation of the PPTg. In addition, we also found that the firing rate of STN and SNr neurons displaying burst and random pattern were decreased by low frequency stimulation of PPTg, while the neurons displaying regular pattern were not affected. These results indicate that low frequency stimulation of the PPTg affects neuronal activity in both the STN and SNr, and may represent electrophysiological efficacy of low frequency PPN stimulation.

  9. Comparative study of the neurotrophic effects elicited by VEGF-B and GDNF in preclinical in vivo models of Parkinson's disease.

    PubMed

    Yue, X; Hariri, D J; Caballero, B; Zhang, S; Bartlett, M J; Kaut, O; Mount, D W; Wüllner, U; Sherman, S J; Falk, T

    2014-01-31

    Vascular endothelial growth factor B (VEGF-B) has recently been shown to be a promising novel neuroprotective agent for several neurodegenerative conditions. In the current study we extended previous work on neuroprotective potential for Parkinson's disease (PD) by testing an expanded dose range of VEGF-B (1 and 10 μg) and directly comparing both neuroprotective and neurorestorative effects of VEGF-B in progressive unilateral 6-hydroxydopamine (6-OHDA) PD models to a single dose of glial cell line-derived neurotrophic factor (GDNF, 10 μg), that has been established by several groups as a standard in both preclinical PD models. In the amphetamine-induced rotational tests the treatment with 1 and 10 μg VEGF-B resulted in significantly improved motor function of 6-OHDA-lesioned rats compared to vehicle-treated 6-OHDA-lesioned rats in the neuroprotection paradigm. Both doses of VEGF-B caused an increase in tyrosine hydroxylase (TH)-positive cell and fiber count in the substantia nigra (SN) and striatum in the neuroprotective experiment. The effect size was comparable to the effects seen with GDNF. In the neurorestoration paradigm, VEGF-B injection had no significant effect in either the behavioral or the immunohistochemical analyses, whereas GDNF injection significantly improved the amphetamine-induced rotational behavior and reduced TH-positive neuronal cell loss in the SN. We also present a strong positive correlation (p=1.9e-50) of the expression of VEGF-B with nuclear-encoded mitochondrial genes involved in fatty acid metabolism in rat midbrain, pointing to the mitochondria as a site of action of VEGF-B. GDNF showed a positive correlation with nuclear-encoded mitochondrial genes that was not nearly as strong (p=0.018). VEGF-B counteracted rotenone-induced reduction of (a) fatty acid transport protein 1 and 4 levels and (b) both Akt protein and phosphorylation levels in SH-SY5Y cells. We further verified VEGF-B expression in the human SN pars compacta of healthy

  10. Nogo-A Neutralization Improves Graft Function in a Rat Model of Parkinson’s Disease

    PubMed Central

    Seiler, Stefanie; Di Santo, Stefano; Widmer, Hans Rudolf

    2016-01-01

    Transplantation of fetal human ventral mesencephalic (VM) dopaminergic neurons into the striatum is a promising strategy to compensate for the characteristic dopamine deficit observed in Parkinson’s disease (PD). This therapeutic approach, however, is currently limited by the high number of fetuses needed for transplantation and the poor survival and functional integration of grafted dopaminergic neurons into the host brain. Accumulating evidence indicates that contrasting inhibitory signals endowed in the central nervous system (CNS) might support neuronal regeneration. Hence, in the present study we aimed at improving survival and integration of grafted cells in the host brain by neutralizing Nogo-A, one of the most potent neurite growth inhibitors in the CNS. For that purpose, VM tissue cultures were transplanted into rats with a partial 6-hydroxydopamine (6-OHDA) lesion causing a hemi-PD model and concomitantly treated for 2 weeks with intra-ventricular infusion of neutralizing anti-Nogo-A antibodies. Motor behavior using the cylinder test was assessed prior to and after transplantation as functional outcome. At the end of the experimental period the number of dopaminergic fibers growing into the host brain, the number of surviving dopaminergic neurons in the grafts as well as graft size was examined. We found that anti-Nogo-A antibody infusion significantly improved the asymmetrical forelimb use observed after lesions as compared to controls. Importantly, a significantly three-fold higher dopaminergic fiber outgrowth from the transplants was detected in the Nogo-A antibody treated group as compared to controls. Furthermore, Nogo-A neutralization showed a tendency for increased survival of dopaminergic neurons (by two-fold) in the grafts. No significant differences were observed for graft volume and the number of dopaminergic neurons co-expressing G-protein-coupled inward rectifier potassium channel subunit two between groups. In sum, our findings support the

  11. Animal models to guide clinical drug development in ADHD: lost in translation?

    PubMed Central

    Wickens, Jeffery R; Hyland, Brian I; Tripp, Gail

    2011-01-01

    We review strategies for developing animal models for examining and selecting compounds with potential therapeutic benefit in attention-deficit hyperactivity disorder (ADHD). ADHD is a behavioural disorder of unknown aetiology and pathophysiology. Current understanding suggests that genetic factors play an important role in the aetiology of ADHD. The involvement of dopaminergic and noradrenergic systems in the pathophysiology of ADHD is probable. We review the clinical features of ADHD including inattention, hyperactivity and impulsivity and how these are operationalized for laboratory study. Measures of temporal discounting (but not premature responding) appear to predict known drug effects well (treatment validity). Open-field measures of overactivity commonly used do not have treatment validity in human populations. A number of animal models have been proposed that simulate the symptoms of ADHD. The most commonly used are the spontaneously hypertensive rat (SHR) and the 6-hydroxydopamine-lesioned (6-OHDA) animals. To date, however, the SHR lacks treatment validity, and the effects of drugs on symptoms of impulsivity and inattention have not been studied extensively in 6-OHDA-lesioned animals. At the present stage of development, there are no in vivo models of proven effectiveness for examining and selecting compounds with potential therapeutic benefit in ADHD. However, temporal discounting is an emerging theme in theories of ADHD, and there is good evidence of increased value of delayed reward following treatment with stimulant drugs. Therefore, operant behaviour paradigms that measure the effects of drugs in situations of delayed reinforcement, whether in normal rats or selected models, show promise for the future. LINKED ARTICLES This article is part of a themed issue on Translational Neuropharmacology. To view the other articles in this issue visit http://dx.doi.org/10.1111/bph.2011.164.issue-4 PMID:21480864

  12. Enhanced Efficacy of Human Brain-Derived Neural Stem Cells by Transplantation of Cell Aggregates in a Rat Model of Parkinson's Disease

    PubMed Central

    Shin, Eun Sil; Hwang, Onyou; Hwang, Yu-Shik; Suh, Jun-Kyo Francis; Chun, Young Il

    2014-01-01

    Objective Neural tissue transplantation has been a promising strategy for the treatment of Parkinson's disease (PD). However, transplantation has the disadvantages of low-cell survival and/or development of dyskinesia. Transplantation of cell aggregates has the potential to overcome these problems, because the cells can extend their axons into the host brain and establish synaptic connections with host neurons. In this present study, aggregates of human brain-derived neural stem cells (HB-NSC) were transplanted into a PD animal model and compared to previous report on transplantation of single-cell suspensions. Methods Rats received an injection of 6-OHDA into the right medial forebrain bundle to generate the PD model and followed by injections of PBS only, or HB-NSC aggregates in PBS into the ipsilateral striatum. Behavioral tests, multitracer (2-deoxy-2-[18F]-fluoro-D-glucose ([18F]-FDG) and [18F]-N-(3-fluoropropyl)-2-carbomethoxy-3-(4-iodophenyl)nortropane ([18F]-FP-CIT) microPET scans, as well as immunohistochemical (IHC) and immunofluorescent (IF) staining were conducted to evaluate the results. Results The stepping test showed significant improvement of contralateral forelimb control in the HB-NSC group from 6-10 weeks compared to the control group (p<0.05). [18F]-FP-CIT microPET at 10 weeks posttransplantation demonstrated a significant increase in uptake in the HB-NSC group compared to pretransplantation (p<0.05). In IHC and IF staining, tyrosine hydroxylase and human β2 microglobulin (a human cell marker) positive cells were visualized at the transplant site. Conclusion These results suggest that the HB-NSC aggregates can survive in the striatum and exert therapeutic effects in a PD model by secreting dopamine. PMID:25535514

  13. Effect of acupuncture on 6-hydroxydopamine-induced nigrostratal dopaminergic neuronal cell death in rats.

    PubMed

    Kim, Yeung-Kee; Lim, Hyung-Ho; Song, Yun-Kyung; Lee, Hee-Hyuk; Lim, Sabina; Han, Seung-Moo; Kim, Chang-Ju

    In this study, we investigated the effect of acupuncture at the Zusanli acupoint (ST36) on the nigrostriatal dopaminergic neuronal cell death in the rats with Parkinson's disease. Two weeks after unilateral injection of 6-hydroxydopamine (6-OHDA) into the striatum, an apomorphine-induced rotational behavior test showed significant rotational asymmetry in the rats with Parkinson's disease. Immunostaining for tyrosine hydroxylase demonstrated a dopaminergic neuronal loss in the substantia nigra and dopaminergic fiber loss in the striatum. Acupuncture at the ST36 for 14 days significantly inhibited rotational asymmetry in the rats with Parkinson's disease, and also protected against 6-OHDA-induced nigrostriatal dopaminergic neuronal loss. These effects of acupuncture were not observed for the non-acupoint (hip) acupuncture. The present study shows that acupuncture at the ST36 acupoint can be used as a useful strategy for the treatment of Parkinson's disease.

  14. Human Albumin Prevents 6-Hydroxydopamine-Induced Loss of Tyrosine Hydroxylase in In Vitro and In Vivo

    PubMed Central

    Zhang, Li-Juan; Xue, Yue-Qiang; Yang, Chun; Yang, Wei-Hua; Chen, Long; Zhang, Qian-Jin; Qu, Ting-Yu; Huang, Shile; Zhao, Li-Ru; Wang, Xiao-Min; Duan, Wei-Ming

    2012-01-01

    Human albumin has recently been demonstrated to protect brain neurons from injury in rat ischemic brain. However, there is no information available about whether human albumin can prevent loss of tyrosine hydroxylase (TH) expression of dopaminergic (DA) neurons induced by 6-hydroxydopamine (6-OHDA) toxicity that is most commonly used to create a rat model of Parkinson's disease (PD). In the present study, two microliters of 1.25% human albumin were stereotaxically injected into the right striatum of rats one day before or 7 days after the 6-OHDA lesion in the same side. D-Amphetamine-induced rotational asymmetry was measured 7 days, 3 and 10 weeks after 6-OHDA lesion. We observed that intrastriatal administration of human albumin significantly reduced the degree of rotational asymmetry. The number of TH-immunoreactive neurons present in the substantia nigra was greater in 6-OHDA lesioned rats following human albumin-treatment than non-human albumin treatment. TH-immunoreactivity in the 6-OHDA-lesioned striatum was also significantly increased in the human albumin-treated rats. To examine the mechanisms underlying the effects of human albumin, we challenged PC12 cells with 6-OHDA as an in vitro model of PD. Incubation with human albumin prevented 6-OHDA-induced reduction of cell viability in PC12 cell cultures, as measured by MTT assay. Furthermore, human albumin reduced 6-OHDA-induced formation of reactive oxygen species (ROS) and apoptosis in cultured PC12 cells, as assessed by flow cytometry. Western blot analysis showed that human albumin inhibited 6-OHDA-induced activation of JNK, c-Jun, ERK, and p38 mitogen-activated protein kinases (MAPK) signaling in PC12 cultures challenged with 6-OHDA. Human albumin may protect against 6-OHDA toxicity by influencing MAPK pathway followed by anti-ROS formation and anti-apoptosis. PMID:22815976

  15. Methanolic extract of Hibiscus asper leaves improves spatial memory deficits in the 6-hydroxydopamine-lesion rodent model of Parkinson's disease.

    PubMed

    Foyet, Harquin Simplice; Hritcu, Lucian; Ciobica, Alin; Stefan, Marius; Kamtchouing, Pierre; Cojocaru, Dumitru

    2011-01-27

    While the Hibiscus asper Hook.f. (Malvaceae) is a traditional herb largely used in tropical region of the Africa as vegetable, potent sedative, tonic and restorative, anti-inflammatory and antidepressive drug, there is very little scientific data concerning the efficacy of this. We investigated antioxidant activity and the effects of methanolic extract of Hibiscus asper leaves on neurological capacity of male Wistar rats subjected to unilateral 6-hydroxydopamine (6-OHDA)-lesion. Two model systems: 2,4-dinitrophenyl-1-picryl hydrazyl (DPPH) radical scavenging activity and β-carotene bleaching inhibition assay were used to measure the antioxidant activities of the plan extract. We also investigated the neuroprotective effect of methanolic extract of Hibiscus asper leaves (50 and 100 mg/kg) in male Wistar rats subjected to unilateral 6-hydroxydopamine (6-OHDA)-lesion rat model. Methanolic extract of Hibiscus asper leaves showed potent antioxidant and free radical scavenging activity. Chronic administration of methanolic extract (50 and 100 mg/kg, i.p., daily, for 7 days) significantly reduce anxiety-like behavior and inhibit depression in elevated plus-maze and forced swimming tests, suggesting anxiolytic and antidepressant activity. Also, spatial memory performance in Y-maze and radial arm-maze tasks was improved, suggesting positive effects on memory formation. Taken together, our results suggest that the methanolic extract of Hibiscus asper leaves have antioxidant effects and might provide an opportunity to management neurological abnormalities in Parkinson's disease conditions. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  16. The CB(1) antagonist rimonabant is adjunctively therapeutic as well as monotherapeutic in an animal model of Parkinson's disease.

    PubMed

    Kelsey, J E; Harris, O; Cassin, J

    2009-11-05

    Acute injections of 8mg/kg of 3,4-dihydroxy-l-phenylalanine (l-DOPA) or 0.05mg/kg rimonabant equally improved contralateral forepaw stepping in rats with unilateral 6-hydroxydopamine (6-OHDA) lesions, and their combination improved stepping more than either drug alone. However, 0.05mg/kg rimonabant did not alter the changes in stepping produced by acute injections of a dyskinesic dose of 35mg/kg l-DOPA. Thus, not only is a cannabinoid antagonist monotherapeutic in this animal model of Parkinson's disease, but it also enhances the therapeutic effect of a moderate, but not a high, dose of l-DOPA.

  17. Evidence for an Additive Neurorestorative Effect of Simultaneously Administered CDNF and GDNF in Hemiparkinsonian Rats: Implications for Different Mechanism of Action

    PubMed Central

    De Lorenzo, Francesca; Stepanova, Polina; Bäck, Susanne; Yu, Li-Ying; Pörsti, Eeva; Männistö, Pekka T.; Tuominen, Raimo K.

    2017-01-01

    Abstract Parkinson’s disease (PD) is a neurodegenerative disorder associated with a progressive loss of dopaminergic (DAergic) neurons of the substantia nigra (SN) and the accumulation of intracellular inclusions containing α-synuclein. Current therapies do not stop the progression of the disease, and the efficacy of these treatments wanes over time. Neurotrophic factors (NTFs) are naturally occurring proteins promoting the survival and differentiation of neurons and the maintenance of neuronal contacts. CDNF (cerebral dopamine NTF) and GDNF (glial cell line-derived NTF) are able to protect DAergic neurons against toxin-induced degeneration in experimental models of PD. Here, we report an additive neurorestorative effect of coadministration of CDNF and GDNF in the unilateral 6-hydroxydopamine (6-OHDA) lesion model of PD in rats. NTFs were given into the striatum four weeks after unilateral intrastriatal injection of 6-OHDA (20 µg). Amphetamine-induced (2.5 mg/kg, i.p.) rotational behavior was measured every two weeks. Number of tyrosine hydroxylase (TH)-positive cells from SN pars compacta (SNpc) and density of TH-positive fibers in the striatum were analyzed at 12 weeks after lesion. CDNF and GDNF alone restored the DAergic function, and one specific dose combination had an additive effect: CDNF (2.5µg) and GDNF (1µg) coadministration led to a stronger trophic effect relative to either of the single treatments alone. The additive effect may indicate different mechanism of action for the NTFs. Indeed, both NTFs activated the survival promoting PI3 kinase (PI3K)-Akt signaling pathway, but only CDNF decreased the expression level of tested endoplasmatic reticulum (ER) stress markers ATF6, glucose-regulated protein 78 (GRP78), and phosphorylation of eukaryotic initiation factor 2α subunit (eIF2α). PMID:28303260

  18. Influence of chronic L-DOPA treatment on immune response following allogeneic and xenogeneic graft in a rat model of Parkinson's disease.

    PubMed

    Breger, Ludivine S; Kienle, Korbinian; Smith, Gaynor A; Dunnett, Stephen B; Lane, Emma L

    2017-03-01

    Although intrastriatal transplantation of fetal cells for the treatment of Parkinson's disease had shown encouraging results in initial open-label clinical trials, subsequent double-blind studies reported more debatable outcomes. These studies highlighted the need for greater preclinical analysis of the parameters that may influence the success of cell therapy. While much of this has focused on the cells and location of the transplants, few have attempted to replicate potentially critical patient centered factors. Of particular relevance is that patients will be under continued L-DOPA treatment prior to and following transplantation, and that typically the grafts will not be immunologically compatible with the host. The aim of this study was therefore to determine the effect of chronic L-DOPA administered during different phases of the transplantation process on the survival and function of grafts with differing degrees of immunological compatibility. To that end, unilaterally 6-OHDA lesioned rats received sham surgery, allogeneic or xenogeneic transplants, while being treated with L-DOPA before and/or after transplantation. Irrespective of the L-DOPA treatment, dopaminergic grafts improved function and reduced the onset of L-DOPA induced dyskinesia. Importantly, although L-DOPA administered post transplantation was found to have no detrimental effect on graft survival, it did significantly promote the immune response around xenogeneic transplants, despite the administration of immunosuppressive treatment (cyclosporine). This study is the first to systematically examine the effect of L-DOPA on graft tolerance, which is dependent on the donor-host compatibility. These findings emphasize the importance of using animal models that adequately represent the patient paradigm.

  19. Acute L: -DOPA effect on hydroxyl radical- and DOPAC-levels in striatal microdialysates of parkinsonian rats.

    PubMed

    Nowak, Przemysław; Kostrzewa, Rose Anna; Skaba, Dariusz; Kostrzewa, Richard M

    2010-04-01

    The object of the current study was to determine the effect of L: -3,4-dihydroxyphenylalanine (L: -DOPA) on the in vivo striatal microdialysate levels of the respective dopamine and serotonin metabolites 3,4-dihydroxyphenlalanine (DOPAC) and 5-hydroxyindoleacetic acid (5-HIAA) and hydroxyl radical level (HO(*); 2,3- and 2,5-dihydroxybenzoic acid, 2,3- and 2,5-DHBA) in adult rats made parkinsonian by treatment at 3 days after birth with the neurotoxin 6-hydroxydopamine (6-OHDA; 66.7 microg, base form, on each side; desipramine pretreatment, 1 h). Using HPLC/ED we found that in 6-OHDA-lesioned rats the basal striatal extraneuronal level of DOPAC was dramatically reduced and constituted only approximately 4.5% of referenced value (intact rats). Conversely, the striatal microdialysate level of 5-HIAA was elevated 2-fold in 6-OHDA-lesioned rats. Acute L: -DOPA (60 mg/kg i.p.; S-carbidopa pretreatment, 12.5 mg/kg i.p., 30 min) produced a rapid rise in the extraneuronal DOPAC in both tested groups but to a much greater extent in intact rats (P < 0.05). Levels of HO(*) (spin-trap products of salicylate, 2,3- and 2,5-DHBA) were elevated 2-fold in 6-OHDA-lesioned rats. However, L: -DOPA did not enhance HO(*) production; acute 6-OHDOPA treatment (60 mg/kg i.p.) also did not alter HO(*) production. In summary, L: -DOPA, an effective drug in ameliorating PD symptoms, did not acutely pose a risk for HO(*) generation in parkinsonian rats. We conclude that L: -DOPA is not likely to generate reactive oxygen species in humans nor is L: -DOPA likely to accelerate PD in humans.

  20. Impaired hepatic function and central dopaminergic denervation in a rodent model of Parkinson's disease: a self-perpetuating crosstalk?

    PubMed

    Vairetti, Mariapia; Ferrigno, Andrea; Rizzo, Vittoria; Ambrosi, Giulia; Bianchi, Alberto; Richelmi, Plinio; Blandini, Fabio; Armentero, Marie-Therese

    2012-02-01

    In Parkinson's disease (PD), aside from the central lesion, involvement of visceral organs has been proposed as part of the complex clinical picture of the disease. The issue is still poorly understood and relatively unexplored. In this study we used a classic rodent model of nigrostriatal degeneration, induced by the intrastriatal injection of 6-hydroxydopamine (6-OHDA), to investigate whether and how a PD-like central dopaminergic denervation may influence hepatic functions. Rats received an intrastriatal injection of 6-OHDA or saline (sham), and blood, cerebrospinal fluid, liver and brain samples were obtained for up to 8 weeks after surgery. Specimens were analyzed for changes in cytokine and thyroid hormone levels, as well as liver mitochondrial alterations. Hepatic mitochondria isolated from animals bearing extended nigrostriatal lesion displayed increased ROS production, while membrane potential (ΔΨ) and ATP production were significantly decreased. Reduced ATP production correlated with nigral neuronal loss. Thyroid hormone levels were significantly increased in serum of PD rats compared to sham animals while steady expression of selected cytokines was detected in all groups. Hepatic enzyme functions were comparable in all animals. Our study indicates for the first time that in a rodent model of PD, hepatic mitochondria dysfunctions arise as a consequence of nigrostriatal degeneration, and that thyroid hormone represents a key interface in this CNS-liver interaction. Liver plays a fundamental detoxifying function and a better understanding of PD-related hepatic mitochondrial alterations, which might further promote neurodegeneration, may represent an important step for the development of novel therapeutic strategies.

  1. Neuroprotective effect of D-psicose on 6-hydroxydopamine-induced apoptosis in rat pheochromocytoma (PC12) cells.

    PubMed

    Takata, Maki K; Yamaguchi, Fuminori; Nakanose, Koichi; Watanabe, Yasuo; Hatano, Naoya; Tsukamoto, Ikuko; Nagata, Mitsuhiro; Izumori, Ken; Tokuda, Masaaki

    2005-11-01

    We evaluated the neuroprotective effects of D-psicose, one of the rare sugars, on 6-hydroxydopamine (6-OHDA)-induced apoptosis in catecholaminergic PC12 cells, the in vitro model of Parkinson's disease (PD). Apoptotic characteristics of PC12 cells were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and terminal deoxynucleotidyl transferase mediated dUTP nick end-labeling (TUNEL) assay. The results showed that D-psicose at a concentration of 50 mM, exerted significant protective effects against the 6-OHDA (200 muM)-induced PC12 cell apoptosis, while other sugars had little or no protective effects. We have observed a significant increase in the level of intracellular glutathione after 24 h in 6-OHDA (200 muM) treated cells, while a decrease in the level was observed at 3 h and 6 h. Also, a synergistic exposure to D-psicose and 6-OHDA for 24 h showed a significant increase in intracellular glutathione level. Therefore, these results suggest that D-psicose may play a potential role as a neuroprotective agent in the treatment of neurodegenerative diseases by inducing an up-regulation of intracellular glutathione.

  2. Amantadine increases L-DOPA-derived extracellular dopamine in the striatum of 6-hydroxydopamine-lesioned rats.

    PubMed

    Arai, Akira; Kannari, Kazuya; Shen, Huo; Maeda, Tetsuya; Suda, Toshihiro; Matsunaga, Muneo

    2003-05-16

    We investigated the effect of amantadine on L-DOPA-derived extracellular dopamine (DA) levels and aromatic L-amino acid decarboxylase (AADC) activity in the striatum of rats with nigrostriatal dopaminergic denervation by 6-hydroxydopamine (6-OHDA). Pretreatment with 30 mg/kg amantadine increased the cumulative amount of extracellular DA in the striatum of 6-OHDA-lesioned rats treated with 10 mg/kg benserazide and 50 mg/kg L-DOPA to 250% of that without amantadine (P<0.01). Under pretreatment with 10 mg/kg benserazide, AADC activity after 30 mg/kg amantadine administration was reduced to 43% of controls (P<0.01). Amantadine-induced increase in L-DOPA-derived extracellular DA provides the basis for the clinical usefulness of amantadine in combination with L-DOPA. However, the effect of amantadine on L-DOPA-derived extracellular DA may not be caused by changes in AADC activity.

  3. Arachidonic acid incorporation and turnover is decreased in sympathetically denervated rat heart.

    PubMed

    Patrick, Casey B; McHowat, Jane; Rosenberger, Thad A; Rapoport, Stanley I; Murphy, Eric J

    2005-06-01

    Heart sympathetic denervation can accompany Parkinson's disease, but the effect of this denervation on cardiac lipid-mediated signaling is unknown. To address this issue, rats were sympathetically denervated with 6-hydroxydopamine (6-OHDA, 50 mg/kg ip) and infused with 170 muCi/kg of either [1-(14)C]palmitic acid ([1-(14)C]16:0) or [1-(14)C]arachidonic acid ([1-(14)C]20:4 n-6), and kinetic parameters were assessed using a steady-state radiotracer model. Heart norepinephrine and epinephrine levels were decreased 82 and 85%, respectively, in denervated rats, and this correlated with a 34% reduction in weight gain in treated rats. Fatty acid tracer uptake was not significantly different between groups for either tracer, although the dilution coefficient lambda was increased in [1-(14)C]20:4 n-6-infused rats, which indicates that less 20:4 n-6 was recycled in denervated rats. In [1-(14)C]16:0-infused rats, incorporation rate and turnover values of 16:0 in stable lipid compartments were unchanged, which is indicative of preservation of beta-oxidation. In [1-(14)C]20:4 n-6-infused rats, there were dramatic reductions in incorporation rate (60-84%) and turnover value (56-85%) in denervated rats that were dependent upon the lipid compartment. In addition, phospholipase A(2) activity was reduced 40% in treated rats, which is consistent with the reduction observed in 20:4 n-6 turnover. These results demonstrate marked reductions in 20:4 n-6 incorporation rate and turnover in sympathetic denervated rats and thereby suggest an effect on lipid-mediated signal transduction mediated by a reduction in phospholipase A(2) activity.

  4. Neuroprotection by a novel brain permeable iron chelator, VK-28, against 6-hydroxydopamine lession in rats.

    PubMed

    Shachar, Dorit Ben; Kahana, Nava; Kampel, Vladimir; Warshawsky, Abraham; Youdim, Moussa B H

    2004-02-01

    Significant increase in iron occurs in the substantia nigra pars compacta of Parkinsonian subjects, and in 6-hydroxydopamine (6-OHDA) treated rats and monkeys. This increase in iron has been attributed to its release from ferritin and is associated with the generation of reactive oxygen species and the onset of oxidative stress-induced neurodegeneration. Several iron chelators with hydroxyquinoline backbone were synthesized and their ability to inhibit basal as well as iron-induced mitochondrial lipid peroxidation was examined. The neuroprotective potential of the brain permeable iron chelator, VK-28 (5-[4-(2-hydroxyethyl) piperazine-1-ylmethyl]-quinoline-8-ol), injected either intraventricularly (ICV) or intraperitoneally (IP), to 6-OHDA lesioned rats was investigated. VK-28 inhibited both basal and Fe/ascorbate induced mitochondrial membrane lipid peroxidation, with an IC(50) (12.7 microM) value comparable to that of the prototype iron chelator, desferal, which does not cross the blood brain barrier. At an ICV pretreatment dose as low as 1 microg, VK-28 was able to completely protect against ICV 6-OHDA (250 microg) induced striatal dopaminergic lesion, as measured by dopamine (DA), dihydroxyphenylacetic acid (DOPAC) and homovanilic acid (HVA) levels. IP injection of rats with VK-28 (1 and 5 mg/kg) daily for 10 and 7 days, respectively, demonstrated significant neuroprotection against ICV 6-OHDA at the higher dose, with 68% protection against loss of dopamine at 5mg/kg dosage of VK-28. The present study is the first to show neuroprotection with a brain permeable iron chelator. The latter can have implications for the treatment of Parkinson's disease and other neurodegenerative diseases (Alzheimer's disease, Friedreich ataxia, aceruloplasminemia, Hallervorden Spatz syndrome) where abnormal iron accumulation in the brain is thought to be associated with the degenerative processes.

  5. L-DOPA-induced dyskinesia in the intrastriatal 6-hydroxydopamine model of parkinson's disease: relation to motor and cellular parameters of nigrostriatal function.

    PubMed

    Winkler, Christian; Kirik, Deniz; Björklund, Anders; Cenci, M Angela

    2002-07-01

    In order to assess the role of striatal dopamine (DA) afferents in L-DOPA-induced dyskinesia, we have studied a large series of rats sustaining 2, 3, or 4 unilateral injections of 6-hydroxydopamine (6-OHDA) in the lateral striatum. This type of lesion produced a dose-dependent depletion of DA fibers in the caudate-putamen, which was most pronounced in the lateral aspects of this structure. An additional group of rats was injected with 6-OHDA in the medial forebrain bundle to obtain complete DA denervation on one side of the brain. During a course of chronic L-DOPA treatment, rats with intrastriatal 6-OHDA lesions developed abnormal involuntary movements (AIMs), which mapped onto striatal domains exhibiting at least approximately 90% denervation, as judged by DA transporter autoradiography. The denervated areas showed local upregulation of preproenkephalin and prodynorphin mRNA, and FosB-like immunoreactivity, which were highly correlated with the rats' AIM scores. When compared to completely DA-denervated animals, the rats with intrastriatal 6-OHDA lesions showed an overall lower incidence, lower severity and different topographic distribution of AIMs. The involvement of proximal limb and axial muscles in the abnormal movements was proportional to the spreading of the lesion from lateral towards medial aspects of the caudate-putamen. Locomotive AIMs were only seen in rats with complete lesions, but not in any of the animals with intrastriatal 6-OHDA (which showed > 5% DA fiber sparing in the medial striatum). Intrastriatally 6-OHDA-lesioned rats had a larger therapeutic window for L-DOPA than did rats with complete bundle lesions, since they exhibited an overall lower predisposition to dyskinesia but a similar degree of drug-induced motor improvement in a test of forelimb stepping. Our results are the first to demonstrate that selective and partial DA denervation in the sensorimotor part of the striatum can confer cellular and behavioral supersensitivity to L

  6. Transgenic Rat Models of Huntington's Disease.

    PubMed

    Carreira, João Casaca; Jahanshahi, Ali; Zeef, Dagmar; Kocabicak, Ersoy; Vlamings, Rinske; von Hörsten, Stephan; Temel, Yasin

    2015-01-01

    Several animal models for Huntington's disease (HD) have been created in order to investigate mechanisms of disease, and to evaluate the potency of novel therapies. Here, we describe the characteristics of the two transgenic rat models: transgenic rat model of HD (fragment model) and the Bacterial Artificial Chromosome HD model (full-length model). We discuss their genetic, behavioural, neuropathological and neurophysiological features.

  7. Trophic influence of the sympathetic nervous system on the rat portal vein.

    PubMed

    Aprigliano, O; Hermsmeyer, K

    1977-08-01

    Adrenergic denervation of the rat portal vein was produced in vivo by the sympatholytic agent 6-hydroxydopamine (6-OHDA). Treatment of rats with 6-OHDA decreased the responses of the portal veins to nerve stimulation, reduced 3H-norepinephrine (NE) uptake, and decreased catecholamine fluorescence, indicating that partial adrenergic denervation was achieved. The main findings of this study indicate that the in vivo denervation produced: (1) a (time-dependent) increase in sensitivity of the veins to NE, which was not of prejunctional origin, (2) an increase in sensitivity to BaC12, and (3) a partial depolarization of the myovascular cells. The results suggest that the in vivo denervation of the portal veins by 6-OHDA produces a postjunctional alteration, which may be due to the removal of a trophic influence of the sympathetic nervous system. It is proposed that the partial depolarization and associated ionic changes may be components of the mechanism. These results provide the first direct evidence that membrane excitability changes are involved in trophic nerve-muscle interactions in blood vessels.

  8. L-DOPA-induced dyregulation of extrastriatal dopamine and serotonin and affective symptoms in a bilateral rat model of Parkinson’s disease

    PubMed Central

    Jaunarajs, Karen L. Eskow; George, Jessica A.; Bishop, Christopher

    2012-01-01

    Convergent evidence indicates that raphestriatal serotonin (5-HT) neurons can convert and release dopamine (DA) derived from exogenous administration of the pharmacotherapeutic L-3,4-dihydroxyphenyl-L-alanine(L-DOPA) as a treatment for Parkinson’s disease (PD). While aspects of such neuroplasticity may be beneficial, chronic L-DOPA may also modify native 5-HT function, precipitating the appearance prevalent non-motor PD symptoms such as anxiety and depression. To examine this, male Sprague-Dawley rats were rendered parkinsonian with bilateral medial forebrain bundle 6-OHDA infusions and treated for at least 28 days with vehicle or L-DOPA. In the first experiment, striatal, hippocampal, amygdalar, and prefrontal cortex DA and 5-HT levels were examined at various post-treatment time-points. In experiment 2, L-DOPA’s effects on DA and 5-HT cell bodies in the substantia nigra pars compacta and dorsal raphe, respectively, were examined. Finally, the effects of L-DOPA on affective behaviors were assessed in locomotor chambers, social interaction, forced swim, and elevated plus maze behavioral tests. Bilateral 6-OHDA lesion induced approximately 80% DA and 30% 5-HT depletion in the striatum compared to sham-lesioned controls, while monoamine levels remained largely unchanged in extrastriatal regions. Tissue levels of DA were increased at the expense of 5-HT levels in parkinsonian rats subjected to chronic L-DOPA injections in all regions sampled, though DA or 5-HT cell bodies were unaffected. Behaviorally, rats could only be tested 24 hours after their last L-DOPA injection due to severe dyskinesia. Despite this, prior exposure to chronic L-DOPA treatment exerted a pronounced anxiogenic phenotype. Collectively, these results suggest that chronic L-DOPA treatment may interfere with the balance of DA and 5-HT function in affect-related brain regions and could induce and/or exacerbate non-motor symptoms in PD. PMID:22659568

  9. High-Frequency Stimulation of the Subthalamic Nucleus Restores Neural and Behavioral Functions During Reaction Time Task in a Rat Model of Parkinson’s Disease

    PubMed Central

    Li, Xiang-Hong; Wang, Jin-Yan; Gao, Ge; Chang, Jing-Yu; Woodward, Donald J.; Luo, Fei

    2015-01-01

    Deep brain stimulation (DBS) has been used in the clinic to treat Parkinson’s disease (PD) and other neuropsychiatric disorders. Our previous work has shown that DBS in the subthalamic nucleus (STN) can improve major motor deficits, and induce a variety of neural responses in rats with unilateral dopamine (DA) lesions. In the present study, we examined the effect of STN DBS on reaction time (RT) performance and parallel changes in neural activity in the cortico-basal ganglia regions of partially bilateral DA- lesioned rats. We recorded neural activity with a multiple-channel single-unit electrode system in the primary motor cortex (MI), the STN, and the substantia nigra pars reticulata (SNr) during RT test. RT performance was severely impaired following bilateral injection of 6-OHDA into the dorsolateral part of the striatum. In parallel with such behavioral impairments, the number of responsive neurons to different behavioral events was remarkably decreased after DA lesion. Bilateral STN DBS improved RT performance in 6-OHDA lesioned rats, and restored operational behavior-related neural responses in cortico-basal ganglia regions. These behavioral and electrophysiological effects of DBS lasted nearly an hour after DBS termination. These results demonstrate that a partial DA lesion-induced impairment of RT performance is associated with changes in neural activity in the cortico-basal ganglia circuit. Furthermore, STN DBS can reverse changes in behavior and neural activity caused by partial DA depletion. The observed long-lasting beneficial effect of STN DBS suggests the involvement of the mechanism of neural plasticity in modulating corticobasal ganglia circuits. PMID:20025062

  10. Acupuncture inhibits oxidative stress and rotational behavior in 6-hydroxydopamine lesioned rat.

    PubMed

    Yu, Yong-Peng; Ju, Wei-Ping; Li, Zhen-Guang; Wang, Dao-Zhen; Wang, Yuan-Chen; Xie, An-Mu

    2010-06-08

    Increasing evidence suggests the beneficial effects of acupuncture on Parkinson's disease (PD). Although clinical evidence for the acupuncture anti-Parkinson's disease effect has been demonstrated, the precise mechanism still remains elusive. It has been suggested a relationship between PD and reactive oxygen species (ROS) can result in neurodegeneration. The aim of this study was to evaluate the status of oxidative stress, as well as the antioxidant enzyme response, and the role of acupuncture stimulation at GB34 (Yanglingquan), LR3 (Taichong), ST36 (Zusanli) and SP10 (Xuehai) acupoints on regulating oxidative stress in the nigrostriatal system in the 6-hydroxydopamine (6-OHDA) lesioned rat. Two weeks after unilateral injection of 6-OHDA into the left medial forebrain bundle (MFB), an apomorphine induced rotational behavior test was performed. The levels of enzymatic, viz., superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and nonenzymatic, viz., reduced glutathione (GSH), and the levels of malondialdehyde (MDA) in the nigrostriatal system were measured to assess the oxidative stress status. Brain MDA levels significantly increased, while GSH levels were decreased in impaired groups with 6-OHDA injection only, accompanied by a marked reduction in the level of SOD and GSH-Px. The levels of oxidative stress related parameters except CAT, as well as the rotational asymmetry, were reversed by acupuncture stimulation. These results showed that acupuncture treatment displayed antioxidative and/or neuroprotective properties in the 6-OHDA lesioned rat and these protective properties might be mediated, at least in part, by involving regulation of the antioxidant defense system.

  11. Effects of Subthalamic Nucleus Lesions and Stimulation upon Corticostriatal Afferents in the 6-Hydroxydopamine-Lesioned Rat

    PubMed Central

    Walker, Ruth H.; Moore, Cindy; Davies, Georgia; Dirling, Lisa B.; Koch, Rick J.; Meshul, Charles K.

    2012-01-01

    Abnormalities of striatal glutamate neurotransmission may play a role in the pathophysiology of Parkinson's disease and may respond to neurosurgical interventions, specifically stimulation or lesioning of the subthalamic nucleus (STN). The major glutamatergic afferent pathways to the striatum are from the cortex and thalamus, and are thus likely to be sources of striatal neuronally-released glutamate. Corticostriatal terminals can be distinguished within the striatum at the electron microscopic level as their synaptic vesicles contain the vesicular glutamate transporter, VGLUT1. The majority of terminals which are immunolabeled for glutamate but are not VGLUT1 positive are likely to be thalamostriatal afferents. We compared the effects of short term, high frequency, STN stimulation and lesioning in 6-hydroxydopamine (6OHDA)-lesioned rats upon striatal terminals immunolabeled for both presynaptic glutamate and VGLUT1. 6OHDA lesions resulted in a small but significant increase in the proportions of VGLUT1-labeled terminals making synapses on dendritic shafts rather than spines. STN stimulation for one hour, but not STN lesions, increased the proportion of synapses upon spines. The density of presynaptic glutamate immuno-gold labeling was unchanged in both VGLUT1-labeled and -unlabeled terminals in 6OHDA-lesioned rats compared to controls. Rats with 6OHDA lesions+STN stimulation showed a decrease in nerve terminal glutamate immuno-gold labeling in both VGLUT1-labeled and -unlabeled terminals. STN lesions resulted in a significant decrease in the density of presynaptic immuno-gold-labeled glutamate only in VGLUT1-labeled terminals. STN interventions may achieve at least part of their therapeutic effect in PD by normalizing the location of corticostriatal glutamatergic terminals and by altering striatal glutamatergic neurotransmission. PMID:22427909

  12. Experimental mammary carcinogenesis - Rat models.

    PubMed

    Alvarado, Antonieta; Faustino-Rocha, Ana I; Colaço, Bruno; Oliveira, Paula A

    2017-03-15

    Mammary cancer is one of the most common cancers, victimizing more than half a million of women worldwide every year. Despite all the studies in this field, the current therapeutic approaches are not effective and have several devastating effects for patients. In this way, the need to better understand the mammary cancer biopathology and find effective therapies led to the development of several rodent models over years. With this review, the authors intended to provide the readers with an overview of the rat models used to study mammary carcinogenesis, with a special emphasis on chemically-induced models.

  13. Rho kinase inhibition by fasudil in the striatal 6-hydroxydopamine lesion mouse model of Parkinson disease.

    PubMed

    Tatenhorst, Lars; Tönges, Lars; Saal, Kim-Ann; Koch, Jan C; Szegő, Éva M; Bähr, Mathias; Lingor, Paul

    2014-08-01

    Chronic degeneration of nigrostriatal projections, followed by nigral dopaminergic cell death, is a key feature of Parkinson disease (PD). This study examines the neuroprotective potential of the rho kinase inhibitor fasudil in the 6-hydroxydopamine (6-OHDA) mouse model of PD in vivo. C57Bl/6 mice were lesioned by striatal stereotactic injections with 4 μg of 6-OHDA and treated with fasudil 30 or 100 mg/kg body weight via drinking water. Motor behavior was tested biweekly; histologic and biochemical analyses were performed at 4 and 12 weeks after lesion. Motor behavior was severely impaired after 6-OHDA lesion and was not improved by fasudil treatment. Fasudil 100 mg/kg did not significantly increase the number of dopaminergic cells in the substantia nigra after 12 weeks versus lesion controls. Interestingly, however, high-performance liquid chromatography analysis of dopamine metabolites revealed that striatal levels of 3,4-dihydroxyphenylacetic acid were significantly increased after 12 weeks, suggesting a regenerative response. In contrast to recent findings in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridin model, fasudil effects seem limited in this severe 6-OHDA model of PD. Nevertheless, high therapeutic concentrations of fasudil are suggestive of a proregenerative potential for dopaminergic neurons, making further evaluations of rho kinase inhibition as a proregenerative therapeutic strategy in PD promising.

  14. Perinatal manganese exposure and hydroxyl radical formation in rat brain.

    PubMed

    Bałasz, Michał; Szkilnik, Ryszard; Brus, Ryszard; Malinowska-Borowska, Jolanta; Kasperczyk, Sławomir; Nowak, Damian; Kostrzewa, Richard M; Nowak, Przemysław

    2015-01-01

    The present study was designed to investigate the role of pre- and postnatal manganese (Mn) exposure on hydroxyl radical (HO(•)) formation in the brains of dopamine (DA) partially denervated rats (Parkinsonian rats). Wistar rats were given tap water containing 10,000 ppm manganese chloride during the duration of pregnancy and until the time of weaning. Control rat dams consumed tap water without added Mn. Three days after birth, rats of both groups were treated with 6-hydroxydopamine at one of three doses (15, 30, or 67 µg, intraventricular on each side), or saline vehicle. We found that Mn content in the brain, kidney, liver, and bone was significantly elevated in dams exposed to Mn during pregnancy. In neonates, the major organs that accumulated Mn were the femoral bone and liver. However, Mn was not elevated in tissues in adulthood. To determine the possible effect on generation of the reactive species, HO(•) in Mn-induced neurotoxicity, we analyzed the contents of 2.3- and 2.5-dihydroxybenzoic acid (spin trap products of salicylate; HO(•) being an index of in vivo HO(•) generation), as well as antioxidant enzyme activities of superoxide dismutase (SOD) isoenzymes and glutathione S-transferase (GST). 6-OHDA-depletion of DA produced enhanced HO(•) formation in the brain tissue of newborn and adulthood rats that had been exposed to Mn, and the latter effect did not depend on the extent of DA denervation. Additionally, the extraneuronal, microdialysate, content of HO(•) in neostriatum was likewise elevated in 6-OHDA-lesioned rats. Interestingly, there was no difference in extraneuronal HO(•) formation in the neostriatum of Mn-exposed versus control rats. In summary, findings in this study indicate that Mn crosses the placenta but in contrast to other heavy metals, Mn is not deposited long term in tissues. Also, damage to the dopaminergic system acts as a "trigger mechanism," initiating a cascade of adverse events leading to a protracted increase in

  15. Advances on genetic rat models of epilepsy.

    PubMed

    Serikawa, Tadao; Mashimo, Tomoji; Kuramoro, Takashi; Voigt, Birger; Ohno, Yukihiro; Sasa, Masashi

    2015-01-01

    Considering the suitability of laboratory rats in epilepsy research, we and other groups have been developing genetic models of epilepsy in this species. After epileptic rats or seizure-susceptible rats were sporadically found in outbred stocks, the epileptic traits were usually genetically-fixed by selective breeding. So far, the absence seizure models GAERS and WAG/Rij, audiogenic seizure models GEPR-3 and GEPR-9, generalized tonic-clonic seizure models IER, NER and WER, and Canavan-disease related epileptic models TRM and SER have been established. Dissection of the genetic bases including causative genes in these epileptic rat models would be a significant step toward understanding epileptogenesis. N-ethyl-N-nitrosourea (ENU) mutagenesis provides a systematic approach which allowed us to develop two novel epileptic rat models: heat-induced seizure susceptible (Hiss) rats with an Scn1a missense mutation and autosomal dominant lateral temporal epilepsy (ADLTE) model rats with an Lgi1 missense mutation. In addition, we have established episodic ataxia type 1 (EA1) model rats with a Kcna1 missense mutation derived from the ENU-induced rat mutant stock, and identified a Cacna1a missense mutation in a N-Methyl-N-nitrosourea (MNU)-induced mutant rat strain GRY, resulting in the discovery of episodic ataxia type 2 (EA2) model rats. Thus, epileptic rat models have been established on the two paths: 'phenotype to gene' and 'gene to phenotype'. In the near future, development of novel epileptic rat models will be extensively promoted by the use of sophisticated genome editing technologies.

  16. Advances on genetic rat models of epilepsy

    PubMed Central

    Serikawa, Tadao; Mashimo, Tomoji; Kuramoto, Takashi; Voigt, Birger; Ohno, Yukihiro; Sasa, Masashi

    2014-01-01

    Considering the suitability of laboratory rats in epilepsy research, we and other groups have been developing genetic models of epilepsy in this species. After epileptic rats or seizure-susceptible rats were sporadically found in outbred stocks, the epileptic traits were usually genetically-fixed by selective breeding. So far, the absence seizure models GAERS and WAG/Rij, audiogenic seizure models GEPR-3 and GEPR-9, generalized tonic-clonic seizure models IER, NER and WER, and Canavan-disease related epileptic models TRM and SER have been established. Dissection of the genetic bases including causative genes in these epileptic rat models would be a significant step toward understanding epileptogenesis. N-ethyl-N-nitrosourea (ENU) mutagenesis provides a systematic approach which allowed us to develop two novel epileptic rat models: heat-induced seizure susceptible (Hiss) rats with an Scn1a missense mutation and autosomal dominant lateral temporal epilepsy (ADLTE) model rats with an Lgi1 missense mutation. In addition, we have established episodic ataxia type 1 (EA1) model rats with a Kcna1 missense mutation derived from the ENU-induced rat mutant stock, and identified a Cacna1a missense mutation in a N-Methyl-N-nitrosourea (MNU)-induced mutant rat strain GRY, resulting in the discovery of episodic ataxia type 2 (EA2) model rats. Thus, epileptic rat models have been established on the two paths: ‘phenotype to gene’ and ‘gene to phenotype’. In the near future, development of novel epileptic rat models will be extensively promoted by the use of sophisticated genome editing technologies. PMID:25312505

  17. The Metabotropic Glutamate Receptor 4-Positive Allosteric Modulator VU0364770 Produces Efficacy Alone and in Combination with l-DOPA or an Adenosine 2A Antagonist in Preclinical Rodent Models of Parkinson's Disease

    PubMed Central

    Jones, Carrie K.; Bubser, Michael; Thompson, Analisa D.; Dickerson, Jonathan W.; Turle-Lorenzo, Nathalie; Amalric, Marianne; Blobaum, Anna L.; Bridges, Thomas M.; Morrison, Ryan D.; Jadhav, Satyawan; Engers, Darren W.; Italiano, Kimberly; Bode, Jacob; Daniels, J. Scott; Lindsley, Craig W.; Hopkins, Corey R.; Conn, P. Jeffrey

    2012-01-01

    Parkinson's disease (PD) is a debilitating neurodegenerative disorder associated with severe motor impairments caused by the loss of dopaminergic innervation of the striatum. Previous studies have demonstrated that positive allosteric modulators (PAMs) of metabotropic glutamate receptor 4 (mGlu4), including N-phenyl-7-(hydroxyimino)cyclopropa[b]chromen-1a-carboxamide, can produce antiparkinsonian-like effects in preclinical models of PD. However, these early mGlu4 PAMs exhibited unsuitable physiochemical properties for systemic dosing, requiring intracerebroventricular administration and limiting their broader utility as in vivo tools to further understand the role of mGlu4 in the modulation of basal ganglia function relevant to PD. In the present study, we describe the pharmacologic characterization of a systemically active mGlu4 PAM, N-(3-chlorophenyl)picolinamide (VU0364770), in several rodent PD models. VU0364770 showed efficacy alone or when administered in combination with l-DOPA or an adenosine 2A (A2A) receptor antagonist currently in clinical development (preladenant). When administered alone, VU0364770 exhibited efficacy in reversing haloperidol-induced catalepsy, forelimb asymmetry-induced by unilateral 6-hydroxydopamine (6-OHDA) lesions of the median forebrain bundle, and attentional deficits induced by bilateral 6-OHDA nigrostriatal lesions in rats. In addition, VU0364770 enhanced the efficacy of preladenant to reverse haloperidol-induced catalepsy when given in combination. The effects of VU0364770 to reverse forelimb asymmetry were also potentiated when the compound was coadministered with an inactive dose of l-DOPA, suggesting that mGlu4 PAMs may provide l-DOPA-sparing activity. The present findings provide exciting support for the potential role of selective mGlu4 PAMs as a novel approach for the symptomatic treatment of PD and a possible augmentation strategy with either l-DOPA or A2A antagonists. PMID:22088953

  18. The metabotropic glutamate receptor 4-positive allosteric modulator VU0364770 produces efficacy alone and in combination with L-DOPA or an adenosine 2A antagonist in preclinical rodent models of Parkinson's disease.

    PubMed

    Jones, Carrie K; Bubser, Michael; Thompson, Analisa D; Dickerson, Jonathan W; Turle-Lorenzo, Nathalie; Amalric, Marianne; Blobaum, Anna L; Bridges, Thomas M; Morrison, Ryan D; Jadhav, Satyawan; Engers, Darren W; Italiano, Kimberly; Bode, Jacob; Daniels, J Scott; Lindsley, Craig W; Hopkins, Corey R; Conn, P Jeffrey; Niswender, Colleen M

    2012-02-01

    Parkinson's disease (PD) is a debilitating neurodegenerative disorder associated with severe motor impairments caused by the loss of dopaminergic innervation of the striatum. Previous studies have demonstrated that positive allosteric modulators (PAMs) of metabotropic glutamate receptor 4 (mGlu₄), including N-phenyl-7-(hydroxyimino) cyclopropa[b]chromen-1a-carboxamide, can produce antiparkinsonian-like effects in preclinical models of PD. However, these early mGlu₄ PAMsexhibited unsuitable physiochemical properties for systemic dosing, requiring intracerebroventricular administration and limiting their broader utility as in vivo tools to further understand the role of mGlu₄ in the modulation of basal ganglia function relevant to PD. In the present study, we describe the pharmacologic characterization of a systemically active mGlu₄ PAM, N-(3-chlorophenyl)picolinamide (VU0364770), in several rodent PD models. VU0364770 showed efficacy alone or when administered in combination with L-DOPA or an adenosine 2A (A2A) receptor antagonist currently in clinical development (preladenant). When administered alone, VU0364770 exhibited efficacy in reversing haloperidol-induced catalepsy, forelimb asymmetry-induced by unilateral 6-hydroxydopamine (6-OHDA) lesions of the median forebrain bundle, and attentional deficits induced by bilateral 6-OHDA nigrostriatal lesions in rats. In addition, VU0364770 enhanced the efficacy of preladenant to reverse haloperidol-induced catalepsy when given in combination. The effects of VU0364770 to reverse forelimb asymmetry were also potentiated when the compound was coadministered with an inactive dose of L-DOPA, suggesting that mGlu₄ PAMs may provide L-DOPA-sparing activity. The present findings provide exciting support for the potential role of selective mGlu₄ PAMs as a novel approach for the symptomatic treatment of PD and a possible augmentation strategy with either L-DOPA or A2A antagonists.

  19. Cortex Fraxini (Qingpi) Protects Rat Pheochromocytoma Cells against 6-Hydroxydopamine-Induced Apoptosis

    PubMed Central

    Li, Jing-Jie; Zhou, Shi-Ya; Zhang, Huan; Lam, Kim-Hung; Lee, Simon Ming-Yuen; Yu, Peter Hoi-Fu; Chan, Shun-Wan

    2015-01-01

    Parkinson's disease (PD) is a chronic neurodegenerative disorder having close relationship with oxidative stress induced by reactive oxygen species (ROS). Cortex Fraxini (QP) is a kind of traditional Chinese medicinal herb with antioxidant properties. It may be a potential candidate for preventing the development of chronic neurodegenerative diseases. Thus, the key objective of the current study was to investigate the neuroprotective effect of QP water extract on 6-hydroxydopamine (6-OHDA) induced apoptosis in rat pheochromocytoma (PC12) cells. It was found that QP water extract possesses strong antioxidant property with SC50 = 0.15 mg/mL. Total phenolic content of QP water extract was found to be 200.78 ± 2.65 mg GAE/g. QP water extract's free radical scavenging capacity was demonstrated by reversing the increased level of intracellular ROS induced by 6-OHDA, using 2′,7′-dichlorodihydrofluorescein diacetate. Moreover, QP water extract (0.5 mg/mL) could remarkably increase the viability of PC12 cells treated with 6-OHDA. The protective effect of QP water extract was found to be via inhibiting MEK/ERK pathway and reversing PI3-K/Akt/GSK3β pathway. The current results suggest that QP might be a potential candidate for preventing the development of neurodegenerative diseases, such as PD. PMID:26347850

  20. Sexual behavior in male rats after radiofrequency or dopamine-depleting lesions in nucleus accumbens.

    PubMed

    Liu, Y C; Sachs, B D; Salamone, J D

    1998-06-01

    Considerable neurochemical evidence links dopamine (DA) in nucleus accumbens (NAcc) to male sexual behavior. The present experiments were conducted to extend this information to the male's sexual response to remote stimuli from estrous female (noncontact erection; NCE). Male rats were tested for copulation and NCE after either 6-hydroxydopamine (6-OHDA) or radiofrequency (RF) lesions in NAcc). Males with an average 78% depletion of DA in NAcc had a lower incidence of NCE, longer latency to display NCE, and fewer erections. DA-depleted males also had less locomotor activity after injections of d-amphetamine, and reductions in apomorphine-induced yawning, but a normal incidence of penile erection. Males with RF lesions of the NAcc had longer NCE latencies. All males copulated to ejaculation after either 6-OHDA or RF lesions with little or no deficit, although the 6-OHDA-treated males had longer intromission latencies. The NCE deficit supports the hypothesized role of NAcc DA in arousal processes in responding to remote cues from estrous females. The minimal effect of lesions on copulation suggests that the presence of additional proximal stimulation during copulation may overcome the deficits induced by DA depletions or lesions in NAcc.

  1. Behavioral sensitization to different dopamine agonists in a parkinsonian rodent model of drug-induced dyskinesias.

    PubMed

    Delfino, M A; Stefano, A V; Ferrario, J E; Taravini, I R E; Murer, M G; Gershanik, O S

    2004-07-09

    Repeated treatment with dopamine (DA) receptor agonists strongly potentiates contralateral turning behavior due to selective stimulation of D1 or D2-class receptors in 6-hydroxydopamine (6-OHDA)-lesioned rats. This phenomenon, referred to as sensitization, is believed to be related to the motor response complications (dyskinesias, on-off states) that occur during chronic administration of levodopa in Parkinson's disease patients. In recent years a new method for the evaluation of abnormal involuntary movements (AIMs) secondary to dopaminergic stimulation in 6-OHDA-lesioned rats was described. These AIMs resemble dyskinesias as seen in parkinsonian patients under levodopa therapy. Our objective was to evaluate the effects of repeated treatment with different regimes of DA agonists on turning behavior and on an AIMs scale in 6-OHDA lesioned rats, with the aim of discriminating between drugs with different dyskinesia-inducing potential. In addition, we explored the effects of a previous exposure to a DA agonist (priming) on the behavioral response to the subsequent administration of a DA agonist with the same or different pharmacologic profile. Our results show that in apomorphine-treated rats, rotational behavior and AIMs run a parallel course of enhancement, while in those receiving quinpirole there is a dissociation, suggesting that they could be mediated by different mechanisms. The finding of a significant priming effect on subsequent testing of 6-OHDA lesioned rats should be borne in mind as the use of these pharmacological tests in the screening of well lesioned animals could lead to an erroneous interpretation of further results on dyskinesias and rotational behavior. Copyright 2003 Elsevier B.V.

  2. Behavioral effects of aminochrome and dopachrome injected in the rat substantia nigra.

    PubMed

    Díaz-Véliz, G; Mora, S; Dossi, M T; Gómez, P; Arriagada, C; Montiel, J; Aboitiz, F; Segura-Aguilar, J

    2002-11-01

    The exact mechanism of cell death in neurodegenerative diseases remains obscure, although there is evidence that their pathogenesis may involve the formation of free radicals originating from the oxidative metabolism of catecholamines. The purpose of this study was to evaluate the degree of neurodegenerative changes and behavioral impairments induced by unilateral injection into the rat substantia nigra of cyclized o-quinones, aminochrome and dopachrome, derived from oxidizing dopamine and L-DOPA, respectively, with Mn(3+)-pyrophosphate complex. The behavioral changes were compared with those induced after selective lesions of dopaminergic neurons with 6-hydroxydopamine (6-OHDA). Intranigral injection of aminochrome and dopachrome produced impairment in motor and cognitive behaviors. The behavioral impairment was also revealed by apomorphine-induced rotational asymmetry. Apomorphine (0.5 mg/kg sc) significantly increased rotational behavior in rats injected with aminochrome and dopachrome. These rats presented a clear motor bias showing a significant contralateral rotation activity, similar but less vigorous that in rats injected with 6-OHDA. The avoidance conditioning was seriously impaired in rats injected with aminochrome and dopachrome although only dopachrome-injected rats showed a similar hypomotility to 6-OHDA-injected rats. The behavioral effects were correlated to the extent of striatal tyrosine hydroxylase (TH)-positive fiber loss. Rats receiving unilateral intranigral aminochrome and dopachrome injections exhibited a 47.9+/-5.1% and a 39.7+/-4.4% reduction in nigrostriatal TH-positive fiber density. In conclusion, this study provided evidence that oxidizing DA and L-DOPA to cytotoxic quinones, aminochrome and dopachrome appears to be an important mediator of oxidative damage in vivo.

  3. Dissociation of Progressive Dopaminergic Neuronal Death and Behavioral Impairments by Bax Deletion in a Mouse Model of Parkinson's Diseases

    PubMed Central

    Kim, Tae Woo; Moon, Younghye; Kim, Kyungjin; Lee, Jeong Eun; Koh, Hyun Chul; Rhyu, Im Joo; Kim, Hyun; Sun, Woong

    2011-01-01

    Parkinson's disease (PD) is a common, late-onset movement disorder with selective degeneration of dopaminergic (DA) neurons in the substantia nigra (SN). Although the neurotoxin 6-hydroxydopamine (6-OHDA) has been used to induce progressive degeneration of DA neurons in various animal models of PD, the precise molecular pathway and the impact of anti-apoptotic treatment on this neurodegeneration are less understood. Following a striatal injection of 6-OHDA, we observed atrophy and progressive death of DA neurons in wild-type mice. These degenerating DA neurons never exhibited signs of apoptosis (i.e., caspase-3 activation and cytoplasmic release of cytochrome C), but rather show nuclear translocation of apoptosis-inducing factor (AIF), a hallmark of regulated necrosis. However, mice with genetic deletion of the proapoptotic gene Bax (Bax-KO) exhibited a complete absence of 6-OHDA-induced DA neuron death and nuclear translocation of AIF, indicating that 6-OHDA-induced DA neuronal death is mediated by Bax-dependent AIF activation. On the other hand, DA neurons that survived in Bax-KO mice exhibited marked neuronal atrophy, without significant improvement of PD-related behavioral deficits. These findings suggest that anti-apoptotic therapy may not be sufficient for PD treatment, and the prevention of Bax-independent neuronal atrophy may be an important therapeutic target. PMID:22043283

  4. Treatment of Parkinson's disease in rats by Nrf2 transfection using MRI-guided focused ultrasound delivery of nanomicrobubbles.

    PubMed

    Long, Ling; Cai, Xiaodong; Guo, Ruomi; Wang, Ping; Wu, Lili; Yin, Tinghui; Liao, Siyuan; Lu, Zhengqi

    2017-01-01

    Parkinson's disease (PD) is a very common neurological disorder. However, effective therapy is lacking. Although the blood-brain-barrier (BBB) protects the brain, it prevents the delivery of about 90% of drugs and nucleotides into the brain, thereby hindering the development of gene therapy for PD. Magnetic resonance imaging (MRI)-guided focused ultrasound delivery of microbubbles enhances the delivery of gene therapy vectors across the BBB and improves transfection efficiency. In the present study, we delivered nuclear factor E2-related factor 2 (Nrf2, NFE2L2) contained in nanomicrobubbles into the substantia nigra of PD rats by MRI-guided focused ultrasound, and we examined the effect of Nrf2 over-expression in this animal model of PD. The rat model of PD was established by injecting 6-OHDA in the right substantia nigra stereotactically. Plasmids (pDC315 or pDC315/Nrf2) were loaded onto nanomicrobubbles, and then injected through the tail vein with the assistance of MRI-guided focused ultrasound. MRI-guided focused ultrasound delivery of nanomicrobubbles increased gene transfection efficiency. Furthermore, Nrf2 gene transfection reduced reactive oxygen species levels, thereby protecting neurons in the target region.

  5. TRK-820, a selective kappa opioid receptor agonist, could effectively ameliorate L-DOPA-induced dyskinesia symptoms in a rat model of Parkinson's disease.

    PubMed

    Ikeda, Ken; Yoshikawa, Satoru; Kurokawa, Takahiro; Yuzawa, Natsumi; Nakao, Kaoru; Mochizuki, Hidenori

    2009-10-12

    Long-term therapy with L-3,4-dihydroxyphenylalanine (L-DOPA) in parkinsonian patients is known to lead to dyskinesia within a few years, and repeated administration of L-DOPA is also likely to alter the expression of kappa opioid receptors in the basal ganglia, especially the striatum and substantia nigra pars reticulata, suggesting that kappa opioid receptors might be deeply involved in motor functions. Therefore, effects of TRK-820 ((E)-N-[17-(cyclopropylmethyl)-4,5alpha-epoxy-3,14-dihydroxymorphinan-6beta-yl]-3-(furan-3-yl)-N-methylprop-2-enamide monohydrochloride), a selective kappa opioid receptor agonist, were investigated on rotational behavior in unilateral 6-hydroxydopamine (6-OHDA)-treated rats (hemi-parkinsonian rats) and on L-DOPA-induced dyskinesia produced by administering L-DOPA to hemi-parkinsonian rats for 3 weeks (dyskinesia rats). A single administration of subcutaneous TRK-820 significantly increased spontaneous ipsilateral rotational behavior of hemi-parkinsonian rats at 30 microg/kg though the efficacy was moderate and also significantly inhibited L-DOPA-induced dyskinesia at 10 and 30 microg/kg; this inhibition was reversed in the presence of nor-binaltorphimine, a kappa opioid receptor antagonist. In vivo microdialysis study, TRK-820 (30 microg/kg, s.c.) significantly inhibited L-DOPA-derived extracellular dopamine content in the 6-OHDA-treated striatum in dyskinesia rats, but not in hemi-parkinsonian rats. Moreover, the development of L-DOPA-induced dyskinesia was suppressed by the 3-week co-administration of TRK-820 (3 and 10 microg/kg, s.c.) with L-DOPA. These results have suggested that TRK-820 ameliorates L-DOPA-induced dyskinesia with a moderate anti-parkinsonian effect by inhibiting L-DOPA-induced excessive dopamine release through kappa opioid receptors only in dyskinesia rats; therefore, TRK-820 is expected to become a useful agent for the treatment of L-DOPA-induced dyskinesia.

  6. Locomotor effects of imidazoline I2-site-specific ligands and monoamine oxidase inhibitors in rats with a unilateral 6-hydroxydopamine lesion of the nigrostriatal pathway

    PubMed Central

    MacInnes, Nicholas; Duty, Susan

    2004-01-01

    The present study examined the ability of the selective imidazoline I2-site ligands 2-(-2-benzofuranyl)-2-imidazoline (2-BFI) and 2-[4,5-dihydroimidaz-2-yl]-quinoline (BU224) and selected monoamine oxidase (MAO) inhibitors to evoke locomotor activity in rats bearing a lesion of the nigrostriatal pathway. Male Sprague–Dawley rats were injected with 12.5 μg 6-hydroxydopamine (6-OHDA) into the right median forebrain bundle to induce a unilateral lesion of the nigrostriatal tract. After 6 weeks, test drugs were administered either alone or in combination with L-DOPA (L-3,4-dihydroxyphenylamine) and the circling behaviour of animals was monitored as an index of anti-Parkinsonian activity. Intraperitoneal (i.p.) administration of the irreversible MAO-B inhibitor deprenyl (20 mg kg−1) or the imidazoline I2-site ligands BU224 (14 mg kg−1) and 2-BFI (7 and 14 mg kg−1) produced significant increases in ipsiversive rotations compared to vehicle controls totaling, at the highest respective doses tested, 521±120, 131±37 and 92.5±16.3 net contraversive rotations in 30 (deprenyl) or 60 (BU224 and 2-BFI) min. In contrast, the reversible MAO-A inhibitor moclobemide (2.5–10 mg kg−1) and the reversible MAO-B inhibitor lazabemide (2.5–10 mg kg−1) failed to instigate significant rotational behaviour compared to vehicle. Coadministration of lazabemide (10 mg kg−1), moclobemide (10 mg kg−1) or 2-BFI (14 mg kg−1) with L-DOPA (20 mg kg−1) significantly increased either the duration or total number of contraversive rotations emitted over the testing period in comparison to L-DOPA alone. These data suggest that I2-specific ligands have dual effects in the 6-OHDA-lesioned rat model of Parkinson's disease; a first effect associated with an increase in activity in the intact hemisphere, probably via an increase in striatal dopamine content, and a secondary action which, through the previously documented inhibition of MAO-A and/or MAO-B, increases the availability of

  7. Dual actions of (-)-stepholidine on the dopamine receptor-mediated adenylate cyclase activity in rat corpus striatum.

    PubMed

    Dong, Z J; Guo, X; Chen, L J; Han, Y F; Jin, G Z

    1997-01-01

    (-)-Stepholidine (SPD) is an antagonist of normosensitive dopamine (DA) receptors, but it exhibits D1 agonistic action on rotational behaviour in rats with unilateral 6-hydroxydopamine (6-OHDA) lesions of the substantia nigra pars compacta (SNC). In the present study, agonistic and antagonistic effects of SPD on the DA receptor-mediated synaptosomal adenylate cyclase (AC) activity in rat striatum were investigated. After blockade of D2 receptors, SPD augmented AC activity dose-dependently. The EC50 value was 41.1 +/- 8.6 micromol/L. At the concentration of 10 micromol/L, SPD increased cAMP formation from a basal level (50.8 +/- 10.3 pmol/mg protein/min) to 133.7 +/- 31.8 pmol/mg protein/min. The SPD-induced stimulation of AC activity was almost completely reversed by 10 micromol/L Sch23390. These results indicate that SPD possesses an agonistic action on the D1 receptor. Forskolin-stimulated adenylate cyclase (FSAC) activity was used as a model to elucidate the effect of SPD on D2 receptors. The results indicate that DA inhibited FSAC activity dose-dependently, while SPD partially restored FSAC activity. Taken together, these results support the conclusion that SPD has dual actions on DA receptors that mediate AC activity, i.e., an agonistic action on D1 receptors and an antagonistic action on D2 receptors.

  8. Adenoviral vector-mediated GDNF gene therapy in a rodent lesion model of late stage Parkinson's disease.

    PubMed

    Lapchak, P A; Araujo, D M; Hilt, D C; Sheng, J; Jiao, S

    1997-11-28

    A recombinant adenoviral vector encoding the human glial cell line-derived neurotrophic factor (GDNF) gene (Ad-GDNF) was used to express the neurotrophic factor GDNF in the unilaterally 6-hydroxydopamine (6-OHDA) denervated substantia nigra (SN) of adult rats ten weeks following the 6-OHDA injection. 6-OHDA lesions significantly increased apomorphine-induced (contralateral) rotations and reduced striatal and nigral dopamine (DA) levels by 99% and 70%, respectively. Ad-GDNF significantly (P < 0.01) decreased (by 30-40%) apomorphine-induced rotations in lesioned rats for up to two weeks following a single injection. Locomotor activity, assessed 7 days following the Ad-GDNF injection, was also significantly (P < 0.05) increased (by 300-400%). Two weeks after the Ad-GDNF injection, locomotor activity was still significantly increased compared to the Ad-beta-gal-injected 6-OHDA lesioned (control) group. Additionally, in Ad-GDNF-injected rats, there was a significant decrease (10-13%) in weight gain which persisted for approximately two weeks following the injection. Consistent with the behavioral changes, levels of DA and the metabolite dihydroxyphenylacetic acid (DOPAC) were elevated (by 98% and 65%, respectively) in the SN, but not the striatum of Ad-GDNF-injected rats. Overall, a single Ad-GDNF injection had significant effects for 2-3 weeks following administration. These results suggest that virally delivered GDNF promotes the recovery of nigral dopaminergic tone (i.e.: increased DA and DOPAC levels) and improves behavioral performance (i.e.: decreased rotations, increased locomotion) in rodents with extensive nigrostriatal dopaminergic denervation. Moreover, our results suggest that viral delivery of trophic factors may be used eventually to treat neurodegenerative diseases such as Parkinson's disease.

  9. [Evaluation of motor disorders in animal models of Parkinson's disease].

    PubMed

    Campos-Romo, A

    The diagnosis of Parkinson's disease is essentially clinical, that is to say, it is based on the observation of the motor alterations displayed by patients, and for this reason it is considered to be a simple matter. Yet, only 75% of the diagnoses that are carried out clinically are later confirmed in the autopsy. Animal models can be generated by systemic or intracerebral application of neurotoxins, like 6-hydroxydopamine (6-OHDA) for rats or 1-methyl-4-phenyl-1,2, 3,6-tetrahydropyridine (MPTP) for mice and non-human primates, which induce damage in the nigrostriatal dopaminergic system. This gives rise to a variety of motor symptoms such as akinesia, bradykinesia, rigidity, tremor, gait disorders and abnormal postures, which is what makes the evaluation of the changes in the signs of Parkinsonism in animal models such a challenge to researchers today. The paper reviews the variety of paradigms available for evaluating these symptoms in mouse, rat and non-human primate models, which have been used to measure the differences brought about by applying neurotoxins and, in some cases, the improvements produced by different treatments for the Parkinsonian syndromes that were induced. Both the general findings of these works and the factors that influence the trials are discussed, together with the potential problems and benefits that the experimental procedures may have.

  10. Protective effect of hesperidin in a model of Parkinson's disease induced by 6-hydroxydopamine in aged mice.

    PubMed

    Antunes, Michelle S; Goes, André T R; Boeira, Silvana P; Prigol, Marina; Jesse, Cristiano R

    2014-01-01

    Parkinson's disease (PD) may be caused by the interaction of a number of factors, including genetics, toxins, oxidative stress, mitochondrial abnormalities, and aging. Studies have shown that consumption of an antioxidant-rich diet may reduce the incidence of neurodegenerative diseases. The aim of this study was to evaluate the role of the flavonoid hesperidin in an animal model of PD induced by 6-hidroxidopamine (6-OHDA). Aged mice were treated with hesperidin (50 mg/kg) during 28 d after an intracerebroventricular injection of 6-OHDA. The enzymatic activities of superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase, and glutathione S-transferase, the levels of glutathione, reactive oxygen species, total reactive antioxidant potential, dopamine and its levels of metabolites 3,4-dihydroxyphenylacetic acid and homovanillic acid, was analyzed in the striatum. The behavioral parameters (depressive-like, memory, and locomotor) were measured. This study demonstrated that hesperidin (50 mg/kg) treatment was effective in preventing memory impairment in the Morris water maze test, as well as, depressive-like behavior in the tail suspension test. Hesperidin attenuated the 6-OHDA-induced reduction in glutathione peroxidase and catalase activity, total reactive antioxidant potential and the dopamine and its metabolite levels in the striatum of aged mice. 6-OHDA increased reactive oxygen species levels and glutathione reductase activity in the striatum, and these alterations were mitigated by chronic administration of hesperidin. This study demonstrated a protective effect of hesperidin on the neurotoxicity induced by 6-OHDA in aged mice, indicating that it could be useful as a therapy for the treatment of PD. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. PBPK MODELING OF DELTAMETHRIN IN RATS

    EPA Science Inventory

    The pyrethroid pesticide deltamethrin is cleared nearly twice as rapidly in human liver microsomes compared to rat liver microsomes. A species difference such as this could influence the toxic potency of deltamethrin between rats and humans. PBPK modeling is a tool that can be ut...

  12. PBPK MODELING OF DELTAMETHRIN IN RATS

    EPA Science Inventory

    The pyrethroid pesticide deltamethrin is cleared nearly twice as rapidly in human liver microsomes compared to rat liver microsomes. A species difference such as this could influence the toxic potency of deltamethrin between rats and humans. PBPK modeling is a tool that can be ut...

  13. Human olfactory bulb neural stem cells mitigate movement disorders in a rat model of Parkinson's disease.

    PubMed

    Marei, Hany E S; Lashen, Samah; Farag, Amany; Althani, Asmaa; Afifi, Nahla; A, Abd-Elmaksoud; Rezk, Shaymaa; Pallini, Roberto; Casalbore, Patrizia; Cenciarelli, Carlo

    2015-07-01

    Parkinson's disease (PD) is a neurological disorder characterized by the loss of midbrain dopaminergic (DA) neurons. Neural stem cells (NSCs) are multipotent stem cells that are capable of differentiating into different neuronal and glial elements. The production of DA neurons from NSCs could potentially alleviate behavioral deficits in Parkinsonian patients; timely intervention with NSCs might provide a therapeutic strategy for PD. We have isolated and generated highly enriched cultures of neural stem/progenitor cells from the human olfactory bulb (OB). If NSCs can be obtained from OB, it would alleviate ethical concerns associated with the use of embryonic tissue, and provide an easily accessible cell source that would preclude the need for invasive brain surgery. Following isolation and culture, olfactory bulb neural stem cells (OBNSCs) were genetically engineered to express hNGF and GFP. The hNFG-GFP-OBNSCs were transplanted into the striatum of 6-hydroxydopamin (6-OHDA) Parkinsonian rats. The grafted cells survived in the lesion environment for more than eight weeks after implantation with no tumor formation. The grafted cells differentiated in vivo into oligodendrocyte-like (25 ± 2.88%), neuron-like (52.63 ± 4.16%), and astrocyte -like (22.36 ± 1.56%) lineages, which we differentiated based on morphological and immunohistochemical criteria. Transplanted rats exhibited a significant partial correction in stepping and placing in non-pharmacological behavioral tests, pole and rotarod tests. Taken together, our data encourage further investigations of the possible use of OBNSCs as a promising cell-based therapeutic strategy for Parkinson's disease. © 2014 Wiley Periodicals, Inc.

  14. Gravitational Biology: The Rat Model

    NASA Technical Reports Server (NTRS)

    1997-01-01

    In this session, Session JP3, the discussion focuses on the following topics: Morphology of brain, pituitary and thyroid in the rats exposed to altered gravity; Biochemical Properties of B Adrenoceptors After Spaceflight (LMS-STS78) or Hindlimb Suspension in Rats; Influence of Hypergravity on the Development of Monoaminergic Systems in the Rat Spinal Cord; A Vestibular Evoked Potentials (VsEPs) Study of the Function of the Otolith Organs in Different Head Orientations with respect to Earth Gravity Vector in the Rat; Quantitative Observations on the Structure of Selected Proprioceptive Components in Adult Rats that Underwent About Half of their Fetal Development in Space; Effects of a Nine-Day Shuttle Mission on the Development of the Neonatal Rat Nervous System, A Behavioral Study; Muscle Atrophy Associated to Microgravity in Rat, Basic Data For Countermeasures; Simulated Weightlessness by Unloading in the Rat, Results of a Time Course Study of Biochemical Events Occurring During Unloading and Lack of Effect of a rhBNP-2 Treatment on Bone Formation and Bone Mineral Content in Unloading Rats; and Cytological Mechanism of the Osteogenesis Under Microgravity Conditions.

  15. Effects of zingerone [4-(4-hydroxy-3-methoxyphenyl)-2-butanone] and eugenol [2-methoxy-4-(2-propenyl)phenol] on the pathological progress in the 6-hydroxydopamine-induced Parkinson's disease mouse model.

    PubMed

    Kabuto, Hideaki; Yamanushi, Tomoko T

    2011-12-01

    Parkinson's disease (PD) is characterized by progressive degeneration of dopaminergic neurons in the nigrostriatal system and dopamine (DA) depletion in the striatum. The most popular therapeutic medicine for treating PD, 3-(3,4-Dihydroxyphenyl)-L-alanine (L-DOPA), has adverse effects, such as dyskinesia and disease acceleration. As superoxide (·O(2)(-)) and hydroxyl radical (·OH) have been implicated in the pathogenesis of PD, free radical scavenging and antioxidants have attracted attention as agents to prevent disease progression. Rodents injected with 6-hydroxydopamine (6-OHDA) intracerebroventricularly are considered to be a good animal model of PD. Zingerone and eugenol, essential oils extracted from ginger and cloves, are known to have free radical scavenging and antioxidant effects. Therefore, we examined the effects of zingerone and eugenol on the behavioral problems in mouse model and on the DA concentration and antioxidant activities in the striatum after 6-OHDA administration and L-DOPA treatment. Daily oral administration of eugenol/zingerone and injection of L-DOPA intraperitoneally for 4 weeks following a single 6-OHDA injection did not improve abnormal behaviors induced by L-DOPA treatment. 6-OHDA reduced the DA level in the striatum; surprisingly, zingerone and eugenol enhanced the reduction of striatal DA and its metabolites. Zingerone decreased catalase activity, and increased glutathione peroxidase activity and the oxidized L-ascorbate level in the striatum. We previously reported that pre-treatment with zingerone or eugenol prevents 6-OHDA-induced DA depression by preventing lipid peroxidation. However, the present study shows that post-treatment with these substances enhanced the DA decrease. These substances had adverse effects dependent on the time of administration relative to model PD onset. These results suggest that we should be wary of ingesting these spice elements after the onset of PD symptoms.

  16. Partial lesion of dopamine neurons of rat substantia nigra impairs conditioned place aversion but spares conditioned place preference.

    PubMed

    Lima, Bernardo F C; Ramos, Daniele C; Barbiero, Janaína K; Pulido, Laura; Redgrave, Peter; Robinson, Donita L; Gómez-A, Alexander; Da Cunha, Claudio

    2017-05-04

    Midbrain dopamine neurons play critical roles in reward- and aversion-driven associative learning. However, it is not clear whether they do this by a common mechanism or by separate mechanisms that can be dissociated. In the present study we addressed this question by testing whether a partial lesion of the dopamine neurons of the rat SNc has comparable effects on conditioned place preference (CPP) learning and conditioned place aversion (CPA) learning. Partial lesions of dopamine neurons in the rat substantia nigra pars compacta (SNc) induced by bilateral intranigral infusion of 6-hydroxydopamine (6-OHDA, 3μg/side) or 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, 200μg/side) impaired learning of conditioned place aversion (CPA) without affecting conditioned place preference (CPP) learning. Control experiments demonstrated that these lesions did not impair motor performance and did not alter the hedonic value of the sucrose and quinine. The number of dopamine neurons in the caudal part of the SNc positively correlated with the CPP scores of the 6-OHDA rats and negatively correlated with CPA scores of the SHAM rats. In addition, the CPA scores of the 6-OHDA rats positively correlated with the tissue content of striatal dopamine. Insomuch as reward-driven learning depends on an increase in dopamine release by nigral neurons, these findings show that this mechanism is functional even in rats with a partial lesion of the SNc. On the other hand, if aversion-driven learning depends on a reduction of extracellular dopamine in the striatum, the present study suggests that this mechanism is no longer functional after the partial SNc lesion.

  17. The NLRP3 Inflammasome is Involved in the Pathogenesis of Parkinson's Disease in Rats.

    PubMed

    Mao, Zhijuan; Liu, Chanchan; Ji, Suqiong; Yang, Qingmei; Ye, Hongxiang; Han, Haiyan; Xue, Zheng

    2017-04-01

    The etiology and pathogenesis of Parkinson's disease (PD) are complicated and have not been fully elucidated, but an important association has been identified between inflammation and PD. In this study, we investigated the role of the nucleotide-binding oligomerization domain, leucine rich repeat and pyrin domain-containing (NLRP) 3 inflammasome, consisting of NLRP3, caspase-1 and cytokines of the IL-1 family, in lipopolysaccharide (LPS)-induced and 6-hydroxydopamine (6-OHDA)-induced PD rats. Microinjection of different doses of caspase-1 inhibitor (Ac-YVAD-CMK, 300 or 1200 ng/rat) was performed for seven consecutive days. Then, rotational behavior, the number of dopamine (DA) neurons in the substantia nigra pars compacta (SNc), and the mRNA and protein expression levels of NLRP3 inflammasome components were measured 14 days after the microinjection setup was established. Results showed that high mRNA and protein expression levels of NLRP3 inflammasome components were observed in the injected side of the LPS- and 6-OHDA-induced PD rats; Ac-YVAD-CMK inhibited the mRNA and protein expression of NLRP3 inflammasome components in both LPS- and 6-OHDA-induced PD rats. Moreover, the number of rotations was significantly decreased, and the number of DA neurons in the SNc improved. Our data indicate that the NLRP3 inflammasome participates in the pathogenesis of PD and that inhibiting the downstream pathway of the NLRP3/caspase-1/IL-1β axis can alleviate the occurrence of PD symptoms, providing a new basis for the prevention and treatment of PD.

  18. Effect of Buspirone, Fluoxetine and 8-OH-DPAT on Striatal Expression of Bax, Caspase-3 and Bcl-2 Proteins in 6-Hydroxydopamine-Induced Hemi-Parkinsonian Rats.

    PubMed

    Sharifi, Hamdollah; Mohajjel Nayebi, Alireza; Farajnia, Safar; Haddadi, Rasool

    2015-11-01

    The exact pathogenesis of sporadic parkinson's disease (PD) is still unclear. Numerous evidences suggest involvement of apoptosis in the death of dopaminergic neurons. In this study we investigated the effect of sub-chronic administration of buspirone, fluoxetine and 8-hydroxy-2-[di-n-propylamino]tetralin (8-OH-DPAT) in 6-hydroxydopamine (6-OHDA)-lesioned rats and assayed striatal concentrations of apoptotic (Bax, Caspase3) and anti-apoptotic (Bcl-2) proteins. 6-OHDA (8μg/2μl/rat) was injected unilaterally into the central region of the substantia nigra pars copmacta (SNc) of male Wistar rats and then, after 21 days lesioned rats were treated with intraperitonel (i.p) 1 mg/kg injections of buspirone, fluoxetine and 8-OH-DPAT for 10 consecutive days. Striatum of rats was removed at tenth day of drugs administration and were analyzed by western blotting method to measure Bax, caspase3 and Bcl-2 expression. The results showed that the expression of Bax and caspase3 proteins was increased three weeks after 6-OHDA injection while they were decreased significantly in parkinsonian rats which were treated by buspirone, fluoxetine and 8-OH-DPAT. Bcl-2 was decreased and increased in parkinsonian rats and parkinsonian rats treated with buspirone, fluoxetine and 8-OH-DPAT, respectively. Our study indicates that sub-chronic administration of serotonergic drugs such as buspirone, fluoxetine and 8-OH-DPAT restores striatal concentration of apoptotic and anti-apoptotic factors to the basal levels of normal non-lesioned rats. We suggest that these drugs can be used as a potential adjunctive therapy in PD through attenuating neuronal apoptotic process.

  19. G-CSF for mobilizing transplanted bone marrow stem cells in rat model of Parkinson's disease.

    PubMed

    Safari, Manouchehr; Jafari, Behnaz; Zarbakhsh, Sam; Sameni, Hamidreza; Vafaei, Abbas Ali; Mohammadi, Nasrin Khan; Ghahari, Laya

    2016-12-01

    Granulocyte-colony stimulating factor (G-CSF) is used in clinical practice for the treatment of neutropenia and to stimulate generation of hematopoietic stem cells in bone marrow donors. In the present study, the ability of G-CSF in mobilizing exogenous bone marrow stem cells (BMSCs) from peripheral blood into the brain was tested. We for the first time injected a small amount of BMSCs through the tail vein. We choose 25 male Wistar rats (200-250 g) were lesioned by 6-OHDA injected into the left substantia nigra, pars compacta (SNpc). G-CSF (70 µg/kg/day) was given from the 7(th) day after lesion for five days. The BMSCs (2×10(5)) were injected through the dorsal tail vein on the 7(th) day after lesion. The number of rotations was significantly lower in the stem cell therapy group than in the control group. In the third test in the received G-CSF and G-CSF+stem cells groups, animals displayed significant behavioral recovery compared with the control group (P<0.05). There was a significant difference in the average of dopaminergic neurons in SNpc between the control group and G-CSF and G-CS+stem cells groups. We didn't detect any labeling stem cells in SNpc. G-CSF can't mobilize low amounts of exogenous BMSCs from the blood stream to injured SNpc. But G-CSF (70 µg/kg) is more neuroprotective than BMSCs (2×10(5) number[w1] of BMSCs). Results of our study suggest that G-CSF alone is more neuroprotective than BMSCs.

  20. Effects of Nano-MnO2 on Dopaminergic Neurons and the Spatial Learning Capability of Rats

    PubMed Central

    Li, Tao; Shi, Tingting; Li, Xiaobo; Zeng, Shuilin; Yin, Lihong; Pu, Yuepu

    2014-01-01

    This study aimed to observe the effect of intracerebrally injected nano-MnO2 on neurobehavior and the functions of dopaminergic neurons and astrocytes. Nano-MnO2, 6-OHDA, and saline (control) were injected in the substantia nigra and the ventral tegmental area of Sprague-Dawley rat brains. The neurobehavior of rats was evaluated by Morris water maze test. Tyrosine hydroxylase (TH), inducible nitric oxide synthase (iNOS) and glial fibrillary acidic protein (GFAP) expressions in rat brain were detected by immunohistochemistry. Results showed that the escape latencies of nano-MnO2 treated rat increased significantly compared with control. The number of TH-positive cells decreased, GFAP- and iNOS-positive cells increased significantly in the lesion side of the rat brains compared with the contralateral area in nano-MnO2 group. The same tendencies were observed in nano-MnO2-injected rat brains compared with control. However, in the the positive control, 6-OHDA group, escape latencies increased, TH-positive cell number decreased significantly compared with nano-MnO2 group. The alteration of spatial learning abilities of rats induced by nano-MnO2 may be associated with dopaminergic neuronal dysfunction and astrocyte activation. PMID:25101772

  1. Consensus Modeling of Oral Rat Acute Toxicity

    EPA Science Inventory

    An acute toxicity dataset (oral rat LD50) with about 7400 compounds was compiled from the ChemIDplus database. This dataset was divided into a modeling set and a prediction set. The compounds in the prediction set were selected so that they were present in the modeling set used...

  2. Consensus Modeling of Oral Rat Acute Toxicity

    EPA Science Inventory

    An acute toxicity dataset (oral rat LD50) with about 7400 compounds was compiled from the ChemIDplus database. This dataset was divided into a modeling set and a prediction set. The compounds in the prediction set were selected so that they were present in the modeling set used...

  3. Modeling Alzheimer's disease in transgenic rats.

    PubMed

    Do Carmo, Sonia; Cuello, A Claudio

    2013-10-25

    Alzheimer's disease (AD) is the most common form of dementia. At the diagnostic stage, the AD brain is characterized by the accumulation of extracellular amyloid plaques, intracellular neurofibrillary tangles and neuronal loss. Despite the large variety of therapeutic approaches, this condition remains incurable, since at the time of clinical diagnosis, the brain has already suffered irreversible and extensive damage. In recent years, it has become evident that AD starts decades prior to its clinical presentation. In this regard, transgenic animal models can shed much light on the mechanisms underlying this "pre-clinical" stage, enabling the identification and validation of new therapeutic targets. This paper summarizes the formidable efforts to create models mimicking the various aspects of AD pathology in the rat. Transgenic rat models offer distinctive advantages over mice. Rats are physiologically, genetically and morphologically closer to humans. More importantly, the rat has a well-characterized, rich behavioral display. Consequently, rat models of AD should allow a more sophisticated and accurate assessment of the impact of pathology and novel therapeutics on cognitive outcomes.

  4. A rat model for hepatitis E virus

    PubMed Central

    Mishra, Niraj; Verbeken, Erik; Ramaekers, Kaat; Dallmeier, Kai

    2016-01-01

    ABSTRACT Hepatitis E virus (HEV) is one of the prime causes of acute viral hepatitis, and chronic hepatitis E is increasingly recognized as an important problem in the transplant setting. Nevertheless, the fundamental understanding of the biology of HEV replication is limited and there are few therapeutic options. The development of such therapies is partially hindered by the lack of a robust and convenient animal model. We propose the infection of athymic nude rats with the rat HEV strain LA-B350 as such a model. A cDNA clone, pLA-B350, was constructed and the infectivity of its capped RNA transcripts was confirmed in vitro and in vivo. Furthermore, a subgenomic replicon, pLA-B350/luc, was constructed and validated for in vitro antiviral studies. Interestingly, rat HEV proved to be less sensitive to the antiviral activity of α-interferon, ribavirin and mycophenolic acid than genotype 3 HEV (a strain that infects humans). As a proof-of-concept, part of the C-terminal polymerase sequence of pLA-B350/luc was swapped with its genotype 3 HEV counterpart: the resulting chimeric replicon replicated with comparable efficiency as the wild-type construct, confirming that LA-B350 strain is amenable to humanization (replacement of certain sequences or motifs by their counterparts from human HEV strains). Finally, ribavirin effectively inhibited LA-B350 replication in athymic nude rats, confirming the suitability of the rat model for antiviral studies. PMID:27483350

  5. Serotonergic and noradrenergic pathways are required for the anxiolytic-like and antidepressant-like behavioral effects of repeated vagal nerve stimulation in rats.

    PubMed

    Furmaga, Havan; Shah, Aparna; Frazer, Alan

    2011-11-15

    Vagal nerve stimulation (VNS) is used for treatment-refractory depression, but there are few preclinical studies of its effects when administered repeatedly over time using clinically relevant stimulation parameters in nonanesthetized animals. The novelty-suppressed feeding test (NSFT) and forced swim test (FST) were used to evaluate the anxiolytic- and antidepressant-like potential of VNS in rats, respectively. The behavioral effects of VNS were compared with those of desipramine (DMI; 10 mg/kg/day) and sertraline (7.5 mg/kg/day) administered via osmotic minipump. Such experiments were carried out in intact rats as well as those that had selective destruction of either serotonin or noradrenergic neurons in brain caused by the neurotoxins, 5,7-dihyroxytryptamine (5,7-DHT), or 6-hydroxydopamine (6-OHDA). Repeated administration of VNS, DMI, and sertraline decreased latency to feed in the NSFT. In the FST, repeated VNS, DMI, and sertraline caused decreased immobility; the VNS-induced decrease in immobility resulted from increases in both swimming and climbing behaviors. Effects of VNS and sertraline, but not DMI, in both the NSFT and the FST were abolished in rats treated with 5,7-DHT. Effects of DMI in both behavioral tests, but not those of sertraline, were abolished in 6-OHDA treated rats. VNS effects on immobility and climbing in the FST were not blocked in the 6-OHDA-treated rats. There was no significant difference in locomotor activity caused by any of the treatments or by the lesions. Serotonergic nerves are required for repeated VNS-induced anxiolytic- and antidepressant-like effects. Noradrenergic nerves can also be activated by VNS to cause its anxiolytic-like effect. Copyright © 2011 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  6. Acetyl-L-Carnitine via Upegulating Dopamine D1 Receptor and Attenuating Microglial Activation Prevents Neuronal Loss and Improves Memory Functions in Parkinsonian Rats.

    PubMed

    Singh, Sonu; Mishra, Akanksha; Srivastava, Neha; Shukla, Rakesh; Shukla, Shubha

    2016-12-14

    Parkinson's disease is accompanied by nonmotor symptoms including cognitive impairment, which precede the onset of motor symptoms in patients and are regulated by dopamine (DA) receptors and the mesocorticolimbic pathway. The relative contribution of DA receptors and astrocytic glutamate transporter (GLT-1) in cognitive functions is largely unexplored. Similarly, whether microglia-derived increased immune response affects cognitive functions and neuronal survival is not yet understood. We have investigated the effect of acetyl-L-carnitine (ALCAR) on cognitive functions and its possible underlying mechanism of action in 6-hydroxydopamine (6-OHDA)-induced hemiparkinsonian rats. ALCAR treatment in 6-OHDA-lesioned rats improved memory functions as confirmed by decreased latency time and path length in the Morris water maze test. ALCAR further enhanced D1 receptor levels without altering D2 receptor levels in the hippocampus and prefrontal cortex (PFC) regions, suggesting that the D1 receptor is preferentially involved in the regulation of cognitive functions. ALCAR attenuated microglial activation and release of inflammatory mediators through balancing proinflammatory and anti-inflammatory cytokines, which subsequently enhanced the survival of mature neurons in the CA1, CA3, and PFC regions and improved cognitive functions in hemiparkinsonian rats. ALCAR treatment also improved glutathione (GSH) content, while decreasing oxidative stress indices, inducible nitrogen oxide synthase (iNOS) levels, and astrogliosis resulting in the upregulation of GLT-1 levels. Additionally, ALCAR prevented the loss of dopaminergic (DAergic) neurons in ventral tagmental area (VTA)/substantia nigra pars compacta (SNpc) regions of 6-OHDA-lesioned rats, thus maintaining the integrity of the nigrostriatal pathway. Together, these results demonstrate that ALCAR treatment in hemiparkinsonian rats ameliorates neurodegeneration and cognitive deficits, hence suggesting its therapeutic potential in

  7. Long-term survival of encapsulated GDNF secreting cells implanted within the striatum of parkinsonized rats.

    PubMed

    Grandoso, Laura; Ponce, Sara; Manuel, Ivan; Arrúe, Aurora; Ruiz-Ortega, Jose A; Ulibarri, Isabel; Orive, Gorka; Hernández, Rosa M; Rodríguez, Alicia; Rodríguez-Puertas, Rafael; Zumárraga, Mercedes; Linazasoro, Gurutz; Pedraz, Jose Luis; Ugedo, Luisa

    2007-10-01

    Several findings suggest that glial cell line-derived neurotrophic factor (GDNF) may be a useful tool to treat parkinsonism by acting as a neuroprotective and neurotrophic factor for dopaminergic neurotransmission systems. In the present study, we implanted alginate-poly-L-lysine-alginate microcapsules containing immobilized Fischer rat 3T3 fibroblasts transfected to produce GDNF in vitro into the striatum of 6-hydroxydopamine (6-OHDA) lesioned rats. Microencapsulated GDNF secreting cells were stable for at least 3 weeks in vitro. Intrastriatal implantation of microencapsulated GDNF secreting cells into 6-OHDA lesioned rats resulted in a decrease in apomorphine-induced rotations by 84%, 64%, 84%, 60% and 52% (2, 5, 8, 16 and 24 weeks, respectively) with respect to the value before implantation and with respect to the value obtained from the empty microcapsule implanted-group at each time point. Six months after transplantation, immunohistochemical detection of GDNF revealed strong immunoreactivity in the striatal tissue surrounding the microcapsules in the absence of tissue damage due to microcapsule implantation. No changes in the levels of dopamine and its metabolites or of tyrosine hydroxylase immunoreactivity were detected in the striatum. In summary, the implantation of microencapsulated GDNF secreting cells allows the delivery of this molecule into the rat striatum for at least 6 months and results in substantial behavioral improvement.

  8. The Helsinki Rat Microsurgical Sidewall Aneurysm Model

    PubMed Central

    Marbacher, Serge; Marjamaa, Johan; Abdelhameed, Essam; Hernesniemi, Juha; Niemelä, Mika; Frösen, Juhana

    2014-01-01

    Experimental saccular aneurysm models are necessary for testing novel surgical and endovascular treatment options and devices before they are introduced into clinical practice. Furthermore, experimental models are needed to elucidate the complex aneurysm biology leading to rupture of saccular aneurysms. Several different kinds of experimental models for saccular aneurysms have been established in different species. Many of them, however, require special skills, expensive equipment, or special environments, which limits their widespread use. A simple, robust, and inexpensive experimental model is needed as a standardized tool that can be used in a standardized manner in various institutions. The microsurgical rat abdominal aortic sidewall aneurysm model combines the possibility to study both novel endovascular treatment strategies and the molecular basis of aneurysm biology in a standardized and inexpensive manner. Standardized grafts by means of shape, size, and geometry are harvested from a donor rat's descending thoracic aorta and then transplanted to a syngenic recipient rat. The aneurysms are sutured end-to-side with continuous or interrupted 9-0 nylon sutures to the infrarenal abdominal aorta. We present step-by-step procedural instructions, information on necessary equipment, and discuss important anatomical and surgical details for successful microsurgical creation of an abdominal aortic sidewall aneurysm in the rat. PMID:25350840

  9. Striatal dysfunction increases basal ganglia output during motor cortex activation in parkinsonian rats.

    PubMed

    Belluscio, Mariano A; Riquelme, Luis A; Murer, M Gustavo

    2007-05-01

    During movement, inhibitory neurons in the basal ganglia output nuclei show complex modulations of firing, which are presumptively driven by corticostriatal and corticosubthalamic input. Reductions in discharge should facilitate movement by disinhibiting thalamic and brain stem nuclei while increases would do the opposite. A proposal that nigrostriatal dopamine pathway degeneration disrupts trans-striatal pathways' balance resulting in sustained overactivity of basal ganglia output nuclei neurons and Parkinson's disease clinical signs is not fully supported by experimental evidence, which instead shows abnormal synchronous oscillatory activity in animal models and patients. Yet, the possibility that variation in motor cortex activity drives transient overactivity in output nuclei neurons in parkinsonism has not been explored. In Sprague-Dawley rats with 6-hydroxydopamine (6-OHDA)-induced nigrostriatal lesions, approximately 50% substantia nigra pars reticulata (SNpr) units show abnormal cortically driven slow oscillations of discharge. Moreover, these units selectively show abnormal responses to motor cortex stimulation consisting in augmented excitations of an odd latency, which overlapped that of inhibitory responses presumptively mediated by the trans-striatal direct pathway in control rats. Delivering D1 or D2 dopamine agonists into the striatum of parkinsonian rats by reverse microdialysis reduced these abnormal excitations but had no effect on pathological oscillations. The present study establishes that dopamine-deficiency related changes of striatal function contribute to producing abnormally augmented excitatory responses to motor cortex stimulation in the SNpr. If a similar transient overactivity of basal ganglia output were driven by motor cortex input during movement, it could contribute to impeding movement initiation or execution in Parkinson's disease.

  10. Granger causality supports abnormal functional connectivity of beta oscillations in the dorsolateral striatum and substantia nigra pars reticulata in hemiparkinsonian rats.

    PubMed

    Wang, Qiang; Li, Min; Xie, Zhengyuan; Cai, Junbin; Li, Nanxiang; Xiao, Hu; Wang, Ning; Wang, Jinyan; Luo, Fei; Zhang, Wangming

    2017-08-17

    Synchronized oscillatory neuronal activity in the beta frequency range has been reported in the basal ganglia (BG) of patients with Parkinson disease (PD) and PD animal models. The coherent abnormal oscillatory activities in the dorsolateral striatum (dStr) and substantia nigra pars reticulata (SNr) that accompany parkinsonian states have not been resolved. In this study, we recorded local field potentials (LFPs) in the dStr and SNr of 6-hydroxydopamine (6-OHDA)-induced dopamine (DA)-lesioned rats in an awake, resting state. Analyses of power spectral density and coherence data demonstrated augmented LFP power in the 24-36-Hz (high beta) range in both the dStr and SNr together with increased dStr-SNr coherence in the 24-36-Hz range, relative to sham controls; both effects were reversed by levodopa (L-dopa) treatment. Partial Granger causality analysis revealed a dStr→SNr propagation directionality of these beta oscillations. These findings support the involvement of increased synchronization of high beta activity in the dStr and the SNr, and suggest that dorsolateral striatal activity plays a determinant role in leading the coherent activity with the SNr in the development of parkinsonian pathophysiology.

  11. Targeting the D1-N-methyl-D-aspartate receptor complex reduces L-dopa-induced dyskinesia in 6-hydroxydopamine-lesioned Parkinson's rats.

    PubMed

    Song, Lu; Zhang, Zhanzhao; Hu, Rongguo; Cheng, Jie; Li, Lin; Fan, Qinyi; Wu, Na; Gan, Jing; Zhou, Mingzhu; Liu, Zhenguo

    2016-01-01

    L-3,4-dihydroxyphenylalanine (L-dopa) remains the most effective therapy for Parkinson's disease (PD), but its long-term administration is associated with the development of debilitating motor complications known as L-dopa-induced dyskinesia (LID). Enhanced function of dopamine D1 receptor (D1R) and N-methyl-D-aspartate receptor (NMDAR) is believed to participate in the pathogenesis of LID. Given the existence of physical and functional interactions between D1R and NMDAR, we explored the effects of uncoupling D1R and NMDA GluN1 (GluN1) interaction on LID by using the Tat-conjugated interfering peptide (Tat-D1-t2). In this study, we demonstrated in 6-hydroxydopamine (6-OHDA)-lesioned PD rat model that intrastriatal injection of Tat-D1-t2 alleviated dyskinetic behaviors and downregulated the phosphorylation of DARPP-32 at Thr34 induced by levodopa. Moreover, we also showed intrastriatal administration of Tat-D1-t2 elicited alterations in membranous GluN1 and D1R expression. These findings indicate that D1R/GluN1 complexes may be a molecular target with therapeutic potential for the treatment of dyskinesia in Parkinson's patients.

  12. A novel thiol antioxidant that crosses the blood brain barrier protects dopaminergic neurons in experimental models of Parkinson's disease.

    PubMed

    Bahat-Stroomza, Merav; Gilgun-Sherki, Yossi; Offen, Daniel; Panet, Hana; Saada, Ann; Krool-Galron, Nili; Barzilai, Aari; Atlas, Daphne; Melamed, Eldad

    2005-02-01

    It is believed that oxidative stress (OS) plays an important role in the loss of dopaminergic nigrostriatal neurons in Parkinson's disease (PD) and that treatment with antioxidants might be neuroprotective. However, most currently available antioxidants cannot readily penetrate the blood brain barrier after systemic administration. We now report that AD4, the novel low molecular weight thiol antioxidant and the N-acytel cysteine (NAC) related compound, is capable of penetrating the brain and protects neurons in general and especially dopaminergic cells against various OS-generating neurotoxins in tissue cultures. Moreover, we found that treatment with AD4 markedly decreased the damage of dopaminergic neurons in three experimental models of PD. AD4 suppressed amphetamine-induced rotational behaviour in rats with unilateral 6-OHDA-induced nigral lesion. It attenuated the reduction in striatal dopamine levels in mice treated with 1-methyl-4-phenyl-1,2,3,6,-tetrahydropyridine (MPTP). It also reduced the dopaminergic neuronal loss following chronic intrajugular administration of rotenone in rats. Our findings suggest that AD4 is a novel potential new neuroprotective drug that might be effective at slowing down nigral neuronal degeneration and illness progression in patients with PD.

  13. Motor disorders and impaired electrical power of pallidal EEG improved by gallic acid in animal model of Parkinson's disease.

    PubMed

    Sameri, Maryam Jafar; Sarkaki, Alireza; Farbood, Yaghoub; Mansouri, Seyed Mohammad Taghi

    2011-12-15

    The aim of this study was evaluation the effect of Gallic acid on movement disorders and pallidal electrical power in animal model of Parkinson's Disease (PD). PD is clinically characterized by development of motor disturbances, such as bradykinesia, resting tremors, rigidity and a later loss ofpostural reflexes. Oxidative stress is a hallmark factor where the oxidation of dopamine generates Reactive Oxygen Species (ROS) and an unbalanced production ROS induces neuronal damage, therefor leading the neuronal death. Gallic Acid (GA) and its derivatives are present in the plant kingdom and acts as a potent antioxidant. Wistar male rats divided into seven groups randomly with 8 in each. Animals in all groups except control received 8 microg/2 microL 6-hydroxydopamine dissolved in normal saline contains 0.01% ascorbate or vehicle in right Medial Forbrain Bundle (MFB) and a bipolar wire electrode was implanted in the left globus pallidus nucleus of all animals under stereotaxic surgery. Two weeks later PD was approved by contralateral rotation signs induced by apomorphine and then movements and electrical power of pallidal were evaluated. Motor functions and pallidal electrical power were impaired and GA could improve motor dysfunctions and gamma wave power in parkinsonian rats' significantly with higher dose of GA (200 mg kg(-1)). Present result showed that GA may act as a potent antioxidant and free radical scavenger to reverse motor disorders and pallidal gamma wave power after 6-OHDA neurotoxicity in brain.

  14. Digital replantation teaching model in rats.

    PubMed

    Ad-El, D D; Harper, A; Hoffman, L A

    2000-01-01

    Replant surgery is a complex procedure that requires advanced microsurgical skills and is usually performed as an emergency operation, lasting many hours. For these reasons, teaching replantation is difficult. Although teaching models exist, they are often too general or complicated for routine use and do not simulate the stages and the pitfalls of human replant surgery. We have designed a model that is simple and imitates human replant surgery. After reviewing the rat anatomy, students dissect and replant a rat hind limb that has been sharply amputated by the instructor. They follow the same principles of "real" surgery like debridement, minimizing ischemia time, and stable fixation before anatomosis of vessels. After marking the structures, bony fixation followed by vessel and nerve anastomosis are performed. Muscle is reattached to the skin and limb vascularity evaluated. After we designed this model, plastic surgery residents performed the technique on 10 rats. An 80% limb viability rate was achieved. This model is simple to perform, simulates all the relevant structures and pitfalls of human surgery, and the rats are relatively cheap and can be used for other parallel projects.

  15. Pharmacologically controlled, discontinuous GDNF gene therapy restores motor function in a rat model of Parkinson's disease.

    PubMed

    Tereshchenko, Julia; Maddalena, Andrea; Bähr, Mathias; Kügler, Sebastian

    2014-05-01

    Neurotrophic factors have raised hopes to be able to cure symptoms and to prevent progressive neurodegeneration in devastating neurological diseases. Gene therapy by means of viral vectors can overcome the hurdle of targeted delivery, but its current configuration is irreversible and thus much less controllable than that of classical pharmacotherapies. We thus aimed at developing a strategy allowing for both curative and controllable neurotrophic factor expression. Therefore, the short-term, intermittent and reversible expression of a neutrophic factor was evaluated for therapeutic efficacy in a slowly progressive animal model of Parkinson's disease (PD). We demonstrate that short-term induced expression of glial cell line derived neurotrophic factor (GDNF) is sufficient to provide i) substantial protection of nigral dopaminergic neurons from degeneration and ii) restoration of dopamine supply and motor behaviour in the partial striatal 6-OHDA model PD. These neurorestorative effects of GDNF lasted several weeks beyond the time of its expression. Later on, therapeutic efficacy ceased, but was restored by a second short induction of GDNF expression, demonstrating that monthly application of the inducing drug mifepristone was sufficient to maintain neuroprotective and neurorestorative GDNF levels. These findings suggest that forthcoming gene therapies for PD or other neurodegenerative disorders can be designed in a way that low frequency application of an approved drug can provide controllable and therapeutically efficient levels of GDNF or other neurotrophic factors. Neurotrophic factor expression can be withdrawn in case of off-target effects or sufficient clinical benefit, a feature that may eventually increase the acceptance of gene therapy for less advanced patients, which may profit better from such approaches. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Repeated administration of the monoamine reuptake inhibitor BTS 74 398 induces ipsilateral circling in the 6-hydroxydopamine lesioned rat without sensitizing motor behaviours.

    PubMed

    Lane, E L; Cheetham, S C; Jenner, P

    2005-01-01

    BTS 74 398 (1-[1-(3,4-dichlorophenyl)cyclobutyl]-2-(3-diaminethylaminopropylthio)ethanone monocitrate) is a monoamine reuptake inhibitor that reverses motor deficits in MPTP-treated (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) common marmosets without provoking established dyskinesia. However, it is not known whether BTS 74 398 primes the basal ganglia for dyskinesia induction. In this study, the ability of BTS 74 398 to sensitize 6-hydroxydopamine (6-OHDA)-lesioned rats for the production of abnormal motor behaviours and the induction of striatal DeltaFosB were determined in comparison with l-3,4-dihydroxyphenylalanine methyl ester (L-dopa). Acute administration of BTS 74 398 induced a dose-dependent ipsilateral circling response in unilaterally 6-OHDA-lesioned rats whereas L-dopa produced dose-dependent contraversive rotation. The ipsilateral circling response to BTS 74 398 did not alter during 21 days of administration. In contrast, L-dopa treatment for 21 days caused a marked increase in rotational response. Repeated administration of both L-dopa and BTS 74 398 increased general motor activity and stereotypic behaviour. In L-dopa-treated rats, orolingual, locomotive, forelimb and axial abnormal movements developed whereas BTS 74 398 produced only locomotion with a side bias but no other abnormal movements. Sensitization of circling responses and the development of abnormal movements in 6-OHDA-lesioned rats have been associated with the potential of dopaminergic drugs to induce dyskinesia. Furthermore, striatal DeltaFosB immunoreactivity, shown to correlate with dyskinesia induction, was increased by L-dopa but was unaffected by repeated BTS 74 398 administration. The lack of such changes following repeated BTS 74 398 treatment suggests that it may be an effective antiparkinsonian therapy that is unlikely to produce involuntary movements.

  17. Dopamine-dependent modulation of rat globus pallidus excitation by nicotine acetylcholine receptors.

    PubMed

    Ríos, Alain; Barrientos, Rafael; Alatorre, Alberto; Delgado, Alfonso; Perez-Capistran, Teresa; Chuc-Meza, Eliezer; García-Ramirez, Martha; Querejeta, Enrique

    2016-02-01

    The globus pallidus (GP) coordinates information processing in the basal ganglia nuclei. The contribution of nicotinic cholinergic receptors (nAChRs) to the spiking activity of GP neurons is largely unknown. Several studies have reported that the effect of nAChRs in other nuclei depends on dopaminergic input. Via in vivo single unit extracellular recordings and intranuclear drug infusions, we analyzed the effects of local activation and blockade of nAChRs in neurons of both sham and 6-hydroxydopamine (6-OHDA)-lesioned rats. In sham rats, the local application of nicotine and edrophonium (an acetylcholinesterase inhibitor) increases GP neurons spiking rate. Local application of mecamylamine, a neuronal nicotinic cholinergic antagonist, diminishes pallidal neurons spiking rate, an effect not produced by d-tubocurarine, a peripheral nicotinic cholinergic antagonist. Moreover, mecamylamine blocks the excitatory effect evoked by nicotine and edrophonium. In 6-OHDA-lesioned rats, local infusion of nicotine does not change pallidal neurons firing rate. Our results show that there is a tonic cholinergic input to the GP that increases their spiking rate through the activation of nAChRs and that this effect depends on functional dopaminergic pathways.

  18. [Effect of astaxanthin on preeclampsia rat model].

    PubMed

    Xuan Rong-rong; Gao Xin; Wu, Wei; Chen, Hai-min

    2014-10-01

    The effect of astaxanthin on N(Ω)-nitro-L-arginine methyl ester (L-NAME) induced preeclampsia disease rats was investigated. Thirty pregnant Sprague-Dawley rats were randomly divided into three groups (n = 10): blank group, L-NAME group and astaxanthin group. From day 5 to 20, astaxanthin group rats were treated with astaxanthin (25 mg x kg(-1) x d(-1) x bw(-1)) from pregnancy (day 5). To establish the preeclamptic rat model, L-NAME group and astaxanthin group rats were injected with L-NAME (125 mg x kg(-1) x d(-1) x bw(-1)) from days 10-20 of pregnancy. The blood pressure and urine protein were recorded. Serum of each group was collected and malondialdehyde (MDA), superoxide dismutase (SOD) and nitric oxide synthase (NOS) activities were analyzed. Pathological changes were observed with HE stain. The expression of NF-κB (nuclear factor kappa B), ROCK II (Rho-associated protein kinase II), HO-1 (heme oxygenase-1) and Caspase 3 were analyzed with immunohistochemistry. L-NAME induced typical preeclampsia symptoms, such as the increased blood pressure, urinary protein, the content of MDA, etc. Astaxanthin significantly reduced the blood pressure (P < 0.01), the content of MDA (P < 0.05), and increased the activity of SOD (P < 0.05) of preeclampsia rats. The urinary protein, NO, and NOS were also decreased. HE stain revealed that after treated with astaxanthin, the thickness of basilal membrane was improved and the content of trophoblast cells and spiral arteries was reduced. Immunohistochemistry results revealed that the expressions of NF-κB, ROCK II and Caspase 3 in placenta tissue were effectively decreased, and HO-1 was increased. Results indicated that astaxanthin can improve the preeclampsia symptoms by effectively reducing the oxidative stress and inflammatory damages of preeclampsia. It revealed that astaxanthin may be benefit for prevention and treatment of preeclampsia disease.

  19. On the rat model of human osteopenias and osteoporoses

    NASA Technical Reports Server (NTRS)

    Frost, Harold M.; Jee, Webster S. S.

    1992-01-01

    The idea that rats cannot model human osteopenias errs. The same mechanisms control gains in bone mass (longitudinal bone growth and modeling drifts) and losses (BMU-based remodeling), in young and aged rats and humans. Furthermore, they respond similarly in rats and man to mechanical influences, hormones, drugs and other agents.

  20. On the rat model of human osteopenias and osteoporoses

    NASA Technical Reports Server (NTRS)

    Frost, Harold M.; Jee, Webster S. S.

    1992-01-01

    The idea that rats cannot model human osteopenias errs. The same mechanisms control gains in bone mass (longitudinal bone growth and modeling drifts) and losses (BMU-based remodeling), in young and aged rats and humans. Furthermore, they respond similarly in rats and man to mechanical influences, hormones, drugs and other agents.

  1. The Impact of Exercise on the Vulnerability of Dopamine Neurons to Cell Death in Animal Models of Parkinson’s Disease

    DTIC Science & Technology

    2006-07-01

    and methamphetamine Our basic assumption is that protective treatments alter both post-translational and translational events so as to reduce the...the MN9D cells, which included changes in gene expression, alterations in protein synthesis , and post-translational state. Although we have not yet...cellular models. • Identified several of the mechanisms underlying preconditioning by 6-OHDA and methamphetamine in an in vitro model. • Replicated

  2. Intrastriatal injection of botulinum neurotoxin-A is not cytotoxic in rat brain - A histological and stereological analysis.

    PubMed

    Mehlan, Juliane; Brosig, Hans; Schmitt, Oliver; Mix, Eilhard; Wree, Andreas; Hawlitschka, Alexander

    2016-01-01

    Parkinson's disease (PD) is caused by progressive degeneration of dopaminergic neurons in the substantia nigra pars compacta, resulting in a deficiency of dopamine in the striatum and an increased release of acetylcholine by tonically active interneurons. Botulinum neurotoxin-A (BoNT-A) is well known for blocking transmitter release by cholinergic presynaptic terminals. Treating striatal hypercholinism by local application of BoNT-A could be a possible new local therapy option of PD. In previous studies of our group, we analyzed the effect of BoNT-A injection into the CPu of 6-OHDA lesioned hemiparkinsonian rats. Our studies showed that BoNT-A application in hemiparkinson rat model is capable of abolishing apomorphine induced rotations for approximately 3 months. Regularly occurring axonal swellings in the BoNT-A infiltrated striata were also discovered, which we named BoNT-A induced varicosities (BiVs). Résumé: Here we investigated the long-term effect of the injection of 1ng BoNT-A into the right CPu of naive Wistar rats on the number of ChAT-ir interneurons as well as on the numeric density and the volumetric size of the BiVs in the CPu. Significant differences in the number of ChAT-ir neurons between the right BoNT-A treated CPu and the left untreated CPu were not detected up to 12 month post BoNT-A injection. The numeric density of BiVs in the treated CPu reached a maximum 3 months after BoNT-A treatment and decreased afterwards, whereas the volume of single BiVs increased steadily throughout the whole time course of the experiment.

  3. [Research of modified rat laryngeal transplantation model].

    PubMed

    Li, Hao; Peng, Han-wei; Zeng, Zong-yuan; Guo, Zhu-ming

    2006-07-01

    To study modified rat laryngeal transplantation model. Eighty isogeneic histocompatible F344 rats were randomized into control and experimental groups. Strome model of laryngeal transplantation was established in the the control group, and in the experimental group, the ascending pharyngeal artery was preserved and the base of the tongue, larynx and pharyngolarynx were harvested as a complex allograft followed by end-to-end anastomosis of the both allograft common carotid arteries with the recipient common carotid artery and the anterior jugular vein, respectively. The arterial and nenous patency rate and allograft viability rate were compared between the two groups. The artery and vein patency rates and graft survival rate were 30%, 15%, and 30% in the control group, and 75%, 65%, and 80% in the experimental group, respectively, showing significant difference between the two groups (P<0.05). In modified rat laryngeal transplantation model, the allograft viability rate and vessel patency rate are improved, which provides a good model for immunological study of larynx transplantation.

  4. Neuroprotective effects of swimming training in a mouse model of Parkinson's disease induced by 6-hydroxydopamine.

    PubMed

    Goes, A T R; Souza, L C; Filho, C B; Del Fabbro, L; De Gomes, M G; Boeira, S P; Jesse, C R

    2014-01-03

    Parkinson's disease (PD) is characterized by progressive dopamine (DA) depletion in the striatum. Exercise has been shown to be a promising non-pharmacological approach to reduce the risk of neurodegeneration diseases. This study was designed to investigate the potential neuroprotective effect of swimming training (ST) in a mouse model of PD induced by 6-hydroxydopamine (6-OHDA) in mice. The present study demonstrated that a 4-week ST was effective in attenuating the following impairments resulting from 6-OHDA exposure: (i) depressive-like behavior in the tail suspension test; (ii) increase in the number of falls in the rotarod test; (iii) impairment on long-term memory in the object recognition test; (iv) increase of the reactive species and interleukin 1-beta (IL-1β) levels; (v) inhibition of the glutathione peroxidase (GPx) activity; (vi) rise of the glutathione reductase (GR) and glutathione S-transferase (GST) activities and vii) decrease of DA, homovanillic acid (HVA) and 3,4-dihydroxyphenylacetic acid (DOPAC) le