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Sample records for mouse substantia nigra

  1. Bilateral upregulation of α-synuclein expression in the mouse substantia nigra by intracranial rotenone treatment.

    PubMed

    Carriere, Candace H; Kang, Na Hyea; Niles, Lennard P

    2017-02-01

    The pesticide rotenone has been shown to cause systemic inhibition of mitochondrial complex I activity, with consequent degeneration of dopamine neurons along the nigrostriatal pathway, as observed in Parkinson's disease (PD). Recently, intracranial infusion of rotenone was found to increase the protein levels of the Lewy body constituents, α-synuclein and small ubiquitin-related modifier-1(SUMO-1), in the lesioned hemisphere of the mouse brain. These findings are supportive of a mouse model of PD, but information about the dopamine-synthesizing enzyme, tyrosine hydroxylase (TH), an essential marker of dopaminergic status, was not reported. Clarification of this issue is important because an intracranial rotenone mouse model of Parkinson's disease has not been established. Towards this end, the present study examined the effects of intracranial rotenone treatment on TH and α-synuclein immunohistochemistry in addition to forelimb motor function. Mice were unilaterally infused with either vehicle or rotenone (2μg/site) in both the medial forebrain bundle and the substantia nigra. The forelimb asymmetry (cylinder) test indicated a significant decrease in use of the contralateral forelimb in lesioned animals as compared to the sham group. Densitometric analysis revealed a significant depletion of TH immunofluorescence within the ipsilateral striatum and substantia nigra of lesioned animals. Moreover, a significant bilateral increase in α-synuclein immunofluorescence was found in the substantia nigra of lesioned mice, as compared to control animals. These findings indicate that this intracranial rotenone mouse model will be useful for studies of neurodegenerative disorders such as PD. Copyright © 2016 Elsevier GmbH. All rights reserved.

  2. On the properties of identified dopaminergic neurons in the mouse substantia nigra and ventral tegmental area.

    PubMed

    Krashia, Paraskevi; Martini, Alessandro; Nobili, Annalisa; Aversa, Daniela; D'Amelio, Marcello; Berretta, Nicola; Guatteo, Ezia; Mercuri, Nicola Biagio

    2017-01-01

    We studied the properties of dopaminergic neurons in the substantia nigra pars compacta (SNpc) and ventral tegmental area (VTA) in mice expressing the enhanced green fluorescent protein (eGFP) under the control of the tyrosine hydroxylase promoter (TH-GFP). By using a practical map of cell positioning in distinct SNpc and VTA subregions in horizontal midbrain slices we saw that the spontaneous firing, membrane properties, cell body size and magnitude of the hyperpolarization-activated current (Ih ) in TH-GFP-positive neurons (TH-GFP(+) ) vary significantly among subregions, following a mediolateral gradient. Block of Ih with Zd7288 inhibited firing in the most lateral subregions, but had little effect in the intermediate/medial VTA. In addition, TH-GFP(+) cells were excited by Met(5) -Enkephalin. Extracellular recordings from a large neuron number showed that all TH-GFP(+) cells were inhibited by dopamine, suggesting that this is a reliable approach for identifying dopaminergic neurons in vitro. Simultaneous recordings from dopamine-sensitive and dopamine-insensitive neurons showed that dopamine-insensitive cells (putative non-dopaminergic neurons) are unaffected by Zd7288 but inhibited by Met(5) -Enkephalin. Under patch-clamp, dopamine generated a quantitatively similar outward current in most TH-GFP(+) neurons, although medial VTA cells showed reduced dopamine sensitivity. Pargyline prolonged the dopamine current, whereas cocaine enhanced dopamine-mediated responses in both the SNpc and the VTA. Our work provides new insights into the variability in mouse midbrain dopaminergic neurons along the medial-lateral axis and points to the necessity of a combination of different electrophysiological and pharmacological approaches for reliably identifying these cells to distinguish them from non-dopaminergic neurons in the midbrain.

  3. Neuroprotection and neuronal differentiation studies using substantia nigra dopaminergic cells derived from transgenic mouse embryos.

    PubMed

    Son, J H; Chun, H S; Joh, T H; Cho, S; Conti, B; Lee, J W

    1999-01-01

    The major pathological lesion of Parkinson's disease (PD) is the selective cell death of dopaminergic (DA) neurons in substantia nigra (SN). Although the initial cause and subsequent molecular signaling mechanisms leading to DA cell death underlying the PD process remain elusive, brain-derived neurotrophic factor (BDNF) is thought to exert neuroprotective as well as neurotrophic roles for the survival and differentiation of DA neurons in SN. Addressing molecular mechanisms of BDNF action in both primary embryonic mesencephalic cultures and in vivo animal models has been technically difficult because DA neurons in SN are relatively rare and present with many heterogeneous cell populations in midbrain. We have developed and characterized a DA neuronal cell line of embryonic SN origin that is more accessible to molecular analysis and can be used as an in vitro model system for studying SN DA neurons. A clonal SN DA neuronal progenitor cell line SN4741, arrested at an early DA developmental stage, was established from transgenic mouse embryos containing the targeted expression of the thermolabile SV40Tag in SN DA neurons. The phenotypic and morphological differentiation of the SN4741 cells could be manipulated by environmental cues in vitro. Exogenous BDNF treatment produced significant neuroprotection against 1-methyl-4-phenylpyridinium, glutamate, and nitric oxide-induced neurotoxicity in the SN4741 cells. Simultaneous phosphorylation of receptor tyrosine kinase B accompanied the neuroprotection. This SN DA neuronal cell line provides a unique model system to circumvent the limitations associated with primary mesencephalic cultures for the elucidation of molecular mechanisms of BDNF action on DA neurons of the SN.

  4. Dopaminergic Neurodegeneration in the Mouse Is Associated with Decrease of Viscoelasticity of Substantia Nigra Tissue

    PubMed Central

    Hain, Elisabeth G.; Klein, Charlotte; Munder, Tonia; Braun, Juergen; Riek, Kerstin; Mueller, Susanne; Sack, Ingolf; Steiner, Barbara

    2016-01-01

    The biomechanical properties of brain tissue are altered by histopathological changes due to neurodegenerative diseases like Parkinson's disease (PD). Such alterations can be measured by magnetic resonance elastography (MRE) as a non-invasive technique to determine viscoelastic parameters of the brain. Until now, the correlation between histopathological mechanisms and observed alterations in tissue viscoelasticity in neurodegenerative diseases is still not completely understood. Thus, the objective of this study was to evaluate (1) the validity of MRE to detect viscoelastic changes in small and specific brain regions: the substantia nigra (SN), midbrain and hippocampus in a mouse model of PD, and (2) if the induced dopaminergic neurodegeneration and inflammation in the SN is reflected by local changes in viscoelasticity. Therefore, MRE measurements of the SN, midbrain and hippocampus were performed in adult female mice before and at five time points after 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridin hydrochloride (MPTP) treatment specifically lesioning dopaminergic neurons in the SN. At each time point, additional mice were utilized for histological analysis of the SN. After treatment cessation, we observed opposed viscoelastic changes in the midbrain, hippocampus and SN with the midbrain showing a gradual rise and the hippocampus a distinct transient increase of viscous and elastic parameters, while viscosity and–to a lesser extent—elasticity in the SN decreased over time. The decrease in viscosity and elasticity in the SN was paralleled by a reduced number of neurons due to the MPTP-induced neurodegeneration. In conclusion, MRE is highly sensitive to detect local viscoelastic changes in specific and even small brain regions. Moreover, we confirmed that neuronal cells likely constitute the backbone of the adult brain mainly accounting for its viscoelasticity. Therefore, MRE could be established as a new potential instrument for clinical evaluation and

  5. Bursting Activity of Substantia Nigra pars Reticulata Neurons in Mouse Parkinsonism in Awake and Anesthetized States

    PubMed Central

    Lobb, CJ; Jaeger, D

    2015-01-01

    Electrophysiological changes in basal ganglia neurons are hypothesized to underlie motor dysfunction in Parkinson’s disease (PD). Previous results in head-restrained MPTP-treated non-human primates have suggested that increased bursting within the basal ganglia and related thalamic and cortical areas may be a hallmark of pathophysiological activity. In this study, we investigated whether there is increased bursting in substantia nigra pars reticulata (SNpr) output neurons in anesthetized and awake, head-restrained unilaterally lesioned 6-OHDA mice when compared to control mice. Confirming previous studies, we show that there are significant changes in the firing rate and pattern in SNpr neuron activity under urethane anesthesia. The regular firing pattern of control urethane-anesthetized SNpr neurons was not present in the 6-OHDA-lesioned group, as the latter neurons instead became phase locked with cortical slow wave activity (SWA). Next, we examined whether such robust electrophysiological changes between groups carried over to the awake state. SNpr neurons from both groups fired at much higher frequencies in the awake state than in the anesthetized state and surprisingly showed only modest changes between awake control and 6-OHDA groups. While there were no differences in firing rate between groups in the awake state, an increase in the coefficient of variation (CV) was observed in the 6-OHDA group. Contrary to the bursting hypothesis, this increased CV was not due to changes in bursting but was instead due to a mild increase in pausing. Together, these results suggest that differences in SNpr activity between control and 6-OHDA lesioned mice may be strongly influenced by changes in network activity during different arousal and behavioral states. PMID:25576395

  6. Cell survival and differentiation with nanocrystalline glass-like carbon using substantia nigra dopaminergic cells derived from transgenic mouse embryos

    PubMed Central

    Romero, Pablo; Estivill-Torrús, Guillermo; Guzmán de Villoria, Roberto

    2017-01-01

    Regenerative medicine requires, in many cases, physical supports to facilitate appropriate cellular architecture, cell polarization and the improvement of the correct differentiation processes of embryonic stem cells, induced pluripotent cells or adult cells. Because the interest in carbon nanomaterials has grown within the last decade in light of a wide variety of applications, the aim of this study was to test and evaluate the suitability and cytocompatibility of a particular nanometer-thin nanocrystalline glass-like carbon film (NGLC) composed of curved graphene flakes joined by an amorphous carbon matrix. This material is a disordered structure with high transparency and electrical conductivity. For this purpose, we used a cell line (SN4741) from substantia nigra dopaminergic cells derived from transgenic mouse embryos. Cells were cultured either in a powder of increasing concentrations of NGLC microflakes (82±37μm) in the medium or on top of nanometer-thin films bathed in the same culture medium. The metabolism activity of SN4741 cells in presence of NGLC was assessed using methylthiazolyldiphenyl-tetrazolium (MTT) and apoptosis/necrosis flow cytometry assay respectively. Growth and proliferation as well as senescence were demonstrated by western blot (WB) of proliferating cell nuclear antigen (PCNA), monoclonal phosphorylate Histone 3 (serine 10) (PH3) and SMP30 marker. Specific dopaminergic differentiation was confirmed by the WB analysis of tyrosine hydroxylase (TH). Cell maturation and neural capability were characterized using specific markers (SYP: synaptophysin and GIRK2: G-protein-regulated inward-rectifier potassium channel 2 protein) via immunofluorescence and coexistence measurements. The results demonstrated cell positive biocompatibility with different concentrations of NGLC. The cells underwent a process of adaptation of SN4741 cells to NGLC where their metabolism decreases. This process is related to a decrease of PH3 expression and

  7. Cell survival and differentiation with nanocrystalline glass-like carbon using substantia nigra dopaminergic cells derived from transgenic mouse embryos.

    PubMed

    Rodriguez-Losada, Noela; Romero, Pablo; Estivill-Torrús, Guillermo; Guzmán de Villoria, Roberto; Aguirre, Jose A

    2017-01-01

    Regenerative medicine requires, in many cases, physical supports to facilitate appropriate cellular architecture, cell polarization and the improvement of the correct differentiation processes of embryonic stem cells, induced pluripotent cells or adult cells. Because the interest in carbon nanomaterials has grown within the last decade in light of a wide variety of applications, the aim of this study was to test and evaluate the suitability and cytocompatibility of a particular nanometer-thin nanocrystalline glass-like carbon film (NGLC) composed of curved graphene flakes joined by an amorphous carbon matrix. This material is a disordered structure with high transparency and electrical conductivity. For this purpose, we used a cell line (SN4741) from substantia nigra dopaminergic cells derived from transgenic mouse embryos. Cells were cultured either in a powder of increasing concentrations of NGLC microflakes (82±37μm) in the medium or on top of nanometer-thin films bathed in the same culture medium. The metabolism activity of SN4741 cells in presence of NGLC was assessed using methylthiazolyldiphenyl-tetrazolium (MTT) and apoptosis/necrosis flow cytometry assay respectively. Growth and proliferation as well as senescence were demonstrated by western blot (WB) of proliferating cell nuclear antigen (PCNA), monoclonal phosphorylate Histone 3 (serine 10) (PH3) and SMP30 marker. Specific dopaminergic differentiation was confirmed by the WB analysis of tyrosine hydroxylase (TH). Cell maturation and neural capability were characterized using specific markers (SYP: synaptophysin and GIRK2: G-protein-regulated inward-rectifier potassium channel 2 protein) via immunofluorescence and coexistence measurements. The results demonstrated cell positive biocompatibility with different concentrations of NGLC. The cells underwent a process of adaptation of SN4741 cells to NGLC where their metabolism decreases. This process is related to a decrease of PH3 expression and

  8. Specific vulnerability of substantia nigra compacta neurons.

    PubMed

    Smidt, Marten P

    2009-01-01

    The specific loss of substantia nigra compacta (SNc) neurons in Parkinson's disease (PD) has been the main driving force in initiating research efforts to unravel the apparent SNc-specific vulnerability. Initially, metabolic constraints due to high dopamine turnover have been the main focus in the attempts to solve this issue. Recently, it has become clear that fundamental differences in the molecular signature are adding to the neuronal vulnerability and provide specific molecular dependencies. Here, the different processes that define the molecular background of SNc vulnerability are summarized.

  9. Light pigmentation phenotype is correlated with increased substantia nigra echogenicity.

    PubMed

    Rumpf, Jost-Julian; Schirmer, Maria; Fricke, Christopher; Weise, David; Wagner, Justinus Aspasios; Simon, Jan; Classen, Joseph

    2015-11-01

    This study was undertaken to address the question of whether pigmentation may be mechanistically linked with Parkinson's disease. In a cross-sectional, observational study, 116 healthy subjects received transcranial sonography of the substantia nigra. Pigmentation phenotype was assessed using the Fitzpatrick skin phototype classification, and five additional phenotypic pigmentation traits as well as a photographic method (Melanin index) in a subgroup of 46 subjects. Lighter skin phototype was associated with larger echogenic substantia nigra area and increased prevalence of abnormally enlarged echogenic substantia nigra area. The strongest association of substantia nigra echogenicity and phenotypic pigmentation traits was found for hair color and facial tanning. Findings suggest an increasing prevalence of structural abnormality of substantia nigra with decreasing darkness of skin and thus may provide additional evidence in favor of a pathogenic link of pigmentation and Parkinson's disease. © 2015 International Parkinson and Movement Disorder Society.

  10. Complex I, iron, and ferritin in Parkinson's disease substantia nigra.

    PubMed

    Mann, V M; Cooper, J M; Daniel, S E; Srai, K; Jenner, P; Marsden, C D; Schapira, A H

    1994-12-01

    Elevated iron levels, enhanced oxidative damage, and complex I deficiency have been identified in the substantia nigra of Parkinson's disease patients. To understand the interrelationship of these abnormalities, we analyzed iron levels, ferritin levels, and complex I activity in the substantia nigra of patients with Parkinson's disease. Total iron levels were increased significantly, ferritin levels were unchanged, and complex I activities were decreased significantly in the substantia nigra samples. The failure of ferritin levels to increase with elevated iron concentrations suggests that the amount of reactive iron may increase in the substantia nigra of Parkinson's disease patients. There was no correlation between the iron levels and complex I activity or the iron-ferritin ratio and complex I activity in the substantia nigra samples.

  11. rAAV2/7 vector-mediated overexpression of alpha-synuclein in mouse substantia nigra induces protein aggregation and progressive dose-dependent neurodegeneration

    PubMed Central

    2013-01-01

    Background Alpha-synuclein is a key protein implicated in the pathogenesis of Parkinson's disease (PD). It is the main component of the Lewy bodies, a cardinal neuropathological feature in the disease. In addition, whole locus multiplications and point mutations in the gene coding for alpha-synuclein lead to autosomal dominant monogenic PD. Over the past decade, research on PD has impelled the development of new animal models based on alpha-synuclein. In this context, transgenic mouse lines have failed to reproduce several hallmarks of PD, especially the strong and progressive dopaminergic neurodegeneration over time that occurs in the patients. In contrast, viral vector-based models in rats and non-human primates display prominent, although highly variable, nigral dopaminergic neuron loss. However, the few studies available on viral vector-mediated overexpression of alpha-synuclein in mice report a weak neurodegenerative process and no clear Lewy body-like pathology. To address this issue, we performed a comprehensive comparative study of alpha-synuclein overexpression by means of recombinant adeno-associated viral vectors serotype 2/7 (rAAV2/7) at different doses in adult mouse substantia nigra. Results We noted a significant and dose-dependent alpha-synucleinopathy over time upon nigral viral vector-mediated alpha-synuclein overexpression. We obtained a strong, progressive and dose-dependent loss of dopaminergic neurons in the substantia nigra, reaching a maximum of 82% after 8 weeks. This effect correlated with a reduction in tyrosine hydroxylase immunoreactivity in the striatum. Moreover, behavioural analysis revealed significant motor impairments from 12 weeks after injection on. In addition, we detected the presence of alpha-synuclein-positive aggregates in the remaining surviving neurons. When comparing wild-type to mutant A53T alpha-synuclein at the same vector dose, both induced a similar degree of cell death. These data were supported by a biochemical

  12. rAAV2/7 vector-mediated overexpression of alpha-synuclein in mouse substantia nigra induces protein aggregation and progressive dose-dependent neurodegeneration.

    PubMed

    Oliveras-Salvá, Marusela; Van der Perren, Anke; Casadei, Nicolas; Stroobants, Stijn; Nuber, Silke; D'Hooge, Rudi; Van den Haute, Chris; Baekelandt, Veerle

    2013-11-25

    Alpha-synuclein is a key protein implicated in the pathogenesis of Parkinson's disease (PD). It is the main component of the Lewy bodies, a cardinal neuropathological feature in the disease. In addition, whole locus multiplications and point mutations in the gene coding for alpha-synuclein lead to autosomal dominant monogenic PD. Over the past decade, research on PD has impelled the development of new animal models based on alpha-synuclein. In this context, transgenic mouse lines have failed to reproduce several hallmarks of PD, especially the strong and progressive dopaminergic neurodegeneration over time that occurs in the patients. In contrast, viral vector-based models in rats and non-human primates display prominent, although highly variable, nigral dopaminergic neuron loss. However, the few studies available on viral vector-mediated overexpression of alpha-synuclein in mice report a weak neurodegenerative process and no clear Lewy body-like pathology. To address this issue, we performed a comprehensive comparative study of alpha-synuclein overexpression by means of recombinant adeno-associated viral vectors serotype 2/7 (rAAV2/7) at different doses in adult mouse substantia nigra. We noted a significant and dose-dependent alpha-synucleinopathy over time upon nigral viral vector-mediated alpha-synuclein overexpression. We obtained a strong, progressive and dose-dependent loss of dopaminergic neurons in the substantia nigra, reaching a maximum of 82% after 8 weeks. This effect correlated with a reduction in tyrosine hydroxylase immunoreactivity in the striatum. Moreover, behavioural analysis revealed significant motor impairments from 12 weeks after injection on. In addition, we detected the presence of alpha-synuclein-positive aggregates in the remaining surviving neurons. When comparing wild-type to mutant A53T alpha-synuclein at the same vector dose, both induced a similar degree of cell death. These data were supported by a biochemical analysis that showed

  13. Voltammetric characterization of the effect of monoamine uptake inhibitors and releasers on dopamine and serotonin uptake in mouse caudate-putamen and substantia nigra slices

    PubMed Central

    John, Carrie E.; Jones, Sara R.

    2007-01-01

    Summary Fast scan cyclic voltammetry is an electrochemical technique used to measure dynamics of transporter-mediated monoamine uptake in real time and provides a tool to evaluate the detailed effects of monoamine uptake inhibitors and releasers on dopamine and serotonin transporter function. We measured the effects of cocaine, methylphenidate, 2β-propanoyl–3β-(4tolyl) tropane (PTT), fluoxetine, amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA), phentermine and fenfluramine on dopamine and serotonin uptake following electrically stimulated release in mouse caudate-putamen and substantia nigra pars reticulata slices. We determined rank orders of uptake inhibition effects based on two variables; increases in apparent Km for dopamine and serotonin uptake and inhibition constant (Ki) values. For example, the rank order of uptake inhibition based on apparent Km values at the dopamine transporter was amphetamine ≥ PTT ≥ methylphenidate ≫ methamphetamine = phentermine = MDMA > cocaine ≫ fluoxetine = fenfluramine, and at the serotonin transporter was fluoxetine = methamphetamine = fenfluramine = MDMA > amphetamine = cocaine = PTT ≥ methylphenidate > phentermine. Additionally, changes in electrically stimulated release were documented. This is the first study using voltammetry to measure the effects of a wide range of monoamine uptake inhibitors and releasers on dopamine and serotonin uptake in mouse brain slices. These studies also highlight methodological considerations for comparison of effects between heterogeneous brain regions. PMID:17459426

  14. Postnatal development of neurons, interneurons and glial cells in the substantia nigra of mice.

    PubMed

    Abe, Manami; Kimoto, Hiroki; Eto, Risa; Sasaki, Taeko; Kato, Hiroyuki; Kasahara, Jiro; Araki, Tsutomu

    2010-08-01

    We investigated postnatal alterations of neurons, interneurons and glial cells in the mouse substantia nigra using immunohistochemistry. Tyrosine hydroxylase (TH), neuronal nuclei (NeuN), parvalbumin (PV), neuronal nitric oxide synthase (nNOS), glial fibrillary acidic protein (GFAP), ionized calcium-binding adaptor molecule 1 (Iba 1), CNPase (2',3'-cyclic nucleotide 3'-phosphodiesterase), brain-derived neurotrophic factor (BDNF) and glial cell-line-derived neurotrophic factor (GDNF) immunoreactivity were measured in 1-, 2-, 4- and 8-week-old mice. In the present study, the maturation of NeuN-immunopositive neurons preceded the production of TH in the substantia nigra during postnatal development in mice. Furthermore, the maturation of nNOS-immunopositive interneurons preceded the maturation of PV-immunopositive interneurons in the substantia nigra during postnatal development. Among astrocytes, microglia and oligodendrocytes, in contrast, the development process of oligodendrocytes is delayed in the substantia nigra. Our double-labeled immunohistochemical study suggests that the neurotrophic factors such as BDNF and GDNF secreted by GFAP-positive astrocytes may play some role in maturation of neurons, interneurons and glial cells of the substantia nigra during postnatal development in mice. Thus, our findings provide valuable information on the development processes of the substantia nigra.

  15. Caudate stimulation and substantia nigra activity in the rat.

    PubMed Central

    Dray, A; Gonye, T J; Oakley, N R

    1976-01-01

    1. The responses of spontaneously active single neurones in the substantia nigra and overlying mesencephalic reticular formation have been analysed during the electrical stimulation of the ipsilateral caudate nucleus. Experiments were performed in rats anaesthetized with urethane or pentobarbitone. All recordings were made extracellularly with multi-barrelled glass micropipettes which were also used to test neuronal responsiveness to electrophoretically administered substances. The micropipette tip position was marked and the distribution of neurones studied has been analysed. 2. Single shock stimulation of the caudate nucleus inhibited neuronal activity in the substantia nigra (270/320 cells: mean latency 5-4 msec) and in the mesencephalic reticular formation (62/72 cells: mean latency 16-6 msec). However, these effects were often accompanied by periods of excitation. In pentobarbitone anaesthetized animals the latency and duration of these substantia nigra inhibitions was increased. 3. Compared with the zona reticulata, fewer neurones in the zona compacta of the substantia nigra responded to caudate stimulation in both urethane or pentobarbitone anaesthetized animals. 4. The activity of most cells was depressed by electrophoretically administered GABA or glycine and increased by acetylcholine or glutamate. Neurones of the mesencephalic reticular formation were less sensitive to GABA and glycine than substantia nigra neurones. Within the substantia nigra, both zona compacta and zona reticulata neurones were more sensitive to GABA than to glycine. Over-all, glutamate was a more potent excitant than acetylcholine (ACh). 5. Electrophoretic bicuculline methochloride (BMC) consistently reduced GABA but not glycine depression of substantia nigra neurones. Approximately twice as much BMC was required to reduce the endogenous inhibition of the same substantia nigra neurones and the amplitude of concomitantly evoked positive field potential as was required to abolish

  16. Substantia nigra osmoregulation: taurine and ATP involvement.

    PubMed

    Morales, Ingrid; Dopico, Jose G; Sabate, Magdalena; Gonzalez-Hernandez, Tomas; Rodriguez, Manuel

    2007-05-01

    An extracellular nonsynaptic taurine pool of glial origin was recently reported in the substantia nigra (SN). There is previous evidence showing taurine as an inhibitory neurotransmitter in the SN, but the physiological role of this nonsynaptic pool of taurine has not been explored. By using microdialysis methods, we studied the action of local osmolarity on the nonsynaptic taurine pool in the SN of the rat. Hypoosmolar pulses (285-80 mosM) administered in the SN by the microdialysis probe increased extrasynaptic taurine in a dose-dependent way, a response that was counteracted by compensating osmolarity with choline. The opposite effect (taurine decrease) was observed when osmolarity was increased. Under basal conditions, the blockade of either the AMPA-kainate glutamate receptors with 6-cyano-7-nitroquinoxaline-2,3-dionine disodium or the purinergic receptors with pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid modified the taurine concentration, suggesting that both receptors modulate the extrasynaptic pool of taurine. In addition, these drugs decreased the taurine response to hypoosmolar pulses, suggesting roles for glutamatergic and purinergic receptors in the taurine response to osmolarity. The participation of purinergic receptors was also supported by the fact that ATP (which, under basal conditions, increased the extrasynaptic taurine in a dose-dependent way) administered in doses saturating purinergic receptors also decreased the taurine response to hypoosmolarity. Taken together, present data suggest osmoregulation as a role of the nonsynaptic taurine pool of the SN, a function that also involves glutamate and ATP and that could influence the nigral cell vulnerability in Parkinson's disease.

  17. Dopamine D1 Receptor Immunoreactivity on Fine Processes of GFAP-Positive Astrocytes in the Substantia Nigra Pars Reticulata of Adult Mouse

    PubMed Central

    Nagatomo, Katsuhiro; Suga, Sechiko; Saitoh, Masato; Kogawa, Masahito; Kobayashi, Kazuto; Yamamoto, Yoshio; Yamada, Katsuya

    2017-01-01

    Substantia nigra pars reticulata (SNr), the major output nucleus of the basal ganglia, receives dopamine from dendrites extending from dopaminergic neurons of the adjacent nucleus pars compacta (SNc), which is known for its selective degeneration in Parkinson's disease. As a recipient for dendritically released dopamine, the dopamine D1 receptor (D1R) is a primary candidate due to its very dense immunoreactivity in the SNr. However, the precise location of D1R remains unclear at the cellular level in the SNr except for that reported on axons/axon terminals of presumably striatal GABAergic neurons. To address this, we used D1R promotor-controlled, mVenus-expressing transgenic mice. When cells were acutely dissociated from SNr of mouse brain, prominent mVenus fluorescence was detected in fine processes of glia-like cells, but no such fluorescence was detected from neurons in the same preparation, except for the synaptic bouton-like structure on the neurons. Double immunolabeling of SNr cells dissociated from adult wild-type mice brain further revealed marked D1R immunoreactivity in the processes of glial fibrillary acidic protein (GFAP)-positive astrocytes. Such D1R imunoreactivity was significantly stronger in the SNr astrocytes than that in those of the visual cortex in the same preparation. Interestingly, GFAP-positive astrocytes dissociated from the striatum demonstrated D1R immunoreactivity, either remarkable or minimal, similarly to that shown in neurons in this nucleus. In contrast, in the SNr and visual cortex, only weak D1R immunoreactivity was detected in the neurons tested. These results suggest that the SNr astrocyte may be a candidate recipient for dendritically released dopamine. Further study is required to fully elucidate the physiological roles of divergent dopamine receptor immunoreactivity profiles in GFAP-positive astrocytes. PMID:28203148

  18. A cytoarchitectonic and chemoarchitectonic analysis of the dopamine cell groups in the substantia nigra, ventral tegmental area, and retrorubral field in the mouse.

    PubMed

    Fu, Yuhong; Yuan, Yuan; Halliday, Glenda; Rusznák, Zoltán; Watson, Charles; Paxinos, George

    2012-04-01

    The three main dopamine cell groups of the brain are located in the substantia nigra (A9), ventral tegmental area (A10), and retrorubral field (A8). Several subdivisions of these cell groups have been identified in rats and humans but have not been well described in mice, despite the increasing use of mice in neurodegenerative models designed to selectively damage A9 dopamine neurons. The aim of this study was to determine whether typical subdivisions of these dopamine cell groups are present in mice. The dopamine neuron groups were analysed in 15 adult C57BL/6J mice by anatomically localising tyrosine hydroxylase (TH), dopamine transporter protein (DAT), calbindin, and the G-protein-activated inward rectifier potassium channel 2 (GIRK2) proteins. Measurements of the labeling intensity, neuronal morphology, and the proportion of neurons double-labeled with TH, DAT, calbindin, or GIRK2 were used to differentiate subregions. Coronal maps were prepared and reconstructed in 3D. The A8 cell group had the largest dopamine neurons. Five subregions of A9 were identified: the reticular part with few dopamine neurons, the larger dorsal and smaller ventral dopamine tiers, and the medial and lateral parts of A9. The latter has groups containing some calbindin-immunoreactive dopamine neurons. The greatest diversity of dopamine cell types was identified in the seven subregions of A10. The main dopamine cell groups in the mouse brain are similar in terms of diversity to those observed in rats and humans. These findings are relevant to models using mice to analyse the selective vulnerability of different types of dopamine neurons.

  19. Alterations in striatal dopamine catabolism precede loss of substantia nigra neurons in a mouse model of Juvenile Neuronal Ceroid Lipofuscinosis

    PubMed Central

    Weimer, Jill M.; Benedict, Jared W.; Elshatory, Yasser M.; Short, Douglas W.; Ramirez-Montealegre, Denia; Ryan, Deborah A.; Alexander, Noreen A.; Federoff, Howard J.; Cooper, Jonathan D.; Pearce, David A.

    2016-01-01

    Batten disease, or juvenile neuronal ceroid lipofuscinosis (JNCL), results from mutations in the CLN3 gene. This disorder presents clinically around the age of five years with visual deficits progressing to include seizures, cognitive impairment, motor deterioration, hallucinations, and premature death by the third to forth decade of life. The motor deficits include coordination and gait abnormalities, myoclonic jerks, inability to initiate movements, and spasticity. Previous work from our laboratory has identified an early reduction in catechol-O-methyltransferase (COMT), an enzyme responsible for the efficient degradation of dopamine. Alterations in the kinetics of dopamine metabolism could cause the accumulation of undegraded or unsequestered dopamine leading to the formation of toxic dopamine intermediates. We report an imbalance in the catabolism of dopamine in three month Cln3-/- mice persisting through nine months of age that may be causal to oxidative damage within the striatum at nine months of age. Combined with the previously reported inflammatory changes and loss of post-synaptic D1α receptors, this could facilitate cell loss in striatal projection regions and underlie a general locomotion deficit that becomes apparent at twelve months of age in Cln3-/- mice. This study provides evidence for early changes in the kinetics of COMT in the Cln3-/- mouse striatum, affecting the turnover of dopamine, likely leading to neuron loss and motor deficits. These data provide novel insights into the basis of motor deficits in JNCL and how alterations in dopamine catabolism may result in oxidative damage and localized neuronal loss in this disorder. PMID:17617387

  20. Effect of total flavonoids from Scutellaria baicalensis on dopaminergic neurons in the substantia nigra

    PubMed Central

    Li, Xue-Li; Xu, Xiao-Fan; Bu, Qing-Xia; Jin, Wei-Rong; Sun, Qian-Ru; Feng, De-Peng; Zhang, Qing-Jv; Wang, Le-Xin

    2016-01-01

    The aim of the present study was to investigate the effect of Scutellaria baicalensis stem-leaf total flavonoid (SSTF) on the dopaminergic neurons in the substantia nigra in a mouse model of Parkinson's disease (PD). The mouse model was established by intravenous injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). SSTF (5 mg/kg) was administered to the mice before or after MPTP injection, and the effects of SSTF on the behavior of the mice and the dopaminergic neurons in the substantia nigra were assessed. In addition, the level of serum malondialdehyde (MDA) was measured. Following injection of MPTP, the number of dopaminergic neurons in the substantia nigra was decreased and the neurons appeared atrophic. In addition, the level of serum MDA in the MPTP mice increased. The mean behavioral scores and the number of dopaminergic neurons in the SSTF treatment groups were significantly higher than in the MPTP group (P<0.05), and the mean serum MDA levels were significantly lower (P<0.05). Thus, SSTF improves the behaviors and the numbers of dopaminergic neurons in the substantia nigra in MPTP-induced PD in mice. These beneficial effects appear to be associated with the reduction in serum MDA. PMID:27446544

  1. Bidirectional Modulation of Substantia Nigra Activity by Motivational State

    PubMed Central

    Rossi, Mark A.; Fan, David; Barter, Joseph W.; Yin, Henry H.

    2013-01-01

    A major output nucleus of the basal ganglia is the substantia nigra pars reticulata, which sends GABAergic projections to brainstem and thalamic nuclei. The GABAergic (GABA) neurons are reciprocally connected with nearby dopaminergic neurons, which project mainly to the basal ganglia, a set of subcortical nuclei critical for goal-directed behaviors. Here we examined the impact of motivational states on the activity of GABA neurons in the substantia nigra pars reticulata and the neighboring dopaminergic (DA) neurons in the pars compacta. Both types of neurons show short-latency bursts to a cue predicting a food reward. As mice became sated by repeated consumption of food pellets, one class of neurons reduced cue-elicited firing, whereas another class of neurons progressively increased firing. Extinction or pre-feeding just before the test session dramatically reduced the phasic responses and their motivational modulation. These results suggest that signals related to the current motivational state bidirectionally modulate behavior and the magnitude of phasic response of both DA and GABA neurons in the substantia nigra. PMID:23936522

  2. Neuroprotective changes in degeneration-related gene expression in the substantia nigra following acupuncture in an MPTP mouse model of Parkinsonism: Microarray analysis.

    PubMed

    Yeo, Sujung; An, Keon Sang; Hong, Yeon-Mi; Choi, Yeong-Gon; Rosen, Bruce; Kim, Sung-Hoon; Lim, Sabina

    2015-03-01

    Parkinson's disease (PD) is a neurodegenerative disorder characterized by the death of dopamine-generating cells in the substantia nigra (SN). Acupuncture stimulation results in an enhanced survival of dopaminergic neurons in the SN in Parkinsonism animal models. The present study investigated changes in gene expression profiles measured using whole transcript array in the SN region related to the inhibitory effects of acupuncture in a chronic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) Parkinsonism model. In this model, acupuncture stimulation at GB34 and LR3 attenuated the decrease in tyrosine hydroxylase in the SN region; stimulation at non-acupoints did not suppress this decrease. Gene array analysis revealed that 22 (10 annotated genes: Cdh1, Itih2, Mpzl2, Rdh9, Serping1, Slc6a13, Slc6a20a, Slc6a4, Tph2, and Ucma) probes that were up-regulated in MPTP animals relative to controls were exclusively down-regulated by acupuncture stimulation. In addition, 17 (two annotated genes: 4921530L21Rik and Gm13931) probes that were down-regulated in MPTP animals compared to controls were exclusively up-regulated by acupuncture stimulation. These findings indicate that the 39 probes (12 annotated genes) affected by MPTP and acupuncture may be responsible for the inhibitory effects of acupuncture on degeneration-related gene expression in the SN following damage induced by MPTP intoxication.

  3. Normalization of Spiroperidol Binding in the Denervated Rat Striatum by Homologous Grafts of Substantia Nigra

    NASA Astrophysics Data System (ADS)

    Freed, William J.; Ko, Grant N.; Niehoff, Debra L.; Kuhar, Michael J.; Hoffer, Barry J.; Olson, Lars; Cannon-Spoor, H. Eleanor; Morihisa, John M.; Jed Wyatt, Richard

    1983-11-01

    Transplantation of embryonic substantia nigra into the adult rat brain decreases the motor asymmetry that is produced by dopamine receptor supersensitivity after a unilateral lesion of the substantia nigra. The authors report that this effect of transplantation is specific to grafts of substantia nigra. They also report that, in conjunction with the decrease in motor asymmetry, these grafts cause postsynaptic dopaminergic binding sites to return to normal density as measured by tritiated spiroperidol autoradiography. Thus, in animals with brain lesions, grafts of substantia nigra produce a long-term alteration in the functional status of host brain cell receptors that is associated with a reduction in the behavioral deficit.

  4. Proteome analysis of human substantia nigra in Parkinson's disease

    PubMed Central

    Werner, Cornelius J; Heyny-von Haussen, Roland; Mall, Gerhard; Wolf, Sabine

    2008-01-01

    Background Parkinson's disease (PD) is the most common neurodegenerative disorder involving the motor system. Although not being the only region involved in PD, affection of the substantia nigra and its projections is responsible for some of the most debilitating features of the disease. To further advance a comprehensive understanding of nigral pathology, we conducted a tissue based comparative proteome study of healthy and diseased human substantia nigra. Results The gross number of differentially regulated proteins in PD was 221. In total, we identified 37 proteins, of which 16 were differentially expressed. Identified differential proteins comprised elements of iron metabolism (H-ferritin) and glutathione-related redox metabolism (GST M3, GST P1, GST O1), including novel redox proteins (SH3BGRL). Additionally, many glial or related proteins were found to be differentially regulated in PD (GFAP, GMFB, galectin-1, sorcin), as well as proteins belonging to metabolic pathways sparsely described in PD, such as adenosyl homocysteinase (methylation), aldehyde dehydrogenase 1 and cellular retinol-binding protein 1 (aldehyde metabolism). Further differentially regulated proteins included annexin V, beta-tubulin cofactor A, coactosin-like protein and V-type ATPase subunit 1. Proteins that were similarly expressed in healthy or diseased substantia nigra comprised housekeeping proteins such as COX5A, Rho GDI alpha, actin gamma 1, creatin-kinase B, lactate dehydrogenase B, disulfide isomerase ER-60, Rab GDI beta, methyl glyoxalase 1 (AGE metabolism) and glutamine synthetase. Interestingly, also DJ-1 and UCH-L1 were expressed similarly. Furthermore, proteins believed to serve as internal standards were found to be expressed in a constant manner, such as 14-3-3 epsilon and hCRMP-2, thus lending further validity to our results. Conclusion Using an approach encompassing high sensitivity and high resolution, we show that alterations of SN in PD include many more proteins than

  5. Microstimulation of the human substantia nigra alters reinforcement learning.

    PubMed

    Ramayya, Ashwin G; Misra, Amrit; Baltuch, Gordon H; Kahana, Michael J

    2014-05-14

    Animal studies have shown that substantia nigra (SN) dopaminergic (DA) neurons strengthen action-reward associations during reinforcement learning, but their role in human learning is not known. Here, we applied microstimulation in the SN of 11 patients undergoing deep brain stimulation surgery for the treatment of Parkinson's disease as they performed a two-alternative probability learning task in which rewards were contingent on stimuli, rather than actions. Subjects demonstrated decreased learning from reward trials that were accompanied by phasic SN microstimulation compared with reward trials without stimulation. Subjects who showed large decreases in learning also showed an increased bias toward repeating actions after stimulation trials; therefore, stimulation may have decreased learning by strengthening action-reward associations rather than stimulus-reward associations. Our findings build on previous studies implicating SN DA neurons in preferentially strengthening action-reward associations during reinforcement learning.

  6. Extracellular taurine in the substantia nigra: taurine-glutamate interaction.

    PubMed

    García Dopico, José; Perdomo Díaz, Juan; Alonso, Teofilo Jorge; González Hernández, Tomás; Castro Fuentes, Rafael; Rodríguez Díaz, Manuel

    2004-05-15

    Taurine has been proposed as an inhibitory transmitter in the substantia nigra (SN), but the mechanisms involved in its release and uptake remain practically unexplored. We studied the extracellular pool of taurine in the rat's SN by using microdialysis methods, paying particular attention to the taurine-glutamate (GLU) interaction. Extracellular taurine increased after cell depolarization with high-K(+) in a Ca(2+)-dependent manner, being modified by the local perfusion of GLU, GLU receptor agonists, and zinc. Nigral administration of taurine increased the extracellular concentration of gamma-aminobutyric acid (GABA) and GLU, the transmitters of the two main inputs of the SN. The modification of the glial metabolism with fluocitrate and L-methionine sulfoximine also changed the extracellular concentration of taurine. The complex regulation of the extracellular pool of taurine, its interaction with GABA and GLU, and the involvement of glial cells in its regulation suggest a volume transmission role for taurine in the SN.

  7. Microstimulation of the Human Substantia Nigra Alters Reinforcement Learning

    PubMed Central

    Ramayya, Ashwin G.; Misra, Amrit

    2014-01-01

    Animal studies have shown that substantia nigra (SN) dopaminergic (DA) neurons strengthen action–reward associations during reinforcement learning, but their role in human learning is not known. Here, we applied microstimulation in the SN of 11 patients undergoing deep brain stimulation surgery for the treatment of Parkinson's disease as they performed a two-alternative probability learning task in which rewards were contingent on stimuli, rather than actions. Subjects demonstrated decreased learning from reward trials that were accompanied by phasic SN microstimulation compared with reward trials without stimulation. Subjects who showed large decreases in learning also showed an increased bias toward repeating actions after stimulation trials; therefore, stimulation may have decreased learning by strengthening action–reward associations rather than stimulus–reward associations. Our findings build on previous studies implicating SN DA neurons in preferentially strengthening action–reward associations during reinforcement learning. PMID:24828643

  8. 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.

  9. Down-regulation of Bcl-2 in rat substantia nigra after focal cerebral ischemia.

    PubMed

    Arango-Dávila, Cesar A; Cardona-Gomez, Gloria P; Gallego-Gomez, Juan C; Garcia-Segura, Luis M; Pimienta, Hernán J

    2004-06-28

    After occlusion of the middle cerebral artery in rats, a robust neuronal loss occurs in the ipsilateral substantia nigra reticulata. In this study we have assessed whether degeneration of the substantia nigra is accompanied by changes in the expression of the anti-apoptotic protein Bcl-2. Neuronal loss was assessed by neuronal nuclei (NeuN) immunoreactivity. A significant decrease of Bcl-2 expression was observed in the substantia nigra 12, 24 and 72 h after middle cerebral artery occlusion. These results suggest that the secondary neuronal loss in the substantia nigra could be related with the modification of proteins regulating programmed cell death. Exo-focal cell death may explain the appearance of neuropsychiatric symptoms that are not correlated with the primary site of lesion.

  10. Structural abnormality of the substantia nigra in children with attention-deficit hyperactivity disorder

    PubMed Central

    Romanos, Marcel; Weise, David; Schliesser, Mira; Schecklmann, Martin; Löffler, Julia; Warnke, Andreas; Gerlach, Manfred; Classen, Joseph; Mehler-Wex, Claudia

    2010-01-01

    Background Structural abnormality of the substantia nigra can be detected by transcranial sonography in neuropsychiatric disorders such as Parkinson disease and restless legs syndrome. We investigated echogenicity of the substantia nigra as a potential structural marker for dysfunction of the nigrostriatal dopamine system in children with attention-deficit hyperactivity disorder (ADHD). Methods We used a blinded design and determined echogenicity of the substantia nigra by use of transcranial sonography in 22 children with ADHD and 22 healthy controls matched for age and sex. Results The echogenic substantia nigra area was significantly larger in ADHD patients than in healthy controls (F1,42 = 9.298, p = 0.004, effect size = 0.92). We found no effects of age or sex. Limitations Owing to a lack of dimensional assessment, we could not analyze the correlation between echogenicity and clinical symptoms. Conclusion Our results support the hypothesis that the nigrostriatal dopaminergic system is abnormal in children with ADHD. PMID:20040247

  11. Longitudinal changes in free-water within the substantia nigra of Parkinson's disease.

    PubMed

    Ofori, Edward; Pasternak, Ofer; Planetta, Peggy J; Li, Hong; Burciu, Roxana G; Snyder, Amy F; Lai, Song; Okun, Michael S; Vaillancourt, David E

    2015-08-01

    There is a clear need to develop non-invasive markers of substantia nigra progression in Parkinson's disease. We previously found elevated free-water levels in the substantia nigra for patients with Parkinson's disease compared with controls in single-site and multi-site cohorts. Here, we test the hypotheses that free-water levels in the substantia nigra of Parkinson's disease increase following 1 year of progression, and that baseline free-water levels in the substantia nigra predict the change in bradykinesia following 1 year. We conducted a longitudinal study in controls (n = 19) and patients with Parkinson's disease (n = 25). Diffusion imaging and clinical data were collected at baseline and after 1 year. Free-water analyses were performed on diffusion imaging data using blinded, hand-drawn regions of interest in the posterior substantia nigra. A group effect indicated free-water values were increased in the posterior substantia nigra of patients with Parkinson's disease compared with controls (P = 0.003) and we observed a significant group × time interaction (P < 0.05). Free-water values increased for the Parkinson's disease group after 1 year (P = 0.006), whereas control free-water values did not change. Baseline free-water values predicted the 1 year change in bradykinesia scores (r = 0.74, P < 0.001) and 1 year change in Montreal Cognitive Assessment scores (r = -0.44, P = 0.03). Free-water in the posterior substantia nigra is elevated in Parkinson's disease, increases with progression of Parkinson's disease, and predicts subsequent changes in bradykinesia and cognitive status over 1 year. These findings demonstrate that free-water provides a potential non-invasive progression marker of the substantia nigra.

  12. In vivo imaging markers of neurodegeneration of the substantia nigra.

    PubMed

    Auer, Dorothee P

    2009-01-01

    Non invasive detection and monitoring of substantia nigra degeneration is a long sought aim for neuroscientists, clinicians and pharmaceutical companies with an interest in Parkinson's disease (PD). Functional imaging techniques are established tools to assess the extent of striatal dopaminergic denervation that indirectly reflects nigral degeneration. They allow characterization of the dopaminergic denervation during the premotor phase of PD and have clinical value to establish the diagnosis in parkinsonism, but have proven to be unsatisfactory as surrogate markers in recent treatment trials. There is strong research interest in developing new imaging tests for nigral degeneration using a variety of structural brain imaging techniques. Nigral hyperechogenicity assessed by transcranial sonography emerges as a robust and low cost test to diagnose PD. Additionally, various advanced magnetic resonance imaging contrasts and high field magnetic resonance spectroscopy show promising sensitivity to nigral pathology in PD. Qualification of these emerging imaging tests against defined biomarker criteria is a complex and challenging task ahead. More systematic validation studies analogous to clinical trials are needed to meet the expectations and criteria defined by regulatory bodies before imaging biomarkers can be used as surrogate endpoints for neuroprotective or restorative trials.

  13. Substantia nigra echogenicity correlated with clinical features of Parkinson's disease.

    PubMed

    Zhou, Hai-Yan; Sun, Qian; Tan, Yu-Yan; Hu, Yun-Yun; Zhan, Wei-Wei; Li, Dun-Hui; Wang, Ying; Xiao, Qin; Liu, Jun; Chen, Sheng-Di

    2016-03-01

    Transcranial sonography can display structural alterations in the substantia nigra (SN) of patients with Parkinson's disease (PD), and is considered to be a potential useful tool for the diagnosis of PD. The aim of this study was to assess the correlation between SN echogenicity and clinical features in Chinese patients with PD. A total of 420 subjects including 290 patients with PD and 130 controls were recruited from the neurological clinic or the community. Transcranial sonographic evaluations of the SN were performed in all subjects, and motor and non-motor symptoms were thoroughly assessed by a series of rating scales in PD patients. Two hundred and one patients were successfully assessed by transcranial sonography. SN hyperechogenicity was found to be associated with male sex (p = 0.004), higher scores on the Unified Parkinson's Disease Rating Scale (UPDRS) part II (p = 0.001) and autonomic symptoms scores (p = 0.003). Moreover, regression analysis revealed that UPDRS part II scores (odds ratio = 1.141, p < 0.001) and gender (odds ratio = 2.409, p = 0.007) could be the independent predictors for SN hyperechogenicity; in addition, among all items of UPDRS part II, speech, dressing, hygiene, and turning in bed and adjusting bed clothes significantly correlated with SN hyperechogenicity. This is the first report suggesting the correlation between SN echogenicity and UPDRS part II, and we conclude that increased SN echogenicity might reflect more severe disease disability or poorer medical response. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Parkin is protective for substantia nigra dopamine neurons in a tau gene transfer neurodegeneration model.

    PubMed

    Klein, Ronald L; Dayton, Robert D; Henderson, Karen M; Petrucelli, Leonard

    2006-06-19

    Parkin is a ubiquitin ligase involved in the ubiquitin-proteasome system. Elevating parkin expression in cells reduces markers of oxidative stress while blocking parkin expression increases oxidative stress. In parkin gene knock down mouse and fly models, mitochondria function is deficient. Parkin is neuroprotective against a variety of toxic insults, while it remains unclear which of the above properties of parkin may mediate the protective actions. One of the models for which parkin is protective is overexpression of alpha-synuclein, a protein that self-aggregates in Parkinson disease. The microtubule-associated protein tau is another protein that self-aggregates in specific neurodegenerative diseases that also involve loss of dopamine neurons such as frontotemporal dementia with parkinsonism linked to chromosome 17, progressive supranuclear palsy and corticobasal degeneration. We recently developed a tau-induced dopaminergic degeneration model in rats using adeno-associated virus vectors. In this study, we successfully targeted either a mixed tau/parkin vector or mixed tau/control vector to the rat substantia nigra. While there was significant loss of dopamine neurons in the tau/control group relative to uninjected substantia nigra, there was no cell loss in the tau/parkin group. We found no difference in total tau levels between tau/control and tau/parkin groups. Parkin therefore protects dopamine neurons against tau as it does against alpha-synuclein, which further supports parkin as a therapeutic target for diseases involving loss of dopamine neurons.

  15. Intrinsic and integrative properties of substantia nigra pars reticulata neurons

    PubMed Central

    Zhou, Fu-Ming; Lee, Christian R.

    2011-01-01

    The GABA projection neurons of the substantia nigra pars reticulata (SNr) are output neurons for the basal ganglia and thus critical for movement control. Their most striking neurophysiological feature is sustained, spontaneous high frequency spike firing. A fundamental question is: what are the key ion channels supporting the remarkable firing capability in these neurons? Recent studies indicate that these neurons express tonically active TRPC3 channels that conduct a Na-dependent inward current even at hyperpolarized membrane potentials. When the membrane potential reaches −60 mV, a voltage-gated persistent sodium current (INaP) starts to activate, further depolarizing the membrane potential. At or slightly below −50 mV, the large transient voltage-activated sodium current (INaT) starts to activate and eventually triggers the rapid rising phase of action potentials. SNr GABA neurons have a higher density of (INaT), contributing to the faster rise and larger amplitude of action potentials, compared with the slow-spiking dopamine neurons. INaT also recovers from inactivation more quickly in SNr GABA neurons than in nigral dopamine neurons. In SNr GABA neurons, the rising phase of the action potential triggers the activation of high-threshold, inactivation-resistant Kv3-like channels that can rapidly repolarize the membrane. These intrinsic ion channels provide SNr GABA neurons with the ability to fire spontaneous and sustained high frequency spikes. Additionally, robust GABA inputs from direct pathway medium spiny neurons in the striatum and GABA neurons in the globus pallidus may inhibit and silence SNr GABA neurons, whereas glutamate synaptic input from the subthalamic nucleus may induce burst firing in SNr GABA neurons. Thus, afferent GABA and glutamate synaptic inputs sculpt the tonic high frequency firing of SNr GABA neurons and the consequent inhibition of their targets into an integrated motor control signal that is further fine-tuned by neuromodulators

  16. Substantia nigra depigmentation and exposure to encephalitis lethargica.

    PubMed

    Hack, Nawaz; Jicha, Gregory A; Abell, Annalisa; Dean, Dawson; Vitek, Jerrold L; Berger, Joseph R

    2012-12-01

    Parkinsonism has occasionally been reported as a consequence of infectious diseases. The present study examines the clinical and pathological correlates of parkinsonism across birth cohorts in relation to critical exposure to the encephalitis lethargica epidemic in the early 1900s. The study population consisted of 678 participants in the Nun Study, of whom 432 died and came to autopsy. Qualitative indices of substantia nigra (SN) depigmentation were verified in a subset of 40 randomly selected subjects using quantitative stereological techniques. SN depigmentation, detected neuropathologically, was correlated with clinical parameters of Parkinson disease, age, and birth cohort. SN depigmentation was detected in 57 (13.2%) of the cohort. Although qualitative SN depigmentation correlated modestly with age (p = 0.02), it correlated best with birth cohort (p = 0.009) for women born in the years 1895-1899. Quantitative measures of SN depigmentation were increased in this birth cohort compared to age matched subjects from flanking birth cohorts 1890-1894 and 1900-1904 (p < 0.001). SN depigmentation correlated with speed of 6- and 50-foot walk (p < 0.0001), up and go test (p < 0.0001), and hand coordination (p < 0.0001). Subjects in the birth cohort 1895-1899 would have been in their late teens and 20s at the onset and during the peak of the encephalitis lethargica epidemic. These were precisely the age ranges of persons who were most often affected by the illness. These data suggest the possibility that the coexistence of parkinsonism and SN depigmentation in this birth cohort may have resulted from the yet undetermined infectious agent responsible for encephalitis lethargica. Copyright © 2012 American Neurological Association.

  17. Unitary synaptic connections among substantia nigra pars reticulata neurons

    PubMed Central

    Wilson, Charles J.

    2016-01-01

    Neurons in substantia nigra pars reticulata (SNr) are synaptically coupled by local axon collaterals, providing a potential mechanism for local signal processing. Because SNr neurons fire spontaneously, these synapses are constantly active. To investigate their properties, we recorded spontaneous inhibitory postsynaptic currents (sIPSCs) from SNr neurons in brain slices, in which afferents from upstream nuclei are severed, and the cells fire rhythmically. The sIPSC trains contained a mixture of periodic and aperiodic events. Autocorrelation analysis of sIPSC trains showed that a majority of cells had one to four active unitary inputs. The properties of the unitary IPSCs (uIPSCs) were analyzed for cells with one unitary input, using a model of periodic presynaptic firing and stochastic synaptic transmission. The inferred presynaptic firing rates and coefficient of variation of interspike intervals (ISIs) corresponded well with direct measurements of spiking in SNr neurons. Methods were developed to estimate the success probability, amplitude distributions, and kinetics of the uIPSCs, while removing the contribution from aperiodic sIPSCs. The sIPSC amplitudes were not increased upon release from halorhodopsin silencing, suggesting that most synapses were not depressed at the spontaneous firing rate. Gramicidin perforated-patch recordings indicated that the average reversal potential of spontaneous inhibitory postsynaptic potentials was −64 mV. Because of the change in driving force across the ISI, the unitary inputs are predicted to have a larger postsynaptic impact when they arrive late in the ISI. Simulations of network activity suggest that this very sparse inhibitory coupling may act to desynchronize the activity of SNr neurons while having only a small effect on firing rate. PMID:26961101

  18. [(18)F]AV-1451 binding to neuromelanin in the substantia nigra in PD and PSP.

    PubMed

    Coakeley, Sarah; Cho, Sang Soo; Koshimori, Yuko; Rusjan, Pablo; Ghadery, Christine; Kim, Jinhee; Lang, Anthony E; Houle, Sylvain; Strafella, Antonio P

    2017-09-07

    This study investigated binding of [(18)F]AV-1451 to neuromelanin in the substantia nigra of patients with Parkinson's disease (PD) and progressive supranuclear palsy (PSP). [(18)F]AV-1451 is a positron emission tomography radiotracer designed to bind pathological tau. A post-mortem study using [(18)F]AV-1451 discovered off-target binding properties to neuromelanin in the substantia nigra. A subsequent clinical study reported a 30% decrease in [(18)F]AV-1451 binding in the midbrain of PD patients. A total of 12 patients and 10 healthy age-matched controls were recruited. An anatomical MRI and a 90-min PET scan, using [(18)F]AV-1451, were acquired from all participants. The standardized uptake value ratio (SUVR) from 60 to 90 min post-injection was calculated for the substantia nigra, using the cerebellar cortex as the reference region. The substantia nigra was delineated using automated region of interest software. An independent samples ANOVA and LSD post hoc testing were used to test for differences in [(18)F]AV-1451 SUVR between groups. Substantia nigra SUVR from 60 to 90 min was significantly greater in HC compared to both PSP and PD groups. Although the PD group had the lowest SUVR, there was no significant difference in substantia nigra uptake between PD and PSP. [(18)F]AV-1451 may be the first PET radiotracer capable of imaging neurodegeneration of the substantia nigra in parkinsonisms. Further testing must be done in PD and atypical parkinsonian disorders to support this off-target use of [(18)F]AV-1451.

  19. Effects of treadmill exercise on behavioral recovery and neural changes in the substantia nigra and striatum of the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-lesioned mouse.

    PubMed

    Smith, Beth A; Goldberg, Natalie R S; Meshul, Charles K

    2011-04-22

    Our goal was to extend our understanding of the neural changes behind motor recovery with treadmill exercise in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned mouse. We determined the extent of dopamine (DA) terminal changes using Western immunoblotting [striatal dopamine transporter (DAT) and tyrosine hydroxylase (TH)] and alterations in the mean number of DA cells/section by immunohistochemistry and Nissl staining [TH-labeled cells and thionin-stained cells in the substantia nigra pars compacta (SN-PC)]. We measured recovery of gait performance and amount of spontaneous physical activity using the parallel rod activity chamber (PRAC). We hypothesized that the decrease in TH-labeled neurons in the SN-PC due to MPTP will be partially reversed by treadmill exercise, leading to recovery of motor behavior as measured by the PRAC. Following MPTP or vehicle administration, mice ran on the treadmill for 1h/day at 18cm/s, 5days/week. Results showed that treadmill exercise improves gait performance and increases physical activity while promoting increased protein expression of striatal DAT and TH. Exercise was effective for all mice; however, effects of early treadmill-based intervention appear to have an additional and unique benefit in mice who received MPTP. We are the first to show that, even following a nearly 50% decrease in the mean number of TH-labeled neurons/section in the SN-PC following MPTP, treadmill exercise leads to an increase of neurons in the SN-PC and improved motor behavior. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Effects of treadmill exercise on behavioral recovery and neural changes in the substantia nigra and striatum of the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-lesioned mouse

    PubMed Central

    Goldberg, Natalie R.S.; Meshul, Charles K.

    2011-01-01

    Our goal was to extend our understanding of the neural changes behind motor recovery with treadmill exercise in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned mouse. We determined the extent of dopamine (DA) terminal changes using western immunoblotting [striatal dopamine transporter (DAT) and tyrosine hydroxylase (TH)] and alterations in the mean number of DA cells/section by immunohistochemistry and Nissl staining [TH-labeled cells and thionin-stained cells in the substantia nigra pars compacta (SN-PC)]. We measured recovery of gait performance and amount of spontaneous physical activity using the parallel rod activity chamber (PRAC). We hypothesized that the decrease in TH-labeled neurons in the SN-PC due to MPTP will be partially reversed by treadmill exercise, leading to recovery of motor behavior as measured by the PRAC. Following MPTP or vehicle administration, mice ran on the treadmill for 1 hour per day at 18 cm/s, 5 days per week. Results showed that treadmill exercise improves gait performance and increases physical activity while promoting increased protein expression of striatal DAT and TH. Exercise was effective for all mice, however effects of early treadmill-based intervention appear to have an additional and unique benefit in mice who received MPTP. We are the first to show that, even following a nearly 50% decrease in the mean number of TH-labeled neurons/section in the SN-PC following MPTP, treadmill exercise leads to an increase of neurons in the SN-PC and improved motor behavior. PMID:21315689

  1. Biomonitorization of iron accumulation in the substantia nigra from Lewy body disease patients

    PubMed Central

    Fernández, Belén; Ferrer, Isidro; Gil, Fernando; Hilfiker, Sabine

    2017-01-01

    Iron levels in the healthy human brain are known to be high in certain areas such as the substantia nigra (SN), and increase further with age. In addition, there is some evidence for a further increase in iron load in the SN of Parkinson's disease (PD) patients as compared to controls, which correlates with motor disability. Here, we have analyzed total iron levels in cells as well as mouse and human brain samples by atomic absorption spectroscopy (AAS). Our data indicate that iron load is more pronounced in cells with dopaminergic features. Moreover, region-specific differences in iron load reflecting those in the human brain were detected in rodent brains as well. Whilst altered iron load was not observed in other regions also affected in PD patients, we report a significant increase in iron load in the SN of Lewy body disease patients as compared to Alzheimer's disease (AD) patients or controls, which correlates with neurodegeneration in this brain area. PMID:28529891

  2. Transient Activation of GABAB Receptors Suppresses SK Channel Currents in Substantia Nigra Pars Compacta Dopaminergic Neurons

    PubMed Central

    Estep, Chad M.; Galtieri, Daniel J.; Zampese, Enrico; Goldberg, Joshua A.; Brichta, Lars; Greengard, Paul; Surmeier, D. James

    2016-01-01

    Dopaminergic (DA) neurons in the substantia nigra pars compacta (SNc) are richly innervated by GABAergic neurons. The postsynaptic effects of GABA on SNc DA neurons are mediated by a mixture of GABAA and GABAB receptors. Although activation of GABAA receptors inhibits spike generation, the consequences of GABAB receptor activation are less well characterized. To help fill this gap, perforated patch recordings were made from young adult mouse SNc DA neurons. Sustained stimulation of GABAB receptors hyperpolarized SNc DA neurons, as previously described. However, transient stimulation of GABAB receptors by optical uncaging of GABA did not; rather, it reduced the opening of small-conductance, calcium-activated K+ (SK) channels and increased the irregularity of spiking. This modulation was attributable to inhibition of adenylyl cyclase and protein kinase A. Thus, because suppression of SK channel activity increases the probability of burst spiking, transient co-activation of GABAA and GABAB receptors could promote a pause-burst pattern of spiking. PMID:28036359

  3. In vivo protein targets for increased quinoprotein adduct formation in aged substantia nigra.

    PubMed

    Yu, Guohua; Liu, Huiyan; Zhou, Wei; Zhu, Xuewei; Yu, Chao; Wang, Na; Zhang, Yi; Ma, Ji; Zhao, Yulan; Xu, Yuanyuan; Liao, Lujian; Ji, Hongfang; Yuan, Chonggang; Ma, Jiyan

    2015-09-01

    The selective vulnerability of dopaminergic neurons in the substantia nigra pars compacta in Parkinson's disease, a late age onset neurodegenerative disorder, indicates the involvement of dopamine metabolism in the pathogenesis. Dopamine oxidation produces dopamine o-quinone, which covalently modifies cysteinyl proteins forming quinoprotein adduct. Although quinoprotein formation correlates with increased dopaminergic neurotoxicity, the in vivo protein targets for quinone modification remain unclear. Using two-dimensional gel electrophoresis and nitroblue tetrazolium/glycinate redox-cycling staining, we compared quinoprotein adducts in the substantia nigra of 2- and 15-month old rats and for the first time identified the in vivo protein targets with increased quinone modification in aged substantia nigra. Interestingly, several key enzymes in energy metabolism and mitochondrial function were selectively modified by quinone during aging. In vitro analyses confirmed that two of identified enzymes, l-lactate dehydrogenase (LDH) and malate dehydrogenase (MDH), were readily conjugated by dopamine o-quinone, resulting in a significant reduction in enzyme activity. Since the proteomic approach to detect quinoprotein adducts represents a single analysis comparing pools of substantia nigra from young or old rats, these findings need to be verified in the future. Nonetheless, our results reveal that the enzymatic activity of LDH and MDH can be compromised by quinone modification, suggesting a role of energy metabolism impairment in the selective vulnerability of aged substantia nigra dopaminergic neurons in Parkinson's disease. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Genome-wide analysis of DNA methylation during antagonism of DMOG to MnCl2-induced cytotoxicity in the mouse substantia nigra

    PubMed Central

    Yang, Nannan; Wei, Yang; Wang, Tan; Guo, Jifeng; Sun, Qiying; Hu, Yacen; Yan, Xinxiang; Zhu, Xiongwei; Tang, Beisha; Xu, Qian

    2016-01-01

    Exposure to excessive manganese (Mn) causes manganism, a progressive neurodegenerative disorder similar to idiopathic Parkinson’s disease (IPD). The detailed mechanisms of Mn neurotoxicity in nerve cells, especially in dopaminergic neurons are not yet fully understood. Meanwhile, it is unknown whether there exists a potential antagonist or effective drug for treating neuron damage in manganism. In the present study, we report the discovery of an HIF prolyl-hydroxylase inhibitor, DMOG [N-(2-Methoxy-2-oxoacetyl) glycine methyl ester], that can partially inhibit manganese toxicity not only in the neuroblastoma cell line SH-SY5Y in vitro but also in a mouse model in vivo. A genome-wide methylation DNA analysis was performed using microarray hybridization. Intriguingly, DNA methylation in the promoter region of 226 genes was found to be regulated by MnCl2, while the methylation effects of MnCl2 could be restored with combinatorial DMOG treatment. Furthermore, we found that genes with converted promoter methylation during DMOG antagonism were associated across several categories of molecular function, including mitochondria integrity maintain, cell cycle and DNA damage response, and ion transportation. Collectively, our results serve as the basis of a mechanism analysis of neuron damage in manganism and may supply possible gene targets for clinical therapy. PMID:27380887

  5. Ventral Tegmental Area and Substantia Nigra Neural Correlates of Spatial Learning

    ERIC Educational Resources Information Center

    Martig, Adria K.; Mizumori, Sheri J. Y.

    2011-01-01

    The ventral tegmental area (VTA) and substantia nigra pars compacta (SNc) may provide modulatory signals that, respectively, influence hippocampal (HPC)- and striatal-dependent memory. Electrophysiological studies investigating neural correlates of learning and memory of dopamine (DA) neurons during classical conditioning tasks have found DA…

  6. Ventral Tegmental Area and Substantia Nigra Neural Correlates of Spatial Learning

    ERIC Educational Resources Information Center

    Martig, Adria K.; Mizumori, Sheri J. Y.

    2011-01-01

    The ventral tegmental area (VTA) and substantia nigra pars compacta (SNc) may provide modulatory signals that, respectively, influence hippocampal (HPC)- and striatal-dependent memory. Electrophysiological studies investigating neural correlates of learning and memory of dopamine (DA) neurons during classical conditioning tasks have found DA…

  7. Regional differences in the vulnerability of substantia nigra dopaminergic neurons in weaver mice.

    PubMed

    Marti, Joaquín; Santa-Cruz, María C; Molina, Vanessa; Serra, Roger; Bayer, Shirley A; Ghetti, Bernardino; Hervás, José P

    2009-01-01

    Vulnerability of midbrain dopaminergic (DA) neurons in the weaver mouse was studied at postnatal (P) days 8 and 90, in chosen coronal levels throughout the anteroposterior (AP) extent of the substantia nigra pars compacta (SNc). Wild-type (+/+) and homozygous weaver (wv/wv) mice used were the offspring of pregnant dams injected in several cases with tritiated thymidine on embryonic days 11-15. DA neurons were identified for their tyrosine hydroxylase immunoreactivity. Data reveal that at P8, the frequency of both +/+ and wv/wv late-generated DA cells increases from rostral to caudal SNc. No apparent DA-cell loss was observed at P8 in the mutant genotype, irrespective of the AP level considered. However, throughout the AP, there was a significant reduction in the number of these neurons at any level in 90-day-old weavers. Comparison of P8 and P90 +/+ SNc suggests that cell death is not a major aspect in the developmental regulation of normal DA neurons, although numerical cell depletion in the postnatal development of weaver SNc probably results from the amplification of a basal cell-death process, which affected all the coronal levels studied.

  8. Coexistence of glutamatergic spine synapses and shaft synapses in substantia nigra dopamine neurons

    PubMed Central

    Jang, Miae; Bum Um, Ki; Jang, Jinyoung; Jin Kim, Hyun; Cho, Hana; Chung, Sungkwon; Kyu Park, Myoung

    2015-01-01

    Dopamine neurons of the substantia nigra have long been believed to have multiple aspiny dendrites which receive many glutamatergic synaptic inputs from several regions of the brain. But, here, using high-resolution two-photon confocal microscopy in the mouse brain slices, we found a substantial number of common dendritic spines in the nigral dopamine neurons including thin, mushroom, and stubby types of spines. However, the number of dendritic spines of the dopamine neurons was approximately five times lower than that of CA1 pyramidal neurons. Immunostaining and morphological analysis revealed that glutamatergic shaft synapses were present two times more than spine synapses. Using local two-photon glutamate uncaging techniques, we confirmed that shaft synapses and spine synapses had both AMPA and NMDA receptors, but the AMPA/NMDA current ratios differed. The evoked postsynaptic potentials of spine synapses showed lower amplitudes but longer half-widths than those of shaft synapses. Therefore, we provide the first evidence that the midbrain dopamine neurons have two morphologically and functionally distinct types of glutamatergic synapses, spine synapses and shaft synapses, on the same dendrite. This peculiar organization could be a new basis for unraveling many physiological and pathological functions of the midbrain dopamine neurons. PMID:26435058

  9. Tonic Firing Rate Controls Dendritic Ca2+ Signaling and Synaptic Gain in Substantia Nigra Dopamine Neurons

    PubMed Central

    Hage, Travis A.

    2015-01-01

    Substantia nigra dopamine neurons fire tonically resulting in action potential backpropagation and dendritic Ca2+ influx. Using Ca2+ imaging in acute mouse brain slices, we find a surprisingly steep relationship between tonic firing rate and dendritic Ca2+. Increasing the tonic rate from 1 to 6 Hz generated Ca2+ signals up to fivefold greater than predicted by linear summation of single spike-evoked Ca2+-transients. This “Ca2+ supralinearity” was produced largely by depolarization of the interspike voltage leading to activation of subthreshold Ca2+ channels and was present throughout the proximal and distal dendrites. Two-photon glutamate uncaging experiments show somatic depolarization enhances NMDA receptor-mediated Ca2+ signals >400 μm distal to the soma, due to unusually tight electrotonic coupling of the soma to distal dendrites. Consequently, we find that fast tonic firing intensifies synaptically driven burst firing output in dopamine neurons. These results show that modulation of background firing rate precisely tunes dendritic Ca2+ signaling and provides a simple yet powerful mechanism to dynamically regulate the gain of synaptic input. PMID:25855191

  10. Coexistence of glutamatergic spine synapses and shaft synapses in substantia nigra dopamine neurons.

    PubMed

    Jang, Miae; Um, Ki Bum; Jang, Jinyoung; Kim, Hyun Jin; Cho, Hana; Chung, Sungkwon; Park, Myoung Kyu

    2015-10-05

    Dopamine neurons of the substantia nigra have long been believed to have multiple aspiny dendrites which receive many glutamatergic synaptic inputs from several regions of the brain. But, here, using high-resolution two-photon confocal microscopy in the mouse brain slices, we found a substantial number of common dendritic spines in the nigral dopamine neurons including thin, mushroom, and stubby types of spines. However, the number of dendritic spines of the dopamine neurons was approximately five times lower than that of CA1 pyramidal neurons. Immunostaining and morphological analysis revealed that glutamatergic shaft synapses were present two times more than spine synapses. Using local two-photon glutamate uncaging techniques, we confirmed that shaft synapses and spine synapses had both AMPA and NMDA receptors, but the AMPA/NMDA current ratios differed. The evoked postsynaptic potentials of spine synapses showed lower amplitudes but longer half-widths than those of shaft synapses. Therefore, we provide the first evidence that the midbrain dopamine neurons have two morphologically and functionally distinct types of glutamatergic synapses, spine synapses and shaft synapses, on the same dendrite. This peculiar organization could be a new basis for unraveling many physiological and pathological functions of the midbrain dopamine neurons.

  11. The leak channel NALCN controls tonic firing and glycolytic sensitivity of substantia nigra pars reticulata neurons

    PubMed Central

    Lutas, Andrew; Lahmann, Carolina; Soumillon, Magali; Yellen, Gary

    2016-01-01

    Certain neuron types fire spontaneously at high rates, an ability that is crucial for their function in brain circuits. The spontaneously active GABAergic neurons of the substantia nigra pars reticulata (SNr), a major output of the basal ganglia, provide tonic inhibition of downstream brain areas. A depolarizing 'leak' current supports this firing pattern, but its molecular basis remains poorly understood. To understand how SNr neurons maintain tonic activity, we used single-cell RNA sequencing to determine the transcriptome of individual mouse SNr neurons. We discovered that SNr neurons express the sodium leak channel, NALCN, and that SNr neurons lacking NALCN have impaired spontaneous firing. In addition, NALCN is involved in the modulation of excitability by changes in glycolysis and by activation of muscarinic acetylcholine receptors. Our findings suggest that disruption of NALCN could impair the basal ganglia circuit, which may underlie the severe motor deficits in humans carrying mutations in NALCN. DOI: http://dx.doi.org/10.7554/eLife.15271.001 PMID:27177420

  12. Isoforms of the Erythropoietin receptor in dopaminergic neurons of the Substantia Nigra.

    PubMed

    Marcuzzi, Federica; Zucchelli, Silvia; Bertuzzi, Maria; Santoro, Claudio; Tell, Gianluca; Carninci, Piero; Gustincich, Stefano

    2016-11-01

    Erythropoietin receptor (EpoR) regulates erythrocytes differentiation in blood. In the brain, EpoR has been shown to protect several neuronal cell types from cell death, including the A9 dopaminergic neurons (DA) of the Substantia Nigra (SN). These cells form the nigrostriatal pathway and are devoted to the control of postural reflexes and voluntary movements. Selective degeneration of A9 DA neurons leads to Parkinson's disease. By the use of nanoCAGE, a technology that allows the identification of Transcription Start Sites (TSSs) at a genome-wide level, we have described the promoter-level expression atlas of mouse A9 DA neurons purified with Laser Capture Microdissection (LCM). Here, we identify mRNA variants of the Erythropoietin Receptor (DA-EpoR) transcribed from alternative TSSs. Experimental validation and full-length cDNA cloning is integrated with gene expression analysis in the FANTOM5 database. In DA neurons, the EpoR gene encodes for a N-terminal truncated receptor. Based on STAT5 phosphorylation assays, we show that the new variant of N-terminally truncated EpoR acts as decoy when co-expressed with the full-length form. A similar isoform is also found in human. This work highlights new complexities in the regulation of Erythropoietin (EPO) signaling in the brain.

  13. Ciliary neurotrophic factor prevents degeneration of adult rat substantia nigra dopaminergic neurons in vivo.

    PubMed Central

    Hagg, T; Varon, S

    1993-01-01

    We have investigated the neuroprotective effects of recombinant human ciliary neurotrophic factor (CNTF) for injured dopaminergic neurons of the adult rat substantia nigra compacta. Fourteen days after a unilateral transection of the nigrostriatal pathway two-thirds of the neurons (identified by retrograde labeling) had degenerated. In sharp contrast, 73% (a few cases, > 90%) of this cell loss was prevented by continuous infusion of CNTF close to the injured neurons. However, CNTF did not prevent the disappearance of the transmitter-synthesizing enzyme tyrosine hydroxylase. Thus, CNTF has potent neurotrophic effects for injured adult rat dopaminergic substantia nigra neurons, whose degeneration plays a major causative role in Parkinson disease. Images Fig. 2 Fig. 3 PMID:8101002

  14. Oleoylethanolamide exerts partial and dose-dependent neuroprotection of substantia nigra dopamine neurons.

    PubMed

    Galan-Rodriguez, B; Suarez, J; Gonzalez-Aparicio, R; Bermudez-Silva, F J; Maldonado, R; Robledo, P; Rodriguez de Fonseca, F; Fernandez-Espejo, E

    2009-03-01

    Oleoylethanolamide (OEA), agonist of nuclear PPAR-alpha receptors and antagonist of vanilloid TRPV1 receptors, has been reported to show cytoprotective properties. In this study, OEA-induced neuroprotection has been tested in vitro and in vivo models of 6-OHDA-induced degeneration of substantia nigra dopamine neurons. First, PPAR-alpha receptors were confirmed to be located in the nigrostriatal circuit, these receptors being expressed by dopamine neurons of the substantia nigra, and intrinsic neurons and fibers bundles of the dorsal striatum. In the substantia nigra, their location was confined to the ventral tier. The in vitro study showed that 1 microM OEA exerted a significantly neuroprotective effect on cultured nigral dopamine neurons, effects following U-shaped dose-response curves. Regarding the in vivo study, rats were locally injected with OEA into the right striatum and vehicle into the left striatum 30 min before 6-OHDA-induced striatal lesion. In the short term, signals of heme oxygenase-1 (oxidation marker, 24 and 48 h post-lesion) and OX6 (reactive microglia marker, 96 h post-lesion) were found to be significantly less intense in the striatum pretreated with 5 microM OEA. In the long term (1 month), reduction in striatal TH and synaptophysin was less intense whether the right striatum was pretreated with 5 microM OEA, and nigral TH+ neuron death was significantly reduced after pretreatment with 1 and 5 microM OEA. In vivo effects also followed U-shaped dose-response curves. In conclusion, OEA shows U-shaped partial and dose-dependent neuroprotective properties both in vitro and in vivo models of substantia nigra dopamine neuron degeneration. The occurrence of U-shaped dose-response relationships normally suggests toxicity due to high drug concentration or that opposing intracellular pathways are activated by different OEA doses.

  15. Functional Dopaminergic Neurons in Substantia Nigra are Required for Transcranial Magnetic Stimulation-Induced Motor Plasticity.

    PubMed

    Hsieh, Tsung-Hsun; Huang, Ying-Zu; Rotenberg, Alexander; Pascual-Leone, Alvaro; Chiang, Yung-Hsiao; Wang, Jia-Yi; Chen, Jia-Jin J

    2015-07-01

    Repetitive magnetic stimulation (rTMS), including theta burst stimulation (TBS), is capable of modulating motor cortical excitability through plasticity-like mechanisms and might have therapeutic potential for Parkinson's disease (PD). An animal model would be helpful for elucidating the mechanism of rTMS that remain unclear and controversial. Here, we have established a TMS model in rat and applied this model to study the impact of substantia nigra dopamine neuron on TBS-induced motor plasticity in PD rats. In parallel with human results, continuous TBS (cTBS) successfully suppressed motor evoked potentials (MEPs), while MEPs increased after intermittent TBS (iTBS) in healthy rats. We then tested the effect of iTBS in early and advanced 6-hydroxydopamine (6-OHDA)-lesioned PD. Moreover, dopaminergic neurons in substantia nigra and rotation behavior were assessed to correlate with the amount of iTBS-induced plasticity. In results, iTBS-induced potentiation was reduced in early PD rats and was absent in advanced PD rats. Such reduction in plasticity strongly correlated with the dopaminergic cell loss and the count of rotation in PD rats. In conclusion, we have established a TMS PD rat model. With the help of this model, we confirmed the loss of domaninergic neurons in substantia nigra resulting in reduced rTMS-induced motor plasticity in PD.

  16. Proteomic characterization of neuromelanin granules isolated from human substantia nigra by laser-microdissection.

    PubMed

    Plum, Sarah; Steinbach, Simone; Attems, Johannes; Keers, Sharon; Riederer, Peter; Gerlach, Manfred; May, Caroline; Marcus, Katrin

    2016-11-14

    Neuromelanin is a complex polymer pigment found primarily in the dopaminergic neurons of human substantia nigra. Neuromelanin pigment is stored in granules including a protein matrix and lipid droplets. Neuromelanin granules are yet only partially characterised regarding their structure and function. To clarify the exact function of neuromelanin granules in humans, their enrichment and in-depth characterization from human substantia nigra is necessary. Previously published global proteome studies of neuromelanin granules in human substantia nigra required high tissue amounts. Due to the limited availability of human brain tissue we established a new method based on laser microdissection combined with mass spectrometry for the isolation and analysis of neuromelanin granules. With this method it is possible for the first time to isolate a sufficient amount of neuromelanin granules for global proteomics analysis from ten 10 μm tissue sections. In total 1,000 proteins were identified associated with neuromelanin granules. More than 68% of those proteins were also identified in previously performed studies. Our results confirm and further extend previously described findings, supporting the connection of neuromelanin granules to iron homeostasis and lysosomes or endosomes. Hence, this method is suitable for the donor specific enrichment and proteomic analysis of neuromelanin granules.

  17. Proteomic characterization of neuromelanin granules isolated from human substantia nigra by laser-microdissection

    PubMed Central

    Plum, Sarah; Steinbach, Simone; Attems, Johannes; Keers, Sharon; Riederer, Peter; Gerlach, Manfred; May, Caroline; Marcus, Katrin

    2016-01-01

    Neuromelanin is a complex polymer pigment found primarily in the dopaminergic neurons of human substantia nigra. Neuromelanin pigment is stored in granules including a protein matrix and lipid droplets. Neuromelanin granules are yet only partially characterised regarding their structure and function. To clarify the exact function of neuromelanin granules in humans, their enrichment and in-depth characterization from human substantia nigra is necessary. Previously published global proteome studies of neuromelanin granules in human substantia nigra required high tissue amounts. Due to the limited availability of human brain tissue we established a new method based on laser microdissection combined with mass spectrometry for the isolation and analysis of neuromelanin granules. With this method it is possible for the first time to isolate a sufficient amount of neuromelanin granules for global proteomics analysis from ten 10 μm tissue sections. In total 1,000 proteins were identified associated with neuromelanin granules. More than 68% of those proteins were also identified in previously performed studies. Our results confirm and further extend previously described findings, supporting the connection of neuromelanin granules to iron homeostasis and lysosomes or endosomes. Hence, this method is suitable for the donor specific enrichment and proteomic analysis of neuromelanin granules. PMID:27841354

  18. Iron accumulation in the substantia nigra of patients with Alzheimer disease and parkinsonism.

    PubMed

    Brar, Sonia; Henderson, David; Schenck, John; Zimmerman, Earl A

    2009-03-01

    Preliminary studies have shown an increase in iron accumulation in the substantia nigra but not in the hippocampus in patients with Parkinson disease without dementia and the reverse in patients with Alzheimer disease (AD) and no parkinsonism. To determine whether iron levels (measured as T2 shortening on magnetic resonance images) are greater in the substantia nigra of patients with AD who have parkinsonism than in those with AD alone. Case-control study. Albany Medical College, Albany, New York. Fifteen patients with only AD (controls) and 18 with AD as well as parkinsonism, aged 56 to 89 years, and with a total Clinical Dementia Rating of 5.0 to 11.5. Patients were selected according to the purity of their disease; patients with a Unified Parkinson's Disease Rating Scale motor score of 15 or greater were considered to have parkinsonism. Main Outcome Measure Area under the curve for short T2 (30 milliseconds) in patients with only AD vs patients with AD who developed parkinsonism. Patients who developed parkinsonism along with their existing dementia had significantly more iron in their substantia nigra than did patients with AD alone (P = .03, 2-sample t test). Iron accumulation may be a predictor of parkinsonism. The development of parkinsonism during the course of AD appears to be associated with the accumulation of iron, which in turn may contribute to the pathogenesis of neurologic decline.

  19. MPDZ EXPRESSION IN THE CAUDOLATERAL SUBSTANTIA NIGRA PARS RETICULATA IS CRUCIALLY INVOLVED IN ALCOHOL WITHDRAWAL

    PubMed Central

    Kruse, L.C.; Walter, N.A.R.; Buck, K.J.

    2014-01-01

    Association studies implicate the multiple PDZ domain protein (MUPP1/MPDZ) gene in risk for alcoholism in humans and alcohol withdrawal in mice. Although manipulation of the Mpdz gene by homologous recombination and bacterial artificial chromosome transgenesis has suggested that its expression affects alcohol withdrawal risk, the potential confounding effects of linked genes and developmental compensation currently limit interpretation. Here, using RNA interference, we directly test the impact of Mpdz expression on alcohol withdrawal severity and provide brain regional mechanistic information. Lentiviral-mediated delivery of Mpdz short hairpin RNA (shRNA) to the caudolateral substantia nigra pars reticulata significantly reduces Mpdz expression and exacerbates alcohol withdrawal convulsions compared to control mice delivered a scrambled shRNA. Neither baseline nor pentylenetetrazol enhanced convulsions differed between Mpdz shRNA and control animals, indicating that Mpdz expression in the caudolateral substantia nigra pars reticulata does not generally affect seizure susceptibility. To our knowledge, these represent the first in vivo Mpdz RNA interference analyses, and provide the first direct evidence that Mpdz expression impacts behavior. Our results confirm that Mpdz is a quantitative trait gene for alcohol withdrawal and demonstrate that its expression in the caudolateral substantia nigra pars reticulata is crucially involved in risk for alcohol withdrawal. PMID:25109596

  20. Protective Mechanisms Against Apoptic Neurodegeneration in the Substantia Nigra

    DTIC Science & Technology

    2001-09-01

    with Huntington cDNA and in Huntington’s disease brain. Pilot results show that intravenously injected, bone-marrow derived stem cells form neuron...for MPTP, the role of AP-1 transcription in this paradigm, and neurotoxicity of quinolinic acid in JNK knockout and Huntington’s disease mouse models

  1. AAV Vector-Mediated Gene Delivery to Substantia Nigra Dopamine Neurons: Implications for Gene Therapy and Disease Models

    PubMed Central

    Albert, Katrina; Voutilainen, Merja H.; Domanskyi, Andrii; Airavaara, Mikko

    2017-01-01

    Gene delivery using adeno-associated virus (AAV) vectors is a widely used method to transduce neurons in the brain, especially due to its safety, efficacy, and long-lasting expression. In addition, by varying AAV serotype, promotor, and titer, it is possible to affect the cell specificity of expression or the expression levels of the protein of interest. Dopamine neurons in the substantia nigra projecting to the striatum, comprising the nigrostriatal pathway, are involved in movement control and degenerate in Parkinson’s disease. AAV-based gene targeting to the projection area of these neurons in the striatum has been studied extensively to induce the production of neurotrophic factors for disease-modifying therapies for Parkinson’s disease. Much less emphasis has been put on AAV-based gene therapy targeting dopamine neurons in substantia nigra. We will review the literature related to targeting striatum and/or substantia nigra dopamine neurons using AAVs in order to express neuroprotective and neurorestorative molecules, as well as produce animal disease models of Parkinson’s disease. We discuss difficulties in targeting substantia nigra dopamine neurons and their vulnerability to stress in general. Therefore, choosing a proper control for experimental work is not trivial. Since the axons along the nigrostriatal tract are the first to degenerate in Parkinson’s disease, the location to deliver the therapy must be carefully considered. We also review studies using AAV-α-synuclein (α-syn) to target substantia nigra dopamine neurons to produce an α-syn overexpression disease model in rats. Though these studies are able to produce mild dopamine system degeneration in the striatum and substantia nigra and some behavioural effects, there are studies pointing to the toxicity of AAV-carrying green fluorescent protein (GFP), which is often used as a control. Therefore, we discuss the potential difficulties in overexpressing proteins in general in the substantia

  2. AAV Vector-Mediated Gene Delivery to Substantia Nigra Dopamine Neurons: Implications for Gene Therapy and Disease Models.

    PubMed

    Albert, Katrina; Voutilainen, Merja H; Domanskyi, Andrii; Airavaara, Mikko

    2017-02-08

    Gene delivery using adeno-associated virus (AAV) vectors is a widely used method to transduce neurons in the brain, especially due to its safety, efficacy, and long-lasting expression. In addition, by varying AAV serotype, promotor, and titer, it is possible to affect the cell specificity of expression or the expression levels of the protein of interest. Dopamine neurons in the substantia nigra projecting to the striatum, comprising the nigrostriatal pathway, are involved in movement control and degenerate in Parkinson's disease. AAV-based gene targeting to the projection area of these neurons in the striatum has been studied extensively to induce the production of neurotrophic factors for disease-modifying therapies for Parkinson's disease. Much less emphasis has been put on AAV-based gene therapy targeting dopamine neurons in substantia nigra. We will review the literature related to targeting striatum and/or substantia nigra dopamine neurons using AAVs in order to express neuroprotective and neurorestorative molecules, as well as produce animal disease models of Parkinson's disease. We discuss difficulties in targeting substantia nigra dopamine neurons and their vulnerability to stress in general. Therefore, choosing a proper control for experimental work is not trivial. Since the axons along the nigrostriatal tract are the first to degenerate in Parkinson's disease, the location to deliver the therapy must be carefully considered. We also review studies using AAV-a-synuclein (a-syn) to target substantia nigra dopamine neurons to produce an α-syn overexpression disease model in rats. Though these studies are able to produce mild dopamine system degeneration in the striatum and substantia nigra and some behavioural effects, there are studies pointing to the toxicity of AAV-carrying green fluorescent protein (GFP), which is often used as a control. Therefore, we discuss the potential difficulties in overexpressing proteins in general in the substantia nigra.

  3. Ultra-High Field MRI Post Mortem Structural Connectivity of the Human Subthalamic Nucleus, Substantia Nigra, and Globus Pallidus

    PubMed Central

    Plantinga, Birgit R.; Roebroeck, Alard; Kemper, Valentin G.; Uludağ, Kâmil; Melse, Maartje; Mai, Jürgen; Kuijf, Mark L.; Herrler, Andreas; Jahanshahi, Ali; ter Haar Romeny, Bart M.; Temel, Yasin

    2016-01-01

    Introduction: The subthalamic nucleus, substantia nigra, and globus pallidus, three nuclei of the human basal ganglia, play an important role in motor, associative, and limbic processing. The network of the basal ganglia is generally characterized by a direct, indirect, and hyperdirect pathway. This study aims to investigate the mesoscopic nature of these connections between the subthalamic nucleus, substantia nigra, and globus pallidus and their surrounding structures. Methods: A human post mortem brain specimen including the substantia nigra, subthalamic nucleus, and globus pallidus was scanned on a 7 T MRI scanner. High resolution diffusion weighted images were used to reconstruct the fibers intersecting the substantia nigra, subthalamic nucleus, and globus pallidus. The course and density of these tracks was analyzed. Results: Most of the commonly established projections of the subthalamic nucleus, substantia nigra, and globus pallidus were successfully reconstructed. However, some of the reconstructed fiber tracks such as the connections of the substantia nigra pars compacta to the other included nuclei and the connections with the anterior commissure have not been shown previously. In addition, the quantitative tractography approach showed a typical degree of connectivity previously not documented. An example is the relatively larger projections of the subthalamic nucleus to the substantia nigra pars reticulata when compared to the projections to the globus pallidus internus. Discussion: This study shows that ultra-high field post mortem tractography allows for detailed 3D reconstruction of the projections of deep brain structures in humans. Although the results should be interpreted carefully, the newly identified connections contribute to our understanding of the basal ganglia. PMID:27378864

  4. Characterization of the axon initial segment of mice substantia nigra dopaminergic neurons.

    PubMed

    González-Cabrera, Cristian; Meza, Rodrigo; Ulloa, Lorena; Merino-Sepúlveda, Paulina; Luco, Valentina; Sanhueza, Ana; Oñate-Ponce, Alejandro; Bolam, J Paul; Henny, Pablo

    2017-11-01

    The axon initial segment (AIS) is the site of initiation of action potentials and influences action potential waveform, firing pattern, and rate. In view of the fundamental aspects of motor function and behavior that depend on the firing of substantia nigra pars compacta (SNc) dopaminergic neurons, we identified and characterized their AIS in the mouse. Immunostaining for tyrosine hydroxylase (TH), sodium channels (Nav ) and ankyrin-G (Ank-G) was used to visualize the AIS of dopaminergic neurons. Reconstructions of sampled AIS of dopaminergic neurons revealed variable lengths (12-60 μm) and diameters (0.2-0.8 μm), and an average of 50% reduction in diameter between their widest and thinnest parts. Ultrastructural analysis revealed submembranous localization of Ank-G at nodes of Ranvier and AIS. Serial ultrathin section analysis and 3D reconstructions revealed that Ank-G colocalized with TH only at the AIS. Few cases of synaptic innervation of the AIS of dopaminergic neurons were observed. mRNA in situ hybridization of brain-specific Nav subunits revealed the expression of Nav 1.2 by most SNc neurons and a small proportion expressing Nav 1.6. The presence of sodium channels, along with the submembranous location of Ank-G is consistent with the role of AIS in action potential generation. Differences in the size of the AIS likely underlie differences in firing pattern, while the tapering diameter of AIS may define a trigger zone for action potentials. Finally, the conspicuous expression of Nav 1.2 by the majority of dopaminergic neurons may explain their high threshold for firing and their low discharge rate. © 2017 Wiley Periodicals, Inc.

  5. GIRK2 expression in dopamine neurons of the substantia nigra and ventral tegmental area.

    PubMed

    Reyes, Stefanie; Fu, Yuhong; Double, Kay; Thompson, Lachlan; Kirik, Deniz; Paxinos, George; Halliday, Glenda M

    2012-08-15

    G-protein-regulated inward-rectifier potassium channel 2 (GIRK2) is reported to be expressed only within certain dopamine neurons of the substantia nigra (SN), although very limited data are available in humans. We examined the localization of GIRK2 in the SN and adjacent ventral tegmental area (VTA) of humans and mice by using either neuromelanin pigment or immunolabeling with tyrosine hydroxylase (TH) or calbindin. GIRK2 immunoreactivity was found in nearly every human pigmented neuron or mouse TH-immunoreactive neuron in both the SN and VTA, although considerable variability in the intensity of GIRK2 staining was observed. The relative intensity of GIRK2 immunoreactivity in TH-immunoreactive neurons was determined; in both species nearly all SN TH-immunoreactive neurons had strong GIRK2 immunoreactivity compared with only 50-60% of VTA neurons. Most paranigral VTA neurons also contained calbindin immunoreactivity, and approximately 25% of these and nearby VTA neurons also had strong GIRK2 immunoreactivity. These data show that high amounts of GIRK2 protein are found in most SN neurons as well as in a proportion of nearby VTA neurons. The single previous human study may have been compromised by the fixation method used and the postmortem delay of their controls, whereas other studies suggesting that GIRK2 is located only in limited neuronal groups within the SN have erroneously included VTA regions as part of the SN. In particular, the dorsal layer of dopamine neurons directly underneath the red nucleus is considered a VTA region in humans but is commonly considered the dorsal tier of the SN in laboratory species.

  6. Oxygen and glucose deprivation (OGD)-induced spreading depression in the Substantia Nigra.

    PubMed

    Karunasinghe, Rashika N; Lipski, Janusz

    2013-08-21

    Spreading depression (SD) is a profound depolarization of neurons and glia that propagates in a wave-like manner across susceptible brain regions, and can develop during periods of compromised cellular energy such as ischemia, when it influences the severity of acute neuronal damage. Although SD has been well characterized in the cerebral cortex and hippocampus, little is known of this event in the Substantia Nigra (SN), a brainstem nucleus engaged in motor control and reward-related behavior. Transverse brain slices (250 μm; P21-23 rats) containing the SN were subject to oxygen and glucose deprivation (OGD) tests, modeling brain ischemia. SD developed in lateral aspects of the SN within 3.3±0.2 min of OGD onset, and spread through the Substantia Nigra pars reticulata (SNr), as indicated by fast-occurring and propagating increased tissue light transmittance and negative shift of extracellular DC potential. These events were associated with profound mitochondrial membrane depolarization (ΔΨm) throughout the SN, as demonstrated by increased Rhodamine 123 fluorescence. Extracellular recordings from individual SNr neurons indicated rapid depolarization followed by depolarizing block, while dopaminergic neurons in the Substantia Nigra pars compacta (SNc) showed inhibition of firing associated with hyperpolarization. SD evoked in the SNr was similar to OGD-induced SD in the CA1 region in hippocampal slices. In the hippocampus, SD also developed during anoxia or aglycemia alone (associated with less profound ΔΨm than OGD), while these conditions rarely led to SD in the SNr. Our results demonstrate that OGD consistently evokes SD in the SN, and that this phenomenon only involves the SNr. It remains to be established whether nigral SD contributes to neuronal damage associated with a sudden-onset form of Parkinson's disease known as 'vascular parkinsonism'.

  7. The substantia nigra is a major target for neurovirulent influenza A virus

    PubMed Central

    1995-01-01

    Clinical and immunohistochemical studies were done for 3-39 d on mice after intracerebral inoculation with the neurovirulent A/WSN/33 (H1N1; WSN) strain of influenza A virus, the nonneurovirulent A/Aichi/2/68 (H3N2; Aichi) strain, and two reassortant viruses between them. The virus strains with the WSN gene segment coding for neuraminidase induced meningoencephalitis in mice. The mice inoculated with the R96 strain, which has only the neuraminidase gene from the WSN strain, had mild symptoms and weak positive immunostaining to the anti-WSN antibody in meningeal regions. Both the WSN and R404BP strains, which contain the WSN gene segments coding for neuraminidase and matrix protein, were clearly neurovirulent both clinically and pathologically. On day 3 after inoculation with either of these two strains, WSN antigen was detected in meningeal and ependymal areas, neurons of circumventricular regions, the cerebral and cerebellar cortices, the substantia nigra zona compacta, and the ventral tegmental area. On day 7, meningeal reactions and neuronal staining were still seen, and advanced accumulation of the viral antigen was evident in the substantia nigra zona compacta and hippocampus. Double immunostaining demonstrated that the WSN antigen was only seen in neurons and not in microglia or reactive astrocytes. Immunostaining for the lectin maackia amurensis agglutinin, which recognizes the Neu5Ac alpha 2,3 Gal sequence, which serves as a binding site for influenza A virus on target cell membranes, showed that positive staining was localized in the ventral substantia nigra and hippocampus. These results suggest that neurovirulent influenza A viruses could be one of the causative agents for postencephalitic parkinsonism. PMID:7760004

  8. Near-Infrared Confocal Laser Reflectance Cytoarchitectural Imaging of the Substantia Nigra and Cerebellum in the Fresh Human Cadaver.

    PubMed

    Cheyuo, Cletus; Grand, Walter; Balos, Lucia L

    2017-01-01

    Cytoarchitectural neuroimaging remains critical for diagnosis of many brain diseases. Fluorescent dye-enhanced, near-infrared confocal in situ cellular imaging of the brain has been reported. However, impermeability of the blood-brain barrier to most fluorescent dyes limits clinical utility of this modality. The differential degree of reflectance from brain tissue with unenhanced near-infrared imaging may represent an alternative technique for in situ cytoarchitectural neuroimaging. We assessed the utility of unenhanced near-infrared confocal laser reflectance imaging of the cytoarchitecture of the cerebellum and substantia nigra in 2 fresh human cadaver brains using a confocal near-infrared laser probe. Cellular images based on near-infrared differential reflectance were captured at depths of 20-180 μm from the brain surface. Parts of the cerebellum and substantia nigra imaged using the probe were subsequently excised and stained with hematoxylin and eosin for histologic correlation. Near-infrared reflectance imaging revealed the 3-layered cytoarchitecture of the cerebellum, with Purkinje cells appearing hyperreflectant. In the substantia nigra, neurons appeared hyporeflectant with hyperreflectant neuromelanin cytoplasmic inclusions. Cytoarchitecture of the cerebellum and substantia nigra revealed on near-infrared imaging closely correlated with the histology on hematoxylin-eosin staining. We showed that unenhanced near-infrared reflectance imaging of fresh human cadaver brain can reliably identify and distinguish neurons and detailed cytoarchitecture of the cerebellum and substantia nigra. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Environment- and activity-dependent dopamine neurotransmitter plasticity in the adult substantia nigra.

    PubMed

    Aumann, Tim D

    2016-04-01

    The ability of neurons to change the amount or type of neurotransmitter they use, or 'neurotransmitter plasticity', is an emerging new form of adult brain plasticity. For example, it has recently been shown that neurons in the adult rat hypothalamus up- or down-regulate dopamine (DA) neurotransmission in response to the amount of light the animal receives (photoperiod), and that this in turn affects anxiety- and depressive-like behaviors (Dulcis et al., 2013). In this Chapter I consolidate recent evidence from my laboratory suggesting neurons in the adult mouse substantia nigra pars compacta (SNc) also undergo DA neurotransmitter plasticity in response to persistent changes in their electrical activity, including that driven by the mouse's environment or behavior. Specifically, we have shown that the amounts of tyrosine hydroxylase (TH, the rate-limiting enzyme in DA synthesis) gene promoter activity, TH mRNA and TH protein in SNc neurons increases or decreases after ∼20h of altered electrical activity. Also, infusion of ion-channel agonists or antagonists into the midbrain for 2 weeks results in ∼10% (∼500 neurons) more or fewer TH immunoreactive (TH+) SNc neurons, with no change in the total number of SNc neurons (TH+ and TH-). Targeting ion-channels mediating cell-autonomous pacemaker activity in, or synaptic input and afferent pathways to, SNc neurons are equally effective in this regard. In addition, exposing mice to different environments (sex pairing or environment enrichment) for 1-2 weeks induces ∼10% more or fewer TH+ SNc (and ventral tegmental area or VTA) neurons and this is abolished by concurrent blockade of synaptic transmission in midbrain. Although further research is required to establish SNc (and VTA) DA neurotransmitter plasticity, and to determine whether it alters brain function and behavior, it is an exciting prospect because: (1) It may play important roles in movement, motor learning, reward, motivation, memory and cognition; and (2

  10. Increased frequency of alpha-synuclein in the substantia nigra in human immunodeficiency virus infection.

    PubMed

    Khanlou, Negar; Moore, David J; Chana, Gursharan; Cherner, Mariana; Lazzaretto, Deborah; Dawes, Sharron; Grant, Igor; Masliah, Eliezer; Everall, Ian P

    2009-04-01

    The frequency of neurodegenerative markers among long surviving human immunodeficiency virus (HIV)-infected individuals is unknown, therefore, the present study investigated the frequency of alpha-synuclein, beta-amyloid, and HIV-associated brain pathology in the brains of older HIV-infected individuals. We examined the substantia nigra of 73 clinically well-characterized HIV-infected individuals aged 50 to 76 years from the National NeuroAIDS Tissue Consortium. We also examined the frontal and temporal cortical regions of a subset of 36 individuals. Neuritic alpha-synuclein expression was found in 16% (12/73) of the substantia nigra of the HIV+cases and none of the older control cases (0/18). beta-Amyloid deposits were prevalent and found in nearly all of the HIV+cases (35/36). Despite these increases of degenerative pathology, HIV-associated brain pathology was present in only 10% of cases. Among older HIV+adults, HIV-associated brain pathology does not appear elevated; however, the frequency of both alpha-synuclein and beta-amyloid is higher than that found in older healthy persons. The increased prevalence of alpha-synuclein and beta-amyloid in the brains of older HIV-infected individuals may predict an increased risk of developing neurodegenerative disease.

  11. Defective mitochondrial DNA homeostasis in the substantia nigra in Parkinson disease.

    PubMed

    Dölle, Christian; Flønes, Irene; Nido, Gonzalo S; Miletic, Hrvoje; Osuagwu, Nelson; Kristoffersen, Stine; Lilleng, Peer K; Larsen, Jan Petter; Tysnes, Ole-Bjørn; Haugarvoll, Kristoffer; Bindoff, Laurence A; Tzoulis, Charalampos

    2016-11-22

    Increased somatic mitochondrial DNA (mtDNA) mutagenesis causes premature aging in mice, and mtDNA damage accumulates in the human brain with aging and neurodegenerative disorders such as Parkinson disease (PD). Here, we study the complete spectrum of mtDNA changes, including deletions, copy-number variation and point mutations, in single neurons from the dopaminergic substantia nigra and other brain areas of individuals with Parkinson disease and neurologically healthy controls. We show that in dopaminergic substantia nigra neurons of healthy individuals, mtDNA copy number increases with age, maintaining the pool of wild-type mtDNA population in spite of accumulating deletions. This upregulation fails to occur in individuals with Parkinson disease, however, resulting in depletion of the wild-type mtDNA population. By contrast, neuronal mtDNA point mutational load is not increased in Parkinson disease. Our findings suggest that dysregulation of mtDNA homeostasis is a key process in the pathogenesis of neuronal loss in Parkinson disease.

  12. Verbascoside promotes the regeneration of tyrosine hydroxylase-immunoreactive neurons in the substantia nigra

    PubMed Central

    Liang, Jian-qing; Wang, Li; He, Jian-cheng; Hua, Xian-dong

    2016-01-01

    Tyrosine hydroxylase is a key enzyme in dopamine biosynthesis. Change in tyrosine hydroxylase expression in the nigrostriatal system is closely related to the occurrence and development of Parkinson's disease. Verbascoside, an extract from Radix Rehmanniae Praeparata has been shown to be clinically effective in treating Parkinson's disease. However, the underlying mechanisms remain unclear. It is hypothesized that the effects of verbascoside on Parkinson's disease are related to tyrosine hydroxylase expression change in the nigrostriatal system. Rat models of Parkinson's disease were established and verbascoside (60 mg/kg) was administered intraperitoneally once a day. After 6 weeks of verbascoside treatment, rat rotational behavior was alleviated; tyrosine hydroxylase mRNA and protein expression and the number of tyrosine hydroxylase-immunoreactive neurons in the rat right substantia nigra were significantly higher than the Parkinson's model group. These findings suggest that the mechanism by which verbascoside treats Parkinson's disease is related to the regeneration of tyrosine hydroxylase-immunoreactive neurons in the substantia nigra. PMID:26981096

  13. Defective mitochondrial DNA homeostasis in the substantia nigra in Parkinson disease

    PubMed Central

    Dölle, Christian; Flønes, Irene; Nido, Gonzalo S.; Miletic, Hrvoje; Osuagwu, Nelson; Kristoffersen, Stine; Lilleng, Peer K.; Larsen, Jan Petter; Tysnes, Ole-Bjørn; Haugarvoll, Kristoffer; Bindoff, Laurence A.; Tzoulis, Charalampos

    2016-01-01

    Increased somatic mitochondrial DNA (mtDNA) mutagenesis causes premature aging in mice, and mtDNA damage accumulates in the human brain with aging and neurodegenerative disorders such as Parkinson disease (PD). Here, we study the complete spectrum of mtDNA changes, including deletions, copy-number variation and point mutations, in single neurons from the dopaminergic substantia nigra and other brain areas of individuals with Parkinson disease and neurologically healthy controls. We show that in dopaminergic substantia nigra neurons of healthy individuals, mtDNA copy number increases with age, maintaining the pool of wild-type mtDNA population in spite of accumulating deletions. This upregulation fails to occur in individuals with Parkinson disease, however, resulting in depletion of the wild-type mtDNA population. By contrast, neuronal mtDNA point mutational load is not increased in Parkinson disease. Our findings suggest that dysregulation of mtDNA homeostasis is a key process in the pathogenesis of neuronal loss in Parkinson disease. PMID:27874000

  14. The substantia nigra and ventral tegmental dopaminergic neurons from development to degeneration.

    PubMed

    Fu, YuHong; Paxinos, George; Watson, Charles; Halliday, Glenda M

    2016-10-01

    The pathology of Parkinson's disease (PD) is characterised by the loss of neurons in the substantia nigra parcompacta (A9), which results in the insufficient release of dopamine, and the appearance of motor symptoms. Not all neurons in the A9 subregions degenerate in PD, and the dopaminergic (DA) neurons located in the neighboring ventral tegmental area (A10) are relatively resistant to PD pathogenesis. An increasing number of quantitative studies using human tissue samples of these brain regions have revealed important biological differences. In this review, we first describe current knowledge on the multi-segmental neuromere origin of these DA neurons. We then compare the continued transcription factor and protein expression profile and morphological differences distinguishing subregions within the A9 substantia nigra, and between A9 and A10 DA neurons. We conclude that the expression of three types of factors and proteins contributes to the diversity observed in these DA neurons and potentially to their differential vulnerability to PD. In particular, the specific axonal structure of A9 neurons and the way A9 neurons maintain their DA usage makes them easily exposed to energy deficits, calcium overload and oxidative stress, all contributing to their decreased survival in PD. We highlight knowledge gaps in our understanding of the cellular biomarkers for and their different functions in DA neurons, knowledge which may assist to identify underpinning disease mechansims that could be targeted for the treatment of any subregional dysfunction and loss of these DA neurons.

  15. Protection of the aged substantia nigra of the rat against oxidative damage by (-)-deprenyl.

    PubMed Central

    de la Cruz, C. P.; Revilla, E.; Steffen, V.; Rodríguez-Gómez, J. A.; Cano, J.; Machado, A.

    1996-01-01

    1. We have studied the effect of (-)-deprenyl on the oxidative damage that the rat substantia nigra suffers during aging. 2. (-)-Deprenyl (2 mg kg-1, three times a week) administered for two months, beginning at 22 months of age, produced a significant increase in tyrosine hydroxylase (TH) activity (2.67 +/- 0.40 and 3.64 +/- 0.38 nmol mg-1 protein h-1 in untreated aged rats and treated aged rats respectively, P < 0.05) and in TH amount (0.072 +/- 0.012 and 0.128 +/- 0.38 absorbance 405 nm in untreated aged and treated aged rats respectively, P < 0.05). 3. The proteins of aged rat substantia nigra showed a significant decrease of carbonyl groups in treated animals compared with saline-injected control rats (136.2 +/- 21.8 and 71.5 +/- 13.2 c.p.m. microgram-1 protein in untreated aged and treated aged rats respectively, P < 0.05). 4. The carbonyl groups measured in TH enzyme showed a statistically significant decrease (42.3%) after (-)-deprenyl treatment (471.4 +/- 73.0 and 271.9 +/- 50.00 c.p.m. in untreated aged and treated aged rats respectively, P < 0.001). 5. All these results suggest that oxidative damage produced during aging is prevented by (-)-deprenyl treatment and could explain the effect of this drug in Parkinson's disease (PD) and other degenerative diseases such as Alzheimer's disease. PMID:8732287

  16. Navigation-supported diagnosis of the substantia nigra by matching midbrain sonography and MRI

    NASA Astrophysics Data System (ADS)

    Salah, Zein; Weise, David; Preim, Bernhard; Classen, Joseph; Rose, Georg

    2012-03-01

    Transcranial sonography (TCS) is a well-established neuroimaging technique that allows for visualizing several brainstem structures, including the substantia nigra, and helps for the diagnosis and differential diagnosis of various movement disorders, especially in Parkinsonian syndromes. However, proximate brainstem anatomy can hardly be recognized due to the limited image quality of B-scans. In this paper, a visualization system for the diagnosis of the substantia nigra is presented, which utilizes neuronavigated TCS to reconstruct tomographical slices from registered MRI datasets and visualizes them simultaneously with corresponding TCS planes in realtime. To generate MRI tomographical slices, the tracking data of the calibrated ultrasound probe are passed to an optimized slicing algorithm, which computes cross sections at arbitrary positions and orientations from the registered MRI dataset. The extracted MRI cross sections are finally fused with the region of interest from the ultrasound image. The system allows for the computation and visualization of slices at a near real-time rate. Primary tests of the system show an added value to the pure sonographic imaging. The system also allows for reconstructing volumetric (3D) ultrasonic data of the region of interest, and thus contributes to enhancing the diagnostic yield of midbrain sonography.

  17. Dopamine transporter mRNA content in human substantia nigra decreases precipitously with age.

    PubMed Central

    Bannon, M J; Poosch, M S; Xia, Y; Goebel, D J; Cassin, B; Kapatos, G

    1992-01-01

    The dopamine transporter is the primary means of inactivating synaptic dopamine as well as a major site of action for psychostimulants (such as cocaine and amphetamine) and for neurotoxins that induce parkinsonism. In the present study, a human dopamine transporter partial cDNA clone obtained by polymerase chain reaction exhibited 87% and 89% identity at the nucleic acid and amino acid levels, respectively, with transmembrane domains 3-5 of the rat homolog. This clone was used to quantitate human dopamine transporter mRNA by nuclease protection assay. The postmortem content of dopamine transporter mRNA in the substantia nigrae of 18- to 57-yr-old subjects was relatively constant, while in subjects greater than 57 yr old, a precipitous (greater than 95%) decline in substantia nigra dopamine transporter mRNA was evident. In contrast, tyrosine hydroxylase mRNA in the same samples declined in a linear manner with increasing age. In situ hybridization experiments confirmed the profound loss of dopamine transporter gene expression in melanin-positive (presumptive dopamine) nigral neurons. These data may begin to shed light on compensatory changes occurring in human dopamine neurons during normal aging. Images PMID:1353885

  18. Hyperechogenicity of the Substantia Nigra in Parkinson's Disease: Insights from Two Brothers with Markedly Different Disease Durations

    PubMed Central

    Hall, Julie M.; Georgiades, Matthew J.; Hammond, Deborah A.; Feng, Xiaoting; Moustafa, Ahmed A.; Todd, Gabrielle

    2017-01-01

    We present clinical features and substantia nigra morphology for two brothers with Parkinson's disease (PD) aged 60 and 59 years. The brothers were diagnosed at 41 and 50 years of age, respectively. Both patients exhibited an abnormally large area of substantia nigra echogenicity bilaterally when viewed with transcranial ultrasound. The abnormality was similar in both brothers despite one having a much longer disease duration than the other. These findings further highlight that transcranial ultrasound is not associated with severity of clinical symptoms, but it might assist in the diagnosis of PD provided that it is combined with other variables known to precede PD. PMID:28168069

  19. Stimulation of the substantia nigra influences the specification of memory-guided saccades.

    PubMed

    Mahamed, Safraaz; Garrison, Tiffany J; Shires, Joel; Basso, Michele A

    2014-02-01

    In the absence of sensory information, we rely on past experience or memories to guide our actions. Because previous experimental and clinical reports implicate basal ganglia nuclei in the generation of movement in the absence of sensory stimuli, we ask here whether one output nucleus of the basal ganglia, the substantia nigra pars reticulata (nigra), influences the specification of an eye movement in the absence of sensory information to guide the movement. We manipulated the level of activity of neurons in the nigra by introducing electrical stimulation to the nigra at different time intervals while monkeys made saccades to different locations in two conditions: one in which the target location remained visible and a second in which the target location appeared only briefly, requiring information stored in memory to specify the movement. Electrical manipulation of the nigra occurring during the delay period of the task, when information about the target was maintained in memory, altered the direction and the occurrence of subsequent saccades. Stimulation during other intervals of the memory task or during the delay period of the visually guided saccade task had less effect on eye movements. On stimulated trials, and only when the visual stimulus was absent, monkeys occasionally (∼20% of the time) failed to make saccades. When monkeys made saccades in the absence of a visual stimulus, stimulation of the nigra resulted in a rotation of the endpoints ipsilaterally (∼2°) and increased the reaction time of contralaterally directed saccades. When the visual stimulus was present, stimulation of the nigra resulted in no significant rotation and decreased the reaction time of contralaterally directed saccades slightly. Based on these measurements, stimulation during the delay period of the memory-guided saccade task influenced the metrics of saccades much more than did stimulation during the same period of the visually guided saccade task. Because these effects

  20. Stimulation of the substantia nigra influences the specification of memory-guided saccades

    PubMed Central

    Mahamed, Safraaz; Garrison, Tiffany J.; Shires, Joel

    2013-01-01

    In the absence of sensory information, we rely on past experience or memories to guide our actions. Because previous experimental and clinical reports implicate basal ganglia nuclei in the generation of movement in the absence of sensory stimuli, we ask here whether one output nucleus of the basal ganglia, the substantia nigra pars reticulata (nigra), influences the specification of an eye movement in the absence of sensory information to guide the movement. We manipulated the level of activity of neurons in the nigra by introducing electrical stimulation to the nigra at different time intervals while monkeys made saccades to different locations in two conditions: one in which the target location remained visible and a second in which the target location appeared only briefly, requiring information stored in memory to specify the movement. Electrical manipulation of the nigra occurring during the delay period of the task, when information about the target was maintained in memory, altered the direction and the occurrence of subsequent saccades. Stimulation during other intervals of the memory task or during the delay period of the visually guided saccade task had less effect on eye movements. On stimulated trials, and only when the visual stimulus was absent, monkeys occasionally (∼20% of the time) failed to make saccades. When monkeys made saccades in the absence of a visual stimulus, stimulation of the nigra resulted in a rotation of the endpoints ipsilaterally (∼2°) and increased the reaction time of contralaterally directed saccades. When the visual stimulus was present, stimulation of the nigra resulted in no significant rotation and decreased the reaction time of contralaterally directed saccades slightly. Based on these measurements, stimulation during the delay period of the memory-guided saccade task influenced the metrics of saccades much more than did stimulation during the same period of the visually guided saccade task. Because these effects

  1. Oxidative stress-dependent changes in immune responses and cell death in the substantia nigra after ozone exposure in rat

    PubMed Central

    Rivas-Arancibia, Selva; Zimbrón, Luis Fernando Hernández; Rodríguez-Martínez, Erika; Maldonado, Perla D.; Borgonio Pérez, Gabino; Sepúlveda-Parada, María

    2015-01-01

    Parkinson's disease has been associated with the selective loss of neurons in the substantia nigra pars compacta. Increasing evidence suggests that oxidative stress plays a major role. The resulting increase in reactive oxygen species triggers a sequence of events that leads to cell damage, activation of microglia cells and neuroinflammatory responses. Our objective was to study whether chronic exposure to low doses of ozone, which produces oxidative stress itself, induces progressive cell death in conjunction with glial alterations in the substantia nigra. Animals were exposed to an ozone-free air stream (control) or to low doses of ozone for 7, 15, 30, 60, or 90 days. Each group underwent (1) spectrophotometric analysis for protein oxidation; (2) western blot testing for microglia reactivity and nuclear factor kappa B expression levels; and (3) immunohistochemistry for cytochrome c, GFAP, Iba-1, NFkB, and COX-2. Our results indicate that ozone induces an increase in protein oxidation levels, changes in activated astrocytes and microglia, and cell death. NFkB and cytochrome c showed an increase until 30 days of exposure, while cyclooxygenase 2 in the substantia nigra increased from 7 days up to 90 days of repetitive ozone exposure. These results suggest that oxidative stress caused by ozone exposure induces changes in inflammatory responses and progressive cell death in the substantia nigra in rats, which could also be occurring in Parkinson's disease. PMID:25999851

  2. Oxidative stress-dependent changes in immune responses and cell death in the substantia nigra after ozone exposure in rat.

    PubMed

    Rivas-Arancibia, Selva; Zimbrón, Luis Fernando Hernández; Rodríguez-Martínez, Erika; Maldonado, Perla D; Borgonio Pérez, Gabino; Sepúlveda-Parada, María

    2015-01-01

    Parkinson's disease has been associated with the selective loss of neurons in the substantia nigra pars compacta. Increasing evidence suggests that oxidative stress plays a major role. The resulting increase in reactive oxygen species triggers a sequence of events that leads to cell damage, activation of microglia cells and neuroinflammatory responses. Our objective was to study whether chronic exposure to low doses of ozone, which produces oxidative stress itself, induces progressive cell death in conjunction with glial alterations in the substantia nigra. Animals were exposed to an ozone-free air stream (control) or to low doses of ozone for 7, 15, 30, 60, or 90 days. Each group underwent (1) spectrophotometric analysis for protein oxidation; (2) western blot testing for microglia reactivity and nuclear factor kappa B expression levels; and (3) immunohistochemistry for cytochrome c, GFAP, Iba-1, NFkB, and COX-2. Our results indicate that ozone induces an increase in protein oxidation levels, changes in activated astrocytes and microglia, and cell death. NFkB and cytochrome c showed an increase until 30 days of exposure, while cyclooxygenase 2 in the substantia nigra increased from 7 days up to 90 days of repetitive ozone exposure. These results suggest that oxidative stress caused by ozone exposure induces changes in inflammatory responses and progressive cell death in the substantia nigra in rats, which could also be occurring in Parkinson's disease.

  3. Encephalitis Lethargica With Isolated Substantia Nigra Lesions Followed by a Second Encephalitis in a Child With Humoral Immunodeficiency.

    PubMed

    Yang, Lu; Jia, Guijuan; Li, Baomin; Lei, Gefei; Sun, Ruopeng

    2015-12-01

    Encephalitis lethargica is an encephalitic illness with multiple nervous system symptoms. Lesions only involving substantia nigra on magnetic resonance imaging are uncommon, especially in children. A second encephalitis illness after encephalitis lethargica has never been reported before. We describe a 7-year-old boy with humoral immunity deficiency who developed encephalitis lethargica associated with bilateral substantia nigra lesions on magnetic resonance imaging. After a nearly complete recovery, he developed encephalitis once again. He was diagnosed with encephalitis lethargica with somnolence, akinetic mutism, and ophthalmoplegia after intermittent fever. Cerebrospinal fluid pleocytosis and positive oligoclonal bands were documented. Symmetrical substantia nigra lesions on high-intensity magnetic resonance imaging gradually evolved into a liquid signal. He had almost recovered when he developed fatigue and hypersomnia and was diagnosed with encephalitis again, supported by mild pleocytosis in cerebrospinal fluid and subcortical white matter lesions in the frontal lobes. His symptoms resolved following administration of corticosteroids and immunoglobulins. This is the first report of an immune-deficient child to develop encephalitis lethargica with isolated substantia nigra lesions on magnetic resonance imaging and a second encephalitis illness after recovery from encephalitis lethargica. Copyright © 2015. Published by Elsevier Inc.

  4. Cav1.3 channels control D2-autoreceptor responses via NCS-1 in substantia nigra dopamine neurons

    PubMed Central

    Dragicevic, Elena; Poetschke, Christina; Duda, Johanna; Schlaudraff, Falk; Lammel, Stephan; Schiemann, Julia; Fauler, Michael; Hetzel, Andrea; Watanabe, Masahiko; Lujan, Rafael; Malenka, Robert C.; Striessnig, Joerg

    2014-01-01

    Dopamine midbrain neurons within the substantia nigra are particularly prone to degeneration in Parkinson’s disease. Their selective loss causes the major motor symptoms of Parkinson’s disease, but the causes for the high vulnerability of SN DA neurons, compared to neighbouring, more resistant ventral tegmental area dopamine neurons, are still unclear. Consequently, there is still no cure available for Parkinson’s disease. Current therapies compensate the progressive loss of dopamine by administering its precursor l-DOPA and/or dopamine D2-receptor agonists. D2-autoreceptors and Cav1.3-containing L-type Ca2+ channels both contribute to Parkinson’s disease pathology. L-type Ca2+ channel blockers protect SN DA neurons from degeneration in Parkinson’s disease and its mouse models, and they are in clinical trials for neuroprotective Parkinson’s disease therapy. However, their physiological functions in SN DA neurons remain unclear. D2-autoreceptors tune firing rates and dopamine release of SN DA neurons in a negative feedback loop through activation of G-protein coupled potassium channels (GIRK2, or KCNJ6). Mature SN DA neurons display prominent, non-desensitizing somatodendritic D2-autoreceptor responses that show pronounced desensitization in PARK-gene Parkinson’s disease mouse models. We analysed surviving human SN DA neurons from patients with Parkinson’s disease and from controls, and detected elevated messenger RNA levels of D2-autoreceptors and GIRK2 in Parkinson’s disease. By electrophysiological analysis of postnatal juvenile and adult mouse SN DA neurons in in vitro brain-slices, we observed that D2-autoreceptor desensitization is reduced with postnatal maturation. Furthermore, a transient high-dopamine state in vivo, caused by one injection of either l-DOPA or cocaine, induced adult-like, non-desensitizing D2-autoreceptor responses, selectively in juvenile SN DA neurons, but not ventral tegmental area dopamine neurons. With pharmacological

  5. Cannabinoids excite dopamine neurons in the ventral tegmentum and substantia nigra.

    PubMed

    French, E D; Dillon, K; Wu, X

    1997-02-10

    Extracellular recordings were used to determine the effects of cannabinoids on the activity of dopamine neurons within the ventral tegmental area (VTA) and substantia nigra pars compacta (SNC). Systemic administration of the natural psychoactive cannabinoid delta 9-tetrahydrocannabinol (delta 9-THC) and the synthetic cannabimimetic aminoalkylindole WIN 55,212-2 produced dose-dependent increases in firing rate and burst firing in both neuronal populations. These effects appear to be specific as the non-psychoactive cannabidiol and the inactive enantiomer WIN 55,212-3 failed to alter either parameter of neuronal excitability. Furthermore, dopamine neurons in the VTA were more sensitive than those in the SNC to the stimulatory actions of delta 9-THC. These results may provide a mechanism by which psychoactive cannabinoids increase extracellular dopamine levels in mesolimbic and striatal tissues, and thereby contribute to the reinforcing effects of marijuana.

  6. Cellular distribution and localisation of iron in adult rat brain ( substantia nigra)

    NASA Astrophysics Data System (ADS)

    Meinecke, Ch.; Morawski, M.; Reinert, T.; Arendt, T.; Butz, T.

    2006-08-01

    Iron appears to be one of the main factors in the metal induced neurodegeneration. Quantitative information on cellular, sub-cellular and cell specific distributions of iron is therefore important to assess. The investigations reported here were carried out on a brain from an adult rat. Therefore, 6 μm thick embedded, unstained brain sections containing the midbrain (substantia nigra, SN) were analysed. Particle induced X-ray emission (PIXE) using a focussed proton beam (beam - diameter app. 1 μm) was performed to determine the quantitative iron content on a cellular and sub-cellular level. The integral analysis shows that the iron content in the SN pars reticulata is twice as high than in the SN pars compacta. The analysis of the iron content on the cellular level revealed no remarkable differences between glia cells and neurons. This is in contrast to other studies using staining techniques.

  7. Effects of barbiturates on ATP-sensitive K channels in rat substantia nigra.

    PubMed

    Ohtsuka, T; Ishiwa, D; Kamiya, Y; Itoh, H; Nagata, I; Saito, Y; Yamada, Y; Sumitomo, M; Andoh, T

    2006-01-01

    ATP-sensitive K channels are widely expressed in cytoplasmic membranes of neurons, and they couple cell metabolism to excitability. They are thought to be involved in neuroprotection against cell damage during hypoxia, ischemia and excitotoxicity by hyperpolarizing neurons and reducing excitability. Although barbiturates are often used in patients with brain ischemia, the effects of these agents on neuronal ATP-sensitive K channels have not been clarified. We studied the effects of thiopental and pentobarbital on surface ATP-sensitive K channels in principal neurons of rat substantia nigra pars compacta. Whole cell voltage- and current-clamp recordings were made using rat midbrain slices. ATP-sensitive K channels were activated by intracellular dialysis with an ATP-free pipette solution during perfusion with a glucose-free solution. When the pipette solution contained 4mM ATP and the perfusing solution contained 25 mM glucose, the membrane current at -60 mV remained stable. When intracellular ATP was depleted, hyperpolarization and an outward current developed slowly. Although thiopental did not affect the membrane current in the presence of ATP and glucose, it reversibly inhibited the hyperpolarization and outward current induced by intracellular ATP depletion at 100 and 300 microM. Thiopental reduced the ATP depletion-induced outward current by 4.7%, 36.7% and 87% at 30, 100 and 300 microM, respectively. The high dose of pentobarbital also exhibited similar effects on ATP-sensitive K channels. These results suggest that barbiturates at high concentrations but not at clinically relevant concentrations inhibit ATP-sensitive K channels activated by intracellular ATP depletion in rat substantia nigra.

  8. Functional heterogeneity of NMDA receptors in rat substantia nigra pars compacta and reticulata neurones

    PubMed Central

    Suárez, F.; Zhao, Q.; Monaghan, D. T.; Jane, D. E.; Jones, S.; Gibb, A. J.

    2014-01-01

    The nigra substantia nigra pars compacta (SNc) and substantia pars reticulata (SNr) form two major basal ganglia components with different functional roles. SNc dopaminergic (DA) neurones are vulnerable to cell death in Parkinson's disease, and NMDA receptor activation is a potential contributing mechanism. We have investigated the sensitivity of whole-cell and synaptic NMDA responses to intracellular ATP and GTP application in the SNc and SNr from rats on postnatal day (P) 7 and P28. Both NMDA current density (pA/pF) and desensitization to prolonged or repeated NMDA application were greater in the SNr than in the SNc. When ATP levels were not supplemented, responses to prolonged NMDA administration desensitized in P7 SNc DA neurones but not at P28. At P28, SNr neurones desensitized more than SNc neurones, with or without added ATP. Responses to brief NMDA applications and synaptic NMDA currents were not sensitive to inclusion of ATP in the pipette solution. To investigate these differences between the SNc and SNr, NR2 subunit-selective antagonists were tested. NMDA currents were inhibited by ifenprodil (10 μm) and UBP141 (4 μm), but not by Zn2+ (100 nm), in both the SNr and SNc, suggesting that SNc and SNr neurones express similar receptor subunits; NR2B and NR2D, but not NR2A. The different NMDA response properties in the SNc and SNr may be caused by differences in receptor modulation and/or trafficking. The vulnerability of SNc DA neurones to cell death is not correlated with NMDA current density or receptor subtypes, but could in part be related to inadequate NMDA receptor desensitization. PMID:20618827

  9. Enhanced training protects memory against amnesia produced by concurrent inactivation of amygdala and striatum, amygdala and substantia nigra, or striatum and substantia nigra

    PubMed Central

    Salado-Castillo, Rigoberto; Sánchez-Alavéz, Manuel; Quirarte, Gina L.; Martínez García, María Isabel; Prado-Alcalá, Roberto A.

    2011-01-01

    Memory is markedly impaired when normal activity of any of a number of cerebral structures is disturbed after a learning experience. A growing body of evidence indicates, however, that such interference with neuronal function becomes negligible when the learning experience is significantly enhanced. We now report on the effects of enhanced training on retention after temporary inactivation of cerebral nuclei known to be involved in memory, namely the substantia nigra (SN), striatum (STR), and amygdala (AMY). When training was conducted with a relatively low intensity of footshock (1.0 mA), post-training infusion of lidocaine into the SN, STR, or AMY produced a marked memory deficit. Increasing the aversive stimulation to 2.0 mA protected memory from the amnesic effect of intranigral lidocaine, but there was still a deficit after its infusion into the STR and AMY. Administration of lidocaine into each of these nuclei, in the groups that had been trained with 3.0 mA, was completely ineffective in producing alterations in memory consolidation. Simultaneous infusion of lidocaine into STR + SN, AMY + SN, or AMY + STR was also ineffective in altering memory formation when the highest footshock intensity was used for training. To our knowledge, this is the first demonstration that an enhanced learning experience guards against memory deficits after simultaneous temporary interruption of neural activity of brain nuclei heretofore thought to be necessary for memory formation. These findings support the proposition that brain structures involved in memory processing are functionally connected in series during memory consolidation and that, after an enhanced learning experience, these structures become functionally connected in parallel. PMID:22203796

  10. Rapid increase of Nurr1 expression in the substantia nigra after 6-hydroxydopamine lesion in the striatum of the rat.

    PubMed

    Ojeda, Viviana; Fuentealba, José Antonio; Galleguillos, Danny; Andrés, María Estela

    2003-09-01

    Nurr1 is a transcription factor essential for the genesis of ventral dopaminergic neurons. In this study, we investigated the expression of Nurr1 protein and mRNA in the adult rat brain by using immunohistochemistry and in situ hybridization, respectively. Another aim of our study was to investigate Nurr1 expression in substantia nigra after dopamine depletion induced by the injection of 6-hydroxydopamine in the striatum. We observed that Nurr1 mRNA and protein are expressed in several brain regions, including cortex, hippocampus, substantia nigra, and ventral tegmental area, in agreement with previous reports using in situ hybridization. Additionally, we found that Nurr1 is expressed in brain regions that have not been previously reported, such as striatum, septum, and superior colliculus. Highest levels of expression were found in cortex, medial septum, dentate gyrus, some hypothalamic nuclei, and substantia nigra. Interestingly, we observed that, in the superior colliculus, Nurr1 protein is localized in the cytoplasm of cells, whereas, in other regions, it was localized mainly in the nuclei, suggesting that Nurr1 subcellular localization is regulated and may have functional implications. Dopamine depletion induced by an injection of 6-hydroxydopamine into the striatum produced an increase in the number of cells expressing Nurr1 mRNA and protein in both substantia nigra compacta and substantia nigra reticulata, ipsilateral and contralateral to the lesioned side, measured 24 hr after the 6-hydroxydopamine injection. These results suggest that Nurr1 may be involved in many neuronal functions in the adult central nervous system and, in particular, might be related to the compensation processes that take place in dopaminergic cells in order to normalize extracellular dopamine levels in the striatum. Copyright 2003 Wiley-Liss, Inc.

  11. Aging causes morphological alterations in astrocytes and microglia in human substantia nigra pars compacta.

    PubMed

    Jyothi, H J; Vidyadhara, D J; Mahadevan, Anita; Philip, Mariamma; Parmar, Suresh Kumar; Manohari, S Gowri; Shankar, S K; Raju, Trichur R; Alladi, Phalguni Anand

    2015-12-01

    Age being a risk factor for Parkinson's disease, assessment of age-related changes in the human substantia nigra may elucidate its pathogenesis. Increase in Marinesco bodies, α-synuclein, free radicals and so forth in the aging nigral neurons are clear indicators of neurodegeneration. Here, we report the glial responses in aging human nigra. The glial numbers were determined on Nissl-stained sections. The expression of glial fibrillary acidic protein, S100β, 2', 3'-cyclic nucleotide 3' phosphodiesterase, and Iba1 was assessed on cryosections of autopsied midbrains by immunohistochemistry and densitometry. The glial counts showed a biphasic increase, of which, the first prominent phase from fetal age to birth could be physiological gliogenesis whereas the second one after middle age may reflect mild age-related gliosis. Astrocytic morphology was altered, but glial fibrillary acidic protein expression increased only mildly. Presence of type-4 microglia suggests possibility of neuroinflammation. Mild reduction in 2', 3'-cyclic nucleotide 3' phosphodiesterase-labeled area denotes subtle demyelination. Stable age-related S100β expression indicates absence of calcium overload. Against the expected prominent gliosis, subtle age-related morphological alterations in human nigral glia attribute them a participatory role in aging.

  12. Metabolism Regulates the Spontaneous Firing of Substantia Nigra Pars Reticulata Neurons via KATP and Nonselective Cation Channels

    PubMed Central

    Lutas, Andrew; Birnbaumer, Lutz

    2014-01-01

    Neurons use glucose to fuel glycolysis and provide substrates for mitochondrial respiration, but neurons can also use alternative fuels that bypass glycolysis and feed directly into mitochondria. To determine whether neuronal pacemaking depends on active glucose metabolism, we switched the metabolic fuel from glucose to alternative fuels, lactate or β-hydroxybutyrate, while monitoring the spontaneous firing of GABAergic neurons in mouse substantia nigra pars reticulata (SNr) brain slices. We found that alternative fuels, in the absence of glucose, sustained SNr spontaneous firing at basal rates, but glycolysis may still be supported by glycogen in the absence of glucose. To prevent any glycogen-fueled glycolysis, we directly inhibited glycolysis using either 2-deoxyglucose or iodoacetic acid. Inhibiting glycolysis in the presence of alternative fuels lowered SNr firing to a slower sustained firing rate. Surprisingly, we found that the decrease in SNr firing was not mediated by ATP-sensitive potassium (KATP) channel activity, but if we lowered the perfusion flow rate or omitted the alternative fuel, KATP channels were activated and could silence SNr firing. The KATP-independent slowing of SNr firing that occurred with glycolytic inhibition in the presence of alternative fuels was consistent with a decrease in a nonselective cationic conductance. Although mitochondrial metabolism alone can prevent severe energy deprivation and KATP channel activation in SNr neurons, active glucose metabolism appears important for keeping open a class of ion channels that is crucial for the high spontaneous firing rate of SNr neurons. PMID:25471572

  13. Repetitive administration of tetrabenazine induces irreversible changes in locomotion and morphology of the substantia nigra in rats.

    PubMed

    Satou, T; Anderson, A J; Itoh, T; Tamai, Y; Hayashi, Y; Hashimoto, S

    2001-09-01

    We investigated the effects of a 7 day repetitive administration of tetrabenazine (TBZ), which depletes monoamines, on both locomotor behavior and histomorphometrial findings of substantia nigra in rats. These results were compared with the effects of a single dose of TBZ, which is a common paradigm in animal models of depression. A single dose of TBZ causes reversible decrease of voluntary movement and no histological changes. In contrast, as for repetitive administration, this experiment demonstrated irreversible and significant decrease in spontaneous locomotion, as well as histological changes in the neurons of the substantia nigra pars compacta. These results have led us to propose that prolonged TBZ administration could provide a novel and useful model for the behavioral characteristics and anatomical pathology of Parkinson's disease as one of the oxidative stress models induced by abnormal dopamine metabolism.

  14. Substantia nigra pars reticulata neurons code initiation of a serial pattern: implications for natural action sequences and sequential disorders.

    PubMed

    Meyer-Luehmann, Melanie; Thompson, Jeffrey F; Berridge, Kent C; Aldridge, J Wayne

    2002-10-01

    Sequences of movements are initiated abnormally in neurological disorders involving basal ganglia dysfunction, such as Parkinson's disease or Tourette's syndrome. The substantia nigra pars reticulata (SNpr) is one of the two primary output structures of the basal ganglia. However, little is known about how substantia nigra mediates the initiation of normal movement sequences. We studied its role in coding initiation of a sequentially stereotyped but natural movement sequence by recording neuronal activity in SNpr during behavioural performance of 'syntactic grooming chains'. These are rule-governed sequences of up to 25 grooming movements emitted in four predictable (syntactic) phases, which occur spontaneously during grooming behaviour by rats and other rodents. Our results show that neuronal activation in central SNpr codes the onset of this entire rule-governed sequential pattern of grooming actions, not elemental grooming movements. We conclude that the context of sequential pattern may be more important than the elemental motor parameters in determining SNpr neuronal activation.

  15. Electroacupuncture-regulated neurotrophic factor mRNA expression in the substantia nigra of Parkinson's disease rats.

    PubMed

    Wang, Shuju; Fang, Jianqiao; Ma, Jun; Wang, Yanchun; Liang, Shaorong; Zhou, Dan; Sun, Guojie

    2013-02-25

    Acupuncture for the treatment of Parkinson's disease has a precise clinical outcome. This study investigated the effect of electroacupuncture at Fengfu (GV16) and Taichong (LR3) acupoints in rat models of Parkinson's disease induced by subcutaneous injection of rotenone into rat neck and back. Reverse transcription-PCR demonstrated that brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor mRNA expression was significantly increased in the substantia nigra of rat models of Parkinson's disease, and that abnormal behavior of rats was significantly improved following electroacupuncture treatment. These results indicated that electroacupuncture treatment upregulated brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor mRNA expression in the substantia nigra of rat models of Parkinson's disease. Thus, electroacupuncture may be useful in the treatment of Parkinson's disease.

  16. Treadmill training improves motor skills and increases tyrosine hydroxylase immunoreactivity in the substantia nigra pars compacta in diabetic rats.

    PubMed

    Nascimento, Patrícia S do; Lovatel, Gisele A; Barbosa, Sílvia; Ilha, Jocemar; Centenaro, Lígia A; Malysz, Tais; Xavier, Léder L; Schaan, Beatriz D; Achaval, Matilde

    2011-03-25

    The aim of this study was to evaluate the effects of treadmill training on motor skills and immunoreactivity to tyrosine hydroxylase in the substantia nigra pars compacta and ventral tegmental area from diabetic rats induced by streptozotocin. Male Wistar rats were divided into three groups: control, diabetic and trained diabetic. Treadmill training was performed for 8weeks. Blood glucose concentrations and body weight were evaluated 48h after diabetes induction and every 30days thereafter. Motor skills were evaluated on the rotarod and open field tests. Then, animals were transcardially perfused and the brains were post-fixed, cryoprotected and sectioned in a cryostat. Immunohistochemistry for tyrosine hydroxylase analyses was done in the ventral tegmental area and in the substantia nigra. Motor skills showed that diabetic animals had a decrease in the latency to fall and enhanced number of falls in the rotarod test compared to control and trained diabetic animals. In the open field, diabetic animals had a decrease in the number of crossed squares, rearings and spent a less time moving compared to control and trained diabetic animals. In diabetic animals, optical densitometry of immunohistochemistry showed that tyrosine hydroxylase reaction decreased in the ventral tegmental area and in the neurons and process in the substantia nigra. In the later region, that decrease was reversed by treadmill training. In conclusion, we demonstrated that treadmill training can reverse the loss of the motor skills, which was correlated to tyrosine hydroxylase immunoreactivity in the substantia nigra of diabetic animals without pharmacological treatment. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Lateral Asymmetry and Spatial Difference of Iron Deposition in the Substantia Nigra of Patients with Parkinson Disease Measured with Quantitative Susceptibility Mapping.

    PubMed

    Azuma, M; Hirai, T; Yamada, K; Yamashita, S; Ando, Y; Tateishi, M; Iryo, Y; Yoneda, T; Kitajima, M; Wang, Y; Yamashita, Y

    2016-05-01

    Quantitative susceptibility mapping is useful for assessing iron deposition in the substantia nigra of patients with Parkinson disease. We aimed to determine whether quantitative susceptibility mapping is useful for assessing the lateral asymmetry and spatial difference in iron deposits in the substantia nigra of patients with Parkinson disease. Our study population comprised 24 patients with Parkinson disease and 24 age- and sex-matched healthy controls. They underwent 3T MR imaging by using a 3D multiecho gradient-echo sequence. On reconstructed quantitative susceptibility mapping, we measured the susceptibility values in the anterior, middle, and posterior parts of the substantia nigra, the whole substantia nigra, and other deep gray matter structures in both hemibrains. To identify the more and less affected hemibrains in patients with Parkinson disease, we assessed the severity of movement symptoms for each hemibrain by using the Unified Parkinson's Disease Rating Scale. In the posterior substantia nigra of patients with Parkinson disease, the mean susceptibility value was significantly higher in the more than the less affected hemibrain substantia nigra (P < .05). This value was significantly higher in both the more and less affected hemibrains of patients with Parkinson disease than in controls (P < .05). Asymmetry of the mean susceptibility values was significantly greater for patients than controls (P < .05). Receiver operating characteristic analysis showed that quantitative susceptibility mapping of the posterior substantia nigra in the more affected hemibrain provided the highest power for discriminating patients with Parkinson disease from the controls. Quantitative susceptibility mapping is useful for assessing the lateral asymmetry and spatial difference of iron deposition in the substantia nigra of patients with Parkinson disease. © 2016 by American Journal of Neuroradiology.

  18. Substantia nigra vulnerability after a single moderate diffuse brain injury in the rat

    PubMed Central

    van Bregt, Daniel R.; Thomas, Theresa Currier; Hinzman, Jason M.; Cao, Tuoxin; Liu, Mei; Bing, Guoying; Gerhardt, Greg A.; Pauly, James R.; Lifshitz, Jonathan

    2012-01-01

    Dementia and parkinsonism are late-onset symptoms associated with repetitive head injury, as documented in multiple contact-sport athletes. Clinical symptomatology is the likely phenotype of chronic degeneration and circuit disruption in the substantia nigra (SN). To investigate the initiating neuropathology, we hypothesize that a single diffuse brain injury is sufficient to initiate SN neuropathology including neuronal loss, vascular disruption and microglial activation, contributing to neurodegeneration and altered dopamine regulation. Adult, male Sprague-Dawley rats were subjected to sham or moderate midline fluid percussion brain injury. Stereological estimates indicated a significant 44% loss of the estimated total neuron number in the SN at 28-days post-injury, without atrophy of neuronal nuclear volumes, including 25% loss of tyrosine hydroxylase positive neurons by 28-days post-injury. Multi-focal vascular compromise occurred 1–2 days post-injury, with ensuing microglial activation (significant 40% increase at 4-days). Neurodegeneration (silver-stain technique) encompassed on average 21% of the SN by 7-days post-injury and increased to 29% by 28-days compared to sham (1%). Whole tissue SN, but not striatum, dopamine metabolism was altered at 28-days post-injury, without appreciable gene or protein changes in dopamine synthesis or regulation elements. Together, single moderate diffuse brain injury resulted in SN neurovascular pathology potentially associated with neuroinflammation or dopamine dysregulation. Compensatory mechanisms may preserve dopamine signaling acutely, but subsequent SN damage with aging or additional injury may expose clinical symptomatology of motor ataxias and dementia. PMID:22178300

  19. Dissociation between iron accumulation and ferritin upregulation in the aged substantia nigra: attenuation by dietary restriction

    PubMed Central

    Walker, Thomas; Michaelides, Christos; Ekonomou, Antigoni; Geraki, Kalotina; Parkes, Harold G; Suessmilch, Maria; Herlihy, Amy H; Crum, William R; So, Po-Wah

    2016-01-01

    Despite regulation, brain iron increases with aging and may enhance aging processes including neuroinflammation. Increases in magnetic resonance imaging transverse relaxation rates, R2 and R2*, in the brain have been observed during aging. We show R2 and R2* correlate well with iron content via direct correlation to semi-quantitative synchrotron-based X-ray fluorescence iron mapping, with age-associated R2 and R2* increases reflecting iron accumulation. Iron accumulation was concomitant with increased ferritin immunoreactivity in basal ganglia regions except in the substantia nigra (SN). The unexpected dissociation of iron accumulation from ferritin-upregulation in the SN suggests iron dyshomeostasis in the SN. Occurring alongside microgliosis and astrogliosis, iron dyshomeotasis may contribute to the particular vulnerability of the SN. Dietary restriction (DR) has long been touted to ameliorate brain aging and we show DR attenuated agerelated in vivo R2 increases in the SN over ages 7 – 19 months, concomitant with normal iron-induction of ferritin expression and decreased microgliosis. Iron is known to induce microgliosis and conversely, microgliosis can induce iron accumulation, which of these may be the initial pathological aging event warrants further investigation. We suggest iron chelation therapies and anti-inflammatory treatments may be putative ‘antibrain aging’ therapies and combining these strategies may be synergistic. PMID:27743512

  20. The inhibitory microcircuit of the substantia nigra provides feedback gain control of the basal ganglia output

    PubMed Central

    Brown, Jennifer; Pan, Wei-Xing; Dudman, Joshua Tate

    2014-01-01

    Dysfunction of the basal ganglia produces severe deficits in the timing, initiation, and vigor of movement. These diverse impairments suggest a control system gone awry. In engineered systems, feedback is critical for control. By contrast, models of the basal ganglia highlight feedforward circuitry and ignore intrinsic feedback circuits. In this study, we show that feedback via axon collaterals of substantia nigra projection neurons control the gain of the basal ganglia output. Through a combination of physiology, optogenetics, anatomy, and circuit mapping, we elaborate a general circuit mechanism for gain control in a microcircuit lacking interneurons. Our data suggest that diverse tonic firing rates, weak unitary connections and a spatially diffuse collateral circuit with distinct topography and kinetics from feedforward input is sufficient to implement divisive feedback inhibition. The importance of feedback for engineered systems implies that the intranigral microcircuit, despite its absence from canonical models, could be essential to basal ganglia function. DOI: http://dx.doi.org/10.7554/eLife.02397.001 PMID:24849626

  1. Chronic intrastriatal dopamine infusions in rats with unilateral lesions of the substantia nigra

    SciTech Connect

    Hargraves, R.; Freed, W.J.

    1987-03-09

    This study examined the effects of continuously supplied dopamine delivered directly into the dopamine-deficient striatum. Rats received unilateral lesions of the substantia nigra by stereotaxic administration of 6-hydroxydopamine and were tested for apomorphine-induced rotational behavior and general activity. Osmotic mini-pumps were filled with dopamine in various concentrations, implanted subcutaneously and connected to a cannula implanted directly into the striatum. The system delivered solution at a rate of .5 ..mu..l/hr for two weeks. Dopamine in a dosage of 0.5 ..mu..g/per hour reduced apomorphine-induced rotational behavior by a mean of 52 +/- 5.8% (mean +/- SEM n=20) with a maximal individual decrease of 99%. There was no change in general activity or increase in stereotype behavior. Infusions of vehicle solutions did not decrease rotational behavior. Spread of the infused dopamine and its metabolites was estimated by adding /sup 3/H-dopamine to the pumps in tracer quantities. Radioactivity was highly concentrated at the infusion site and decreased rapidly within a few mm from the infusion site. Continuous infusion methods may eventually prove to be effective in the treatment of nigro-striatal degenerative disease. 12 references, 4 figures.

  2. Motor asymmetry and substantia nigra volume are related to spatial delayed response performance in Parkinson disease.

    PubMed

    Foster, Erin R; Black, Kevin J; Antenor-Dorsey, Jo Ann V; Perlmutter, Joel S; Hershey, Tamara

    2008-06-01

    Studies suggest motor deficit asymmetry may help predict the pattern of cognitive impairment in individuals with Parkinson disease (PD). We tested this hypothesis using a highly validated and sensitive spatial memory task, spatial delayed response (SDR), and clinical and neuroimaging measures of PD asymmetry. We predicted SDR performance would be more impaired by PD-related changes in the right side of the brain than in the left. PD (n=35) and control (n=28) participants performed the SDR task. PD participants either had worse motor deficits on the right (RPD) or left (LPD) side of the body. Some participants also had magnetic resonance imaging for measurement of their substantia nigra (SN) volumes. The LPD group performed worse on the SDR task than the RPD and control groups. Right SN volume accounted for a unique and significant portion of the variance in SDR error, with smaller volume predicting poorer performance. In conclusion, left motor dysfunction and smaller right SN volume are associated with poorer spatial memory.

  3. Age-related gene expression changes in substantia nigra dopamine neurons of the rat.

    PubMed

    Parkinson, Gemma M; Dayas, Christopher V; Smith, Doug W

    2015-07-01

    Ageing affects most, if not all, functional systems in the body. For example, the somatic motor nervous system, responsible for initiating and regulating motor output to skeletal musculature, is vulnerable to ageing. The nigrostriatal dopamine pathway is one component of this system, with deficits in dopamine signalling contributing to major motor dysfunction, as exemplified in Parkinson's disease (PD). However, while the dopamine deficit in PD is due to degeneration of substantia nigra (SN) dopamine (DA) neurons, it is unclear whether there is sufficient loss of SN DA neurons with ageing to explain observed motor impairments. Instead, evidence suggests that age-related loss of DA neuron function may be more important than frank cell loss. To further elucidate the mechanisms of functional decline, we have investigated age-related changes in gene expression specifically in laser microdissected SN DA neurons. There were significant age-related changes in the expression of genes associated with neurotrophic factor signalling and the regulation of tyrosine hydroxylase activity. Furthermore, reduced expression of the DA neuron-associated transcription factor, Nurr1, may contribute to these changes. Together, these results suggest that altered neurotrophic signalling and tyrosine hydroxylase activity may contribute to altered DA neuron signalling and motor nervous system regulation in ageing.

  4. Dual immunofluorescence study of citrullinated proteins in Parkinson diseased substantia nigra.

    PubMed

    Nicholas, Anthony P

    2011-05-09

    Deimination is a post-translational modification of proteins in which selected arginine amino acids are enzymatically converted to citrullines. Using dual-color immunofluorescence and an established monoclonal antibody (F95) against peptidyl-citrulline moieties, the present study is the first to compare immunohistochemical staining patterns for deiminated proteins in human substantia nigra (SN) from patients with Parkinson disease (PD) versus similar control specimens supplied by the Harvard Brain Bank. In control SN sections, many tyrosine hydroxylase (TH)-immunoreactive dopamine neurons were seen surrounded either by small fibers immunoreactive for deiminated proteins, or large reactive astrocytes, co-localized with glial fibrillary acidic protein (GFAP). However, in SN specimens from PD patients, immunoreactivity for deiminated proteins was also demonstrated within the cytoplasm of many surviving dopamine neurons that were also immunoreactive for TH, but this staining was not specifically restricted to Lewy bodies. Although the identity of neuronal deiminated proteins in these SN dopamine neurons is unknown, the present study provides evidence that the anatomical expression of these proteins in PD is altered and thus suggests that deimination may be involved in the pathophysiology of this disease. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  5. Substantia nigra hyperechogenicity is related to decline in verbal memory in healthy elderly adults.

    PubMed

    Yilmaz, R; Behnke, S; Liepelt-Scarfone, I; Roeben, B; Pausch, C; Runkel, A; Heinzel, S; Niebler, R; Suenkel, U; Eschweiler, G W; Maetzler, W; Berg, D

    2016-05-01

    Deficits in cognition have been reported in Parkinson's disease (PD) already in the early and even in the pre-motor stages. Whilst substantia nigra hyperechogenicity measured by transcranial B-mode sonography (TCS) represents a strong PD marker and is associated with an increased risk for PD in still healthy individuals, its association with cognitive performance in prodromal PD stages is not well established. Two different cohorts of healthy elderly individuals were assessed by TCS and two different neuropsychological test batteries covering executive functions, verbal memory, language, visuo-constructional function and attention. Cognitive performance was compared between individuals with hyperechogenicity (SN+) and without hyperechogenicity (SN-). In both cohorts, SN+ individuals performed significantly worse than the SN- group in tests assessing verbal memory (word list delayed recall P = 0.05, logical memory II P < 0.017). Significant differences in Mini-Mental State Examination score (cohort 1, P = 0.02) and executive function tests (cohort 2, Stroop Color-Word Reading, P = 0.004) could only be shown in one of the two cohorts. No between-group effects were found in other cognitive tests and domains. These results indicate that individuals with the PD risk marker SN+ perform worse in verbal memory compared to SN- independent of the assessment battery. Memory performance should be assessed in detail in individuals at risk for PD. © 2016 EAN.

  6. The neuronal structure of the substantia nigra in the guinea pig: Nissl and Golgi study.

    PubMed

    Bogus-Nowakowska, K; Szteyn, S; Robak, A

    2000-01-01

    The studies were carried out on the mesencephalos of adult guinea pigs. The preparations were made by means of the Golgi technique, as well as the Nissl and Klüver-Barrera methods. Four types of neurons were distinguished in the substantia nigra (SN) of the guinea pig: 1. Bipolar neurons of two kinds: the neurons of the first kind have elongated, fusiform perikarya (25-40 microns), whereas the cells of the second kind have rounded and oval perikarya (15-22 microns). These neurons possess two dendritic trunks which arise from the opposite poles of the cell body and run for a relatively long distance. The bipolar neurons are the most numerous in the pars compacta of SN. 2. Triangular neurons with three primary dendrites arising conically from a perikaryon (20-35 microns). They are the most often observed type of neurons in the pars reticulata of SN. 3. Multipolar neurons with quadrangular or oval perikarya (22-35 microns) and 4-5 dendritic trunks which spread out in all directions. 4. Pear-shaped neurons (perikarya 15-25 microns), which have one or two primary dendritic trunks arising from one pole of the cell body. In all the types of neurons an axon originates either from the dendritic trunk or from the soma and is observed only in its initial segment.

  7. 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.

  8. Effects of scopolamine on dopamine neurons in the substantia nigra: role of the pedunculopontine tegmental nucleus.

    PubMed

    Di Giovanni, Giuseppe; Shi, Wei-Xing

    2009-08-01

    Previous neurochemical and behavioral studies suggest that muscarinic receptor antagonism has an excitatory effect on the nigrostriatal dopamine (DA) system. Using in vivo extracellular single unit recording, this study examined whether blockade of the muscarinic receptor by scopolamine alters the firing properties of DA neurons in the substantia nigra (SN). Scopolamine was administered either systemically or locally to DA neurons using microiontophoresis. Surprisingly, scopolamine did not cause any significant change in either the firing rate or pattern of the spontaneously active DA neurons. However, systemic injection of scopolamine significantly increased the number of active DA neurons in the SN. Local infusion of scopolamine into the pedunculopontine tegmental nucleus (PPT) mimicked the effect induced by systemically administered scopolamine, significantly increasing the number of active DA neurons without altering the firing rate and pattern. These results suggest that the reported increase in striatal DA release induced by scopolamine is in part mediated by activation of silent nigral DA neurons. The experiments with PPT local infusion further suggest that part of the effect of scopolamine may be due to its blockade of the inhibitory muscarinic autoreceptors on PPT cholinergic cells. The latter effect may lead to activation of quiescent DA neurons by increasing acetylcholine (ACh) release in the SN or in other brain areas providing inputs to DA neurons. Further understanding of the mechanism of action of scopolamine may help us further understand the role of ACh in both the pathophysiology and treatment of DA-related disorders including schizophrenia and Parkinson's disease.

  9. Intrastriatally Infused Exogenous CDNF Is Endocytosed and Retrogradely Transported to Substantia Nigra

    PubMed Central

    Vihinen, Helena; Bienemann, Ali; Palgi, Jaan; Voutilainen, Merja H.; Booms, Sigrid; Arumäe, Urmas

    2017-01-01

    Abstract Cerebral dopamine neurotrophic factor (CDNF) protects the nigrostriatal dopaminergic (DA) neurons in rodent models of Parkinson’s disease and restores DA circuitry when delivered after these neurons have begun to degenerate. These DA neurons have been suggested to transport striatal CDNF retrogradely to the substantia nigra (SN). However, in cultured cells the binding and internalization of extracellular CDNF has not been reported. The first aim of this study was to examine the cellular localization and pharmacokinetic properties of recombinant human CDNF (rhCDNF) protein after its infusion into rat brain parenchyma. Second, we aimed to study whether the transport of rhCDNF from the striatum to the SN results from its retrograde transport via DA neurons or from its anterograde transport via striatal GABAergic projection neurons. We show that after intrastriatal infusion, rhCDNF diffuses rapidly and broadly, and is cleared with a half-life of 5.5 h. Confocal microscopy analysis of brain sections at 2 and 6 h after infusion of rhCDNF revealed its widespread unspecific internalization by cortical and striatal neurons, exhibiting different patterns of subcellular rhCDNF distribution. Electron microscopy analysis showed that rhCDNF is present inside the endosomes and multivesicular bodies. In addition, we present data that after intrastriatal infusion the rhCDNF found in the SN is almost exclusively localized to the DA neurons, thus showing that it is retrogradely transported. PMID:28275710

  10. Glycine release in the substantia nigra: Interaction with glutamate and GABA.

    PubMed

    Dopico, José García; González-Hernández, Tomás; Pérez, Ingrid Morales; García, Isabel Gómez; Abril, Antonio Milena; Inchausti, José Obeso; Rodríguez Díaz, Manuel

    2006-04-01

    Previous studies have reported a high number of glycine (GLY) receptors in the substantia nigra (SN) but a low number of GLY-neurons, suggesting that taurine, a partial agonist of GLY-receptors, is the natural substrate for SN GLY-receptors. By using microdialysis to quantify amino acids in the extracellular space of the SN, we observed an extracellular pool of GLY in the rat that increased after depolarizing with high-K+ in a Ca2+-dependent manner and that diffuses through the extracellular space. GLY markedly increased after blocking either the tricarboxylic cycle with fluorocitrate or the glutamine synthetase activity with MSO. Because these products act selectively on glial cells, their effects show glia as a key cell in maintaining the extracellular pool of GLY in the SN. Extracellular GLY was modified by glutamate and glutamate receptor agonists. The local administration of GLY modified the extracellular concentration of GABA. Taken together, the complex regulation of the extracellular level of GLY, its possible glial origin and interaction with glutamate and GABA suggest a volume transmitter role for GLY in the SN, a possibility which also agrees with the recent finding of GLY-transporters in this centre.

  11. Loss of striatal Mu/sub 1/ opiate binding by substantia nigra lesions in the rat

    SciTech Connect

    Bodnar, R.J.; Clark, J.A.; Cooper, M.L.; Pasternak, G.W.

    1988-01-01

    Opiate receptors have been identified within the striatum and some have been localized presynaptically to nigrostriatal neurons. Using unilateral ablative lesion of the substantia nigra, the authors examined binding in the ipsilateral and contralateral striata. Lesions significantly lowered both /sup 3/H(D-Ala/sup 2/, MePhe/sup 4/, Gly(ol)/sup 5/) enkephalin (DAGO) and /sup 3/H(D-Ala/sup 2/,Leu/sup 5/) enkephalin (DADL) binding. The inclusion of competitors in these assays revealed a decrease in both mu/sub 1/ and mu/sub 2/ receptors. Mu/sub 1/ binding was slightly more sensitive to the lesioning than mu/sub 2/ binding. Selective mu/sub 1/ and mu/sub 2/ binding assays supported these observations. No change in delta binding was observed in the lesioned striata. These studies raise the possibility that both mu/sub 1/ and mu/sub 2/, but not delta, receptors are localized presynaptically on nigrostriatal neurons.

  12. Intrastriatally Infused Exogenous CDNF Is Endocytosed and Retrogradely Transported to Substantia Nigra.

    PubMed

    Mätlik, Kert; Vihinen, Helena; Bienemann, Ali; Palgi, Jaan; Voutilainen, Merja H; Booms, Sigrid; Lindahl, Maria; Jokitalo, Eija; Saarma, Mart; Huttunen, Henri J; Airavaara, Mikko; Arumäe, Urmas

    2017-01-01

    Cerebral dopamine neurotrophic factor (CDNF) protects the nigrostriatal dopaminergic (DA) neurons in rodent models of Parkinson's disease and restores DA circuitry when delivered after these neurons have begun to degenerate. These DA neurons have been suggested to transport striatal CDNF retrogradely to the substantia nigra (SN). However, in cultured cells the binding and internalization of extracellular CDNF has not been reported. The first aim of this study was to examine the cellular localization and pharmacokinetic properties of recombinant human CDNF (rhCDNF) protein after its infusion into rat brain parenchyma. Second, we aimed to study whether the transport of rhCDNF from the striatum to the SN results from its retrograde transport via DA neurons or from its anterograde transport via striatal GABAergic projection neurons. We show that after intrastriatal infusion, rhCDNF diffuses rapidly and broadly, and is cleared with a half-life of 5.5 h. Confocal microscopy analysis of brain sections at 2 and 6 h after infusion of rhCDNF revealed its widespread unspecific internalization by cortical and striatal neurons, exhibiting different patterns of subcellular rhCDNF distribution. Electron microscopy analysis showed that rhCDNF is present inside the endosomes and multivesicular bodies. In addition, we present data that after intrastriatal infusion the rhCDNF found in the SN is almost exclusively localized to the DA neurons, thus showing that it is retrogradely transported.

  13. SUBSTANTIA NIGRA PARS RETICULATA IS CRUCIALLY INVOLVED IN BARBITURATE AND ETHANOL WITHDRAWAL IN MICE

    PubMed Central

    Chen, Gang; Kozell, Laura B.; Buck, Kari J.

    2011-01-01

    Sedative-hypnotic CNS depressant drugs are widely prescribed to treat a variety of disorders, and are abused for their sedative and euphoric effects. Physiological dependence and associated withdrawal episodes are thought to constitute a motivational force that sustains their use/abuse and may contribute to relapse in dependent individuals. Although no animal model duplicates depressant dependence, models for specific factors, like withdrawal, are useful for identifying potential neural determinants of liability in humans. Recent analyses implicate the caudolateral substantia nigra pars reticulata (clSNr) in withdrawal following acute and repeated ethanol exposures in mice, but did not assess its impact on withdrawal from other sedative-hypnotics or whether intrinsic neurons or fibers of passage are involved. Here, we demonstrate that bilateral chemical (ibotenic acid) lesions of the clSNr attenuate barbiturate (pentobarbital) and ethanol withdrawal. Chemical lesions did not affect convulsions in response to pentylenetetrazol, which blocks GABAA receptor-mediated transmission. Our results demonstrate that the clSNr nucleus itself rather than fibers of passage is crucial to its effects on barbiturate and ethanol withdrawal. These findings support suggest that clSNr could be one of the shared neural substrates mediating withdrawal from sedative-hypnotic drugs. PMID:20974184

  14. p62 Pathology Model in the Rat Substantia Nigra with Filamentous Inclusions and Progressive Neurodegeneration

    PubMed Central

    Jackson, Kasey L.; Lin, Wen-Lang; Miriyala, Sumitra; Dayton, Robert D.; Panchatcharam, Manikandan; McCarthy, Kevin J.; Castanedes-Casey, Monica; Dickson, Dennis W.; Klein, Ronald L.

    2017-01-01

    One of the proteins most frequently found in neuropathological lesions is the ubiquitin binding protein p62 (sequestosome 1). Post-mortem analysis of p62 is a defining diagnostic marker in several neurodegenerative diseases including amyotrophic lateral sclerosis and inclusion body myositis. Since p62 functions in protein degradation pathways including autophagy, the build-up of p62-positive inclusions suggests defects in protein clearance. p62 was expressed unilaterally in the rat substantia nigra with an adeno-associated virus vector (AAV9) in order to study p62 neuropathology. Inclusions formed within neurons from several days to several weeks after gene transfer. By electron microscopy, the inclusions were found to contain packed 10 nm thick filaments, and mitochondria cristae structure was disrupted, resulting in the formation of empty spaces. In corollary cell culture transfections, p62 clearly impaired mitochondrial function. To probe for potential effects on macroautophagy, we co-expressed p62 with a double fluorescent tagged reporter for the autophagosome protein LC3 in the rat. p62 induced a dramatic and specific dissociation of the two tags. By 12 weeks, a rotational behavior phenotype manifested, consistent with a significant loss of dopaminergic neurons analyzed post-mortem. p62 overexpression resulted in a progressive and robust pathology model with neuronal inclusions and neurodegeneration. p62 gene transfer could be a novel methodological probe to disrupt mitochondrial function or autophagy in the brain and other tissues in vivo. PMID:28076378

  15. Proteomic analysis of human substantia nigra identifies novel candidates involved in Parkinson's disease pathogenesis.

    PubMed

    Licker, Virginie; Turck, Natacha; Kövari, Enikö; Burkhardt, Karim; Côte, Mélanie; Surini-Demiri, Maria; Lobrinus, Johannes A; Sanchez, Jean-Charles; Burkhard, Pierre R

    2014-03-01

    Parkinson's disease (PD) pathology spreads throughout the brain following a region-specific process predominantly affecting the substantia nigra (SN) pars compacta. SN exhibits a progressive loss of dopaminergic neurons responsible for the major cardinal motor symptoms, along with the occurrence of Lewy bodies in the surviving neurons. To gain new insights into the underlying pathogenic mechanisms in PD, we studied postmortem nigral tissues dissected from pathologically confirmed PD cases (n = 5) and neurologically intact controls (n = 8). Using a high-throughput shotgun proteomic strategy, we simultaneously identified 1795 proteins with concomitant quantitative data. To date, this represents the most extensive catalog of nigral proteins. Of them, 204 proteins displayed significant expression level changes in PD patients versus controls. These were involved in novel or known pathogenic processes including mitochondrial dysfunction, oxidative stress, or cytoskeleton impairment. We further characterized four candidates that might be relevant to PD pathogenesis. We confirmed the differential expression of ferritin-L and seipin by Western blot and demonstrated the neuronal localization of gamma glutamyl hydrolase and nebulette by immunohistochemistry. Our preliminary findings suggest a role for nebulette overexpression in PD neurodegeneration, through mechanisms that may involve cytoskeleton dynamics disruption. All MS data have been deposited in the ProteomeXchange with identifier PXD000427 (http://proteomecentral.proteomexchange.org/dataset/PXD000427).

  16. Bowel movement frequency in late-life and substantia nigra neuron density at death.

    PubMed

    Petrovitch, Helen; Abbott, Robert D; Ross, G Webster; Nelson, James; Masaki, Kamal H; Tanner, Caroline M; Launer, Lenore J; White, Lon R

    2009-02-15

    Constipation is associated with future risk of Parkinson's disease (PD) and with incidental Lewy bodies (LB) in the locus ceruleus or substantia nigra (SN). Our purpose is to examine the independent association between bowel movement frequency in late-life and postmortem SN neuron density. Bowel movement frequency was assessed in the Honolulu-Asia Aging Study from 1991 to 1993 in 414 men aged 71 to 93 years with later postmortem evaluations. Brains were examined for LB in the SN and locus ceruleus and neurons were counted in four quadrants from a transverse section of SN. In nonsmokers, neuron densities (counts/mm(2)) for men with >1, 1, and <1 bowel movement daily were 18.5, 18.8, 10.1 (P < 0.001) for dorsomedial; 15.3, 16.4, 10.2 (P < 0.03) for ventromedial; and 18.6, 18.3, 10.9 (P = 0.011) for ventrolateral quadrants. Relationships were not significant in the dorsolateral quadrant or in any quadrant among smokers. After adjustment for age, time to death, coffee drinking, tricep skinfold thickness, excessive daytime sleepiness, cognitive function, PD, and incidental LB, density ratios in nonsmokers with 1 or more bowel movement(s) daily were significantly higher compared to those with <1 daily. Constipation is associated with low SN neuron density independent of the presence of LB.

  17. Transient glutathione depletion in the substantia nigra compacta is associated with neuroinflammation in rats.

    PubMed

    Díaz-Hung, Mei-Li; Yglesias-Rivera, Arianna; Hernández-Zimbrón, Luis Fernando; Orozco-Suárez, Sandra; Ruiz-Fuentes, Jenny Laura; Díaz-García, Alexis; León-Martínez, Rilda; Blanco-Lezcano, Lisette; Pavón-Fuentes, Nancy; Lorigados-Pedre, Lourdes

    2016-10-29

    Glutathione (GSH) deficiency has been identified as an early event in the progression of Parkinson's disease. However, the role of GSH in the etiology and pathogenesis of this neurodegenerative disorder is not well established. The aim of this study is to assess the effect of transient GSH depletion in the substantia nigra pars compacta (SNpc) on neuroinflammation after the injection of a single dose of l-buthionine sulfoximine (BSO) into the SNpc of male Sprague-Dawley rats. The results showed that BSO treatment stimulates microglia (p<0.01) and astroglial response (p<0.01), c-Jun N-terminal kinase and inducible nitric oxide synthase (iNOS) (p<0.001) in the SNpc, accompanied by dopaminergic dysfunction. In addition, high levels of tumor necrosis factor α (p<0.01), interleukins IL-1β p<0.01), IL-6 p<0.001) and nitric oxide p<0.01) were found in the treated animals compared to control groups, while no significant differences were found in IL-10 levels. These results suggest that transient GSH depletion can increase the susceptibility of SNpc to degeneration by promoting an inflammatory response and nitrosative stress, reinforcing the possible role of GSH unbalance, oxygen/nitrogen reactive species and neuroinflammation as causal factors on the degeneration of the SNpc.

  18. Convection-enhanced delivery of MANF--volume of distribution analysis in porcine putamen and substantia nigra.

    PubMed

    Barua, N U; Bienemann, A S; Woolley, M; Wyatt, M J; Johnson, D; Lewis, O; Irving, C; Pritchard, G; Gill, S

    2015-10-15

    Mesencephalic astrocyte-derived neurotrophic factor (MANF) is a 20kDa human protein which has both neuroprotective and neurorestorative activity on dopaminergic neurons and therefore may have application for the treatment of Parkinson's Disease. The aims of this study were to determine the translational potential of convection-enhanced delivery (CED) of MANF for the treatment of PD by studying its distribution in porcine putamen and substantia nigra and to correlate histological distribution with co-infused gadolinium-DTPA using real-time magnetic resonance imaging. We describe the distribution of MANF in porcine putamen and substantia nigra using an implantable CED catheter system using co-infused gadolinium-DTPA to allow real-time MRI tracking of infusate distribution. The distribution of gadolinium-DTPA on MRI correlated well with immunohistochemical analysis of MANF distribution. Volumetric analysis of MANF IHC staining indicated a volume of infusion (Vi) to volume of distribution (Vd) ratio of 3 in putamen and 2 in substantia nigra. This study confirms the translational potential of CED of MANF as a novel treatment strategy in PD and also supports the co-infusion of gadolinium as a proxy measure of MANF distribution in future clinical studies. Further study is required to determine the optimum infusion regime, flow rate and frequency of infusions in human trials.

  19. Electrophysiological characterization of substantia nigra dopaminergic neurons in partially lesioned rats: effects of subthalamotomy and levodopa treatment.

    PubMed

    Bilbao, Gaizka; Ruiz-Ortega, Jose Angel; Miguens, Natalia; Ulibarri, Isabel; Linazasoro, Gurutz; Gómez-Urquijo, Sonia; Garibi, Jesús; Ugedo, Luisa

    2006-04-21

    Progressive degeneration of dopaminergic neurons in the substantia nigra pars compacta is the main histopathological characteristic of Parkinson's disease. We studied the electrophysiological characteristics of the spontaneous activity of substantia nigra pars compacta dopaminergic neurons in rats with a partial, unilateral, 6-hydroxydopamine lesion of the nigrostriatal pathway. In addition, the effects of subthalamotomy and prolonged levodopa treatment on the activity of dopaminergic neurons were investigated. As a result of the lesion ( approximately 50% neuronal loss), the number of spontaneously active neurons was significantly reduced. Basal firing rate, burst firing and responsiveness to intravenously administered apomorphine remained unchanged. In contrast, the variation coefficient, a measure of interspike interval regularity, was significantly increased. Ibotenic acid (10 microg) lesion of the ipsilateral subthalamic nucleus in lesioned rats did not modify the electrophysiological parameters. However, prolonged levodopa treatment (100 mg/kg/day + benserazide 25 mg/kg/day, 14 days) reversed the irregularity observed in cells from lesioned rats, while it induced an irregular firing pattern in cells from intact rats. Our results using an experimental model of moderate Parkinson's disease indicate that surviving substantia nigra pars compacta dopaminergic neurons fire irregularly. In this model, subthalamotomy does not modify the firing pattern while levodopa treatment efficiently restores normal firing of SNpc neurons and does not appear to be toxic to them.

  20. Dopamine Pathology in Schizophrenia: Analysis of Total and Phosphorylated Tyrosine Hydroxylase in the Substantia Nigra

    PubMed Central

    Perez-Costas, Emma; Melendez-Ferro, Miguel; Rice, Matthew W.; Conley, Robert R.; Roberts, Rosalinda C.

    2012-01-01

    Introduction: Despite the importance of dopamine neurotransmission in schizophrenia, very few studies have addressed anomalies in the mesencephalic dopaminergic neurons of the substantia nigra/ventral tegmental area (SN/VTA). Tyrosine hydroxylase (TH) is the rate-limiting enzyme for the production of dopamine, and a possible contributor to the anomalies in the dopaminergic neurotransmission observed in schizophrenia. Objectives: In this study, we had three objectives: (1) Compare TH expression (mRNA and protein) in the SN/VTA of schizophrenia and control postmortem samples. (2) Assess the effect of antipsychotic medications on the expression of TH in the SN/VTA. (3) Examine possible regional differences in TH expression anomalies within the SN/VTA. Methods: To achieve these objectives three independent studies were conducted: (1) A pilot study to compare TH mRNA and TH protein levels in the SN/VTA of postmortem samples from schizophrenia and controls. (2) A chronic treatment study was performed in rodents to assess the effect of antipsychotic medications in TH protein levels in the SN/VTA. (3) A second postmortem study was performed to assess TH and phosphorylated TH protein levels in two types of samples: schizophrenia and control samples containing the entire rostro-caudal extent of the SN/VTA, and schizophrenia and control samples containing only mid-caudal regions of the SN/VTA. Results and Conclusion: Our studies showed impairment in the dopaminergic system in schizophrenia that could be mainly (or exclusively) located in the rostral region of the SN/VTA. Our studies also showed that TH protein levels were significantly abnormal in schizophrenia, while mRNA expression levels were not affected, indicating that TH pathology in this region may occur posttranscriptionally. Lastly, our antipsychotic animal treatment study showed that TH protein levels were not significantly affected by antipsychotic treatment, indicating that these anomalies are an intrinsic

  1. c-jun expression in substantia nigra neurons following striatal 6-hydroxydopamine lesions in the rat.

    PubMed

    Jenkins, R; O'Shea, R; Thomas, K L; Hunt, S P

    1993-03-01

    The proto-oncogene c-jun is thought to play a role in the control of growth and differentiation of many cell types. It has been demonstrated previously that damage to axons of peripheral motor or sensory neurons resulted within 24 h in substantially increased levels of the c-jun gene in the parent cell bodies. These increased levels of c-jun protein and messenger RNA are maintained if the damaged nerve is ligated, but return to basal levels if the peripheral nerve is allowed to regenerate. We have examined the expression of immediate early genes in central neurons of the rat and now show that a 6-hydroxydopamine-induced axotomy of the dopaminergic nigrostriatal pathway results in a substantial increase in the levels of c-jun (but not c-fos) messenger RNA and protein within neurons of the substantia nigra pars compacta. However, the central neuronal response differs from the peripheral nerve response in that it becomes maximal at four to eight days post-lesion and is transient, declining to control levels in nigral neurons by 14 days post-lesion. These expression patterns may be related to the differential capacity of central and peripheral neurons to regenerate. The precise role of c-jun in these processes, or in the regenerative response, is unclear but it remains possible that c-jun activation following axon damage leads to an increased expression of genes which are essential for the regenerative response. The nature of the mechanism by which c-jun levels are attenuated in central neurons is also unclear, but inhibitory factors, generated by the central environment, may play a role.

  2. Long-term changes in striatal opioid systems after 6-hydroxydopamine lesion of rat substantia nigra.

    PubMed

    Smith, J A; Leslie, F M; Broide, R S; Loughlin, S E

    1993-08-01

    The effects of unilateral 6-hydroxydopamine lesion of the nigrostriatal pathway on striatal opioid peptides and receptors were determined at different time-intervals, from three days up to 24 weeks, post-lesion. Mu, delta and kappa opioid binding site densities in the ipsilateral caudate-putamen were decreased by 25-50% in rats which exhibited a greater than 90% loss of dopamine uptake sites. Differentiation of radioligand binding to kappa1 and kappa2 subtypes demonstrated a selective loss of kappa2 sites post-lesion. The onset of significant 6-hydroxydopamine lesion-induced changes in striatal opioid binding sites was delayed with respect to the loss of dopamine uptake sites. Furthermore, maximal loss of dopamine uptake sites was apparent within seven days post-lesion, but not until two to four weeks for mu, delta and kappa sites. In animals which exhibited an incomplete loss of dopamine uptake sites (less than 80%) there was no significant change in opioid binding site density. Striatal proenkephalin and prodynorphin messenger RNA levels were increased and decreased, respectively, after complete 6-hydroxydopamine lesion. Modulation of peptide messenger RNA levels was apparent within seven days and was maintained up to 24 weeks post-lesion. In contrast, proenkephalin and prodynorphin messenger RNA levels were unchanged in animals which exhibited an incomplete loss of striatal dopamine uptake sites. Taken together, these observations suggest that the majority of mu, delta and kappa2 opioid binding sites are localized on non-dopaminergic elements in the caudate-putamen, but that substantia nigra innervation plays a role in the control of striatal opioid receptor expression. The 6-hydroxydopamine lesion-induced decreases in striatal opioid binding site density may, in part, be a function of agonist-induced receptor downregulation. Alternatively, both opioid receptor and peptide expression in the caudate-putamen may be directly, but independently, regulated by ventral

  3. Functional territories in primate substantia nigra pars reticulata separately signaling stable and flexible values

    PubMed Central

    Hikosaka, Okihide

    2014-01-01

    Gaze is strongly attracted to visual objects that have been associated with rewards. Key to this function is a basal ganglia circuit originating from the caudate nucleus (CD), mediated by the substantia nigra pars reticulata (SNr), and aiming at the superior colliculus (SC). Notably, subregions of CD encode values of visual objects differently: stably by CD tail [CD(T)] vs. flexibly by CD head [CD(H)]. Are the stable and flexible value signals processed separately throughout the CD-SNr-SC circuit? To answer this question, we identified SNr neurons by their inputs from CD and outputs to SC and examined their sensitivity to object values. The direct input from CD was identified by SNr neuron's inhibitory response to electrical stimulation of CD. We found that SNr neurons were separated into two groups: 1) neurons inhibited by CD(T) stimulation, located in the caudal-dorsal-lateral SNr (cdlSNr), and 2) neurons inhibited by CD(H) stimulation, located in the rostral-ventral-medial SNr (rvmSNr). Most of CD(T)-recipient SNr neurons encoded stable values, whereas CD(H)-recipient SNr neurons tended to encode flexible values. The output to SC was identified by SNr neuron's antidromic response to SC stimulation. Among the antidromically activated neurons, many encoded only stable values, while some encoded only flexible values. These results suggest that CD(T)-cdlSNr-SC circuit and CD(H)-rvmSNr-SC circuit transmit stable and flexible value signals, largely separately, to SC. The speed of signal transmission was faster through CD(T)-cdlSNr-SC circuit than through CD(H)-rvmSNr-SC circuit, which may reflect automatic and controlled gaze orienting guided by these circuits. PMID:25540224

  4. Simultaneous imaging of locus coeruleus and substantia nigra with a quantitative neuromelanin MRI approach.

    PubMed

    Chen, Xiangchuan; Huddleston, Daniel E; Langley, Jason; Ahn, Sinyeob; Barnum, Christopher J; Factor, Stewart A; Levey, Allan I; Hu, Xiaoping

    2014-12-01

    Quantitative MRI of neuromelanin (NM) containing structures (referred to as NM-MRI) in the brainstem, namely the locus coeruleus (LC) and substantia nigra (SN), may assist with the early detection of Parkinson's disease (PD) and Alzheimer's disease (AD) as well as differential diagnosis in the early disease stages. In this study, two gradient echo (GRE) sequences with magnetization transfer contrast (MTC) preparation pulses were developed to simultaneously image the LC and SN. This has been a challenge with NM-MRI techniques used in previous studies due to the relatively high specific absorption rate (SAR) induced by these techniques. In addition, a semi-automated quantitative analysis scheme was applied to estimate volumes and contrast-to-noise ratios (CNR) of the LC and SN based on segmentation of both structures. Compared to a T1-weighted turbo spin echo (TSE) sequence typically used for simultaneous imaging of the LC and SN, the two GRE-MTC sequences exhibited improved performance in terms of higher sensitivity (in CNR) in imaging the SN and lower SAR during the scans. A multiple-measurement protocol was adopted as well so that motion degraded measurements could be removed and artifacts associated with motion could be corrected. The present approach has demonstrated advantages in image acquisition (lower SAR and higher sensitivity), image pre-processing (with motion correction) and quantitative image analysis (segmentation-based estimation of volume and CNR) when compared with existing NM-MRI approaches. This approach has potential for detection and monitoring of neurodegeneration in LC and SN in disease states including AD and PD.

  5. Impact of Combined Subthalamic Nucleus and Substantia Nigra Stimulation on Neuropsychiatric Symptoms in Parkinson's Disease Patients

    PubMed Central

    Horn, A.; Hamel, W.; Koeppen, J. A.; Westphal, M.; Engel, A. K.; Gerloff, C.; Moll, C. K. E.

    2017-01-01

    The goal of the study was to compare the tolerability and the effects of conventional subthalamic nucleus (STN) and combined subthalamic nucleus and substantia nigra (STN+SNr) high-frequency stimulation in regard to neuropsychiatric symptoms in Parkinson's disease patients. In this single center, randomized, double-blind, cross-over clinical trial, twelve patients with advanced Parkinson's disease (1 female; age: 61.3 ± 7.3 years; disease duration: 12.3 ± 5.4 years; Hoehn and Yahr stage: 2.2 ± 0.39) were included. Apathy, fatigue, depression, and impulse control disorder were assessed using a comprehensive set of standardized rating scales and questionnaires such as the Lille Apathy Rating Scale (LARS), Modified Fatigue Impact Scale (MFIS), Becks Depression Inventory (BDI-I), Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease Rating Scale (QUIP-RS), and Parkinson's Disease Questionnaire (PDQ-39). Three patients that were initially assigned to the STN+SNr stimulation mode withdrew from the study within the first week due to discomfort. Statistical comparison of data retrieved from patients who completed the study revealed no significant differences between both stimulation conditions in terms of mean scores of scales measuring apathy, fatigue, depression, impulse control disorder, and quality of life. Individual cases showed an improvement of apathy under combined STN+SNr stimulation. In general, combined STN+SNr stimulation seems to be safe in terms of neuropsychiatric side effects, although careful patient selection and monitoring in the short-term period after changing stimulation settings are recommended. PMID:28246572

  6. Presynaptic GABAB and adenosine A1 receptors regulate synaptic transmission to rat substantia nigra reticulata neurones.

    PubMed Central

    Shen, K Z; Johnson, S W

    1997-01-01

    1. Patch pipettes were used to record whole-cell currents under voltage clamp in substantia nigra zona reticulata (SNR) neurones in the rat midbrain slice. Bipolar electrodes evoked synaptic currents mediated by glutamate (EPSCs) and GABAA receptors (IPSCs). 2. Baclofen reduced the amplitude of IPSCs by 48% at its IC50 value of 0.60 microM. The GABAB antagonist CGP 35348 blocked this effect with a Kd value estimated by Schild analysis of 5 microM. 3. Adenosine reduced IPSCs by 48% at its IC50 value of 56 microM. Adenosine agonists reduced IPSCs with the following rank order of potency: CPA (N6-cyclopentyladenosine) > R-PIA (R(-)N6-(2-phenylisopropyl)adenosine) > CHA (N6-cyclohexyladenosine) = NECA (5'-N-ethylcarboxamidoadenosine) > 2-CADO (2-chloroadenosine) > adenosine. Schild analysis yielded a Kd value of 0.4 nM for antagonism of CPA by the adenosine A1 receptor antagonist DPCPX (8-cyclopentyl-1,3-dipropylxanthine). 4. Both baclofen and adenosine reduced the magnitude of paired-pulse depression of IPSCs, and neither blocked currents evoked by GABA, which was pressure-ejected from micropipettes. 5. Glutamate EPSCs were reduced by baclofen (IC50 = 0.78 microM) and adenosine (IC50 = 57 microM). Schild analysis yielded a Kd value of 11 microM for antagonism of baclofen-induced inhibition of EPSCs by CGP 35348. DPCPX (1 microM) completely blocked the inhibitory effects of adenosine (100 microM) and CPA (100 nM) on EPSCs. Neither adenosine nor baclofen reduced inward currents evoked by glutamate which was pressure-ejected from micropipettes. 6. These results show that presynaptic GABAB and A1 receptors reduce glutamate and GABA release from nerve terminals in the SNR. PMID:9409479

  7. Topography of dyskinesias and torticollis evoked by inhibition of substantia nigra pars reticulata.

    PubMed

    Dybdal, David; Forcelli, Patrick A; Dubach, Mark; Oppedisano, Michael; Holmes, Angela; Malkova, Ludise; Gale, Karen

    2013-04-01

    GABAergic neurons of the substantia nigra pars reticulata (SNpr) and globus pallidus pars interna (GPi) constitute the output pathways of the basal ganglia. In monkeys, choreiform limb dyskinesias have been described after inhibition of the GPi, but not the SNpr. Given the anatomical and functional similarities between these structures, we hypothesized that choreiform dyskinesias could be evoked by inhibition of an appropriate region within the SNpr. The GABAA receptor agonist, muscimol, was infused into various sites within the SNpr and the adjacent STN of freely moving macaques. The effect of the GABAA antagonist, bicuculline (BIC), was also examined. Muscimol (MUS) in SNpr evoked the following: (1) choreiform dyskinesias of the contralateral arm and/or leg from central and lateral sites; (2) contralaterally directed torticollis from central and posterior sites; and (3) contraversive quadrupedal rotation from anterior and lateral sites. MUS infusions into the adjacent SN pars compacta or STN were without effect, ruling out a contribution of drug spread to adjacent structures. BIC in SNpr induced ipsiversive postures without choreiform dyskinesia or torticollis, whereas in the STN, it evoked ballistic movements. This is the first report of choreiform dyskinesia evoked by inhibition of the SNpr. This highly site-specific effect was obtained from a restricted region within the SNpr distinct from that responsible for inducing torticollis. These results suggest that overactivity of different SNpr outputs mediates choreiform dyskinesia and torticollis. These abnormalities are symptoms of dystonia, Huntington's disease, and iatrogenic dyskinesias, suggesting that these conditions may result, in part, from a loss of function in SNpr efferent projections.

  8. Impact of expected value on neural activity in rat substantia nigra pars reticulata.

    PubMed

    Bryden, Daniel W; Johnson, Emily E; Diao, Xiayang; Roesch, Matthew R

    2011-06-01

    The substantia nigra pars reticulata (SNr) is thought to serve as the output of the basal ganglia, whereby associative information from striatum influences behavior via disinhibition of downstream motor areas to motivate behavior. Unfortunately, few studies have examined activity in SNr in rats making decisions based on the value of predicted reward similar to those conducted in primates. To fill this void, we recorded from single neurons in SNr while rats performed a choice task in which different odor cues indicated what reward was available on the left or on the right. The value of reward associated with a leftward or rightward movement was manipulated by varying the size of and delay to reward in separate blocks of trials. Rats were faster or slower depending on whether the expected reward value was high or low, respectively. The number of neurons that increased firing during performance of the task outnumbered those that decreased firing. Both increases and decreases were modulated by expected value and response direction. Neurons that fired more or less strongly for larger reward tended to fire, respectively, more or less strongly for immediate reward, reflecting their common motivational output. Finally, value selectivity was present prior to presentation of cues indicating the nature of the upcoming behavioral response for both increasing- and decreasing-type neurons, reflecting the internal bias or preparatory set of the rat. These results emphasize the importance of increasing-type neurons on behavioral output when animals are making decisions based on predicted reward value. European Journal of Neuroscience © 2011 Federation of European Neuroscience Societies and Blackwell Publishing Ltd. No claim to original US government works.

  9. The h-Current in the Substantia Nigra pars Compacta Neurons: A Re-examination

    PubMed Central

    Gambardella, Cristina; Pignatelli, Angela; Belluzzi, Ottorino

    2012-01-01

    The properties of the hyperpolarization-activated cation current (Ih) were investigated in rat substantia nigra - pars compacta (SNc) principal neurons using patch-clamp recordings in thin slices. A reliable identification of single dopaminergic neurons was made possible by the use of a transgenic line of mice expressing eGFP under the tyrosine hydroxylase promoter. The effects of temperature and different protocols on the Ih kinetics showed that, at 37°C and minimizing the disturbance of the intracellular milieu with perforated patch, this current actually activates at potentials more positive than what is generally indicated, with a half-activation potential of −77.05 mV and with a significant level of opening already at rest, thereby substantially contributing to the control of membrane potential, and ultimately playing a relevant function in the regulation of the cell excitability. The implications of the known influence of intracellular cAMP levels on Ih amplitude and kinetics were examined. The direct application of neurotransmitters (DA, 5-HT and noradrenaline) physiologically released onto SNc neurons and known to act on metabotropic receptors coupled to the cAMP pathway modify the Ih amplitude. Here, we show that direct activation of dopaminergic and of 5-HT receptors results in Ih inhibition of SNc DA cells, whereas noradrenaline has the opposite effect. Together, these data suggest that the modulation of Ih by endogenously released neurotransmitters acting on metabotropic receptors –mainly but not exclusively linked to the cAMP pathway- could contribute significantly to the control of SNc neuron excitability. PMID:23284989

  10. MAPPING DOPAMINERGIC DEFICIENCIES IN THE SUBSTANTIA NIGRA/VENTRAL TEGMENTAL AREA IN SCHIZOPHRENIA

    PubMed Central

    Rice, Matthew W; Roberts, Rosalinda C; Melendez-Ferro, Miguel; Perez-Costas, Emma

    2015-01-01

    Previous work from our laboratory showed deficits in tyrosine hydroxylase protein expression within the substantia nigra/ventral tegmental area (SN/VTA) in schizophrenia. However, little is known about the nature and specific location of these deficits within the SN/VTA. The present study had two aims: 1) test if tyrosine hydroxylase deficits could be explained as the result of neuronal loss; 2) assess if deficits in tyrosine hydroxylase are subregion specific within the SN/VTA, and thus, could affect specific dopaminergic pathways. To achieve these objectives: 1) we obtained estimates of the number of dopaminergic neurons, total number of neurons and their ratio in matched SN/VTA schizophrenia and control samples; 2) we performed a qualitative assessment in SN/VTA schizophrenia and control matched samples that were processed simultaneously for tyrosine hydroxylase immunohistochemistry. We did not find any significant differences in the total number of neurons, dopaminergic neurons, or their ratio. Our qualitative study of TH expression showed a conspicuous decrease in labeling of neuronal processes and cell bodies within the SN/VTA, which was sub-region specific. Dorsal diencephalic dopaminergic populations of the SN/VTA presented the most conspicuous decrease in TH labeling. These data support the existence of pathway-specific dopaminergic deficits that would affect the dopamine input to the cortex without significant neuronal loss. Interestingly, these findings support earlier reports of decreases in tyrosine hydroxylase labeling in the target areas for this dopaminergic input in the prefrontal and entorhinal cortex. Finally, our findings support that tyrosine hydroxylase deficits could contribute to the hypodopaminergic state observed in cortical areas in schizophrenia. PMID:25269834

  11. Assessment of Cytochrome C Oxidase Dysfunction in the Substantia Nigra/Ventral Tegmental Area in Schizophrenia

    PubMed Central

    Rice, Matthew W.; Smith, Kristen L.; Roberts, Rosalinda C.

    2014-01-01

    Perturbations in metabolism are a well-documented but complex facet of schizophrenia pathology. Optimal cellular performance requires the proper functioning of the electron transport chain, which is constituted by four enzymes located within the inner membrane of mitochondria. These enzymes create a proton gradient that is used to power the enzyme ATP synthase, producing ATP, which is crucial for the maintenance of cellular functioning. Anomalies in a single enzyme of the electron transport chain are sufficient to cause disruption of cellular metabolism. The last of these complexes is the cytochrome c oxidase (COX) enzyme, which is composed of thirteen different subunits. COX is a major site for oxidative phosphorylation, and anomalies in this enzyme are one of the most frequent causes of mitochondrial pathology. The objective of the present report was to assess if metabolic anomalies linked to COX dysfunction may contribute to substantia nigra/ventral tegmental area (SN/VTA) pathology in schizophrenia. We tested COX activity in postmortem SN/VTA from schizophrenia and non-psychiatric controls. We also tested the protein expression of key subunits for the assembly and activity of the enzyme, and the effect of antipsychotic medication on subunit expression. COX activity was not significantly different between schizophrenia and non-psychiatric controls. However, we found significant decreases in the expression of subunits II and IV-I of COX in schizophrenia. Interestingly, these decreases were observed in samples containing the entire rostro-caudal extent of the SN/VTA, while no significant differences were observed for samples containing only mid-caudal regions of the SN/VTA. Finally, rats chronically treated with antipsychotic drugs did not show significant changes in COX subunit expression. These findings suggest that COX subunit expression may be compromised in specific sub-regions of the SN/VTA (i.e. rostral regions), which may lead to a faulty assembly of the

  12. Investigation of Long Non-coding RNA Expression Profiles in the Substantia Nigra of Parkinson's Disease.

    PubMed

    Ni, Yaohui; Huang, Hua; Chen, Yaqin; Cao, Maohong; Zhou, Hongzhi; Zhang, Yuanyuan

    2017-03-01

    Genetics is considered as an important risk factor in the pathological changes of Parkinson's disease (PD). Substantia nigra (SN) is thought to be the most vulnerable area in this process. In recent decades, however, few related long non-coding RNAs (lncRNAs) in the SN of PD patients had been identified and the functions of those lncRNAs had been studied even less. In this study, we sought to investigate the lncRNA expression profiles and their potential functions in the SN of PD patients. We screened lncRNA expression profiles in the SN of PD patients using the lncRNA mining approach from the ArrayExpress database, which included GSE20295. The samples were from 11 of PD and 14 of normal tissue samples. We identified 87 lncRNAs that were altered significantly in the SN during the occurrence of PD. Among these lncRNAs, lncRNA AL049437 and lncRNA AK021630 varied most dramatically. AL049437 was up-regulated in the PD samples, while AK021630 was down-regulated. Based on the results, we focused on the potential roles of the two lncRNAs in the pathogenesis of PD by the knockdown of the expression of AL049437 or AK021630 in human neuroblastoma SH-SY5Y cell line. Results indicated that the reduction in AL049437 level increased cell viability, mitochondrial transmembrane potential (Δψm), mitochondrial mass, and tyrosine hydroxylase (TyrH) secretion. By contrast, the knockdown of AK021630 resulted in the opposite effect. Based on these results, we speculated that lncRNA AL049437 likely contributed to the risk of PD, while lncRNA AK021630 likely inhibited the occurrence of PD.

  13. Impact of Combined Subthalamic Nucleus and Substantia Nigra Stimulation on Neuropsychiatric Symptoms in Parkinson's Disease Patients.

    PubMed

    Hidding, U; Gulberti, A; Horn, A; Buhmann, C; Hamel, W; Koeppen, J A; Westphal, M; Engel, A K; Gerloff, C; Weiss, D; Moll, C K E; Pötter-Nerger, M

    2017-01-01

    The goal of the study was to compare the tolerability and the effects of conventional subthalamic nucleus (STN) and combined subthalamic nucleus and substantia nigra (STN+SNr) high-frequency stimulation in regard to neuropsychiatric symptoms in Parkinson's disease patients. In this single center, randomized, double-blind, cross-over clinical trial, twelve patients with advanced Parkinson's disease (1 female; age: 61.3 ± 7.3 years; disease duration: 12.3 ± 5.4 years; Hoehn and Yahr stage: 2.2 ± 0.39) were included. Apathy, fatigue, depression, and impulse control disorder were assessed using a comprehensive set of standardized rating scales and questionnaires such as the Lille Apathy Rating Scale (LARS), Modified Fatigue Impact Scale (MFIS), Becks Depression Inventory (BDI-I), Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease Rating Scale (QUIP-RS), and Parkinson's Disease Questionnaire (PDQ-39). Three patients that were initially assigned to the STN+SNr stimulation mode withdrew from the study within the first week due to discomfort. Statistical comparison of data retrieved from patients who completed the study revealed no significant differences between both stimulation conditions in terms of mean scores of scales measuring apathy, fatigue, depression, impulse control disorder, and quality of life. Individual cases showed an improvement of apathy under combined STN+SNr stimulation. In general, combined STN+SNr stimulation seems to be safe in terms of neuropsychiatric side effects, although careful patient selection and monitoring in the short-term period after changing stimulation settings are recommended.

  14. Autophagy Protects Against Aminochrome-Induced Cell Death in Substantia Nigra-Derived Cell Line

    PubMed Central

    Paris, Irmgard; Muñoz, Patricia; Huenchuguala, Sandro; Couve, Eduardo; Sanders, Laurie H.; Greenamyre, John Timothy; Caviedes, Pablo; Segura-Aguilar, Juan

    2011-01-01

    Aminochrome, the precursor of neuromelanin, has been proposed to be involved in the neurodegeneration neuromelanin-containing dopaminergic neurons in Parkinson’s disease. We aimed to study the mechanism of aminochrome-dependent cell death in a cell line derived from rat substantia nigra. We found that aminochrome (50μM), in the presence of NAD(P)H-quinone oxidoreductase, EC 1.6.99.2 (DT)-diaphorase inhibitor dicoumarol (DIC) (100μM), induces significant cell death (62 ± 3%; p < 0.01), increase in caspase-3 activation (p < 0.001), release of cytochrome C, disruption of mitochondrial membrane potential (p < 0.01), damage of mitochondrial DNA, damage of mitochondria determined with transmission electron microscopy, a dramatic morphological change characterized as cell shrinkage, and significant increase in number of autophagic vacuoles. To determine the role of autophagy on aminochrome-induced cell death, we incubated the cells in the presence of vinblastine and rapamycin. Interestingly, 10μM vinblastine induces a 5.9-fold (p < 0.001) and twofold (p < 0.01) significant increase in cell death when the cells were incubated with 30μM aminochrome in the absence and presence of DIC, respectively, whereas 10μM rapamycin preincubated 24 h before addition of 50μM aminochrome in the absence and the presence of 100μM DIC induces a significant decrease (p < 0.001) in cell death. In conclusion, autophagy seems to be an important protective mechanism against two different aminochrome-induced cell deaths that initially showed apoptotic features. The cell death induced by aminochrome when DT-diaphorase is inhibited requires activation of mitochondrial pathway, whereas the cell death induced by aminochrome alone requires inhibition of autophagy-dependent degrading of damaged organelles and recycling through lysosomes. PMID:21427056

  15. Protective role of hydrogen peroxide in oxygen-deprived dopaminergic neurones of the rat substantia nigra

    PubMed Central

    Geracitano, Raffaella; Tozzi, Alessandro; Berretta, Nicola; Florenzano, Fulvio; Guatteo, Ezia; Viscomi, Maria Teresa; Chiolo, Barbara; Molinari, Marco; Bernardi, Giorgio; Mercuri, Nicola B

    2005-01-01

    Hydrogen peroxide (H2O2) is a reactive oxygen species, responsible for cytotoxic damage through the formation of hydroxyl radicals. Dopamine (DA) neurones of the substantia nigra pars compacta (SNc) are highly sensitive to metabolic stress, and they typically respond to energy deprivation with membrane hyperpolarization, mainly through opening of ATP-dependent K+ channels. Accordingly, H2O2 (3 mm) induced a tolbutamide-sensitive outward current in DA neurones. Conversely, in a hypoxic medium, H2O2 reverted membrane hyperpolarization, which is associated with oxygen deprivation in DA neurones, restored their action potential firing, and reduced the hypoxia-mediated outward current in a concentration-dependent manner, between 0.1 and 3 mm (IC50 0.6 ± 0.1 mm). Notably, H2O2 did not counteract membrane hyperpolarization associated with hypoglycaemia, moreover, when catalase was inhibited with 3-amino-1,2,4-triazole (3-AT; 30 mm), H2O2 did not reduce hypoxia-mediated outward current. The counteracting action of H2O2 on hypoxia-mediated effects was further confirmed by single-unit extracellular recordings of presumed DA neurones in acute midbrain slices preparations, using a planar multi-electrode array device. Whilst a prolonged period of hypoxia (40 min) caused firing suppression, which did not recover after perfusion in normoxic conditions, the presence of H2O2 (3 mm) during this prolonged hypoxic period rescued most of the neurones from irreversible firing inhibition. Accordingly, morphological studies showed that H2O2 counteracts the cytochrome c release provoked by prolonged hypoxic treatment. Taken together, our data suggest that H2O2 prevents the metabolic stress of DA neurones induced by hypoxia by serving as a supplementary source of molecular oxygen, through its degradation by catalase. PMID:16002440

  16. Blockade of substantia nigra dopamine D1 receptors reduces intravenous cocaine reward in rats.

    PubMed

    Quinlan, Matthew G; Sharf, Ruth; Lee, David Y; Wise, Roy A; Ranaldi, Robert

    2004-08-01

    We have recently found that blockade of dopamine D1-type receptors in the ventral tegmental area reduces the rewarding effects of intravenous cocaine; here, we explored the possibility that blockade of D1 receptors in the adjacent substantia nigra (SN)--not usually considered part of reward circuitry--might have similar effects. To test the hypothesis that blockade of dopamine D1 receptors in the SN reduces the rewarding effects of cocaine. Twenty one rats were prepared with intravenous catheters and with bilateral guide cannulae implanted such that injections could be made directly into the SN or just dorsal to the SN. The rats were trained to self-administer intravenous cocaine (1.0 mg/kg per injection) on a fixed-ratio 1 (FR1) schedule of reinforcement. After stable responding developed, 13 of the animals were tested following pretreatment with bilateral microinjections of SCH 23390 at doses of 0, 1, 2 or 4 microg/0.5 microl into the SN and 8 were tested with injections of 0 microg or 4 microg/0.5 microl into a site 2 mm dorsal to the SN site. Microinjections of SCH 23390 in the SN significantly increased rates of cocaine self-administration, while injections dorsal to SN had no significant effect on responding. These data suggest that blockade of dendritically released DA in the SN reduces the rewarding effects of cocaine. These findings complement accumulating evidence that the rewarding effects of cocaine are not restricted to the drug's ability to elevate dopamine levels in the nucleus accumbens.

  17. Psychosis in Spinocerebellar Ataxias: a Case Series and Study of Tyrosine Hydroxylase in Substantia Nigra.

    PubMed

    Turk, Katherine W; Flanagan, Margaret E; Josephson, Samuel; Keene, C Dirk; Jayadev, Suman; Bird, Thomas D

    2017-09-08

    Spinocerebellar ataxias are a genetically heterogeneous group of degenerative diseases typically characterized by progressive ataxia and to various degrees, neuropathy, amyotrophy, and ocular abnormalities. There is increasing evidence for non-motor manifestations associated with cerebellar syndromes including cognitive and psychiatric features. We studied a retrospective clinical case series of eight subjects with spinocerebellar ataxias (SCAs) 2, 3, 7, and 17, all displaying features of psychosis, and also measured tyrosine hydroxylase (TH) staining of the substantia nigra (SN) at autopsy, among four of the subjects. We hypothesized that increased dopamine production in the SN may underlie the pathophysiology of psychosis in SCAs, given evidence of increased dopamine production in the SN in schizophrenia, as measured by TH staining. We analyzed differences in TH staining between the SCA psychosis cohort (n = 4), a heterogeneous ataxic cohort without psychosis (n = 22), and non-diseased age- and sex-matched control group (n = 12). SCA subjects with psychosis did not differ significantly in TH staining versus ataxic cases without psychosis. There was, however, increased TH staining in the ataxic cohort with and without psychosis (n = 26), compared to non-diseased controls (n = 12). Psychotic features were similar across subjects, with the presence of delusions, paranoia, and auditory hallucinations. Our findings are preliminary because of small numbers of subjects and variable neuropathology; however, they suggest that psychosis is a clinical feature of SCAs and may be under-recognized. While the underlying pathophysiology remains to be fully established, it may be related to extra-cerebellar pathology, including a possible propensity for increased dopamine activity in the SN.

  18. 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.

  19. AMP kinase regulates ligand-gated K-ATP channels in substantia nigra dopamine neurons.

    PubMed

    Shen, Ke-Zhong; Wu, Yan-Na; Munhall, Adam C; Johnson, Steven W

    2016-08-25

    AMP-activated protein kinase (AMPK) is a master enzyme that regulates ATP-sensitive K(+) (K-ATP) channels in pancreatic beta-cells and cardiac myocytes. We used patch pipettes to record currents and potentials to investigate effects of AMPK on K-ATP currents in substantia nigra compacta (SNC) dopamine neurons in slices of rat midbrain. When slices were superfused repeatedly with the K-ATP channel opener diazoxide, we were surprised to find that diazoxide currents gradually increased in magnitude, reaching 300% of the control value 60min after starting whole-cell recording. However, diazoxide current increased significantly more, to 472% of control, when recorded in the presence of the AMPK activator A769662. Moreover, superfusing the slice with the AMPK blocking agent dorsomorphin significantly reduced diazoxide current to 38% of control. Control experiments showed that outward currents evoked by the K-ATP channel opener NN-414 also increased over time, but not currents evoked by the GABAB agonist baclofen. Delaying the application of diazoxide after starting whole-cell recording correlated with augmentation of current. Loose-patch recording showed that diazoxide produced a 34% slowing of spontaneous firing rate that did not intensify with repeated applications of diazoxide. However, superfusion with A769662 significantly augmented the inhibitory effect of diazoxide on firing rate. We conclude that K-ATP channel function is augmented by AMPK, which is activated during the process of making whole-cell recordings. Our results suggest that AMPK and K-ATP interactions may play an important role in regulating dopamine neuronal excitability.

  20. Activity-dependent regulation of NMDA receptors in substantia nigra dopaminergic neurones

    PubMed Central

    Wild, Angela R; Jones, Susan; Gibb, Alasdair J

    2014-01-01

    N-Methyl-d-aspartate receptors (NMDARs) are Ca2+-permeable glutamate receptors that play a critical role in synaptic plasticity and promoting cell survival. However, overactive NMDARs can trigger cell death signalling pathways and have been implicated in substantia nigra pars compacta (SNc) pathology in Parkinson's disease. Calcium ion influx through NMDARs recruits Ca2+-dependent proteins that can regulate NMDAR activity. The surface density of NMDARs can also be regulated dynamically in response to receptor activity via Ca2+-independent mechanisms. We have investigated the activity-dependent regulation of NMDARs in SNc dopaminergic neurones. Repeated whole-cell agonist applications resulted in a decline in the amplitude of NMDAR currents (current run-down) that was use dependent and not readily reversible. Run-down was reduced by increasing intracellular Ca2+ buffering or by reducing Ca2+ influx but did not appear to be mediated by the same regulatory proteins that cause Ca2+-dependent run-down in hippocampal neurones. The NMDAR current run-down may be mediated in part by a Ca2+-independent mechanism, because intracellular dialysis with a dynamin-inhibitory peptide reduced run-down, suggesting a role for clathrin-mediated endocytosis in the regulation of the surface density of receptors. Synaptic NMDARs were also subject to current run-down during repeated low-frequency synaptic stimulation in a Ca2+-dependent but dynamin-independent manner. Thus, we report, for the first time, regulation of NMDARs in SNc dopaminergic neurones by changes in intracellular Ca2+ at both synaptic and extrasynaptic sites and provide evidence for activity-dependent changes in receptor trafficking. These mechanisms may contribute to intracellular Ca2+ homeostasis in dopaminergic neurones by limiting Ca2+ influx through the NMDAR. PMID:24344168

  1. Loss of Mecp2 in substantia nigra dopamine neurons compromises the nigrostriatal pathway

    PubMed Central

    Gantz, Stephanie C.; Ford, Christopher P.; Neve, Kim A.; Williams, John T.

    2011-01-01

    Mutations in the methyl-CpG-binding-protein 2 (MeCP2) result in Rett Syndrome (RTT), an X-linked disorder that disrupts neurodevelopment. Girls with RTT exhibit motor deficits similar to Parkinson’s disease, suggesting defects in the nigrostriatal pathway. This study examined age-dependent changes in dopamine neurons of the substantia nigra (SN) from wild type, pre-symptomatic, and symptomatic Mecp2+/− mice. Mecp2+ neurons in the SN in Mecp2+/− mice were indistinguishable in morphology, resting conductance, and dopamine current density from neurons in wild type mice. However, the capacitance, total dendritic length, and resting conductance of Mecp2− neurons were less than that of Mecp2+ neurons as early as four weeks after birth, prior to overt symptoms. These differences were maintained throughout life. In symptomatic Mecp2+/− mice, the current induced by activation of D2 dopamine autoreceptors was significantly less in Mecp2− neurons than Mecp2+ neurons, although D2 receptor density was unaltered in Mecp2+/− mice. Electrochemical measurements revealed that significantly less dopamine was released after stimulation of striatum in adult Mecp2+/− mice compared to wild type. The decrease in size and function of Mecp2− neurons observed in adult Mecp2+/− mice was recapitulated in dopamine neurons from symptomatic Mecp2−/y males. These results show that mutation in Mecp2 results in cell-autonomous defects in the SN early in life and throughout adulthood. Ultimately, dysfunction in terminal dopamine release and D2 autoreceptor dependent currents in dopamine neurons from symptomatic females support the idea that decreased dopamine transmission due to heterogeneous Mecp2 expression contributes to the Parkinsonian features of RTT in Mecp2+/− mice. PMID:21880923

  2. Comparison of 3T and 7T susceptibility-weighted angiography of the substantia nigra in diagnosing Parkinson disease.

    PubMed

    Cosottini, M; Frosini, D; Pesaresi, I; Donatelli, G; Cecchi, P; Costagli, M; Biagi, L; Ceravolo, R; Bonuccelli, U; Tosetti, M

    2015-03-01

    Standard neuroimaging fails in defining the anatomy of the substantia nigra and has a marginal role in the diagnosis of Parkinson disease. Recently 7T MR target imaging of the substantia nigra has been useful in diagnosing Parkinson disease. We performed a comparative study to evaluate whether susceptibility-weighted angiography can diagnose Parkinson disease with a 3T scanner. Fourteen patients with Parkinson disease and 13 healthy subjects underwent MR imaging examination at 3T and 7T by using susceptibility-weighted angiography. Two expert blinded observers and 1 neuroradiology fellow evaluated the 3T and 7T images of the sample to identify substantia nigra abnormalities indicative of Parkinson disease. Diagnostic accuracy and intra- and interobserver agreement were calculated separately for 3T and 7T acquisitions. Susceptibility-weighted angiography 7T MR imaging can diagnose Parkinson disease with a mean sensitivity of 93%, specificity of 100%, and diagnostic accuracy of 96%. 3T MR imaging diagnosed Parkinson disease with a mean sensitivity of 79%, specificity of 94%, and diagnostic accuracy of 86%. Intraobserver and interobserver agreement was excellent at 7T. At 3T, intraobserver agreement was excellent for experts, and interobserver agreement ranged between good and excellent. The less expert reader obtained a diagnostic accuracy of 89% at 3T. Susceptibility-weighted angiography images obtained at 3T and 7T differentiate controls from patients with Parkinson disease with a higher diagnostic accuracy at 7T. The capability of 3T in diagnosing Parkinson disease might encourage its use in clinical practice. The use of the more accurate 7T should be supported by a dedicated cost-effectiveness study. © 2015 by American Journal of Neuroradiology.

  3. Expression of Peroxisome Proliferator-Activated Receptor-γ in the substantia nigra of hemiparkinsonian nonhuman primates

    PubMed Central

    Swanson, Christine R.; Emborg, Marina E.

    2014-01-01

    OBJECTIVE To characterize the distribution of Peroxisome proliferator-activated receptor-gamma (PPAR-γ) in the substantia nigra of normal and MPTP-treated hemiparkinsonian monkeys, in order to validate PPAR-γ as a target for neuroprotection. METHODS Immunohistochemical analysis of PPAR-γ expression was performed in the substantia nigra and other select brain regions of fifteen rhesus monkeys including controls (n = 3), hemiparkinsonian necropsied after 3 (n = 5) or 12 months (n = 3) after MPTP, and animals who received MPTP + 5 mg/kg of the PPAR-γ agonist pioglitazone (n = 4). RESULTS PPAR-γ expression was prominent in the subthalamic nucleus, oculomotor nucleus, ventral tegmental nucleus and to a lesser extent in the putamen; three or twelve months after MPTP, only the lesioned putamen had increased PPAR-γ. Stereological cell quantification in normal subjects showed that approximately 50% of neurons in the substantia nigra pars compacta (SNpc) expressed PPAR-γ. After MPTP there was a significant loss of dopaminergic (DA) neurons in the ipsilateral SNpc and the actual number of TH and PPAR-γ cells were not significantly different at either time point. Pioglitazone dosing protected TH positive neurons, closely matching the number of PPAR-γ expressing cells in the ipsilateral SNpc. Nigral immunofluorescence verified colocalization of PPAR-γ in neurons. DISCUSSION These results demonstrate that PPAR-γ is expressed in the SNpc and putamen of nonhuman primates and, that the DA nigral neurons expressing PPAR-γ are more likely to survive neurotoxin challenge after ligand activation by pioglitazone, therefore providing neuroanatomical validation for the use of PPAR-γ agonists in PD. PMID:24620964

  4. Protective Effects of Vitamin E Consumption against 3MT Electromagnetic Field Effects on Oxidative Parameters in Substantia Nigra in Rats

    PubMed Central

    Ghanbari, Ahmad Ali; Shabani, Kobra; Mohammad Nejad, Daryoush

    2016-01-01

    Introduction: Electromagnetic fields (EMFs) can influence the biological system by the formation of free radicals in cells. The EMFs are able to deteriorate defense system against free radicals that leads to oxidative stress (OS). Lipid peroxidation process (LPO) is an index of oxidative stress, and the Malandialdehyde (MDA) is the final product of LPO. Vitamin E is the most important antioxidant which inhibits the LPO process. The aim of this study was to evaluate the effects of 3MT EMF exposure on oxidative stress parameters in substantia nigra and the role of vitamin E in reducing oxidative stress and preventing of LPO process. Methods: 40 male Wistar rats were randomly divided into 4 groups: 1) Control group: received standard food without exposure to EMF and without consumption of vitamin E, 2) Experimental group 1: was exposed to EMF (3MT) 4 h/day for 50 days, 3) The experimental group 2: received 200 mg/kg vitamin E with gavage every day and also was exposed to EMF (3MT) 4 h/day for 50 days, 4) Sham group: received water with gavage for 50 days. Results: A significant increase in MDA levels and Glutation peroxidase (GSH-Px) activity of the substantia nigra following 50 days exposure to EMF was detected, but the superoxide dismutase (SOD) activity was decreased. Exposure did not change total antioxidant capacity (TAC) levels in plasma. Vitamin E treatment significantly prevented the increase of the MDA levels and GSHPx activity and also prevented the decrease of SOD activity in tissue but did not alter TAC levels. The GSH-Px activity increased because the duration and intensity of exposure were not enough to decrease it. Conclusion: We demonstrated two important findings; that 50 days exposure to 3 MT electromagnetic field caused oxidative stress by increasing the levels of MDA, and decreasing SOD activity in the substantia nigra; and that treatment with the vitamin E significantly prevented the oxidative stress and lipid peroxidation. PMID:27872692

  5. [The nucleolus of the cell is the site of iron accumulation in the substantia nigra neurons of the human brain].

    PubMed

    Sukhorukova, Ye G; Grigoriev, I P; Kolos, Ye A; Korzhenevskiy, D E

    2012-01-01

    Distribution of iron in the substantia nigra of the human brain (10 men and women aged 27-78 years) was studied using Perls' histochemical method. Iron ions were demonstrated in the nigral neuropil and melanin-containing neurons. For the first time the nuclei of some neurons were found to contain iron accumulations. The intranuclear iron inclusions correspond to the nucleolus according to their sharp outline and sizes. Detection of iron in the neuronal nucleolus may contribute to the understanding of mechanisms of iron neurotoxicity for nigral dopaminergic neurons.

  6. [The role of the substantia nigra in the anticonvulsive and antiaggressive effects of diazepam during pharmacological kindling].

    PubMed

    Shandra, A A; Godlevskiĭ, L S; Mazarati, A M; Makul'kin, R F

    1990-01-01

    The seizure activity was investigated on the model of pharmacological kindling which was induced by repeated picrotoxin injections in the subthreshold dose, after the tryptic fragment of T5 protein-human diazepam binding inhibitor (DBI) (10 micrograms) injection into a reticular part of substantia nigra. An increase in the seizure reaction and suppression of the antiseizure diazepam action were observed. Intranigral DBI injection induced no change in a threshold of "attacks" in rats which were induced through electric shocks delivered to animals with an electrode floor and no changes in antiaggressive diazepam action were observed under such conditions.

  7. Iron concentrations and distributions in the parkinsonian substantia nigra of aged and young primate models

    NASA Astrophysics Data System (ADS)

    Ren, M. Q.; Xie, J. P.; Wang, X. S.; Ong, W. Y.; Leong, S. K.; Watt, F.

    2001-07-01

    Parkinson's disease (PD) is a progressive neuronal degenerative brain disease of the elderly, and is caused by the selective degeneration of neurons in the substantia nigra (SN) region of the brain, resulting in a reduced production of the neurotransmitter dopamine. Iron has been linked to dopaminergic cell death in Parkinson's disease because of its potential to promote free radicals, leading to oxidative stress. The present study is aimed at using the techniques of nuclear microscopy to elucidate the iron concentrations and distributions in the SN of both young and old monkeys following unilateral 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioning. A group of three old monkeys (older than 7 years) and a group of three young monkeys (younger than 7 years) were unilaterally MPTP-lesioned (right side) to induce parkinsonism and sacrificed after 35 days. The left side SN was used as a control. This time interval was chosen to correspond to an average 50% loss of dopamine producing cells in the lesioned right side SN. We have observed a significant difference in iron concentrations between the SNs of the young and old monkeys (increasing from an average of 233 to 1092 parts per million dry weight). When comparing the lesioned and non-lesioned SNs of the same animal, we found no significant difference in iron levels for each young monkey. However we have found a slight increase in iron (approximately 10%) between the lesioned SN and control SN for old monkeys. We have also observed that in the SN of younger primates, there is a weak anti-correlation in the SN iron levels with the neuron distribution. In the older monkeys, however, we have observed a proliferation of iron-rich granules, which appear to be more strongly anti-correlated with the distribution of neurons. The iron-cell anti-correlation occurs both in the control as well as the lesioned SN. Our results suggest that iron, particularly in the form of iron-rich deposits, accumulates in specific sites

  8. Cognitive Performance Patterns in Healthy Individuals with Substantia Nigra Hyperechogenicity and Early Parkinson's Disease.

    PubMed

    Yilmaz, Rezzak; Gräber, Susanne; Roeben, Benjamin; Suenkel, Ulrike; von Thaler, Anna-Katharina; Heinzel, Sebastian; Metzger, Florian G; Eschweiler, Gerhard W; Maetzler, Walter; Berg, Daniela; Liepelt-Scarfone, Inga

    2016-01-01

    Introduction: Hyperechogenicity of the substantia nigra (SN+) is a risk marker for Parkinson's disease (PD) which can be detected before the diagnosis. In healthy individuals, SN+ has been associated with slight deficits in specific cognitive functions, suggesting cognitive impairment as a possible pre-diagnostic marker for PD. However, the pattern of cognitive deficits associated with SN+ has not yet been compared with those present in PD. Methods: Data of 262 healthy individuals with normal echogenicity (SN-) and 48 healthy individuals with SN+ were compared with 82 early stage PD patients using the "Consortium to Establish a Registry for Alzheimer's disease" test battery. First, the test clusters (factors) were identified using a principal component analysis (PCA). Mean group performance of cognitive tests belonging to distinct factors, according to the PCA, and single subtest performances were compared using analyses of variance. Second, the number of individuals with abnormal cognitive performances (z-score < -1.0) were compared between groups. Results: Verbal memory, semantic and executive function, and praxis were identified as components of cognitive performances. The SN+ group performed significantly worse than the SN- group in tests assessing semantic and executive function, with a non-significant decrease in verbal memory. On the subtest level, individuals of the SN+ group scored significantly lower than the SN- group on the Boston Naming Test (BNT; p = 0.008). In all subtests, the percentages of PD patients with values below the cut-off for abnormal performance were higher than in the SN- group. Moreover, more individuals from the SN+ group scored below the cut-off in the BNT (SN- = 8.4%, SN+ = 20.8%, p = 0.01) and TMT-B (SN- = 6.9%, SN+ = 16.7%, p = 0.02), compared to the SN- group. Conclusion: This study confirms poorer performance of healthy individuals with SN+ compared to SN- in specific cognitive domains. However, against the SN- group, the

  9. Cognitive Performance Patterns in Healthy Individuals with Substantia Nigra Hyperechogenicity and Early Parkinson’s Disease

    PubMed Central

    Yilmaz, Rezzak; Gräber, Susanne; Roeben, Benjamin; Suenkel, Ulrike; von Thaler, Anna-Katharina; Heinzel, Sebastian; Metzger, Florian G.; Eschweiler, Gerhard W.; Maetzler, Walter; Berg, Daniela; Liepelt-Scarfone, Inga

    2016-01-01

    Introduction: Hyperechogenicity of the substantia nigra (SN+) is a risk marker for Parkinson’s disease (PD) which can be detected before the diagnosis. In healthy individuals, SN+ has been associated with slight deficits in specific cognitive functions, suggesting cognitive impairment as a possible pre-diagnostic marker for PD. However, the pattern of cognitive deficits associated with SN+ has not yet been compared with those present in PD. Methods: Data of 262 healthy individuals with normal echogenicity (SN-) and 48 healthy individuals with SN+ were compared with 82 early stage PD patients using the “Consortium to Establish a Registry for Alzheimer’s disease” test battery. First, the test clusters (factors) were identified using a principal component analysis (PCA). Mean group performance of cognitive tests belonging to distinct factors, according to the PCA, and single subtest performances were compared using analyses of variance. Second, the number of individuals with abnormal cognitive performances (z-score < -1.0) were compared between groups. Results: Verbal memory, semantic and executive function, and praxis were identified as components of cognitive performances. The SN+ group performed significantly worse than the SN- group in tests assessing semantic and executive function, with a non-significant decrease in verbal memory. On the subtest level, individuals of the SN+ group scored significantly lower than the SN- group on the Boston Naming Test (BNT; p = 0.008). In all subtests, the percentages of PD patients with values below the cut-off for abnormal performance were higher than in the SN- group. Moreover, more individuals from the SN+ group scored below the cut-off in the BNT (SN- = 8.4%, SN+ = 20.8%, p = 0.01) and TMT-B (SN- = 6.9%, SN+ = 16.7%, p = 0.02), compared to the SN- group. Conclusion: This study confirms poorer performance of healthy individuals with SN+ compared to SN- in specific cognitive domains. However, against the SN- group

  10. Coupled oscillator model of the dopaminergic neuron of the substantia nigra.

    PubMed

    Wilson, C J; Callaway, J C

    2000-05-01

    Calcium imaging using fura-2 and whole cell recording revealed the effective location of the oscillator mechanism on dopaminergic neurons of the substantia nigra, pars compacta, in slices from rats aged 15-20 days. As previously reported, dopaminergic neurons fired in a slow rhythmic single spiking pattern. The underlying membrane potential oscillation survived blockade of sodium currents with TTX and was enhanced by blockade of voltage-sensitive potassium currents with TEA. Calcium levels increased during the subthreshold depolarizing phase of the membrane potential oscillation and peaked at the onset of the hyperpolarizing phase as expected if the pacemaker potential were due to a low-threshold calcium current and the hyperpolarizing phase to calcium-dependent potassium current. Calcium oscillations were synchronous in the dendrites and soma and were greater in the dendrites than in the soma. Average calcium levels in the dendrites overshot steady-state levels and decayed over the course of seconds after the oscillation was resumed after having been halted by hyperpolarizing currents. Average calcium levels in the soma increased slowly, taking many cycles to achieve steady state. Voltage clamp with calcium imaging revealed the voltage dependence of the somatic calcium current without the artifacts of incomplete spatial voltage control. This showed that the calcium current had little or no inactivation and was half-maximal at -40 to -30 mV. The time constant of calcium removal was measured by the return of calcium to resting levels and depended on diameter. The calcium sensitivity of the calcium-dependent potassium current was estimated by plotting the slow tail current against calcium concentration during the decay of calcium to resting levels at -60 mV. A single compartment model of the dopaminergic neuron consisting of a noninactivating low-threshold calcium current, a calcium-dependent potassium current, and a small leak current reproduced most features of the

  11. Anti-apoptotic effect of Shudipingchan granule in the substantia nigra of rat models of Parkinson's disease

    PubMed Central

    Ye, Qing; Yuan, Xiao-lei; He, Jing; Zhou, Jie; Yuan, Can-xing; Yang, Xu-ming

    2016-01-01

    Levodopa is the gold-standard treatment for Parkinson's disease. However, although it alleviates the clinical symptoms, it cannot delay the progressive apoptosis of dopaminergic neurons or prevent motor complications in the long term. In the present study, we investigated the effect of Shudipingchan granule on neuronal apoptosis in a rat model of Parkinson's disease, established by injecting 6-hydroxydopamine into the substantia nigra pars compacta and ventral tegmental area. We then administered levodopa (20 mg/kg intraperitoneally, twice daily) with or without Shudipingchan granule (7.5 mL/kg intragastrically, twice daily), for 4 weeks. The long-term use of levodopa accelerated apoptosis of nigral cells and worsened behavioral symptoms by activating the extracellular signal-regulated kinase pathway and downstream apoptotic factors. However, administration of Shudipingchan granule with levodopa reduced expression of phosphorylated extracellular signal-regulated kinase 1/2 and Bax, increased tyrosine hydroxylase and Bcl-2, reduced apoptosis in the substantia nigra, and markedly improved dyskinesia. These findings suggest that Shudipingchan granule suppresses neuronal apoptosis by inhibiting the hyperphosphorylation of extracellular signal-regulated kinase and downregulating expression of anti-apoptotic genes. Shudipingchan granule, used in combination with levodopa, can effectively reduce the symptoms of Parkinson's disease. PMID:27904494

  12. Anti-apoptotic effect of Shudipingchan granule in the substantia nigra of rat models of Parkinson's disease.

    PubMed

    Ye, Qing; Yuan, Xiao-Lei; He, Jing; Zhou, Jie; Yuan, Can-Xing; Yang, Xu-Ming

    2016-10-01

    Levodopa is the gold-standard treatment for Parkinson's disease. However, although it alleviates the clinical symptoms, it cannot delay the progressive apoptosis of dopaminergic neurons or prevent motor complications in the long term. In the present study, we investigated the effect of Shudipingchan granule on neuronal apoptosis in a rat model of Parkinson's disease, established by injecting 6-hydroxydopamine into the substantia nigra pars compacta and ventral tegmental area. We then administered levodopa (20 mg/kg intraperitoneally, twice daily) with or without Shudipingchan granule (7.5 mL/kg intragastrically, twice daily), for 4 weeks. The long-term use of levodopa accelerated apoptosis of nigral cells and worsened behavioral symptoms by activating the extracellular signal-regulated kinase pathway and downstream apoptotic factors. However, administration of Shudipingchan granule with levodopa reduced expression of phosphorylated extracellular signal-regulated kinase 1/2 and Bax, increased tyrosine hydroxylase and Bcl-2, reduced apoptosis in the substantia nigra, and markedly improved dyskinesia. These findings suggest that Shudipingchan granule suppresses neuronal apoptosis by inhibiting the hyperphosphorylation of extracellular signal-regulated kinase and downregulating expression of anti-apoptotic genes. Shudipingchan granule, used in combination with levodopa, can effectively reduce the symptoms of Parkinson's disease.

  13. Oxidative stress, progressive damage in the substantia nigra and plasma dopamine oxidation, in rats chronically exposed to ozone.

    PubMed

    Santiago-López, D; Bautista-Martínez, J A; Reyes-Hernandez, C I; Aguilar-Martínez, M; Rivas-Arancibia, S

    2010-09-01

    The purpose of our work was to determine the effects of oxidative stress on the neurodegeneration process in the substantia nigra, and to evaluate dopamine-oxidation metabolites in the plasma using a cyclic voltammetry (CV) technique. We have also studied the correlation between the increases in oxidized dopamine-species levels with the severity of lipid-peroxidation in the plasma. Sixty-four male Wistar rats were divided into four experimental groups and received air (Group I, control) or ozone (0.25 ppm) daily by inhalation for 4h for 15 (Group II), 30 (Group III), and 60 (Group IV) days. The brains were processed for immunohistochemical location of dopamine and p53 in the substantia nigra. Plasma collected from these animals was assayed for oxidized dopamine products using CV and lipid-peroxidation levels were measured. Our results indicate that chronic exposure to low O(3) doses causes that the number of dopaminergic neurons decreased, and p53-immunoreactive cells increases until 30 days; which was a function of the time of exposure to ozone. Oxidative stress produces a significant increase in the levels of the dopamine quinones (DAQs) that correlated well (r=0.962) with lipid peroxides in the plasma during the study period. These results suggest that DAQ could be a reliable, peripheral oxidative indicator of nigral dopaminergic damage in the brain. (c) 2010 Elsevier Ireland Ltd. All rights reserved.

  14. The aberrantly expressed long non-coding RNA in the substantia nigra and corpus striatum of Nrf2-knockout mice.

    PubMed

    Liu, Jian; Xu, Yali; Kang, Yunxiao; Cao, Shanhu; Shi, Geming; Cui, Huixian; Sun, Shaoguang; Wang, Lei

    2017-10-01

    Nuclear factor erythroid 2 like 2 (Nrf2) functions as a neuroprotective agent in Parkinson's disease (PD). This study aimed to investigate the key long non-coding RNAs (lncRNAs) correlated with Nrf2, which might provide valuable information for the exploration of pathogenesis of PD. The lncRNA and mRNA expression profiling of substantia nigra and corpus striatum of Nrf2 (-/-) mice model was obtained from microarray analysis. The animal experiments conducted for this study were approved by the ethics committee of Hebei Medical University. Bioinformatics analyses were conducted, including differentially expressed lncRNAs/mRNA (differentially expressed lncRNA, DEL/differentially expressed mRNA, DEM) identification, DEL-DEM coexpression network construction, and biological functions prediction. Quantitative real-time polymerase chain reaction (qRT-PCR) was subjected to validate abnormally expressed DELs and DEMs in the substantia nigra and corpus striatum of Nrf2 (-/-) mice model. A total of 48 DELs (37 down-regulated and 11 up-regulated) were identified both in Nrf2 (-/-) substantia nigra and corpus striatum; 96 DEMs and 643 DEMs were identified in the substantia nigra and corpus striatum, respectively. DEL-DEM coexpressed network was constructed. LncRNA AK076880, AK036620, and AK020330 had high connectivity with DEMs both in the substantia nigra and corpus striatum. These DEMs were significantly enriched in signaling pathways such as the calcium signaling pathway, Huntington's disease, Alzheimer's disease, mitogen-activated protein kinase (MAPK) signaling pathway, and the Wnt signaling pathway. Generally, qRT-PCR validation results of selected DEMs and DELs were consistent with microarray data. The dysregulated DELs and DEMs in the substantia nigra and corpus striatum of Nrf2 (-/-) mice were identified. Our results might provide useful information for further exploring the pathogenesis mechanism of PD. © 2017 International Society for Neurochemistry.

  15. Novel approaches for correction against the soft matrix effects in the quantitative elemental imaging of human substantia nigra tissue using synchrotron X-ray fluorescence

    NASA Astrophysics Data System (ADS)

    Surowka, A. D.; Wrobel, P.; Marzec, M. M.; Adamek, D.; Szczerbowska-Boruchowska, M.

    2016-09-01

    The inherent structural heterogeneity of biological specimens poses a number of problems for analytical techniques to assess for the elemental composition of a sample, and this is the case with quantitative X-ray fluorescence (XRF). Differences in density along with any possible variation in thickness upon frequently used freeze drying of thin samples could influence the results of the quantification and therefore underlie one of the most critical matrix effects in XRF, often referred to as the mass thickness effect. In our study, we analyzed substantia nigra tissue samples of various thicknesses mounted onto silicon nitride membranes. The aim was to show up the variation in the mass thickness of the different substantia nigra tissue compartments: the neuromelanine pigmented neurons and neuropil could influence the final quantitative results. In that respect, the main goal was to derive several semi- and fully-quantitative methods to correct for the mass thickness effects using either a membrane Si transmission signal or the intensity of incoherently scattered primary X-ray radiation. Also, the pioneer topographic studies on dried substantia nigra tissue specimens demonstrated the drying procedure is accompanied by an around 80% reduction in the samples' thickness. The correction scheme is presented together with the semi-theoretical procedure developed to compute for the mass thickness for substantia nigra tissue structures, and the correction scheme's robustness is also presented.

  16. Nifedipine prevents iron accumulation and reverses iron-overload-induced dopamine neuron degeneration in the substantia nigra of rats.

    PubMed

    Ma, ZeGang; Zhou, Yu; Xie, JunXia

    2012-11-01

    The mechanisms of iron accumulation in substantia nigra (SN) of Parkinson's diseases remain unclear. The objective of this study was to investigate effects of nifedipine on iron-overload-induced iron accumulation and neurodegeneration in SN of rats. By high performance liquid chromatography-electrochemical detection, tyrosine hydroxylase (TH) immunohistochemistry, and iron content array, we first quantified iron content and the number of dopamine neurons in SN of experimental rats treated with iron dextran. We further assessed effects of treatment with nifedipine. Our results showed that nifedipine treatment prevents iron dextran-induced dopamine depletion in the striatum. Consistently, we found that nifedipine restores the number of TH-positive neurons reduced by iron dextran overload and prevents increase of iron content in the SN. These results suggested that nifedipine may suppress iron toxicity in dopamine neurons and prevent neurodegeneration.

  17. Intranasal Administration of Rotenone to Mice Induces Dopaminergic Neurite Degeneration of Dopaminergic Neurons in the Substantia Nigra.

    PubMed

    Sasajima, Hitoshi; Miyazono, Sadaharu; Noguchi, Tomohiro; Kashiwayanagi, Makoto

    2017-01-01

    Exposure to environmental neurotoxins is suspected to be a risk factor for sporadic progressive neurodegenerative diseases. Parkinson's disease has been associated with exposure to the pesticide rotenone, a mitochondrial respiration inhibitor. We previously reported that intranasal administration of rotenone in mice induced dopaminergic (DA) neurodegeneration in the olfactory bulb (OB) and reduced olfactory functions. In the present study, we investigated the DA neurons in the brains of mice that were administered rotenone intranasally for an extended period. We found that the olfactory function of mice was attenuated by rotenone administration. Electrophysiological analysis of the mitral cells, which are output neurons in the OB, revealed that the inhibitory input into the mitral cells was retarded. In the immunohistochemical analysis, neurite degeneration of DA neurons in the substantia nigra was observed in rotenone-administered mice, indicating that rotenone progressively initiated the degeneration of cerebral DA neurons via the nasal route.

  18. Ketogenic diet prevents neuronal firing increase within the substantia nigra during pentylenetetrazole-induced seizure in rats.

    PubMed

    Viggiano, Andrea; Stoddard, Madison; Pisano, Simone; Operto, Francesca Felicia; Iovane, Valentina; Monda, Marcellino; Coppola, Giangennaro

    2016-07-01

    The mechanism responsible for the anti-seizure effect of ketogenic diets is poorly understood. Because the substantia nigra pars reticulata (SNr) is a "gate" center for seizures, the aim of the present experiment was to evaluate if a ketogenic diet modifies the neuronal response of this nucleus when a seizure-inducing drug is administered in rats. Two groups of rats were given a standard diet (group 1) or a ketogenic diet (group 2) for four weeks, then the threshold for seizure induction and the firing rate of putative GABAergic neurons within the SNr were evaluated with progressive infusion of pentylenetetrazole under general anesthesia. The results demonstrated that the ketogenic diet abolished the correlation between the firing rate response of SNr-neurons and the seizure-threshold. This result suggests that the anti-seizure effect of ketogenic diets can be due to a decrease in reactivity of GABAergic SNr-neurons.

  19. Proton MRS of the unilateral substantia nigra in the human brain at 4 tesla: detection of high GABA concentrations.

    PubMed

    Oz, Gülin; Terpstra, Melissa; Tkác, Ivan; Aia, Pratibha; Lowary, Jodi; Tuite, Paul J; Gruetter, Rolf

    2006-02-01

    Parkinson's disease (PD) is characterized by loss of dopaminergic neurons in the substantia nigra (SN), the cause of which is unknown. Characterization of early SN pathology could prove beneficial in the treatment and diagnosis of PD. The present study shows that with the use of short-echo (5 ms) Stimulated-Echo Acquisition Mode (STEAM) spectroscopy and LCModel, a neurochemical profile consisting of 10 metabolites, including gamma-aminobutyric acid (GABA), glutamate (Glu), and glutathione (GSH), can be measured from the unilateral SN at 4 tesla. The neurochemical profile of the SN is unique and characterized by a fourfold higher GABA/Glu ratio compared to the cortex, in excellent agreement with established neurochemistry. The presence of elevated GABA levels in SN was validated with the use of editing, suggesting that partial volume effects were greatly reduced. These findings establish the feasibility of obtaining a neurochemical profile of the unilateral human SN by single-voxel spectroscopy in small volumes.

  20. Dopamine Inhibition Differentially Controls Excitability of Substantia Nigra Dopamine Neuron Subpopulations through T-Type Calcium Channels.

    PubMed

    Evans, Rebekah C; Zhu, Manhua; Khaliq, Zayd M

    2017-03-29

    While there is growing appreciation for diversity among ventral tegmental area dopamine neurons, much less is known regarding functional heterogeneity among the substantia nigra pars compacta (SNc) neurons. Here, we show that calbindin-positive dorsal tier and calbindin-negative ventral tier SNc dopaminergic neurons in mice comprise functionally distinct subpopulations distinguished by their dendritic calcium signaling, rebound excitation, and physiological responses to dopamine D2-receptor (D2) autoinhibition. While dopamine is known to inhibit action potential backpropagation, our experiments revealed an unexpected enhancement of excitatory responses and dendritic calcium signals in the presence of D2-receptor inhibition. Specifically, dopamine inhibition and direct hyperpolarization enabled the generation of low-threshold depolarizations that occurred in an all-or-none or graded manner, due to recruitment of T-type calcium channels. Interestingly, these effects occurred selectively in calbindin-negative dopaminergic neurons within the SNc. Thus, calbindin-positive and calbindin-negative SNc neurons differ substantially in their calcium channel composition and efficacy of excitatory inputs in the presence of dopamine inhibition.SIGNIFICANCE STATEMENT Substantia nigra dopaminergic neurons can be divided into two populations: the calbindin-negative ventral tier, which is vulnerable to neurodegeneration in Parkinson's disease, and the calbindin-positive dorsal tier, which is relatively resilient. Although tonic firing is similar in these subpopulations, we find that their responses to dopamine-mediated inhibition are strikingly different. During inhibition, calbindin-negative neurons exhibit increased sensitivity to excitatory inputs, which can then trigger large dendritic calcium transients due to strong expression of T-type calcium channels. Therefore, SNc neurons differ substantially in their calcium channel composition, which may contribute to their differential

  1. Gene Expression Profiling of Embryonic Human Neural Stem Cells and Dopaminergic Neurons from Adult Human Substantia Nigra

    PubMed Central

    Marei, Hany E. S.; Althani, Asma; Afifi, Nahla; Michetti, Fabrizio; Pescatori, Mario; Pallini, Roberto; Casalbore, Patricia; Cenciarelli, Carlo; Schwartz, Philip; Ahmed, Abd-Elmaksoud

    2011-01-01

    Neural stem cells (NSC) with self-renewal and multipotent properties serve as an ideal cell source for transplantation to treat neurodegenerative insults such as Parkinson's disease. We used Agilent's and Illumina Whole Human Genome Oligonucleotide Microarray to compare the genomic profiles of human embryonic NSC at a single time point in culture, and a multicellular tissue from postmortem adult substantia nigra (SN) which are rich in dopaminergic (DA) neurons. We identified 13525 up-regulated genes in both cell types of which 3737 (27.6%) genes were up-regulated in the hENSC, 4116 (30.4%) genes were up-regulated in the human substantia nigra dopaminergic cells, and 5672 (41.93%) were significantly up-regulated in both cell population. Careful analysis of the data that emerged using DAVID has permitted us to distinguish several genes and pathways that are involved in dopaminergic (DA) differentiation, and to identify the crucial signaling pathways that direct the process of differentiation. The set of genes expressed more highly at hENSC is enriched in molecules known or predicted to be involved in the M phase of the mitotic cell cycle. On the other hand, the genes enriched in SN cells include a different set of functional categories, namely synaptic transmission, central nervous system development, structural constituents of the myelin sheath, the internode region of axons, myelination, cell projection, cell somata, ion transport, and the voltage-gated ion channel complex. Our results were also compared with data from various databases, and between different types of arrays, Agilent versus Illumina. This approach has allowed us to confirm the consistency of our obtained results for a large number of genes that delineate the phenotypical differences of embryonic NSCs, and SN cells. PMID:22163301

  2. Regulation of dopamine D3 receptor in the striatal regions and substantia nigra in diffuse Lewy body disease (DLBD)

    PubMed Central

    Sun, Jianjun; Cairns, Nigel J.; Perlmutter, Joel S.; Mach, Robert H.; Xu, Jinbin

    2013-01-01

    The regulation of D3 receptor has not been well documented in diffuse Lewy body disease (DLBD). In this study, a novel D3 preferring radioligand [3H]WC-10 and a D2-preferring radioligand [3H]raclopride were used and the absolute densities of the dopamine D3 and D2 receptors were determined in the striatal regions and substantia nigra (SN) from postmortem brains from 5 cases DLBD, which included dementia with Lewy bodies (DLB, n=4) and Parkinson disease dementia (PDD, n=1). The densities of the dopamine D1 receptor, vesicular monoamine transporter 2(VMAT2), and dopamine transporter (DAT) were also measured by quantitative autoradiography using [3H]SCH23390, [3H]dihydrotetrabenazine, and [3H]WIN35428, respectively. The densities of these dopaminergic markers were also measured in the same brain regions in 10 age-matched control cases. Dopamine D3 receptor density was significantly increased in the striatal regions including caudate, putamen and nucleus accumbens (NAc). There were no significant changes in the dopamine D1 and D2 receptor densities in any brain regions measured. VMAT2 and DAT densities were reduced in all the brain regions measured in DLB/PDD, however the significant reduction was found in putamen for DAT and in the NAc and SN for VMAT2. The decrease of dopamine pre-synaptic markers implies neuronal loss in the substantia nigra pars compacta (SNpc) in these DLB/PDD cases, while the increase of D3 receptors in striatal regions could be attributed to dopaminergic medication history and psychiatric state such as hallucinations. Whether it also reflects compensatory regulation upon dopaminergic denervation warrants further confirmations on larger populations. PMID:23732230

  3. A one-carbon modification of protein lysine associated with elevated oxidative stress in human substantia nigra.

    PubMed

    Floor, Erik; Maples, Anne M; Rankin, Carolyn A; Yaganti, Vamsee M; Shank, Sylvan S; Nichols, Grant S; O'Laughlin, Michael; Galeva, Nadezhda A; Williams, Todd D

    2006-04-01

    We describe for the first time a naturally occurring lysine modification that is converted to methyllysine by reduction with sodium borohydride. This modification is approximately 1.7 times as abundant in soluble proteins from human substantia nigra pars compacta as in proteins from other brain regions, possibly as a result of elevated oxidative stress in the nigra. Proteins from cultured PC12 cells exposed to oxidative stress conditions also contain elevated levels of this lysine modification. The abundance of the naturally occurring modification is roughly 0.08 nmoles/mg protein in either unstressed brain or PC12 cells. Modification levels remain stable in isolated proteins incubated for 2 h at 37 degrees C in pH 7 buffer. We propose that the endogenous modification is the lysine Schiff base, epsilon-N-methylenelysine, and that lysine modifications may result from a reaction with formaldehyde in vivo. Rat brain contains approximately 60 nmoles/g wet weight of formaldehyde, which probably includes both free and reversibly bound forms. Adding approximately 35 microm HCHO to PC12 cell growth medium introduces methylenelysine modifications in cell proteins and impairs cell viability. The existence of this post-translational modification suggests new mechanisms of oxidative stress that may contribute to tissue degeneration, including loss of nigral dopamine neurons during normal aging and in Parkinson's disease.

  4. Differential Regulation of Action Potential Shape and Burst-Frequency Firing by BK and Kv2 Channels in Substantia Nigra Dopaminergic Neurons.

    PubMed

    Kimm, Tilia; Khaliq, Zayd M; Bean, Bruce P

    2015-12-16

    Little is known about the voltage-dependent potassium currents underlying spike repolarization in midbrain dopaminergic neurons. Studying mouse substantia nigra pars compacta dopaminergic neurons both in brain slice and after acute dissociation, we found that BK calcium-activated potassium channels and Kv2 channels both make major contributions to the depolarization-activated potassium current. Inhibiting Kv2 or BK channels had very different effects on spike shape and evoked firing. Inhibiting Kv2 channels increased spike width and decreased the afterhyperpolarization, as expected for loss of an action potential-activated potassium conductance. BK inhibition also increased spike width but paradoxically increased the afterhyperpolarization. Kv2 channel inhibition steeply increased the slope of the frequency-current (f-I) relationship, whereas BK channel inhibition had little effect on the f-I slope or decreased it, sometimes resulting in slowed firing. Action potential clamp experiments showed that both BK and Kv2 current flow during spike repolarization but with very different kinetics, with Kv2 current activating later and deactivating more slowly. Further experiments revealed that inhibiting either BK or Kv2 alone leads to recruitment of additional current through the other channel type during the action potential as a consequence of changes in spike shape. Enhancement of slowly deactivating Kv2 current can account for the increased afterhyperpolarization produced by BK inhibition and likely underlies the very different effects on the f-I relationship. The cross-regulation of BK and Kv2 activation illustrates that the functional role of a channel cannot be defined in isolation but depends critically on the context of the other conductances in the cell. This work shows that BK calcium-activated potassium channels and Kv2 voltage-activated potassium channels both regulate action potentials in dopamine neurons of the substantia nigra pars compacta. Although both

  5. Differential Regulation of Action Potential Shape and Burst-Frequency Firing by BK and Kv2 Channels in Substantia Nigra Dopaminergic Neurons

    PubMed Central

    Kimm, Tilia; Khaliq, Zayd M.

    2015-01-01

    Little is known about the voltage-dependent potassium currents underlying spike repolarization in midbrain dopaminergic neurons. Studying mouse substantia nigra pars compacta dopaminergic neurons both in brain slice and after acute dissociation, we found that BK calcium-activated potassium channels and Kv2 channels both make major contributions to the depolarization-activated potassium current. Inhibiting Kv2 or BK channels had very different effects on spike shape and evoked firing. Inhibiting Kv2 channels increased spike width and decreased the afterhyperpolarization, as expected for loss of an action potential-activated potassium conductance. BK inhibition also increased spike width but paradoxically increased the afterhyperpolarization. Kv2 channel inhibition steeply increased the slope of the frequency–current (f–I) relationship, whereas BK channel inhibition had little effect on the f–I slope or decreased it, sometimes resulting in slowed firing. Action potential clamp experiments showed that both BK and Kv2 current flow during spike repolarization but with very different kinetics, with Kv2 current activating later and deactivating more slowly. Further experiments revealed that inhibiting either BK or Kv2 alone leads to recruitment of additional current through the other channel type during the action potential as a consequence of changes in spike shape. Enhancement of slowly deactivating Kv2 current can account for the increased afterhyperpolarization produced by BK inhibition and likely underlies the very different effects on the f–I relationship. The cross-regulation of BK and Kv2 activation illustrates that the functional role of a channel cannot be defined in isolation but depends critically on the context of the other conductances in the cell. SIGNIFICANCE STATEMENT This work shows that BK calcium-activated potassium channels and Kv2 voltage-activated potassium channels both regulate action potentials in dopamine neurons of the substantia nigra

  6. Acute Depletion of D2 Receptors from the Rat Substantia Nigra Alters Dopamine Kinetics in the Dorsal Striatum and Drug Responsivity.

    PubMed

    Budygin, Evgeny A; Oleson, Erik B; Lee, Yun Beom; Blume, Lawrence C; Bruno, Michael J; Howlett, Allyn C; Thompson, Alexis C; Bass, Caroline E

    2016-01-01

    Recent studies have used conditional knockout mice to selectively delete the D2 autoreceptor; however, these approaches result in global deletion of D2 autoreceptors early in development. The present study takes a different approach using RNA interference (RNAi) to knockdown the expression of the D2 receptors (D2R) in the substantia nigra (SN), including dopaminergic neurons, which project primarily to the dorsal striatum (dStr) in adult rats. This approach restricts the knockdown primarily to nigrostriatal pathways, leaving mesolimbic D2 autoreceptors intact. Analyses of dopamine (DA) kinetics in the dStr reveal a decrease in DA transporter (DAT) function in the knockdown rats, an effect not observed in D2 autoreceptor knockout mouse models. SN D2 knockdown rats exhibit a behavioral phenotype characterized by persistent enhancement of locomotor activity in a familiar open field, reduced locomotor responsiveness to high doses of cocaine and the ability to overcome haloperidol-induced immobility on the bar test. Together these results demonstrate that presynaptic D2R can be depleted from specific neuronal populations and implicates nigrostriatal D2R in different behavioral responses to psychotropic drugs.

  7. Acute Depletion of D2 Receptors from the Rat Substantia Nigra Alters Dopamine Kinetics in the Dorsal Striatum and Drug Responsivity

    PubMed Central

    Budygin, Evgeny A.; Oleson, Erik B.; Lee, Yun Beom; Blume, Lawrence C.; Bruno, Michael J.; Howlett, Allyn C.; Thompson, Alexis C.; Bass, Caroline E.

    2017-01-01

    Recent studies have used conditional knockout mice to selectively delete the D2 autoreceptor; however, these approaches result in global deletion of D2 autoreceptors early in development. The present study takes a different approach using RNA interference (RNAi) to knockdown the expression of the D2 receptors (D2R) in the substantia nigra (SN), including dopaminergic neurons, which project primarily to the dorsal striatum (dStr) in adult rats. This approach restricts the knockdown primarily to nigrostriatal pathways, leaving mesolimbic D2 autoreceptors intact. Analyses of dopamine (DA) kinetics in the dStr reveal a decrease in DA transporter (DAT) function in the knockdown rats, an effect not observed in D2 autoreceptor knockout mouse models. SN D2 knockdown rats exhibit a behavioral phenotype characterized by persistent enhancement of locomotor activity in a familiar open field, reduced locomotor responsiveness to high doses of cocaine and the ability to overcome haloperidol-induced immobility on the bar test. Together these results demonstrate that presynaptic D2R can be depleted from specific neuronal populations and implicates nigrostriatal D2R in different behavioral responses to psychotropic drugs. PMID:28154530

  8. Mesenchymal stem cell transplantation attenuates blood brain barrier damage and neuroinflammation and protects dopaminergic neurons against MPTP toxicity in the substantia nigra in a model of Parkinson's disease.

    PubMed

    Chao, Yin Xia; He, Bei Ping; Tay, Samuel Sam Wah

    2009-11-30

    Immunomodulatory effects of transplanted mesenchymal stem cells (MSCs) in the treatment of Parkinson's disease were studied in the MPTP-induced mouse model. MPTP treatment induced a significant loss of dopaminergic neurons, decreased expressions of claudin 1, claudin 5 and occludin in the substantia nigra compacta (SNc), and functional damage of the blood brain barrier (BBB). Our study further discovered that infiltration of MBLs into the brain to bind with microglia was detected in the SNc of MPTP-treated mice, suggesting that the BBB compromise and MBL infiltration might be involved in the pathogenesis of MPTP-induced PD. In addition, MPTP treatment also increased the expression of mannose-binding lectins (MBLs) in the liver tissue. Intravenous transplantation of MSCs into MPTP-treated mice led to recovery of BBB integrity, suppression of MBL infiltration at SNc and MBL expression in the liver, suppression of microglial activation and prevention of dopaminergic neuron death. No transplanted MSCs were observed to differentiate into dopaminergic neurons, while the MSCs migrated into the SNc and released TGF-beta1 there. Therefore, intravenous transplantation of MSCs which protect dopaminergic neurons from MPTP toxicity may be engaged in anyone or a combination of these mechanisms: repair of the BBB, reduction of MBL in the brain, inhibition of microglial cytotoxicity, and direct protection of dopaminergic neurons.

  9. Distinct Contributions of Ventromedial and Dorsolateral Subregions of the Human Substantia Nigra to Appetitive and Aversive Learning

    PubMed Central

    Larsen, Tobias; Collette, Sven; Tyszka, Julian M.; Seymour, Ben; O'Doherty, John P.

    2015-01-01

    The role of neurons in the substantia nigra (SN) and ventral tegmental area (VTA) of the midbrain in contributing to the elicitation of reward prediction errors during appetitive learning has been well established. Less is known about the differential contribution of these midbrain regions to appetitive versus aversive learning, especially in humans. Here we scanned human participants with high-resolution fMRI focused on the SN and VTA while they participated in a sequential Pavlovian conditioning paradigm involving an appetitive outcome (a pleasant juice), as well as an aversive outcome (an unpleasant bitter and salty flavor). We found a degree of regional specialization within the SN: Whereas a region of ventromedial SN correlated with a temporal difference reward prediction error during appetitive Pavlovian learning, a dorsolateral area correlated instead with an aversive expected value signal in response to the most distal cue, and to a reward prediction error in response to the most proximal cue to the aversive outcome. Furthermore, participants' affective reactions to both the appetitive and aversive conditioned stimuli more than 1 year after the fMRI experiment was conducted correlated with activation in the ventromedial and dorsolateral SN obtained during the experiment, respectively. These findings suggest that, whereas the human ventromedial SN contributes to long-term learning about rewards, the dorsolateral SN may be particularly important for long-term learning in aversive contexts. SIGNIFICANCE STATEMENT The role of the substantia nigra (SN) and ventral tegmental area (VTA) in appetitive learning is well established, but less is known about their contribution to aversive compared with appetitive learning, especially in humans. We used high-resolution fMRI to measure activity in the SN and VTA while participants underwent higher-order Pavlovian learning. We found a regional specialization within the SN: a ventromedial area was selectively engaged

  10. Dopamine acts on D2 receptors to increase potassium conductance in neurones of the rat substantia nigra zona compacta.

    PubMed Central

    Lacey, M G; Mercuri, N B; North, R A

    1987-01-01

    1. Intracellular recordings were made from neurones in the substantia nigra zona compacta in slices of rat mesencephalon in vitro. The majority of neurones fired action potentials spontaneously at 0.2-5.6 Hz. Dopamine, applied either by superfusion or from the tip of a pressurized pipette, prevented spontaneous action potential firing and hyperpolarized the membrane. 2. When the membrane potential was held negative to the threshold for action potential firing, the hyperpolarization evoked by dopamine was accompanied by a fall in input resistance. Under voltage clamp, dopamine produced an outward membrane current associated with an increase in membrane conductance. The effects of superfused dopamine on firing rate, membrane potential and membrane current were concentration dependent in the range 1-100 microM. 3. The reversal potential for the hyperpolarizations and the outward currents produced by dopamine was -109.7 +/- 1.7 mV (n = 12) when the potassium concentration was 2.5 mM and -74.0 +/- 5.0 mV (n = 4) when the potassium concentration was 10.5 mM. The change in reversal potentials in these and intermediate potassium concentrations was described by the Nernst equation. 4. The outward current induced by dopamine was reversibly reduced by barium (100-300 microM) and by high concentrations of tetraethylammonium (greater than or equal to 10 mM). Calcium-free solutions with cobalt (0.5-2 mM) did not reduce the current in response to dopamine during the first 5 min of their application. Currents and hyperpolarizations caused by dopamine were unaffected by tetrodotoxin (1 microM). 5. The hyperpolarization produced by dopamine was mimicked by the D2 receptor agonist quinpirole (LY 171555, 0.1-3 microM) and was blocked by the D2 receptor agonists domperidone and (-)-sulpiride. Agonists and antagonists at D1 receptors had no effect. 6. (-)-Sulpiride (30 nM-30 microM) produced a progressive shift to the right in the concentration-response curve to either dopamine or

  11. Enkephalin, dynorphin and substance P in postmortem substantia nigra from normals and schizophrenic patients

    SciTech Connect

    Iadarola, M.J.; Ofri, D.; Kleinman, J.E. National Institute of Mental Health, Washington, DC )

    1991-01-01

    Three peptide neuromodulators that are found in high concentration in the subtantia nigra: dynorphin A 1,8-met5-enkephalin-arg6-gly7-leu8 and substance P, were measured by specific radioimmunoassays in nigral tissue from normals and schizophrenics postmortem. Substance P and dynorphin were unchanged between the two groups. However, the proenkephalin-derived peptide was significantly elevated in the schizophrenic group. The immunoreactivity was identified as authentic met5-enkephalin-arg6-gly7-leu8 by high pressure liquid chromatography. The data suggest that a different set of regulatory controls exists for nigral enkephalin peptides as compared to dynorphin and substance P, and that the former system may be disordered in schizophrenia.

  12. Local application of L- threo-hydroxyaspartate and malonate in rats in vivo induces rigidity and damages neurons of the substantia nigra, pars compacta.

    PubMed

    Loopuijt, L D

    2002-10-01

    In order to study neuronal death in Parkinson's disease, neurons of the substantia nigra, pars compacta in rats were exposed to elevated levels of glutamate and decreased levels of energy in vivo and consequences for behavior and neuronal morphology were studied. Thus, repeated local injections (9x) of the glutamate uptake inhibitor L- threo-hydroxyaspartate (L-THA; 833 microM in 0.3 microl) in the presence or absence of the succinate dehydrogenase inhibitor malonate (25 mM in 0.3 microl) were applied during three weeks. 24 h after injection, rigidity and catalepsy were measured, as well as, at the end of the three week period, locomotion, rearing and exploratory behavior. Thereafter, the cytoarchitecture of the substantia nigra, pars compacta of the brains of these rats was described. The L-THA plus malonate injected rats did not differ in their behavior from carrier injected rats, except for rigidity: their scores were higher than that of carrier and L-THA injected rats (P < 0.05), while L-THA injected rats did not differ from carrier injected controls. Observations on cresyl violet sections revealed, that, although many neurons with a shrunken nucleolus and faintly stained cytoplasm were present in both L-THA and L-THA plus malonate treated rats, the ventral edge of the substantia nigra, pars compacta containing modified cells was longer in L-THA plus malonate than in L-THA injected rats (P < 0.05). This indicates, that a minimum amount of damage to neurons in the ventral part of the substantia nigra, pars compacta might be required for the expression of rigidity.

  13. Morphological effects of cytidin-diphosphate-choline on rats with lesions of the substantia nigra: study using horse radish peroxidase method.

    PubMed

    Stanzani, S

    1981-09-15

    Morphological effects of Cytidin-diphosphate-Choline (CDP-choline) (Ni-cholin) on rat brain with Substantia nigra lesions were studied by using the horse radish peroxidase method (HRP). Three groups of animals were studied. Post-lesion axonal and cellular regeneration was detected only in the group of rats treated with CDP-choline q.d. i.m. for 15 days.

  14. Substantia nigra dopaminergic unit activity in behaving cats: effect of arousal on spontaneous discharge and sensory evoked activity.

    PubMed

    Strecker, R E; Jacobs, B L

    1985-12-30

    Single-unit activity of dopaminergic neurons in the substantia nigra was recorded in freely moving cats during a variety of conditions designed to shed light on the hypotheses that these neurons are involved in the regulation of arousal-stress and/or selective attention. Both aversive and non-aversive arousing experimental conditions were used, including tail pinch, immersion of feet in ice-water, white noise, inaccessible food, feeding, grooming, inaccessible rats, and somatosensory stimulation. None of these conditions had an effect on tonic neuronal discharge rate. However, these neurons did exhibit brief excitatory and inhibitory responses to phasic auditory or visual stimuli presented when the cat was sitting quietly. These responses were dramatically attenuated if these stimuli were presented during the aforementioned conditions of behavioral arousal. This sharply contrasts with the inability of these same conditions to influence spontaneous discharge rate. The sensitivity of this neuronal sensory response to the concurrent behavioral condition supports the hypothesis that these neurons are involved in attentional processes or selective responding. The lack of responsiveness of these neurons to a variety of arousal/stress manipulations supports the hypothesis that dopaminergic neurons play a permissive, rather than an active, role in these processes.

  15. Metabolic environment in substantia nigra reticulata is critical for the expression and control of hypoglycemia-induced seizures

    PubMed Central

    Velíšek, Libor; Velíšková, Jana; Chudomel, Ondřej; Poon, Ka-Lai; Robeson, Kimberly; Marshall, Barbara; Sharma, Archana; Moshé, Solomon L.

    2008-01-01

    Seizures represent a common and serious complication of hypoglycemia. Here we studied mechanisms of control of hypoglycemic seizures induced by insulin injection in fasted and non-fasted rats. We demonstrate that fasting predisposes rats to more rapid and consistent development of hypoglycemic seizures. However, the fasting-induced decrease in baseline blood glucose concentration cannot account for the earlier onset of seizures in fasted versus non-fasted rats. Data obtained with c-fos immunohistochemistry and [14C]2-deoxyglucose uptake implicate a prominent involvement of the substantia nigra reticulata (SNR) among other structures in the hypoglycemic seizure control. This is supported by data showing that fasting decreases the SNR expression of KATP channels, which link metabolism with activity, and further confirmed with microinfusions of KATP channel agonist and antagonist. Data obtained with whole cell and perforated patch recordings from SNR neurons in slices in vitro demonstrate that both pre- and postsynaptic KATP channels participate in the failure of the SNR to control hypoglycemic seizures. The results suggest that fasting and insulin-induced hypoglycemia can lead to impairment in the function of the SNR, leading thus to hypoglycemic seizures. PMID:18799669

  16. Comparative Transduction Efficiency of AAV Vector Serotypes 1–6 in the Substantia Nigra and Striatum of the Primate Brain

    PubMed Central

    Markakis, Eleni A; Vives, Kenneth P; Bober, Jeremy; Leichtle, Stefan; Leranth, Csaba; Beecham, Jeff; Elsworth, John D; Roth, Robert H; Samulski, R Jude; Redmond, D Eugene

    2009-01-01

    Vectors derived from adeno-associated virus (AAV) are promising candidates for neural cell transduction in vivo because they are nonpathogenic and achieve long-term transduction in the central nervous system. AAV serotype 2 (AAV2) is the most widely used AAV vector in clinical trials based largely on its ability to transduce neural cells in the rodent and primate brain. Prior work in rodents suggests that other serotypes might be more efficient; however, a systematic evaluation of vector transduction efficiency has not yet been performed in the primate brain. In this study, AAV viral vectors of serotypes 1–6 with an enhanced green-fluorescent protein (GFP) reporter gene were generated at comparable titers, and injected in equal amounts into the brains of Chlorocebus sabaeus. Vector injections were placed in the substantia nigra (SN) and the caudate nucleus (CD). One month after injection, immunohistochemistry for GFP was performed and the total number of GFP+ cells was calculated using unbiased stereology. AAV5 was the most efficient vector, not only transducing significantly more cells than any other serotype, but also transducing both NeuN+ and glial-fibrillary-acidic protein positive (GFAP+) cells. These results suggest that AAV5 is a more effective vector than AAV2 at delivering potentially therapeutic transgenes to the nigrostriatal system of the primate brain. PMID:20010918

  17. Progressive neurodegeneration and motor disabilities induced by chronic expression of IL-1beta in the substantia nigra.

    PubMed

    Ferrari, Carina Cintia; Pott Godoy, María Clara; Tarelli, Rodolfo; Chertoff, Mariela; Depino, Amaicha Mara; Pitossi, Fernando Juan

    2006-10-01

    The functional role of the long-lasting inflammation found in the substantia nigra (SN) of Parkinson's disease (PD) patients and animal models is unclear. Proinflammatory cytokines such as interleukin-1beta (IL-1beta) could be involved in mediating neuronal demise. However, it is unknown whether the chronic expression of cytokines such as IL-1beta in the SN can alter neuronal vitality. The aim of this study was to investigate the effects of the chronic expression of IL-1beta in the adult rat SN using a recombinant adenovirus expressing IL-1beta. The chronic expression of IL-1beta for 60 days induced dopaminergic cell death in the SN and unilateral akinesia starting only at 21 days post-injection. Microglial cell activation and inflammatory cell infiltrate were associated with dopaminergic cell death and motor disabilities. Astrocytic activation was delayed and associated with scar formation. The chronic expression of a single proinflammatory cytokine as IL-1beta in the SN elicited most of the characteristics of PD, including progressive dopaminergic cell death, akinesia and glial activation. Our data suggest that IL-1beta per se is able to mediate inflammatory-mediated toxic effects in the SN if its expression is sustained. This model will be helpful to identify possible therapeutic targets related to inflammation-derived neurodegeneration in the SN.

  18. Diffusion Kurtosis Imaging of Substantia Nigra Is a Sensitive Method for Early Diagnosis and Disease Evaluation in Parkinson's Disease

    PubMed Central

    Zhang, Guohua; Zhang, Yuhu; Zhang, Chengguo; Wang, Yukai; Ma, Guixian; Nie, Kun; Xie, Haiqun; Liu, Jianping; Wang, Lijuan

    2015-01-01

    Background. To diagnose Parkinson disease (PD) in an early stage and accurately evaluate severity, it is important to develop a sensitive method for detecting structural changes in the substantia nigra (SN). Method. Seventy-two untreated patients with early PD and 72 healthy controls underwent diffusion tensor and diffusion kurtosis imaging. Regions of interest were drawn in the rostral, middle, and caudal SN by two blinded and independent raters. Mean kurtosis (MK) and fractional anisotropy in the SN were compared between the groups. Receiver operating characteristic (ROC) and Spearman correlation analyses were used to compare the diagnostic accuracy and correlate imaging findings with Hoehn-Yahr (H-Y) staging and part III of the Unified Parkinson's Disease Rating Scale (UPDRS-III). Result. MK in the SN was increased significantly in PD patients compared with healthy controls. The area under the ROC curve was 0.976 for MK in the SN (sensitivity, 0.944; specificity, 0.917). MK in the SN had a positive correlation with H-Y staging and UPDRS-III scores. Conclusion. Diffusion kurtosis imaging is a sensitive method for PD diagnosis and severity evaluation. MK in the SN is a potential biomarker for imaging studies of early PD that can be widely used in clinic. PMID:26770867

  19. Is the unilateral lesion of the left substantia nigra pars compacta sufficient to induce working memory impairment in rats?

    PubMed

    Bellissimo, Maria Ines; Kouzmine, Ivana; Ferro, Marcelo Machado; de Oliveira, Brás Heleno; Canteras, Newton Sabino; Da Cunha, Claudio

    2004-09-01

    Adult male Wistar rats with a substantia nigra pars compacta (SNc) lesion induced by intranigral administration of 1 micromol 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) were used as a model of early phase Parkinson's disease (PD). This lesion caused a partial depletion of striatal dopamine (DA). The animals were submitted to a spatial working memory version of the water maze task in which they had to find a hidden (submersed) platform using online-maintained information that the platform remains in the same place during four consecutive trials, but that it is moved to another place every training day. Left, but not right SNc-lesioned rats were impaired in finding the platform in the second trial. This result suggests that the left SNc plays a key role in spatial working memory. Control experiments ruled out the possibility that motor impairment, sensory neglect, and/or impairment in the mental representation of the contralateral spatial environment had affected performance of the SNc-lesioned rats.

  20. Age- and Sex-Related Characteristics of Tonic Gaba Currents in the Rat Substantia Nigra Pars Reticulata

    PubMed Central

    Hasson, H.; Bojar, M.; Moshé, S. L.; Galanopoulou, A. S.

    2015-01-01

    Previous studies have shown that the pharmacologic effects of GABAergic drugs and the postsynaptic phasic GABAAergic inhibitory responses in the anterior part of the rat substantia nigra pars reticulata (SNRA) are age- and sex-specific. Here, we investigate whether there are age- and sex-related differences in the expression of the δ GABAA receptor (GABAAR) subunit and GABAAR mediated tonic currents. We have used δ-specific immunochemistry and whole cell patch clamp to study GABAAR mediated tonic currents in the SNRA of male and female postnatal day (PN) PN5-9, PN11-16, and PN25-32 rats. We observed age-related decline, but no sex-specific changes, in bicuculline (BIM) sensitive GABAAR tonic current density, which correlated with the decline in δ subunit in the SNRA between PN15 and 30. Furthermore, we show that the GABAAR tonic currents can be modified by muscimol (GABAAR agonist; partial GABACR agonist), THIP (4,5,6,7-tetrahydroisoxazolo (5,4-c)pyridin-3-ol: α4β3δ GABAARs agonist and GABACR antagonist), and zolpidem (α1-subunit selective GABAAR agonist) in age-and sex-dependent manner specific for each drug. We propose that the emergence of the GABAAR-sensitive anticonvulsant effects of the rat SNRA during development may depend upon the developmental decline in tonic GABAergic inhibition of the activity of rat SNRA neurons, although other sex-specific factors are also involved. PMID:25645446

  1. 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.

  2. Characterization of a Novel Monoclonal Antibody against Human Mitochondrial Ferritin and Its Immunohistochemical Application in Human and Monkey Substantia Nigra

    PubMed Central

    Yang, Mingchun; Yang, Hongkuan; Guan, Hongpeng; Kato, Tomoko; Mukaisho, Kenichi; Sugihara, Hiroyuki; Ogasawara, Kazumasa; Terada, Tomohiro; Tooyama, Ikuo

    2017-01-01

    Mitochondrial ferritin (FtMt) is a novel iron storage protein with high homology to H-ferritin. Unlike the ubiquitously expressed H- and L-ferritin, FtMt is expressed in specific tissues such as the testis, heart, and brain. The function of FtMt is not fully understood; however, evidence suggests that it has a neuroprotective role in neurodegenerative diseases. We have previously reported that FtMt is expressed in catecholaminergic neurons of the monkey brainstem. To explore FtMt expression in human dopaminergic neurons, we designed a novel monoclonal antibody, C65-2, directed against human FtMt. Here, we report the properties of our C65-2 antibody. Western blots analysis and immunoabsorption tests demonstrated that the C65-2 antibody specifically recognized FtMt with no cross-reactivity to H-ferritin. Immunohistochemistry showed that the C65-2 antibody detected FtMt in neurons of the substantia nigra pars compacta (SNc) in humans and monkeys. We confirmed that FtMt is expressed in dopaminergic neurons of the human SNc. Our results suggest that FtMt is involved in various physiological and pathological mechanisms in human dopaminergic neurons, and the C65-2 monoclonal antibody promises to be a useful tool for determining the localization and biological functions of FtMt in the brain. PMID:28386150

  3. Enkephalin, neurotensin, and substance P immunoreactivite neurones of the rat GP following 6-hydroxydopamine lesion of the substantia nigra.

    PubMed

    Martorana, A; Fusco, F R; D'Angelo, V; Sancesario, G; Bernardi, G

    2003-10-01

    The ascending dopaminergic tract influences the activity of GP neurones in normal conditions. Its lesion may lead to an up-regulation of activity in this nucleus that is contrary to what would be expected based on the current model of the basal ganglia function. In this study we investigated the occurrence of enkephalin, neurotensin, and substance P immunoreactivity of the rat globus pallidus (GP) following lesion of the nigrostriatal pathway induced by the injection of the toxin 6-hydroxydopamine into the substantia nigra. Since 60-65% of GP neurones are immunopositive for parvalbumin, the immunoreactivity for peptides was evaluated, considering the different content in parvalbumin of pallidal neurones types, at early and chronic phases of denervation. Our results showed that a lesion of the nigrostriatal pathway induced the expression of enkephalin, neurotensin, and substance P immunoreactivity in numerous pallidal cell bodies. Each subgroup of neurones showed a different pattern of distribution. These modifications equally involved the two main subclasses of neurones. However parvalbumin-negative neurones were modified to a larger extent than the parvalbumin-positive ones. These data indicate that nigrostriatal lesion induces in a wide and unexpected peptide synthesis at least in three different subgroups of GP neurones. These modifications might be useful to further histochemically characterise neurones of the GP.

  4. Effects of adrenal medulla and sciatic nerve co-grafts in rats with unilateral substantia nigra lesions.

    PubMed

    Freed, W J; Willingham, G; Heim, R

    1992-01-01

    Major limitations of adrenal medulla transplantation in animal models of Parkinson's disease have been the relatively small behavioral effects and the poor or inconsistent graft survival. Transplantation of fragments of sural nerve in combination with adrenal medulla has been reported to increase the survival of chromaffin cells in adrenal medulla grafts in primates. In the present study, the possibility was tested that peripheral nerve co-grafts would increase the functional effects of adrenal medulla grafts in a 6-hydroxydopamine-lesioned rat model. Animals received unilateral substantia nigra lesions, and subsequently received intraventricular grafts of adrenal medulla, sciatic nerve, adrenal medulla plus sciatic nerve, or sham grafts consisting of medium only. Functional effects of the grafts were tested using apomorphine-induced rotational behavior. The sciatic nerve co-grafts did not increase the survival of TH-immunoreactive chromaffin cells. The co-grafting treatment also did not augment the overall effect of adrenal medulla grafts on rotational behavior. In the animals with substantial numbers of surviving chromaffin cells, however, the animals with sciatic nerve co-grafts showed greater decreases in rotational behavior as compared to the animals with adrenal medulla grafts alone, even though the number of surviving cells was not increased.

  5. Structural integrity of the substantia nigra and subthalamic nucleus predicts flexibility of instrumental learning in older-age individuals

    PubMed Central

    Chowdhury, Rumana; Guitart-Masip, Marc; Lambert, Christian; Dolan, Raymond J.; Düzel, Emrah

    2013-01-01

    Flexible instrumental learning is required to harness the appropriate behaviors to obtain rewards and to avoid punishments. The precise contribution of dopaminergic midbrain regions (substantia nigra/ventral tegmental area [SN/VTA]) to this form of behavioral adaptation remains unclear. Normal aging is associated with a variable loss of dopamine neurons in the SN/VTA. We therefore tested the relationship between flexible instrumental learning and midbrain structural integrity. We compared task performance on a probabilistic monetary go/no-go task, involving trial and error learning of: “go to win,” “no-go to win,” “go to avoid losing,” and “no-go to avoid losing” in 42 healthy older adults to previous behavioral data from 47 younger adults. Quantitative structural magnetization transfer images were obtained to index regional structural integrity. On average, both some younger and some older participants demonstrated a behavioral asymmetry whereby they were better at learning to act for reward (“go to win” > “no-go to win”), but better at learning not to act to avoid punishment (“no-go to avoid losing” > “go to avoid losing”). Older, but not younger, participants with greater structural integrity of the SN/VTA and the adjacent subthalamic nucleus could overcome this asymmetry. We show that interindividual variability among healthy older adults of the structural integrity within the SN/VTA and subthalamic nucleus relates to effective acquisition of competing instrumental responses. PMID:23623600

  6. Seizure-induced damage to substantia nigra and globus pallidus is accompanied by pronounced intra- and extracellular acidosis

    SciTech Connect

    Inamura, K.; Smith, M.L.; Hansen, A.J.; Siesjoe, B.K. )

    1989-12-01

    Status epilepticus of greater than 30-min duration in rats gives rise to a conspicuous lesion in the substantia nigra pars reticulata (SNPR) and globus pallidus (GP). The objective of the present study was to explore whether the lesion, which encompasses necrosis of both neurons and glial cells, is related to intra- and extracellular acidosis. Using the flurothyl model previously described to produce seizures, we assessed regional pH values with the autoradiographic 5,5-dimethyl(2-14C)oxazolidine-2,4-dione technique. Regional pH values were assessed in animals with continuous seizures for 20 and 60 min, as well as in those allowed to recover for 30 and 120 min after seizure periods of 20 or 60 min. In additional animals, changes in extracellular fluid pH (pHe) were measured with ion-selective microelectrodes, and extracellular fluid (ECF) volume was calculated from the diffusion profile for electrophoretically administered tetramethylammonium. In structures such as the neocortex and the hippocampus, which show intense metabolic activation during seizures, status epilepticus of 20- and 60-min duration was accompanied by a reduction of the composite tissue pH (pHt) of 0.2-0.3 unit. Recovery of pHt was observed upon termination of seizures. In SNPR and in GP, the acidosis was marked to excessive after 20 and 60 min of seizures (delta pHt approximately 0.6 after 60 min).

  7. Normative data of dopaminergic neurotransmission functions in substantia nigra measured with MRI and PET: Neuromelanin, dopamine synthesis, dopamine transporters, and dopamine D2 receptors.

    PubMed

    Ito, Hiroshi; Kawaguchi, Hiroshi; Kodaka, Fumitoshi; Takuwa, Hiroyuki; Ikoma, Yoko; Shimada, Hitoshi; Kimura, Yasuyuki; Seki, Chie; Kubo, Hitoshi; Ishii, Shiro; Takano, Harumasa; Suhara, Tetsuya

    2017-09-01

    The central dopaminergic system is of major importance in the pathophysiology of Parkinson's disease, schizophrenia, and other neuropsychiatric disorders. In the present study, the normative data of dopaminergic neurotransmission functions in the midbrain, consisting of neuromelanin, dopamine synthesis, dopamine transporters and dopamine D2 receptors, were constructed using magnetic resonance (MR) imaging and positron emission tomography (PET). PET studies with L-[β-(11)C]DOPA, [(18)F]FE-PE2I and [(11)C]FLB457 and MRI studies were performed on healthy young men. Neuromelanin accumulation measured by MRI was compared with dopaminergic functions, dopamine synthesis capacity, dopamine transporter binding and dopamine D2 receptor binding measured by PET in the substantia nigra. Although neuromelanin is synthesized from DOPA and dopamine in dopaminergic neurons, neuromelanin accumulation did not correlate with dopamine synthesis capacity in young healthy subjects. The role of dopamine transporters in the substantia nigra is considered to be the transport of dopamine into neurons, and therefore dopamine transporter binding might be related to neuromelanin accumulation; however, no significant correlation was observed between them. A positive correlation between dopamine D2 receptor binding and neuromelanin accumulation was observed, indicating a feedback mechanism by dopaminergic autoreceptors. Discrepancies in regional distribution between neuromelanin accumulation and dopamine synthesis capacity, dopamine transporter binding or dopamine D2 receptor binding were observed in the substantia nigra. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Effects of Zhichan powder on signal transduction and apoptosis-associated gene expression in the substantia nigra of Parkinson's disease rats

    PubMed Central

    Chen, Jiajun; Ma, Jinshu; Qiu, Yafei; Yi, Shihong; Liu, Yongmao; Zhou, Qingwei; Zhang, Pengguo; Wan, Quan; Kuang, Ye

    2012-01-01

    Previous studies have shown that Zhichan powder elevated immunity and suppressed oxidation in mice. Rat models of Parkinson’s disease were induced by stereotaxically injecting 6-hydroxydopamine into the substantia nigra. The rat models were intragastrically treated with Zhichan powder, which is composed of milkvetch root, ginseng, bunge swallowwort root, himalayan teasel root, Magnolia officinalis, Ligustrum lucidum Ait. and szechwan lovage rhizome. Immunohistochemistry and reverse transcription-PCR results demonstrated that mRNA and protein expression of tumor necrosis factor receptor 1, Fas, caspase-8, cytochrome C, Bax, caspase-3, and p53 significantly increased, but Bcl-2 expression significantly decreased in the substantia nigra of rats with Parkinson’s disease. Following Zhichan powder administration, mRNA and protein expression of tumor necrosis factor receptor 1, Fas, caspase-8, cytochrome C, Bax, caspase-3, and p53 diminished, but Bcl-2 expression increased in the rat substantia nigra. These results indicate that Zhichan powder regulates signal transduction protein expression, inhibits apoptosis, and exerts therapeutic effects on Parkinson’s disease. PMID:25558224

  9. Motor stimulant effects of ethanol injected into the substantia nigra pars reticulata: importance of catalase-mediated metabolism and the role of acetaldehyde.

    PubMed

    Arizzi-LaFrance, Maria N; Correa, Mercè; Aragon, Carlos M G; Salamone, John D

    2006-05-01

    A series of experiments was conducted to investigate the locomotor effects of local injections of ethanol and the ethanol metabolite, acetaldehyde, into substantia nigra pars reticulata (SNr). Infusions of ethanol into SNr resulted in a dose-related increase in locomotor activity, with maximal effects at a dose of 1.4 micromol. Ethanol injected into a control site dorsal to substantia nigra failed to stimulate locomotion, and another inactive site was identified in brainstem areas posterior to substantia nigra. The locomotor effects of intranigral ethanol (1.4 micromol) were reduced by coadministration of 10 mg/kg sodium azide, a catalase inhibitor that acts to reduce the metabolism of ethanol into acetaldehyde in the brain. SNr infusions of acetaldehyde, which is the first metabolite of ethanol, also increased locomotion. Taken together, these results indicate that SNr is one of the sites at which ethanol and acetaldehyde may be acting to induce locomotor activity. These results are consistent with the hypothesis that acetaldehyde is a centrally active metabolite of ethanol, and provide further support for the idea that catalase activity is a critical step in the regulation of ethanol-induced motor activity. These studies have implications for understanding the brain mechanisms involved in mediating the ascending limb of the biphasic dose-response curve for the effect of ethanol on locomotor activity.

  10. Reformation of the nigrostriatal pathway by fetal dopaminergic micrografts into the substantia nigra is critically dependent on the age of the host.

    PubMed

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

    1999-09-01

    The aim of this study was to determine whether the growth of axons along the nigrostriatal pathway from fetal dopamine cells, transplanted into the substantia nigra of young postnatal 6-OHDA-lesioned rats, is dependent on the age of the host brain. Neonatal rats were lesioned bilaterally by intraventricular injection of 6-OHDA at postnatal day 1 (P1) and received grafts of E14 ventral mesencephalon at day 3 (group P3), day 10 (group P10), or day 20 (group P20) into the right substantia nigra. One lesioned group was left untransplanted. Six months after surgery the animals were subjected to analysis of drug-induced rotation following injection of amphetamine, apomorphine, a D1 agonist (SKF38393), or a D2 agonist (Quinpirole). Animals transplanted intranigrally at day 3 and day 10 showed a strong amphetamine-induced rotational bias toward the side contralateral to the transplant. Animals transplanted into substantia nigra at P20, like the lesioned control animals, showed no rotational bias. Apomorphine and selective D1 and D2 agonists induced ipsilateral turning behavior in the P3 and P10 group, but not in the P20 or the lesion control groups. Immunofluorescence histochemistry in combination with retrograde axonal tracing, using FluoroGold injection into the ipsilateral caudate-putamen showed colocalization of tyrosine hydroxylase and FluoroGold in large numbers of transplanted neurons in the animals transplanted at postnatal day 3 and postnatal day 10, which was not observed in the group P20. The lesion control group showed a 90% complete lesion of the TH-positive cells in the substantia nigra while largely sparing the neurons in the ventral tegmental area. The results indicate that intranigral grafts can be placed accurately and survive well within the substantia nigra region at various time points during postnatal development. Furthermore, embryonic dopamine neurons have the ability to extend axons along the nigrostriatal pathway and reconnect with the dopamine

  11. Testosterone regulation of sex steroid-related mRNAs and dopamine-related mRNAs in adolescent male rat substantia nigra

    PubMed Central

    2012-01-01

    Background Increased risk of schizophrenia in adolescent males indicates that a link between the development of dopamine-related psychopathology and testosterone-driven brain changes may exist. However, contradictions as to whether testosterone increases or decreases dopamine neurotransmission are found and most studies address this in adult animals. Testosterone-dependent actions in neurons are direct via activation of androgen receptors (AR) or indirect by conversion to 17β-estradiol and activation of estrogen receptors (ER). How midbrain dopamine neurons respond to sex steroids depends on the presence of sex steroid receptor(s) and the level of steroid conversion enzymes (aromatase and 5α-reductase). We investigated whether gonadectomy and sex steroid replacement could influence dopamine levels by changing tyrosine hydroxylase (TH) protein and mRNA and/or dopamine breakdown enzyme mRNA levels [catechol-O-methyl transferase (COMT) and monoamine oxygenase (MAO) A and B] in the adolescent male rat substantia nigra. We hypothesized that adolescent testosterone would regulate sex steroid signaling through regulation of ER and AR mRNAs and through modulation of aromatase and 5α-reductase mRNA levels. Results We find ERα and AR in midbrain dopamine neurons in adolescent male rats, indicating that dopamine neurons are poised to respond to circulating sex steroids. We report that androgens (T and DHT) increase TH protein and increase COMT, MAOA and MAOB mRNAs in the adolescent male rat substantia nigra. We report that all three sex steroids increase AR mRNA. Differential action on ER pathways, with ERα mRNA down-regulation and ERβ mRNA up-regulation by testosterone was found. 5α reductase-1 mRNA was increased by AR activation, and aromatase mRNA was decreased by gonadectomy. Conclusions We conclude that increased testosterone at adolescence can shift the balance of sex steroid signaling to favor androgenic responses through promoting conversion of T to DHT and

  12. 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

  13. Ultrastructural localization of the alpha4-subunit of the neuronal acetylcholine nicotinic receptor in the rat substantia nigra.

    PubMed

    Arroyo-Jim nez, M M; Bourgeois, J P; Marubio, L M; Le Sourd, A M; Ottersen, O P; Rinvik, E; Fairén, A; Changeux, J P

    1999-08-01

    The distribution of the alpha4-subunit of the neuronal nicotinic acetylcholine receptor (nAChR) in the rat brain was examined at light and electron microscopy levels using immunohistochemical staining. In the present study we demonstrate the specificity, in both tissue homogenates and brain sections, of a polyclonal antibody raised against the rat nAChR alpha4-subunit. The characterization of this antibody involved: (1) Western blot analysis of rat brain homogenates and membrane extracts from cells previously transfected with diverse combinations of neuronal nAChR subunits, and (2) immunohistochemistry using transfected cells and rat brain tissue. At the light microscope level, the alpha4-subunit-like-immunoreactivity (LI) was widely distributed in the rat brain and matched the distribution of the alpha4-subunit transcripts observed previously by in situ hybridization. Strong immunohistochemical labeling was detected in the mesencephalic dopaminergic nuclei. The nAChRs in this region are thought to be responsible for the modulation of dopaminergic transmission. The neurotransmitter identity of alpha4-immunolabeled neurons in the substantia nigra pars compacta (SNpc) and the ventral tegmental area was thus assessed by investigating the possible colocalization of the nAChR alpha4-subunit with tyrosine hydroxylase using confocal microscopy. The double labeling experiments unambiguously indicated that the alpha4-subunit-LI is present in dopaminergic neurons. At the electron microscope level, the neurons in the SNpc exhibited alpha4-subunit-LI in association with a minority of postsynaptic densities, suggesting that the alpha4-subunit may be a component of functional nAChRs mediating synaptic transmission between midbrain cholinergic neurons and mesencephalic dopaminergic neurons.

  14. Overexpression of VMAT-2 and DT-diaphorase protects substantia nigra-derived cells against aminochrome neurotoxicity.

    PubMed

    Muñoz, Patricia; Paris, Irmgard; Sanders, Laurie H; Greenamyre, J Timothy; Segura-Aguilar, Juan

    2012-07-01

    We tested the hypothesis that both VMAT-2 and DT-diaphorase are an important cellular defense against aminochrome-dependent neurotoxicity during dopamine oxidation. A cell line with VMAT-2 and DT-diaphorase over-expressed was created. The transfection of RCSN-3 cells with a bicistronic plasmid coding for VMAT-2 fused with GFP-IRES-DT-diaphorase cDNA induced a significant increase in protein expression of VMAT-2 (7-fold; P<0.001) and DT-diaphorase (9-fold; P<0.001), accompanied by a 4- and 5.5-fold significant increase in transport and enzyme activity, respectively. Studies with synaptic vesicles from rat substantia nigra revealed that VMAT-2 uptake of ³H-aminochrome 6.3 ± 0.4nmol/min/mg was similar to dopamine uptake 6.2 ± 0.3nmol/min/mg that which were dependent on ATP. Interestingly, aminochrome uptake was inhibited by 2μM lobeline but not reserpine (1 and 10μM). Incubation of cells overexpressing VMAT-2 and DT-diaphorase with 20μM aminochrome resulted in (i) a significant decrease in cell death (6-fold, P<0.001); (ii) normal ultra structure determined by transmission electron microscopy contrasting with a significant increase of autophagosome and a dramatic remodeling of the mitochondrial inner membrane in wild type cells; (iii) normal level of ATP (256 ± 11μM) contrasting with a significant decrease in wild type cells (121±11μM, P<0.001); and (iv) a significant decrease in DNA laddering (21 ± 8pixels, P<0.001) cells in comparison with wild type cells treated with 20μM aminochrome (269 ± 9). These results support our hypothesis that VMAT-2 and DT-diaphorase are an important defense system against aminochrome formed during dopamine oxidation. © 2012 Elsevier B.V. All rights reserved.

  15. 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.

  16. Omega-3 deficiency and neurodegeneration in the substantia nigra: involvement of increased nitric oxide production and reduced BDNF expression.

    PubMed

    Cardoso, Henriqueta Dias; dos Santos Junior, Eraldo Fonseca; de Santana, David Filipe; Gonçalves-Pimentel, Catarina; Angelim, Monara Kaélle; Isaac, Alinny R; Lagranha, Cláudia Jacques; Guedes, Rubem Carlos Araújo; Beltrão, Eduardo Isidoro; Morya, Edgar; Rodrigues, Marcelo Cairrão Araújo; Andrade-da-Costa, Belmira Lara da Silveira

    2014-06-01

    Our previous study demonstrated that essential fatty acid (EFA) dietary restriction over two generations induced midbrain dopaminergic cell loss and oxidative stress in the substantia nigra (SN) but not in the striatum of young rats. In the present study we hypothesized that omega-3 deficiency until adulthood would reduce striatum's resilience, increase nitric oxide (NO) levels and the number of BDNF-expressing neurons, both potential mechanisms involved in SN neurodegeneration. Second generation rats were raised from gestation on control or EFA-restricted diets until young or adulthood. Lipoperoxidation, NO content, total superoxide dismutase (t-SOD) and catalase enzymatic activities were assessed in the SN and striatum. The number of tyrosine hydroxylase (TH)- and BDNF-expressing neurons was analyzed in the SN. Increased NO levels were observed in the striatum of both young and adult EFA-deficient animals but not in the SN, despite a similar omega-3 depletion (~65%) in these regions. Increased lipoperoxidation and decreased catalase activity were found in both regions, while lower tSOD activity was observed only in the striatum. Fewer TH- (~40%) and BDNF-positive cells (~20%) were detected at the SN compared to the control. The present findings demonstrate a differential effect of omega-3 deficiency on NO production in the rat's nigrostriatal system. Prolonging omega-3 depletion until adulthood impaired striatum's anti-oxidant resources and BDNF distribution in the SN, worsening dopaminergic cell degeneration. Omega-3 deficiency can reduce the nigrostriatal system's ability to maintain homeostasis under oxidative conditions, which may enhance the risk of Parkinson's disease. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Paradoxical lower sensitivity of Locus Coeruleus than Substantia Nigra pars compacta neurons to acute actions of rotenone.

    PubMed

    Yee, Andrew G; Freestone, Peter S; Bai, Ji-Zhong; Lipski, Janusz

    2017-01-01

    Parkinson's disease (PD) is not only associated with degeneration of dopaminergic (DAergic) neurons in the Substantia Nigra, but also with profound loss of noradrenergic neurons in the Locus Coeruleus (LC). Remarkably, LC degeneration may exceed, or even precede the loss of nigral DAergic neurons, suggesting that LC neurons may be more susceptible to damage by various insults. Using a combination of electrophysiology, fluorescence imaging and electrochemistry, we directly compared the responses of LC, nigral DAergic and nigral non-dopaminergic (non-DAergic) neurons in rat brain slices to acute application of rotenone, a mitochondrial toxin used to create animal and in vitro models of PD. Rotenone (0.01-5.0μM) dose-dependently inhibited the firing of all three groups of neurons, primarily by activating KATP channels. The toxin also depolarised mitochondrial potential (Ψm) and released reactive oxygen species (H2O2). When KATP channels were blocked, rotenone (1μM) increased the firing of LC neurons by activating an inward current associated with dose-dependent increase of cytosolic free Ca(2+) ([Ca(2+)]i). This effect was attenuated by blocking oxidative stress-sensitive TRPM2 channels, and by pre-treatment of slices with anti-oxidants. These results demonstrate that rotenone inhibits the activity of LC neurons mainly by activating KATP channels, and increases [Ca(2+)]ivia TRPM2 channels. Since the responses of LC neurons were smaller than those of nigral DAergic neurons, our study shows that LC neurons are paradoxically less sensitive to acute effects of this parkinsonian toxin. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Dopaminergic Presynaptic Modulation of Nigral Afferents: Its Role in the Generation of Recurrent Bursting in Substantia Nigra Pars Reticulata Neurons

    PubMed Central

    de Jesús Aceves, José; Rueda-Orozco, Pavel E.; Hernández, Ricardo; Plata, Víctor; Ibañez-Sandoval, Osvaldo; Galarraga, Elvira; Bargas, José

    2011-01-01

    Previous work has shown the functions associated with activation of dopamine presynaptic receptors in some substantia nigra pars reticulata (SNr) afferents: (i) striatonigral terminals (direct pathway) posses presynaptic dopamine D1-class receptors whose action is to enhance inhibitory postsynaptic currents (IPSCs) and GABA transmission. (ii) Subthalamonigral terminals posses D1- and D2-class receptors where D1-class receptor activation enhances and D2-class receptor activation decreases excitatory postsynaptic currents. Here we report that pallidonigral afferents posses D2-class receptors (D3 and D4 types) that decrease inhibitory synaptic transmission via presynaptic modulation. No action of D1-class agonists was found on pallidonigral synapses. In contrast, administration of D1-receptor antagonists greatly decreased striatonigral IPSCs in the same preparation, suggesting that tonic dopamine levels help in maintaining the function of the striatonigral (direct) pathway. When both D3 and D4 type receptors were blocked, pallidonigral IPSCs increased in amplitude while striatonigral connections had no significant change, suggesting that tonic dopamine levels are repressing a powerful inhibition conveyed by pallidonigral synapses (a branch of the indirect pathway). We then blocked both D1- and D2-class receptors to acutely decrease direct pathway (striatonigral) and enhance indirect pathways (subthalamonigral and pallidonigral) synaptic force. The result was that most SNr projection neurons entered a recurrent bursting firing mode similar to that observed during Parkinsonism in both patients and animal models. These results raise the question as to whether the lack of dopamine in basal ganglia output nuclei is enough to generate some pathological signs of Parkinsonism. PMID:21347219

  19. The role of iron and copper molecules in the neuronal vulnerability of locus coeruleus and substantia nigra during aging.

    PubMed

    Zecca, Luigi; Stroppolo, Antonella; Gatti, Alberto; Tampellini, Davide; Toscani, Marco; Gallorini, Mario; Giaveri, Giuseppe; Arosio, Paolo; Santambrogio, Paolo; Fariello, Ruggero G; Karatekin, Erdem; Kleinman, Mark H; Turro, Nicholas; Hornykiewicz, Oleh; Zucca, Fabio A

    2004-06-29

    In this study, a comparative analysis of metal-related neuronal vulnerability was performed in two brainstem nuclei, the locus coeruleus (LC) and substantia nigra (SN), known targets of the etiological noxae in Parkinson's disease and related disorders. LC and SN pars compacta neurons both degenerate in Parkinson's disease and other Parkinsonisms; however, LC neurons are comparatively less affected and with a variable degree of involvement. In this study, iron, copper, and their major molecular forms like ferritins, ceruloplasmin, neuromelanin (NM), manganese-superoxide dismutase (SOD), and copper/zinc-SOD were measured in LC and SN of normal subjects at different ages. Iron content in LC was much lower than that in SN, and the ratio heavy-chain ferritin/iron in LC was higher than in the SN. The NM concentration was similar in LC and SN, but the iron content in NM of LC was much lower than SN. In both regions, heavy- and light-chain ferritins were present only in glia and were not detectable in neurons. These data suggest that in LC neurons, the iron mobilization and toxicity is lower than that in SN and is efficiently buffered by NM. The bigger damage occurring in SN could be related to the higher content of iron. Ferritins accomplish the same function of buffering iron in glial cells. Ceruloplasmin levels were similar in LC and SN, but copper was higher in LC. However, the copper content in NM of LC was higher than that of SN, indicating a higher copper mobilization in LC neurons. Manganese-SOD and copper/zinc-SOD had similar age trend in LC and SN. These results may explain at least one of the reasons underlying lower vulnerability of LC compared to SN in Parkinsonian syndromes.

  20. Role of the substantia nigra pars reticulata in sensorimotor gating, measured by prepulse inhibition of startle in rats.

    PubMed

    Koch, M; Fendt, M; Kretschmer, B D

    2000-12-20

    The substantia nigra pars reticulata (SNR) is one of the major output nuclei of the basal ganglia. It connects the dorsal and ventral striatum with the thalamus, superior colliculus and pontomedullary brainstem. The SNR is therefore in a strategic position to regulate sensorimotor behavior. We here assessed the effects of SNR lesions on prepulse inhibition (PPI) of the acoustic startle response (ASR), stereotypy and locomotion in drug-free rats, as well as after systemic administration of the dopamine agonist DL-amphetamine (2 mg/kg), and the NMDA receptor antagonists dizocilpine (0.16 mg/kg) and CGP 40116 (2 mg/kg). SNR lesions reduced PPI, enhanced spontaneous sniffing and potentiated the locomotor stimulation by dizocilpine and CGP 40116. PPI was impaired by dizocilpine and CGP 40116 in controls. The ASR was enhanced in controls by dizocilpine and amphetamine. SNR lesions prevented the enhancement of the ASR by amphetamine. A second experiment tested the hypothesis that the SNR mediates PPI via a GABAergic inhibition of the startle pathway. Infusion of the GABA(B) antagonist phaclofen but not the GABA(A) antagonist picrotoxin into the caudal pontine reticular nucleus reduced PPI. Hence, lesion of the SNR reduces sensorimotor gating possibly by elimination of a nigroreticular GABAergic projection interacting with GABA(B) receptors. Moreover, destruction of the SNR enhances the motor stimulatory effects of amphetamine and of the NMDA antagonists dizocilpine and CGP 40116. We conclude that the SNR exerts a tonic GABAergic inhibition on sensorimotor behavior that is regulated by the dorsal and the ventral striatum.

  1. 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.

  2. Firing properties and functional connectivity of substantia nigra pars compacta neurones recorded with a multi-electrode array in vitro.

    PubMed

    Berretta, Nicola; Bernardi, Giorgio; Mercuri, Nicola B

    2010-05-15

    Dopamine (DA) neurones of the substantia nigra pars compacta (SNc) are involved in a wide variety of functions, including motor control and reward-based learning. In order to gain new insights into the firing properties of neuronal ensembles in the SNc, we recorded extracellular single units from spontaneously active neurones, using a multi-electrode array (MEA) device in midbrain slices. The majority of neurones (50.21%) had a low firing frequency (1-3 Hz) and a stable pacemaker-like pattern, while others (44.84%) were irregular, but still firing at a low rate. The remaining population (4.95%) comprised neurones with a regular higher firing rate (5-10 Hz). High rate neurones, on the whole, were insensitive to DA (30 mum), while low rate neurones were mostly inhibited by DA, although responding either with a prominent or a weak inhibition. However, we recorded low rate regular neurones that were insensitive to DA, or irregular low rate neurones excited by DA. Interestingly, we found pairs of active neurones (12.10 +/- 3.14%) with a significant proportion of spikes occurring synchronously. Moreover, the crosscorrelation probability in each pair tended to increase in response to DA. In conclusion, MEA recordings in midbrain slices reveal a much more complex picture than previously reported with regard to the firing pattern and DA sensitivity of spontaneously active SNc neurones. Moreover, the study opens new prospectives for the in vitro investigation of functional connectivity in the midbrain dopaminergic system, thus proposing new targets for the pharmacological treatment of DA-dependent neurological disorders.

  3. Firing properties and functional connectivity of substantia nigra pars compacta neurones recorded with a multi-electrode array in vitro

    PubMed Central

    Berretta, Nicola; Bernardi, Giorgio; Mercuri, Nicola B

    2010-01-01

    Dopamine (DA) neurones of the substantia nigra pars compacta (SNc) are involved in a wide variety of functions, including motor control and reward-based learning. In order to gain new insights into the firing properties of neuronal ensembles in the SNc, we recorded extracellular single units from spontaneously active neurones, using a multi-electrode array (MEA) device in midbrain slices. The majority of neurones (50.21%) had a low firing frequency (1–3 Hz) and a stable pacemaker-like pattern, while others (44.84%) were irregular, but still firing at a low rate. The remaining population (4.95%) comprised neurones with a regular higher firing rate (5–10 Hz). High rate neurones, on the whole, were insensitive to DA (30 μm), while low rate neurones were mostly inhibited by DA, although responding either with a prominent or a weak inhibition. However, we recorded low rate regular neurones that were insensitive to DA, or irregular low rate neurones excited by DA. Interestingly, we found pairs of active neurones (12.10 ± 3.14%) with a significant proportion of spikes occurring synchronously. Moreover, the crosscorrelation probability in each pair tended to increase in response to DA. In conclusion, MEA recordings in midbrain slices reveal a much more complex picture than previously reported with regard to the firing pattern and DA sensitivity of spontaneously active SNc neurones. Moreover, the study opens new prospectives for the in vitro investigation of functional connectivity in the midbrain dopaminergic system, thus proposing new targets for the pharmacological treatment of DA-dependent neurological disorders. PMID:20351050

  4. Neuronal activity in the primate substantia nigra pars reticulata during the performance of simple and memory-guided elbow movements.

    PubMed

    Wichmann, Thomas; Kliem, Michele Ann

    2004-02-01

    The basal ganglia participate in motor functions and are implicated in the pathophysiology of movement disorders. It has been shown in primates that the activity of many neurons in one of the basal ganglia output nuclei, the internal segment of the globus pallidus, changes with active or passive movements. The involvement of the second major output nucleus, the substantia nigra pars reticulata (SNr), in movement is less well established. In this study, the electrophysiologic activity of SNr neurons was studied in two awake Rhesus monkeys while the animals were examined and while they performed elbow movements in two different motor tasks (n = 261 cells). Responses to examination were uncommon and subtle. Twenty-one percent of neurons responded to the target step in a step tracking task, mostly with anticipatory responses, although some cells showed directional, movement-related activity. In a delayed-response task, 17% of cells showed anticipatory activity to an instruction cue preceding the target jump, 11% responded directly to the cue, and 11% showed long-lasting postcue activity. Movement-related responses were seen in 21% in this task. Reward responses occurred in 10% of neurons. Responses to more than one event were common. The results demonstrate that few neurons in the SNr respond directly to passive or active movements, but a large proportion shows responses that may be related to memory, attention, or movement preparation. While internal pallidal segment neurons may be preferentially concerned with controlling elemental movement parameters, neurons in the SNr may be more involved in higher motor functions or nonmotor aspects of behavior.

  5. The Longitudinal Transcriptomic Response of the Substantia Nigra to Intrastriatal 6-Hydroxydopamine Reveals Significant Upregulation of Regeneration-Associated Genes

    PubMed Central

    Cole-Strauss, Allyson; Grabinski, Tessa; Mattingly, Zachary R.; Winn, Mary E.; Steece-Collier, Kathy; Sortwell, Caryl E.; Manfredsson, Fredric P.; Lipton, Jack W.

    2015-01-01

    We hypothesized that the study of gene expression at 1, 2, 4, 6 and 16 weeks in the substantia nigra (SN) after intrastriatal 6-OHDA in the Sprague-Dawley rat (rattus norvegicus) would identify cellular responses during the degenerative process that could be axoprotective. Specifically, we hypothesized that genes expressed within the SN that followed a profile of being highly upregulated early after the lesion (during active axonal degeneration) and then progressively declined to baseline over 16 weeks as DA neurons died are indicative of potential protective responses to the striatal 6-OHDA insult. Utilizing a κ-means cluster analysis strategy, we demonstrated that one such cluster followed this hypothesized expression pattern over time, and that this cluster contained several interrelated transcripts that are classified as regeneration-associated genes (RAGs) including Atf3, Sprr1a, Ecel1, Gadd45a, Gpnmb, Sox11, Mmp19, Srgap1, Rab15,Lifr, Trib3, Tgfb1, and Sema3c. All exemplar transcripts tested from this cluster (Sprr1a, Ecel1, Gadd45a, Atf3 and Sox11) were validated by qPCR and a smaller subset (Sprr1a, Gadd45a and Sox11) were shown to be exclusively localized to SN DA neurons using a dual label approach with RNAScope in situ hybridization and immunohistochemistry. Upregulation of RAGs is typically associated with the response to axonal injury in the peripheral nerves and was not previously reported as part of the axodegenerative process for DA neurons of the SN. Interestingly, as part of this cluster, other transcripts were identified based on their expression pattern but without a RAG provenance in the literature. These "RAG-like" transcripts need further characterization to determine if they possess similar functions to or interact with known RAG transcripts. Ultimately, it is hoped that some of the newly identified axodegeneration-reactive transcripts could be exploited as axoprotective therapies in PD and other neurodegenerative diseases. PMID:25992874

  6. State-Dependent Spike and Local Field Synchronization between Motor Cortex and Substantia Nigra in Hemiparkinsonian Rats

    PubMed Central

    Brazhnik, Elena; Cruz, Ana V.; Avila, Irene; Wahba, Marian I.; Novikov, Nikolay; Ilieva, Neda M.; McCoy, Alex J.; Gerber, Colin; Walters, Judith. R.

    2012-01-01

    Excessive beta frequency oscillatory and synchronized activity has been reported in the basal ganglia of Parkinsonian patients and animal models of the disease. To gain insight into processes underlying this activity, this study explores relationships between oscillatory activity in motor cortex and basal ganglia output in behaving rats after dopamine cell lesion. During inattentive rest, seven days after lesion, increases in motor cortex-substantia nigra pars reticulata (SNpr) coherence emerged in the 8–25 Hz range, with significant increases in local field potential (LFP) power in SNpr but not motor cortex. In contrast, during treadmill walking, marked increases in both motor cortex and SNpr LFP power, as well as coherence, emerged in the 25–40 Hz band with a peak frequency at 30–35 Hz. Spike-triggered waveform averages showed that 77% of SNpr neurons, 77% of putative cortical interneurons and 44% of putative pyramidal neurons were significantly phase-locked to the increased cortical LFP activity in the 25–40 Hz range. Although the mean lag between cortical and SNpr LFPs fluctuated around zero, SNpr neurons phase-locked to cortical LFP oscillations fired, on average, 17 ms after synchronized spiking in motor cortex. High coherence between LFP oscillations in cortex and SNpr supports the view that cortical activity facilitates entrainment and synchronization of activity in basal ganglia after loss of dopamine. However, the dramatic increases in cortical power and relative timing of phase-locked spiking in these areas suggest that additional processes help shape the frequency-specific tuning of the basal ganglia-thalamocortical network during ongoing motor activity. PMID:22674263

  7. Reduced Number of Pigmented Neurons in the Substantia Nigra of Dystonia Patients? Findings from Extensive Neuropathologic, Immunohistochemistry, and Quantitative Analyses

    PubMed Central

    Iacono, Diego; Geraci-Erck, Maria; Peng, Hui; Rabin, Marcie L.; Kurlan, Roger

    2015-01-01

    Background Dystonias (Dys) represent the third most common movement disorder after essential tremor (ET) and Parkinson's disease (PD). While some pathogenetic mechanisms and genetic causes of Dys have been identified, little is known about their neuropathologic features. Previous neuropathologic studies have reported generically defined neuronal loss in various cerebral regions of Dys brains, mostly in the basal ganglia (BG), and specifically in the substantia nigra (SN). Enlarged pigmented neurons in the SN of Dys patients with and without specific genetic mutations (e.g., GAG deletions in DYT1 dystonia) have also been described. Whether or not Dys brains are associated with decreased numbers or other morphometric changes of specific neuronal types is unknown and has never been addressed with quantitative methodologies. Methods Quantitative immunohistochemistry protocols were used to estimate neuronal counts and volumes of nigral pigmented neurons in 13 SN of Dys patients and 13 SN of age-matched control subjects (C). Results We observed a significant reduction (∼20%) of pigmented neurons in the SN of Dys compared to C (p<0.01). Neither significant volumetric changes nor evident neurodegenerative signs were observed in the remaining pool of nigral pigmented neurons in Dys brains. These novel quantitative findings were confirmed after exclusion of possible co-occurring SN pathologies including Lewy pathology, tau-neurofibrillary tangles, β-amyloid deposits, ubiquitin (ubiq), and phosphorylated-TAR DNA-binding protein 43 (pTDP43)-positive inclusions. Discussion A reduced number of nigral pigmented neurons in the absence of evident neurodegenerative signs in Dys brains could indicate previously unconsidered pathogenetic mechanisms of Dys such as neurodevelopmental defects in the SN. PMID:26069855

  8. Differences in pharmacological properties of dopamine release between the substantia nigra and striatum: an in vivo electrochemical study.

    PubMed

    Hoffman, A F; Gerhardt, G A

    1999-04-01

    The properties of dopamine (DA) release in the rat substantia nigra (SN) and striatum were investigated using high-speed chronoamperometric recordings in brain slices. In both brain regions, a 2-min bath superfusion with 30 mM KCl produced robust DA-like electrochemical signals, with the mean amplitude of the signal being >10-fold greater in the striatum than the SN. The reproducibility of the response was confirmed by a second stimulus (S2)/first-stimulus (S1) ratio of >0.8 in both regions. The bath application of tetrodotoxin significantly reduced the S2/S1 ratio in both the striatum and SN, implicating the requirement for voltage-sensitive sodium channels in the DA-release process. However, the application of cadmium chloride, a nonselective blocker of voltage-sensitive calcium channels, reduced the S2/S1 ratio only in the striatum and not within the SN. Moreover, removal of Ca2+ from the buffer did not significantly affect release within the SN, despite a >85% reduction in release within the striatum. In addition, although the D2 receptor antagonist sulpiride enhanced the S2/S1 ratio in the striatum, no effect of this agent was seen in the SN. Finally, the application of d-amphetamine produced DA-like electrochemical signals in both the striatum and SN. However, the amplitude of the d-amphetamine-evoked response, relative to the KCl-evoked release, was much smaller in the striatum than in the SN. Taken together, these data support the hypothesis that differences in the mechanism or mechanisms of release exist between somatodendritic and axonal elements within the nigrostriatal pathway.

  9. Pool size ratio of the substantia nigra in Parkinson's disease derived from two different quantitative magnetization transfer approaches.

    PubMed

    Trujillo, Paula; Summers, Paul E; Smith, Alex K; Smith, Seth A; Mainardi, Luca T; Cerutti, Sergio; Claassen, Daniel O; Costa, Antonella

    2017-10-06

    We sought to measure quantitative magnetization transfer (qMT) properties of the substantia nigra pars compacta (SNc) in patients with Parkinson's disease (PD) and healthy controls (HCs) using a full qMT analysis and determine whether a rapid single-point measurement yields equivalent results for pool size ratio (PSR). Sixteen different MT-prepared MRI scans were obtained at 3 T from 16 PD patients and eight HCs, along with B1, B0, and relaxation time maps. Maps of PSR, free and macromolecular pool transverse relaxation times ([Formula: see text], [Formula: see text]) and rate of MT exchange between pools (k mf ) were generated using a full qMT model. PSR maps were also generated using a single-point qMT model requiring just two MT-prepared images. qMT parameter values of the SNc, red nucleus, cerebral crus, and gray matter were compared between groups and methods. PSR of the SNc was the only qMT parameter to differ significantly between groups (p < 0.05). PSR measured via single-point analysis was less variable than with the full MT model, provided slightly better differentiation of PD patients from HCs (area under curve 0.77 vs. 0.75) with sensitivity of 0.75 and specificity of 0.87, and was better than transverse relaxation time in distinguishing PD patients from HCs (area under curve 0.71, sensitivity 0.87, and specificity 0.50). The increased PSR observed in the SNc of PD patients may provide a novel biomarker of PD, possibly associated with an increased macromolecular content. Single-point PSR mapping with reduced variability and shorter scan times relative to the full qMT model appears clinically feasible.

  10. In vivo gene transfer to dopamine neurons of rat substantia nigra via the high-affinity neurotensin receptor.

    PubMed Central

    Alvarez-Maya, I.; Navarro-Quiroga, I.; Meraz-Ríos, M. A.; Aceves, J.; Martinez-Fong, D.

    2001-01-01

    BACKGROUND: Recently, we synthesized a nonviral gene vector capable of transfecting cell lines taking advantage of neurotensin (NT) internalization. The vector is NT cross-linked with poly-L-lysine, to which a plasmid DNA was bound to form a complex (NT-polyplex). Nigral dopamine neurons are able to internalize NT, thus representing a target for gene transfer via NT-polyplex. This hypothesis was tested here using reporter genes encoding green fluorescent protein or chloramphenicol acetyl transferase. MATERIALS AND METHODS: NT-polyplex was injected into the substantia nigra. Double immunofluorescence labeling was used to reveal the cell type involved in the propidium iodide-labeled polyplex internalization and reporter gene expression. RESULTS: Polyplex internalization was observed within dopamine neurons but not within glial cells, and was prevented by both hypertonic sucrose solution and SR-48692, a selective nonpeptide antagonist of NT receptors. Reporter gene expression was observed in dopamine neurons from 48 hr up to 15 days after NT-polyplex injection, and was prevented by SR-48692. However, no expression was seen when the NT-polyplex was injected into the ansiform lobule of the cerebellum, which contains low- but not high-affinity NT receptors. Neither internalization nor expression was observed in cultured glial cells, despite the NT-polyplex binding to those cells that was prevented by levocabastine, a low-affinity NT receptor antagonist. CONCLUSIONS: These results suggest that high-affinity NT receptors mediate the uptake of NT-polyplex with the subsequent reporter gene expression in vivo. NT polyfection may be used to transfer genes of physiologic interest to nigrostriatal dopamine neurons, and to produce transgenic animal models of dopamine-related diseases. PMID:11471555

  11. Striatal Serotonin 2C receptors decrease nigrostriatal dopamine release by increasing GABA-A receptor tone in the substantia nigra

    PubMed Central

    Burke, M.V.; Nocjar, C.; Sonneborn, A.J.; McCreary, A.C.

    2017-01-01

    Drugs acting at the serotonin-2C (5-HT2C) receptor subtype have shown promise as therapeutics in multiple syndromes including obesity, depression, and Parkinson’s disease. While it is established that 5-HT2C receptor stimulation inhibits DA release, the neural circuits and the localization of the relevant 5-HT2C receptors remain unknown. The present study used dual-probe in vivo microdialysis to investigate the relative contributions of 5-HT2C receptors localized in the rat substantia nigra (SN) and caudate-putamen (CP) in the control of nigrostriatal DA release. Systemic administration (3.0 mg/kg) of the 5-HT2C receptor selective agonist Ro 60-0175 [(α S )-6-Chloro-5-fluoro-α-methyl-1 H-indole-1-ethanamine fumarate] decreased, whereas intrastriatal infusions of the selective 5-HT2C antagonist SB 242084 [6-Chloro-2,3-dihydro-5-methyl-N-[6-[(2-methyl-3-pyridinyl)oxy]-3-pyridinyl]-1 H-indole-1-carboxyamide; 1.0 µM] increased, basal DA in the CP. Depending on the site within the SN pars reticulata (SNpr), infusions of SB 242084 had more modest but significant effects. Moreover, infusions of the GABA-A receptor agonist muscimol (10 µM) into the SNpr completely reversed the increases in striatal DA release produced by intrastriatal infusions of SB 242084. These findings suggest a role for 5-HT2C receptors regulating striatal DA release that is highly localized. 5-HT2C receptors localized in the striatum may represent a primary site of action that is mediated by actions on GABAergic activity in the SN. PMID:25073477

  12. Extended Anatomical Grading in Diffuse Axonal Injury Using MRI: Hemorrhagic Lesions in the Substantia Nigra and Mesencephalic Tegmentum Indicate Poor Long-Term Outcome

    PubMed Central

    Marklund, Niklas; Lannsjö, Marianne; Howells, Tim; Raininko, Raili; Wikström, Johan; Enblad, Per

    2017-01-01

    Abstract Clinical outcome after traumatic diffuse axonal injury (DAI) is difficult to predict. In this study, three magnetic resonance imaging (MRI) sequences were used to quantify the anatomical distribution of lesions, to grade DAI according to the Adams grading system, and to evaluate the value of lesion localization in combination with clinical prognostic factors to improve outcome prediction. Thirty patients (mean 31.2 years ±14.3 standard deviation) with severe DAI (Glasgow Motor Score [GMS] <6) examined with MRI within 1 week post-injury were included. Diffusion-weighted (DW), T2*-weighted gradient echo and susceptibility-weighted (SWI) sequences were used. Extended Glasgow outcome score was assessed after 6 months. Number of DW lesions in the thalamus, basal ganglia, and internal capsule and number of SWI lesions in the mesencephalon correlated significantly with outcome in univariate analysis. Age, GMS at admission, GMS at discharge, and low proportion of good monitoring time with cerebral perfusion pressure <60 mm Hg correlated significantly with outcome in univariate analysis. Multivariate analysis revealed an independent relation with poor outcome for age (p = 0.005) and lesions in the mesencephalic region corresponding to substantia nigra and tegmentum on SWI (p = 0.008). We conclude that higher age and lesions in substantia nigra and mesencephalic tegmentum indicate poor long-term outcome in DAI. We propose an extended MRI classification system based on four stages (stage I—hemispheric lesions, stage II—corpus callosum lesions, stage III—brainstem lesions, and stage IV—substantia nigra or mesencephalic tegmentum lesions); all are subdivided by age (≥/<30 years). PMID:27356857

  13. Differential vulnerability of substantia nigra and corpus striatum to oxidative insult induced by reduced dietary levels of essential fatty acids

    PubMed Central

    Cardoso, Henriqueta D.; Passos, Priscila P.; Lagranha, Claudia J.; Ferraz, Anete C.; Santos Júnior, Eraldo F.; Oliveira, Rafael S.; Oliveira, Pablo E. L.; Santos, Rita de C. F.; Santana, David F.; Borba, Juliana M. C.; Rocha-de-Melo, Ana P.; Guedes, Rubem C. A.; Navarro, Daniela M. A. F.; Santos, Geanne K. N.; Borner, Roseane; Picanço-Diniz, Cristovam W.; Beltrão, Eduardo I.; Silva, Janilson F.; Rodrigues, Marcelo C. A.; Andrade da Costa, Belmira L. S.

    2012-01-01

    Oxidative stress (OS) has been implicated in the etiology of certain neurodegenerative disorders. Some of these disorders have been associated with unbalanced levels of essential fatty acids (EFA). The response of certain brain regions to OS, however, is not uniform and a selective vulnerability or resilience can occur. In our previous study on rat brains, we observed that a two-generation EFA dietary restriction reduced the number and size of dopaminergic neurons in the substantia nigra (SN) rostro-dorso-medial. To understand whether OS contributes to this effect, we assessed the status of lipid peroxidation (LP) and anti-oxidant markers in both SN and corpus striatum (CS) of rats submitted to this dietary treatment for one (F1) or two (F2) generations. Wistar rats were raised from conception on control or experimental diets containing adequate or reduced levels of linoleic and α-linolenic fatty acids, respectively. LP was measured using the thiobarbituric acid reaction method (TBARS) and the total superoxide dismutase (t-SOD) and catalase (CAT) enzymatic activities were assessed. The experimental diet significantly reduced the docosahexaenoic acid (DHA) levels of SN phospholipids in the F1 (~28%) and F2 (~50%) groups. In F1 adult animals of the experimental group there was no LP in both SN and CS. Consistently, there was a significant increase in the t-SOD activity (p < 0.01) in both regions. In EF2 young animals, degeneration in dopaminergic and non-dopaminergic neurons and a significant increase in LP (p < 0.01) and decrease in the CAT activity (p < 0.001) were detected in the SN, while no inter-group difference was found for these parameters in the CS. Conversely, a significant increase in t-SOD activity (p < 0.05) was detected in the CS of the experimental group compared to the control. The results show that unbalanced EFA dietary levels reduce the redox balance in the SN and reveal mechanisms of resilience in the CS under this stressful condition. PMID

  14. Nuclear microscopic investigations into the elemental changes in the substantia nigra of unilaterally MPTP-lesioned Parkinsonian monkeys

    NASA Astrophysics Data System (ADS)

    Thong, P. S. P.; He, Y.; Lee, T.; Watt, F.

    1997-07-01

    Various transition metals, particularly iron, have been implicated in the aetiology of the neurodegenerative disease, Parkinson's disease, in which there is a characteristic loss of cells in the substantia nigra (SN) region of the brain. In this study, monkeys were unilaterally lesioned with the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydro-pyridine (MPTP) to obtain primate models of parkinsonism, with the non-lesioned side of the brain serving as controls. The monkeys were sacrificed at one day, one week, two weeks, one month and one year after lesioning to investigate the time dependent elemental changes in the parkinsonian SN. Sections of the brain encompassing both the lesioned and non-lesioned SNs were analysed using the National University of Singapore nuclear microscope. Adjacent sections were tyrosine hydroxylase (TH) immunohistochemically stained to provide complementary information on dopaminergic cell loss and to facilitate definition of the SN boundaries during data analysis. In one-day and one-week monkeys (representing early stages of the disease), there were no changes in elemental concentrations within experimental errors and the adjacent TH-stained sections did not show apparent cell loss in the SN. At two weeks, cell loss was seen in the lesioned SN compared to the control SN. Although there was no bulk increase in SN iron, localised accumulation of iron in granules containing up to 15% by weight iron was observed in the lesioned SN of one of the two-week monkeys. An average 15% increase in nigral iron, significant at the 90% confidence level ( p < 0.1), was seen in the one-month monkeys. TH-stained sections for the one-month monkeys showed cell loss in the lesioned SN. In one-year samples (representing the advanced stage of the disease) there was a significant ( p < 0.05) 56% increase in iron, 14% increase in phosphorous and a 20% decrease in copper. Here an almost complete loss of cells in the lesioned SN was apparent from the adjacent TH

  15. Combined in-situ imaging of structural organization and elemental composition of substantia nigra neurons in the elderly.

    PubMed

    Surowka, A D; Töpperwien, M; Bernhardt, M; Nicolas, J D; Osterhoff, M; Salditt, T; Adamek, D; Szczerbowska-Boruchowska, M

    2016-12-01

    Human dopaminergic system in general, and substantia nigra (SN) neurons, in particular, are implicated in the pathologies underlying the human brain aging. The interplay between aberrations in the structural organization and elemental composition of SN neuron bodies has recently gained in importance as selected metals: Fe, Cu, Zn, Ca were found to trigger oxidative-stress-mediated aberration in their molecular assembly due to concomitant protein (alpha-synuclein, tau-protein) aggregation, gliosis and finally oxidative stress. In the present study, we demonstrate an integrated approach to the analysis of the structural organization, assembly, and metals' accumulation in two distinct areas of SN: in the neuromelanin neurons and neuropil. By using the highly brilliant source of PETRA III and the Kirkpatrick-Baez nano-focus, large area histological brain slices are scanned at the sub-neuronal resolution, taking advantage of continuous motor movement and reduced acquisition time. Elemental analysis with synchrotron radiation based X-ray Fluorescence (SRXRF) is combined with X-ray Phase Contrast Imaging (XPCI) to correct for inherent aberrations in the samples' density and thickness, often referred to as the mass thickness effect. Based on the raw SRXRF spectra, we observed the accumulation of P, S, Cl, K, Ca, Fe, Cu and Zn predominantly in the SN neurons. However, upon the mass thickness correction, the distributions of Cl became significantly more uniform. Simultaneously with the fluorescence signal, the Small Angle X-ray Scattering (SAXS) is recorded by a pixel detector positioned in the far-field, enabling fast online computation of the darkfield and differential phase contrast (DPC). The data has demonstrated the SN neurons and neuropil produces excellent contrast which is due to their different mass density and scattering strength, indicative of differences in local structure and assembly therein. In all, the results show that combined SRXRF-XPCI-SAXS experiments

  16. Nifedipine- and omega-conotoxin-sensitive Ca2+ conductances in guinea-pig substantia nigra pars compacta neurones.

    PubMed Central

    Nedergaard, S; Flatman, J A; Engberg, I

    1993-01-01

    1. The membrane properties of substantia nigra pars compacta (SNc) neurones were recorded in guinea-pig in vitro brain slices. 2. In the presence of tetrodotoxin (TTX) a Ca(2+)-dependent slow oscillatory potential (SOP) was generated. Application of 0.5-20 microM nifedipine abolished both spontaneous and evoked SOPs. A tetraethylammonium chloride (TEA)-promoted high-threshold Ca2+ spike (HTS) was little affected by nifedipine. On the other hand, omega-conotoxin applied either locally or via the perfusion medium (1-10 microM) blocked a part of the HTS, but it did not alter the SOP. 3. In normal medium nifedipine blocked the spontaneous discharge, decreased the interspike interval (ISI) recorded during depolarizing current injections and selectively reduced the slow component of the spike after-hyperpolarization (AHP). omega-Conotoxin decreased both the rising and falling slopes of the normal action potential, reduced the peak amplitude of the spike AHP, and, in some of the neurones, reduced the ISI during depolarization. The Na+ spikes recorded in Ca(2+)-free medium were not altered by omega-conotoxin. 4. The SOP was not blocked by octanol (100-200 microM), amiloride (100-250 microM), or Ni2+ (100-300 microM). However, at 500 microM Ni2+ attenuated the SOP. 5. Application of apamin (0.5-2.0 microM) induced irregular firing or bursting, abolished the slow component of the spike AHP and reduced its peak amplitude. In the presence of TTX and apamin long-duration plateau potentials occurred, which were subsequently blocked by nifedipine. 6. In Ca(2+)-free, Co(2+)-containing medium TTX-sensitive spikes and voltage plateaux were generated by depolarizing current pulses. It is suggested that a persistent Na+ conductance underlies the plateaux, which may be co-activated during the SOP. 7. The results suggest that the Ca2+ currents underlying the SOP and the HTS are different and that they activate at least two Ca(2+)-dependent K+ conductances. These conductances play major

  17. Functional glycine receptor maturation in the absence of glycinergic input in dopaminergic neurones of the rat substantia nigra.

    PubMed

    Mangin, J M; Guyon, A; Eugène, D; Paupardin-Tritsch, D; Legendre, P

    2002-08-01

    The postnatal maturation pattern of glycine receptor channels (GlyRs) expressed by dopaminergic (DA) neurones of the rat substantia nigra pars compacta (SNc) was investigated using single-channel and whole-cell patch-clamp recordings in brain slices from rats aged 7-21 postnatal days (P). In neonatal rats (P7-P10), GlyRs exhibited a main conductance state of 100-110 pS with a mean open time of 16 ms. In juvenile rats (P19-P22), both the GlyR main conductance state (46-55 pS) and the mean open time (6.8 ms) were decreased. In neonatal rats, application of 30 microM picrotoxin, which is known to block homomeric GlyRs, strongly reduced glycine-evoked responses, while it was much less effective in juvenile rats. These results suggest that these GlyRs correspond functionally to alpha(2) homomeric GlyRs in neonatal rats and alpha(1)/beta heteromeric GlyRs in juvenile rats. A drastic but transient decrease in the glycine responsiveness of DA neurones occurred around P17 concomitant to the functional switch from the homomeric state to the heteromeric state. This age corresponds to a maturation phase for DA neurones. The application of 1 microM gabazine blocked spontaneous or evoked inhibitory synaptic current, while the addition of 1 microM strychnine had no effect, suggesting a lack of functional glycinergic synapses on DA neurones. Although it has been proposed that taurine is co-released with GABA at GABAergic synapses on DA neurones, in the present study the stimulation of GABAergic fibres failed to activate GlyRs. Blockade of taurine transporters and applications of high K(+) and hyposmotic solutions were also unable to induce any strychnine-sensitive current. We conclude that functional maturation of GlyRs can occur in the absence of any detectable GlyR activation in DA neurones of the SNc.

  18. 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.

  19. Differential vulnerability of substantia nigra and corpus striatum to oxidative insult induced by reduced dietary levels of essential fatty acids.

    PubMed

    Cardoso, Henriqueta D; Passos, Priscila P; Lagranha, Claudia J; Ferraz, Anete C; Santos Júnior, Eraldo F; Oliveira, Rafael S; Oliveira, Pablo E L; Santos, Rita de C F; Santana, David F; Borba, Juliana M C; Rocha-de-Melo, Ana P; Guedes, Rubem C A; Navarro, Daniela M A F; Santos, Geanne K N; Borner, Roseane; Picanço-Diniz, Cristovam W; Beltrão, Eduardo I; Silva, Janilson F; Rodrigues, Marcelo C A; Andrade da Costa, Belmira L S

    2012-01-01

    Oxidative stress (OS) has been implicated in the etiology of certain neurodegenerative disorders. Some of these disorders have been associated with unbalanced levels of essential fatty acids (EFA). The response of certain brain regions to OS, however, is not uniform and a selective vulnerability or resilience can occur. In our previous study on rat brains, we observed that a two-generation EFA dietary restriction reduced the number and size of dopaminergic neurons in the substantia nigra (SN) rostro-dorso-medial. To understand whether OS contributes to this effect, we assessed the status of lipid peroxidation (LP) and anti-oxidant markers in both SN and corpus striatum (CS) of rats submitted to this dietary treatment for one (F1) or two (F2) generations. Wistar rats were raised from conception on control or experimental diets containing adequate or reduced levels of linoleic and α-linolenic fatty acids, respectively. LP was measured using the thiobarbituric acid reaction method (TBARS) and the total superoxide dismutase (t-SOD) and catalase (CAT) enzymatic activities were assessed. The experimental diet significantly reduced the docosahexaenoic acid (DHA) levels of SN phospholipids in the F1 (~28%) and F2 (~50%) groups. In F1 adult animals of the experimental group there was no LP in both SN and CS. Consistently, there was a significant increase in the t-SOD activity (p < 0.01) in both regions. In EF2 young animals, degeneration in dopaminergic and non-dopaminergic neurons and a significant increase in LP (p < 0.01) and decrease in the CAT activity (p < 0.001) were detected in the SN, while no inter-group difference was found for these parameters in the CS. Conversely, a significant increase in t-SOD activity (p < 0.05) was detected in the CS of the experimental group compared to the control. The results show that unbalanced EFA dietary levels reduce the redox balance in the SN and reveal mechanisms of resilience in the CS under this stressful condition.

  20. 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

  1. Lipopolysaccharide Induces a Significant Increase in Expression of Iron Regulatory Hormone Hepcidin in the Cortex and Substantia Nigra in Rat Brain

    PubMed Central

    Wang, Qin; Du, Fang; Qian, Zhong-Ming; Ge, Xiao Hu; Zhu, Li; Yung, Wing Ho; Yang, Lei; Ke, Ya

    2008-01-01

    Hepcidin plays an essential role in maintaining normal iron homeostasis outside the brain. This recently discovered iron regulation hormone is predominantly expressed in the liver, and regulated by iron and hypoxia. As an antimicrobial peptide, this hormone is also elevated during infections and inflammation. In this study we investigated the expression of hepcidin mRNA and protein in different brain regions, including the cortex, hippocampus, striatum, and substantia nigra, and the effects of lipopolysaccharide (LPS) on the expression of hepcidin using quantitative real-time RT-PCR and immunofluorescence analysis. Our data provided further evidence for the existence of hepcidin in all the regions we examined. We also demonstrated for the first time that LPS administration by iv injection can regulate the expression of hepcidin mRNA and protein not only in peripheral organs such as the liver, but also in the brain. LPS induced a significant increase in the expression of hepcidin mRNA and protein in the cortex and substantia nigra, but not in the hippocampus and striatum, indicating a regionally specific regulation of LPS on hepcidin in the brain. The relevant mechanisms and the functions of hepcidin in the brain remain to be elucidated. PMID:18450970

  2. Functional applications of novel Semliki Forest virus vectors are limited by vector toxicity in cultures of primary neurons in vitro and in the substantia nigra in vivo.

    PubMed

    Lingor, Paul; Schöll, Ulrike; Bähr, Mathias; Kügler, Sebastian

    2005-03-01

    The Semliki Forest virus (SFV) system has been shown to be highly efficient in transduction of cell lines and primary cells. We employed a novel "noncytotoxic" SFV(PD) vector for transduction of primary ventral midbrain floor cultures in vitro and rat substantia nigra in vivo. Rapid protein expression was noted with preferential transduction of neuronal cells including the dopaminergic subpopulation. To examine the suitability of the SFV vector system for functional gene expression, SFV(PD) vectors encoding for antiapoptotic proteins Bcl-X(L) and XIAP were designed. Despite effective transgene expression, SFV(PD) vectors were unable to rescue dopaminergic neurons from MPP+-induced apoptosis. In vivo, virus injection into substantia nigra resulted in fast onset of transgene expression, but elicited an activation of microglia and an inflammation response. We conclude that the use of novel SFV(PD) vectors is currently limited by persistent neurotoxicity of the vector system. Although SFV(PD) vectors may be useful for protein localization studies in dopaminergic neurons, functional applications will require the development of even less cytopathic vector systems.

  3. Fetal substantia nigra and adrenal medullary grafts placed contralateral to the nigrostriatal lesion side induce a decrease in turning behavior but not in dopamine receptor density.

    PubMed

    Mendoza-Ramírez, J L; Aguilar-Roblero, R; Zainos-Rosales, A; Drucker-Colín, R

    1991-01-01

    Motor asymmetries as well as changes in the density of postsynaptic dopamine receptors produced by unilateral denervation of the striatum have been reduced by both substantia nigra (SN) and adrenal medullary (AM) grafts. Since to this date all studies have placed the grafts on the side ipsilateral to the lesion, the purpose of this study was to determine whether similar effects can be obtained when grafts are placed contralateral to the denervated side. The results of this study showed that 6-hydroxydopamine-lesioned rats followed up to 150 days with contralaterally placed intraventricular fetal substantia nigra grafts and fetal adrenal medulla grafts have a reduction of turning behavior of 41% and 34% respectively. However, contrary to ipsilateral grafts no normalization of dopamine receptor density as measured by [3H]spiperone autoradiography was observed 6 months after SN grafts, however, after AM grafts normalization did occur except in the anterior portion of the striatum. These results suggest that the compensatory motor changes induced by the grafted tissues could be mediated by mechanisms unrelated to changes in receptor density.

  4. Abnormal patterns of microtubule-associated protein-2 (MAP-2) immunolabeling in neuronal nuclei and Lewy bodies in Parkinson's disease substantia nigra brain tissues.

    PubMed

    D'Andrea, M R; Ilyin, S; Plata-Salaman, C R

    2001-06-29

    Parkinson's disease (PD) is a neurodegenerative disorder associated with the appearance of cytoplasmic Lewy bodies (LBs) in dopaminergic neurons of the substantia nigra and the progressive loss of these neurons. Cytoskeleton alterations and associated impairments of neuronal transport may contribute to neuronal death. Microtubule-associated protein-2 (MAP-2), a cytoskeleton protein is localized primarily in neuronal dendrites and is known to stabilize microtubule assembly and mediate their interactions with other neuronal cell components. To determine if alterations in MAP-2 morphology are present in PD neurons, we used single and double immunohistochemical and immunofluorescent techniques to characterize MAP-2 in PD neuronal tissues. We report abnormal MAP-2 immunolabeling in some neurons of the substantia nigra of PD brain tissues, which were not observed in the normal, age-matched, control brain tissues. Furthermore, MAP-2 was co-localized with alpha-synuclein and ubiquitin in cytoplasmic LBs of neurons. Surprisingly, MAP-2 was also found to form fibrous aggregates and crystal-like structures within neuronal nuclei. These PD-associated alterations in MAP-2 morphology and distribution suggest that impaired neuronal transport may contribute to the progression of neuronal loss in the brains of PD patients.

  5. Complex Network-Driven View of Genomic Mechanisms Underlying Parkinson's Disease: Analyses in Dorsal Motor Vagal Nucleus, Locus Coeruleus, and Substantia Nigra

    PubMed Central

    Corradini, Beatriz Raposo; Tampellini, Edilaine; Farfel, José Marcelo; Grinberg, Lea Tenenholz; Moreira-Filho, Carlos Alberto

    2014-01-01

    Parkinson's disease (PD)—classically characterized by severe loss of dopaminergic neurons in the substantia nigra pars compacta—has a caudal-rostral progression, beginning in the dorsal motor vagal nucleus and, in a less extent, in the olfactory system, progressing to the midbrain and eventually to the basal forebrain and the neocortex. About 90% of the cases are idiopathic. To study the molecular mechanisms involved in idiopathic PD we conducted a comparative study of transcriptional interaction networks in the dorsal motor vagal nucleus (VA), locus coeruleus (LC), and substantia nigra (SN) of idiopathic PD in Braak stages 4-5 (PD) and disease-free controls (CT) using postmortem samples. Gene coexpression networks (GCNs) for each brain region (patients and controls) were obtained to identify highly connected relevant genes (hubs) and densely interconnected gene sets (modules). GCN analyses showed differences in topology and module composition between CT and PD networks for each anatomic region. In CT networks, VA, LC, and SN hub modules are predominantly associated with neuroprotection and homeostasis in the ageing brain, whereas in the patient's group, for the three brain regions, hub modules are mostly related to stress response and neuron survival/degeneration mechanisms. PMID:25525598

  6. Genetic inactivation of pleiotrophin triggers amphetamine-induced cell loss in the substantia nigra and enhances amphetamine neurotoxicity in the striatum.

    PubMed

    Gramage, E; Rossi, L; Granado, N; Moratalla, R; Herradón, G

    2010-09-29

    Pleiotrophin (PTN) is a neurotrophic factor with important effects in survival and differentiation of dopaminergic neurons that has been suggested to play important roles in drug of abuse-induced neurotoxicity. To test this hypothesis, we have studied the effects of amphetamine (10 mg/kg, four times, every 2 h) on the nigrostriatal pathway of PTN genetically deficient (PTN-/-) mice. We found that amphetamine causes a significantly enhanced loss of dopaminergic terminals in the striatum of PTN-/- mice compared to wild type (WT+/+) mice. In addition, we found a significant decrease ( approximately 20%) of tyrosine hydroxylase (TH)-positive neurons only in the substantia nigra of amphetamine-treated PTN-/- mice, whereas this area of WT+/+ animals remained unaffected after amphetamine treatment. This effect was accompanied by enhanced amphetamine-induced astrocytosis in the substantia nigra of PTN-/- mice. Interestingly, we found a significant decrease in the phosphorylation levels of p42 extracellular-signal regulated kinase (ERK2) in both saline- and amphetamine-treated PTN-/- mice, whereas phosphorylation of p44 ERK (ERK1) was almost abolished in the striatum of PTN-/- mice compared to WT+/+ mice, suggesting that basal deficiencies in the phosphorylation levels of ERK1/2 could underlie the higher vulnerability of PTN-/- mice to amphetamine-induced neurotoxic effects. The data suggest an important role of PTN in the protection of nigrostriatal pathways against amphetamine insult.

  7. Fluoro-Jade C can specifically stain the degenerative neurons in the substantia nigra of the 1-methyl-4-phenyl-1,2,3,6-tetrahydro pyridine-treated C57BL/6 mice.

    PubMed

    Bian, Gan-Lan; Wei, Li-Chun; Shi, Mei; Wang, Yan-Qin; Cao, Rong; Chen, Liang-Wei

    2007-05-30

    Fluoro-Jade C, a new-developed fluorescent dye, has been successfully applied for identification of neuronal degeneration in the substantia nigra of 1-methyl-4-phenyl-1,2,3,6-tetrahydro pyridine (MPTP)-treated mice in the present study. The animal model was first prepared by intraperitoneal injection of neurotoxicant MPTP that can specifically induce degeneration of dopamine neurons in the substantia nigra of C57BL/6 mice. Fluoro-Jade C was then utilized to stain the midbrain sections and semiquantitation analysis was carried out in comparison with controls. It revealed that Fluoro-Jade C-positive cells showed strong green color in neuronal profile and were observed in the substantia nigra of MPTP-treated mice whereas they were not detected in that of controls. The Fluoro-Jade C-positive cells were mostly shrunken or smaller-sized in their cell bodies in comparing with that of normal dopamine neurons of controls. In the midbrain of MPTP-treated mice, Fluoro-Jade C-positive neuronal cells were exclusively distributed in the substantia nigra pars compacta, but rarely seen in the ventral tegemental area where dopamine neurons were numerously distributed. Double-labeling experiments indicated that a population of Fluoro-Jade C-positive cells (23%) exhibited neuron-specific nuclear protein-immunoreactivity and none of them showed immunoreactivity to glial cell marker glial fibrillary acid protein. However, most of Fluoro-Jade C-positive degenerative neurons (98%) lost their immunoreactivity to dopaminergic marker tyrosine hydroxylase in the substantia nigra of MPTP-treated mice. Taken together with previous observations, this study has presented that Fluoro-Jade C can be sensitively and specifically utilized to identify the neuronal degeneration in the substantia nigra of rodent animals receiving MPTP insult.

  8. Phosphodiesterase 4 inhibition affects both the direct and indirect pathway: an electrophysiological study examining the tri-phasic response in the substantia nigra pars reticulata.

    PubMed

    Heckman, P R A; Schweimer, J V; Sharp, T; Prickaerts, J; Blokland, A

    2017-09-18

    Fronto-striatal circuits constitute the neurobiological basis of many neuropsychiatric disorders. Part of the intracellular signaling within these circuits, including its dopaminergic modulation, is regulated by the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) signaling cascade. Based on the overall expression in human fronto-striatal circuitry, we tested the effects of a cAMP selective phosphodiesterase 4 (PDE4) inhibitor on the tri-phasic response in the dorsomedial substantia nigra pars reticulata (SNr) upon stimulation of the infralimbic cortex in rats. Our results show for the first time that stimulation of the cognitive infralimbic cortex leads to a tri-phasic response in SNr neurons. In addition and in line with previous biochemical and behavioral studies, PDE4 inhibition by roflumilast affects the direct pathway as well as the indirect pathway of which the latter appears more sensitive than the former.

  9. Calcium-activated non-selective cation currents are involved in generation of tonic and bursting activity in dopamine neurons of the substantia nigra pars compacta

    PubMed Central

    Mrejeru, Ana; Wei, Aguan; Ramirez, Jan Marino

    2011-01-01

    Abstract Nigral dopamine neurons are transiently activated by high frequency glutamatergic inputs relaying reward-predicting sensory information. The tonic firing pattern of dopamine cells responds to these inputs with a transient burst of spikes that requires NMDA receptors. Here, we show that NMDA receptor activation further excites the cell by recruiting a calcium-activated non-selective cation current (ICAN) capable of generating a plateau potential. Burst firing in vitro is eliminated after blockade of ICAN with flufenamic acid, 9-phenanthrol, or intracellular BAPTA. ICAN is likely to be mediated by a transient receptor potential (TRP) channel, and RT-PCR was used to confirm expression of TRPM2 and TRPM4 mRNA in substantia nigra pars compacta. We propose that ICAN is selectively activated during burst firing to boost NMDA currents and allow plateau potentials. This boost mechanism may render DA cells vulnerable to excitotoxicity. PMID:21486760

  10. Investigation of morphometric variability of subthalamic nucleus, red nucleus, and substantia nigra in advanced Parkinson's disease patients using automatic segmentation and PCA-based analysis.

    PubMed

    Xiao, Yiming; Jannin, Pierre; D'Albis, Tiziano; Guizard, Nicolas; Haegelen, Claire; Lalys, Florent; Vérin, Marc; Collins, D Louis

    2014-09-01

    Subthalamic nucleus (STN) deep brain stimulation (DBS) is an effective surgical therapy to treat Parkinson's disease (PD). Conventional methods employ standard atlas coordinates to target the STN, which, along with the adjacent red nucleus (RN) and substantia nigra (SN), are not well visualized on conventional T1w MRIs. However, the positions and sizes of the nuclei may be more variable than the standard atlas, thus making the pre-surgical plans inaccurate. We investigated the morphometric variability of the STN, RN and SN by using label-fusion segmentation results from 3T high resolution T2w MRIs of 33 advanced PD patients. In addition to comparing the size and position measurements of the cohort to the Talairach atlas, principal component analysis (PCA) was performed to acquire more intuitive and detailed perspectives of the measured variability. Lastly, the potential correlation between the variability shown by PCA results and the clinical scores was explored.

  11. Molecular and functional differences in voltage-activated sodium currents between GABA projection neurons and dopamine neurons in the substantia nigra.

    PubMed

    Ding, Shengyuan; Wei, Wei; Zhou, Fu-Ming

    2011-12-01

    GABA projection neurons (GABA neurons) in the substantia nigra pars reticulata (SNr) and dopamine projection neurons (DA neurons) in substantia nigra pars compacta (SNc) have strikingly different firing properties. SNc DA neurons fire low-frequency, long-duration spikes, whereas SNr GABA neurons fire high-frequency, short-duration spikes. Since voltage-activated sodium (Na(V)) channels are critical to spike generation, the different firing properties raise the possibility that, compared with DA neurons, Na(V) channels in SNr GABA neurons have higher density, faster kinetics, and less cumulative inactivation. Our quantitative RT-PCR analysis on immunohistochemically identified nigral neurons indicated that mRNAs for pore-forming Na(V)1.1 and Na(V)1.6 subunits and regulatory Na(V)β1 and Na(v)β4 subunits are more abundant in SNr GABA neurons than SNc DA neurons. These α-subunits and β-subunits are key subunits for forming Na(V) channels conducting the transient Na(V) current (I(NaT)), persistent Na current (I(NaP)), and resurgent Na current (I(NaR)). Nucleated patch-clamp recordings showed that I(NaT) had a higher density, a steeper voltage-dependent activation, and a faster deactivation in SNr GABA neurons than in SNc DA neurons. I(NaT) also recovered more quickly from inactivation and had less cumulative inactivation in SNr GABA neurons than in SNc DA neurons. Furthermore, compared with nigral DA neurons, SNr GABA neurons had a larger I(NaR) and I(NaP). Blockade of I(NaP) induced a larger hyperpolarization in SNr GABA neurons than in SNc DA neurons. Taken together, these results indicate that Na(V) channels expressed in fast-spiking SNr GABA neurons and slow-spiking SNc DA neurons are tailored to support their different spiking capabilities.

  12. [Simultaneous micro-transplantation of fetal mesencephalic cells to the striate and substantia nigra pars reticulata in hemi-parkinsonian rats. A study of behavior].

    PubMed

    Blanco, L; Pavón, N; Macías, R; Castillo, L; Díaz, C; García, A; Alvarez, P

    Microtransplantation of fetal dopaminergic cells has been used over the past ten years with good results in models of Parkinson's disease. To evaluate the effect of microtransplantation of fetal dopaminergic cells 'seeded' in the substantia nigra pars reticulata (SNpr) and striate (St) simultaneously. The animals received a transplant or microtransplant of cells into the St and SNpr ipsilateral to the lesion in the substantia nigra pars compacta or to both regions. Depending on the site and technique used the following experimental groups were considered: I. Macrotransplantation to the St (n = 20); II. Microtransplant to the St (n = 20); III. Microtransplant to St + SNpr (n = 20); IV. Microtransplant to St + SNpr (n = 20); V. Macrotransplantation to SNpr (n = 20); VI. Microtransplantation to SNpr (n = 20); and VII. Control (lesion only) (n = 20). The rotations induced by D-amphetamine (5 mg/kg i.p.) and by apomorphine were studied 1, 2, 3 and 6 months and 3 and 6 months respectively after transplantation. Three months after transplantation we studied the motor asymmetry shown by the animals by means of the ladder test. The rotations were reduced in the groups with intrastriate transplantation. Comparison between the surgical techniques showed nonsignificant differences between them. The ladder test showed significant differences in use of the limbs in all experimental groups. Use of the left limb was significantly reduced in all groups. Modification of the rotations seems more sensitive to the site of transplant than to the technique used. It seems that the skills studied using the ladder test are not altered by the microtransplant technique.

  13. Basal ganglia and thalamic input from neurons located within the ventral tier cell cluster region of the substantia nigra pars compacta in the rat.

    PubMed

    Cebrián, Carolina; Prensa, Lucía

    2010-04-15

    The most caudally located dopaminergic (DA) ventral tier neurons of the substantia nigra pars compacta (SNc) form typical cell clusters that are deeply embedded in the substantia nigra pars reticulata (SNr). Here we examine the efferent projections of 35 neurons located in the SNr region where these SNc cell clusters reside. The neuronal cell body was injected with biotinylated dextran amine so as to trace each complete axon in the sagittal or the coronal plane. Electrophysiological guidance guaranteed that the tracer was ejected among neurons displaying a typical SNc discharge pattern. Furthermore, double immunofluorescence and immunohistochemical labeling ensured that the tracer deposits were placed within the DA cell clusters. Three types of projection neurons occurred in the SNc ventral tier cell cluster region: type I neurons, projecting to basal ganglia; type II neurons, targeting both the basal ganglia and thalamus; and type III neurons, projecting only to the thalamus. The striatum was targeted by most of the type I and II neurons and the innervation reached both the striosome/subcallosal streak and matrix compartments. Many nigrostriatal fibers provided collaterals to the globus pallidus and, less frequently, to the subthalamic nucleus. At a thalamic level, type II and III neurons preferentially targeted the reticular, ventral posterolateral, and ventral medial nuclei. Our results reveal that the SNr region where DA ventral tier cell clusters reside harbors neurons projecting to the basal ganglia and/or the thalamus, thus suggesting that neurodegeneration of nigral neurons in Parkinson's disease might affect various extrastriatal basal ganglia structures and multiple thalamic nuclei.

  14. Glucocorticoid receptor is involved in the neuroprotective effect of ginsenoside Rg1 against inflammation-induced dopaminergic neuronal degeneration in substantia nigra.

    PubMed

    Sun, Xian-Chang; Ren, Xiao-Fan; Chen, Lei; Gao, Xian-Qi; Xie, Jun-Xia; Chen, Wen-Fang

    2016-01-01

    Accumulating clinical and experimental evidence suggests that chronic neuroinflammation is associated with dopaminergic neuronal death in Parkinson's disease (PD). Ginsenoside Rg1, the most active components of ginseng, possesses a variety of biological effects on the central nervous system, cardiovascular system and immune system. The present study aimed to evaluate the protective effects of ginsenoside Rg1 on lipopolysaccharide (LPS)-induced microglia activation and dopaminergic neuronal degeneration in rat substantia nigra (SN) and its potential mechanisms. Treatment with Rg1 could ameliorate the apomorphine-induced rotational behavior in LPS-lesioned rats. GR antagonist RU486 partly abolished the protective effect of Rg1. Rg1 treatment significantly attenuated LPS-induced loss of tyrosin hydroxlase (TH) positive neurons in substantial nigra par compacta (SNpc) and decreased content of dopamine (DA) and its metabolites in striatum of the lesioned side. Meanwhile, Rg1 significantly inhibited LPS-induced microglial activation and production of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and nitric oxide (NO). These effects were abolished by co-treatment with RU486. In addition, Rg1 treatment significantly inhibited the LPS-induced phosphorylation of IκB, extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal protein kinase (JNK) and p38 mitogen-activated protein kinase (p38 MAPK) in the lesioned side of substantial nigra. These effect could be also partly blocked by RU486. Taken together, these data indicate that Rg1 has protective effects on mesencephalic dopaminergic neurons from LPS-induced microglia inflammation. GR signaling pathway might be involved in the anti-inflammatory effect of Rg1. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Properly scaled and targeted AAV2-NRTN (neurturin) to the substantia nigra is safe, effective and causes no weight loss: support for nigral targeting in Parkinson's disease.

    PubMed

    Bartus, Raymond T; Brown, Lamar; Wilson, Alistair; Kruegel, Brian; Siffert, Joao; Johnson, Eugene M; Kordower, Jeffrey H; Herzog, Christopher D

    2011-10-01

    Recent analyses of autopsied brains from subjects previously administered AAV2-neurturin (NRTN) gene transfer argues that optimizing the effects of neurotrophic factors in Parkinson's disease (PD) likely requires delivery to both the degenerating cell bodies (in substantia nigra) and their terminals (in striatum). Prior to implementing this novel dosing paradigm in humans, we conducted eight nonclinical experiments with three general objectives: (1) evaluate the feasibility, safety and effectiveness of targeting the substantia nigra (SN) with AAV2-NRTN, (2) better understand and appraise recent warnings of serious weight loss that might occur with targeting the SN with neurotrophic factors, and (3) define an appropriate dose of AAV2-NRTN that should safely and effectively cover the SN in PD patients. Toward these ends, we first determined SN volume for rats, monkeys and humans, and employed these values to calculate comparable dose equivalents for each species by scaling each dose, based on relative SN volume. Using this information, we next injected AAV2-GFP to monkey SN to quantify AAV2-vector distribution and confirm reasonable SN coverage. We then selected and administered a ~200-fold range of AAV2-NRTN doses (and a single AAV2-GDNF dose) to rat SN, producing a wide range of protein expression. In contrast to recent warnings regarding nigra targeting, no dose produced any serious side effects or toxicity, though we replicated the modest reduction in weight gain reported by others with the highest AAV2-NRTN and the AAV2-GDNF dose. A dose-related increase in NRTN expression was seen, with the lower doses limiting NRTN to the peri-SN and the highest dose producing mistargeted NRTN well outside the SN. We then demonstrated that the reduction in weight gain following excessive-doses can be dissociated from NRTN in the targeted SN, and is linked to mistargeted NRTN in the diencephalon. We also showed that prior destruction of the dopaminergic SN neurons via 6-OHDA

  16. Study of Cu chemical state inside single neurons from Parkinson's disease and control substantia nigra using the micro-XANES technique.

    PubMed

    Chwiej, Joanna; Adamek, Dariusz; Szczerbowska-Boruchowska, Magdalena; Krygowska-Wajs, Anna; Bohic, Sylvain; Lankosz, Marek

    2008-01-01

    Parkinson's disease (PD) is referred to as idiopathic disorder, which means that its causes have not been found yet. However, a few processes such as oxidative stress, protein aggregation and mitochondrial dysfunction are suspected to lead to the atrophy and death of substantia nigra (SN) neurons in case of this neurodegenerative disorder. Cu is a trace element whose role in the pathogenesis of PD is widely discussed. The investigation of Cu oxidation state inside single nerve cells from SN of PD and control cases may shed some new light on the role of this element in PD. The differences in Cu chemical state were investigated with the use of X-ray absorption near edge structure (XANES) spectroscopy. The least-square fitting method was applied for the analysis of XANES spectra. The comparison of the positions of white line, multiple scattering and pre-edge peak maximum at the energy scale did not reveal the existence of differences in Cu chemical state between PD and control samples. However, it was found that most of the Cu inside SN neurons occurs in tetrahedral environment and probably as Cu(II).

  17. Diagnostic Accuracy of Transcranial Sonography of the Substantia Nigra in Parkinson’s disease: A Systematic Review and Meta-analysis

    PubMed Central

    Li, Dun-Hui; He, Ya-Chao; Liu, Jun; Chen, Sheng-Di

    2016-01-01

    A large number of articles have reported substantia nigra hyperechogenicity in Parkinson’s disease (PD) and have assessed the diagnostic accuracy of transcranial sonography (TCS); however, the conclusions are discrepant. Consequently, this systematic review and meta-analysis aims to consolidate the available observational studies and provide a comprehensive evaluation of the clinical utility of TCS in PD. Totally, 31 studies containing 4,386 participants from 13 countries were included. A random effects model was utilized to pool the effect sizes. Meta-regression and sensitivity analysis were performed to explore potential heterogeneity. Overall diagnostic accuracy of TCS in differentiating PD from normal controls was quite high, with a pooled sensitivity of 0.83 (95% CI: 0.81–0.85) and a pooled specificity of 0.87 (95% CI: 0.85–0.88). The positive likelihood ratio, the negative likelihood ratio and diagnostic odds ratio were calculated 6.94 (95% CI: 5.09–9.48), 0.19 (95% CI: 0.16–0.23), and 42.89 (95% CI: 30.03–61.25) respectively. Our systematic review of the literature and meta-analysis suggest that TCS has high diagnostic accuracy in the diagnosis of PD when compared to healthy control. PMID:26878893

  18. 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.

  19. A Comparison of Substantia Nigra T1 Hyperintensity in Parkinson's Disease Dementia, Alzheimer's Disease and Age-Matched Controls: Volumetric Analysis of Neuromelanin Imaging

    PubMed Central

    Park, Ju-Yeon; Yun, Won-Sung; Jeon, Ji Yeong; Moon, Yeon Sil; Kim, Heejin; Kwak, Ki-Chang; Lee, Jong-Min; Han, Seol-Heui

    2016-01-01

    Objective Neuromelanin loss of substantia nigra (SN) can be visualized as a T1 signal reduction on T1-weighted high-resolution imaging. We investigated whether volumetric analysis of T1 hyperintensity for SN could be used to differentiate between Parkinson's disease dementia (PDD), Alzheimer's disease (AD) and age-matched controls. Materials and Methods This retrospective study enrolled 10 patients with PDD, 18 patients with AD, and 13 age-matched healthy elderly controls. MR imaging was performed at 3 tesla. To measure the T1 hyperintense area of SN, we obtained an axial thin section high-resolution T1-weighted fast spin echo sequence. The volumes of interest for the T1 hyperintense SN were drawn onto heavily T1-weighted FSE sequences through midbrain level, using the MIPAV software. The measurement differences were tested using the Kruskal-Wallis test followed by a post hoc comparison. Results A comparison of the three groups showed significant differences in terms of volume of T1 hyperintensity (p < 0.001, Bonferroni corrected). The volume of T1 hyperintensity was significantly lower in PDD than in AD and normal controls (p < 0.005, Bonferroni corrected). However, the volume of T1 hyperintensity was not different between AD and normal controls (p = 0.136, Bonferroni corrected). Conclusion The volumetric measurement of the T1 hyperintensity of SN can be an imaging marker for evaluating neuromelanin loss in neurodegenerative diseases and a differential in PDD and AD cases. PMID:27587951

  20. Abnormal Echogenicity of the Substantia Nigra, Raphe Nuclei, and Third-Ventricle Width as Markers of Cognitive Impairment in Parkinsonian Disorders: A Cross-Sectional Study

    PubMed Central

    Bouwmans, Angela E. P.; Leentjens, Albert F. G.; Mess, Werner H.; Weber, Wim E. J.

    2016-01-01

    Background. Patients with Parkinson's disease (PD) have a high risk of cognitive problems. Objective. This study assesses whether abnormal echogenicity of the substantia nigra (SN) and raphe nuclei (RN) and the diameter of third ventricle are markers of cognitive impairment in patients with PD and other forms of parkinsonism. Methods. 126 outpatients with early signs of parkinsonism underwent transcranial sonography (TCS). The scales for the outcome of Parkinson's disease cognition (SCOPA-COG) were used as cognitive measure. Definite neurological diagnosis was established after two-year follow-up. Results. One-third of the patients with PD and half of those with APS had signs of cognitive impairment. The echogenicity of the SN was not related to cognitive impairment. The diameter of the third ventricle was significantly larger in PD patients with cognitive impairment compared to those without. In patients with APS we found a significantly higher frequency of hypoechogenic RN in patients with cognitive problems. Conclusions. Cognitive impairment is already present in a substantial proportion of patients with PD and APS at first referral. In patients with APS the frequency of hypoechogenic RN points to the direction of other pathophysiology with more emphasis on deficits in the serotonergic neurotransmitter system. The larger diameter of the third ventricle in PD patients with cognitive impairment may reflect Alzheimer like brain atrophy, as has been reported in earlier studies. PMID:26881179

  1. 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.

  2. Voxel-based morphometry of the marmoset brain: In vivo detection of volume loss in the substantia nigra of the MPTP-treated Parkinson's disease model.

    PubMed

    Hikishima, K; Ando, K; Komaki, Y; Kawai, K; Yano, R; Inoue, T; Itoh, T; Yamada, M; Momoshima, S; Okano, H J; Okano, H

    2015-08-06

    Movement dysfunction in Parkinson's disease (PD) is caused by the degeneration of dopaminergic (DA) neurons in the substantia nigra (SN). Here, we established a method for voxel-based morphometry (VBM) and automatic tissue segmentation of the marmoset monkey brain using a 7-T animal scanner and applied the method to assess DA degeneration in a PD model, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated animals, with tyrosine-hydroxylase staining. The most significant decreases of local tissue volume were detected in the bilateral SN of MPTP-treated marmoset brains (-53.0% in right and -46.5% in left) and corresponded with the location of DA neurodegeneration found in histology (-65.4% in right). In addition to the SN, the decreases were also confirmed in the locus coeruleus, and lateral hypothalamus. VBM using 7-T MRI was effective in detecting volume loss in the SN of the PD-model marmoset. This study provides a potential basis for the application of VBM with ultra-high field MRI in the clinical diagnosis of PD. The developed method may also offer value in automatic whole-brain evaluation of structural changes for the marmoset monkey.

  3. Meta-Analysis of Parkinson's Disease Transcriptome Data Using TRAM Software: Whole Substantia Nigra Tissue and Single Dopamine Neuron Differential Gene Expression

    PubMed Central

    Mariani, Elisa; Frabetti, Flavia; Tarozzi, Andrea; Pelleri, Maria Chiara; Pizzetti, Fabrizio

    2016-01-01

    The understanding of the genetic basis of the Parkinson's disease (PD) and the correlation between genotype and phenotype has revolutionized our knowledge about the pathogenetic mechanisms of neurodegeneration, opening up exciting new therapeutic and neuroprotective perspectives. Genomic knowledge of PD is still in its early stages and can provide a good start for studies of the molecular mechanisms that underlie the gene expression variations and the epigenetic mechanisms that may contribute to the complex and characteristic phenotype of PD. In this study we used the software TRAM (Transcriptome Mapper) to analyse publicly available microarray data of a total of 151 PD patients and 130 healthy controls substantia nigra (SN) samples, to identify chromosomal segments and gene loci differential expression. In particular, we separately analyzed PD patients and controls data from post-mortem snap-frozen SN whole tissue and from laser microdissected midbrain dopamine (DA) neurons, to better characterize the specific DA neuronal expression profile associated with the late-stage Parkinson's condition. The default "Map" mode analysis resulted in 10 significantly over/under-expressed segments, mapping on 8 different chromosomes for SN whole tissue and in 4 segments mapping on 4 different chromosomes for DA neurons. In conclusion, TRAM software allowed us to confirm the deregulation of some genomic regions and loci involved in key molecular pathways related to neurodegeneration, as well as to provide new insights about genes and non-coding RNA transcripts not yet associated with the disease. PMID:27611585

  4. D4 and D1 dopamine receptors modulate [3H] GABA release in the substantia nigra pars reticulata of the rat.

    PubMed

    Acosta-García, Jacqueline; Hernández-Chan, Nancy; Paz-Bermúdez, Francisco; Sierra, Arturo; Erlij, David; Aceves, Jorge; Florán, Benjamín

    2009-12-01

    Neurons of the globus pallidus express dopamine D4 receptors that can modulate transmitter release by their axon terminals. Indeed, GABA release from pallidal terminals in the subthalamic nucleus and in the reticular nucleus of the thalamus is inhibited by activation of D4 receptors. Here we investigated whether GABA release by pallidal projections to the substantia nigra reticulate (SNr) is also modulated by D4 receptors. Dopamine-stimulated depolarization-induced GABA release in slices of the SNr; however, after selective blockade of D1 receptors, dopamine inhibited release. The selective D4 agonist PD 168,077 (IC(50) = 5.30 nM) mimicked the inhibition of release while the selective D4 antagonist L-745,870 blocked the inhibition. To identify the source of D1 and D4 modulated terminals, we unilaterally injected kainic acid in either the GP or the striatum. After lesions of the pallidum, the D4 induced inhibition of release was blocked while the D1 induced stimulation was still significant. Lesions of the striatum had the converse effects. We conclude that release of dopamine in the SNr enhances GABA release mainly through activation of D1 receptors in striatonigral projections and inhibits release mainly through activation of D4 receptors in pallidonigral projections. Because deficient D4 receptor signaling in globus pallidus terminals will lead to disinhibition of impulse traffic through the thalamus we speculate that the D4 abnormalities observed in ADHD patients may be important in the generation of the syndrome.

  5. Down-regulation of alpha-synuclein expression can rescue dopaminergic cells from cell death in the substantia nigra of Parkinson's disease rat model.

    PubMed

    Hayashita-Kinoh, Hiromi; Yamada, Masanori; Yokota, Takanori; Mizuno, Yoshikuni; Mochizuki, Hideki

    2006-03-24

    Fibrillization and aggregation of alpha-synuclein may play a critical role in neurodegenerative diseases like Parkinson's diseases. Adeno-associated virus (AAV) vector delivery of an alpha-synuclein ribozyme was tested for its silencing effect on degenerating nigrostriatal neurons in the MPP(+) model of Parkinson's disease. We designed alpha-synuclein ribozyme against human alpha-synuclein gene expression and constructed alpha-synuclein ribozymes-carrying rAAV vector (designated rAAV-SynRz). Co-transfection of rAAV-SynRz and rAAV-alpha-synuclein into HEK293 cells resulted in down-regulation of alpha-synuclein protein expression in vitro. Then, rAAV-SynRz was injected into the substantia nigra (SN) of MPP(+)-treated rats. Cell counts of TH-positive neurons in the SN revealed that rAAV-SynRz significantly protected TH-positive cells against apoptotic death, compared with those of rAAV-EGFP or no rAAV injected rats. Our results indicate that the use of rAAV-SynRz allowed the survival of higher number of TH-positive neurons in SN in the MPP(+) model. Down-regulation of alpha-synuclein expression could be potentially a suitable target for gene therapy of Parkinson's disease.

  6. Neuroprotection by Exendin-4 Is GLP-1 Receptor Specific but DA D3 Receptor Dependent, Causing Altered BrdU Incorporation in Subventricular Zone and Substantia Nigra

    PubMed Central

    Harkavyi, A.; Rampersaud, N.; Whitton, P. S.

    2013-01-01

    Glucagon-like peptide-1 receptor (GLP-1R) activation by exendin-4 (EX-4) is effective in preclinical models of Parkinson's disease (PD) and appears to promote neurogenesis even in severely lesioned rats. In the present study, we determined the effects of EX-4 on cellular BrdU incorporation in the rat subventricular zone (SVZ) and substantia nigra (SN). We also determined the specificity of this effect with the GLP-1R antagonist EX-(9-39) as well as the potential role of dopamine (DA) D3 receptors. Rats were administered 6-OHDA and 1 week later given EX-4 alone, with EX-(9-39) or nafadotride (D3 antagonist) and BrdU. Seven days later, rats were challenged with apomorphine to evaluate circling. Extracellular DA was measured using striatal microdialysis and subsequently tissue DA measured. Tyrosine hydroxylase and BrdU were verified using immunohistochemistry. Apomorphine circling was reversed by EX-4 in lesioned rats, an effect reduced by EX-4, while both EX-(9-39) and NAF attenuated this. 6-OHDA decreased extracellular and tissue DA, both reversed by EX-4 but again attenuated by EX-(9-39) or NAF. Analysis of BrdU+ cells in the SVZ revealed increases in 6-OHDA-treated rats which were reversed by EX-4 and antagonised by either EX-(9-39) or NAF, while in the SN the opposite profile was seen. PMID:26316987

  7. Chemical Exchange Saturation Transfer MR Imaging is Superior to Diffusion-Tensor Imaging in the Diagnosis and Severity Evaluation of Parkinson's Disease: A Study on Substantia Nigra and Striatum.

    PubMed

    Li, Chunmei; Wang, Rui; Chen, Haibo; Su, Wen; Li, Shuhua; Zhao, Xuna; Zhou, Jinyuan; Qiao, Jian; Lou, Baohui; Song, Guodong; Chen, Min

    2015-01-01

    Parkinson's disease (PD) is a neurodegenerative disorder characterized by nigrostriatal cell loss. To date, the diagnosis of PD is still based primarily on the clinical manifestations, which may be typical and obvious only in advanced-stage PD. Thus, it is crucial to find a reliable marker for the diagnosis of PD. We conducted this study to assess the diagnostic efficiency of chemical exchange saturation transfer (CEST) imaging and diffusion-tensor imaging (DTI) in PD at 3 T by evaluating changes on substantia nigra and striatum. Twenty-three PD patients and twenty-three age-matched normal controls were recruited. All patients and controls were imaged on a 3-T MR system, using an eight-channel head coil. CEST imaging was acquired in two transverse slices of the head, including substantia nigra and striatum. The magnetization transfer ratio asymmetry at 3.5 ppm, MTRasym(3.5 ppm), and the total CEST signal intensity between 0 and 4 ppm were calculated. Multi-slice DTI was acquired for all the patients and normal controls. Quantitative analysis was performed on the substantia nigra, globus pallidus, putamen, and caudate. The MTRasym(3.5 ppm) value, the total CEST signal intensity, and fractional anisotropy value of the substantia nigra were all significantly lower in PD patients than in normal controls (P = 0.003, P = 0.004, and P < 0.001, respectively). The MTRasym(3.5 ppm) values of the putamen and the caudate were significantly higher in PD patients than in normal controls (P = 0.010 and P = 0.009, respectively). There were no significant differences for the mean diffusivity in these four regions between PD patients and normal controls. In conclusion, CEST MR imaging provided multiple CEST image contrasts in the substantia nigra and the striatum in PD and may be superior to DTI in the diagnosis of PD.

  8. Dietary administration of paraquat for 13 weeks does not result in a loss of dopaminergic neurons in the substantia nigra of C57BL/6J mice.

    PubMed

    Minnema, Daniel J; Travis, Kim Z; Breckenridge, Charles B; Sturgess, Nicholas C; Butt, Mark; Wolf, Jeffrey C; Zadory, Dan; Beck, Melissa J; Mathews, James M; Tisdel, Merrill O; Cook, Andrew R; Botham, Philip A; Smith, Lewis L

    2014-03-01

    Several investigations have reported that mice administered paraquat dichloride (PQ·Cl2) by intraperitoneal injection exhibit a loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc). In this study, male and female C57BL/6J mice were administered PQ·Cl2 in the diet at concentrations of 0 (control), 10, and 50ppm for a duration of 13weeks. A separate group of mice were administered 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) during week 12 as positive controls to produce a loss of dopaminergic neurons in the SNpc. The comparative effects of PQ and MPTP on the SNpc and/or striatum were assessed using neurochemical, neuropathological, and stereological endpoints. Morphological and stereological assessments were performed by investigators 'blinded' to the origin of the tissue. Neither dose of PQ·Cl2 (10 or 50 ppm in the diet) caused a loss of striatal dopamine or dopamine metabolite concentrations in the brains of mice. Pathological assessments of the SNpc and striatum showed no evidence of neuronal degeneration or astrocytic/microglial activation. Furthermore, the number of tyrosine hydroxylase-positive (TH(+)) neurons in the SNpc was not reduced in PQ-treated mice. In contrast, MPTP caused a decrease in striatal dopamine concentration, a reduction in TH(+) neurons in the SNpc, and significant pathological changes including astrocytic and microglial activation in the striatum and SNpc. The MPTP-induced effects were greater in males than in females. It is concluded that 13weeks of continuous dietary exposure of C57BL/6J mice to 50ppm PQ·Cl2 (equivalent to 10.2 and 15.6mg PQ ion/kg body weight/day for males and females, respectively) does not result in the loss of, or damage to, dopaminergic neurons in the SNpc. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

  9. Dietary administration of diquat for 13 weeks does not result in a loss of dopaminergic neurons in the substantia nigra of C57BL/6J mice.

    PubMed

    Minnema, Daniel J; Travis, Kim Z; Breckenridge, Charles B; Sturgess, Nicholas C; Butt, Mark; Wolf, Jeffrey C; Zadory, Dan; Herberth, Mark T; Watson, Scott L; Cook, Andrew R; Botham, Philip A

    2016-03-01

    Male and female C57BL/6J mice were administered diquat dibromide (DQ∙Br2) in their diets at concentrations of 0 (control), 12.5 and 62.5 ppm for 13 weeks to assess the potential effects of DQ on the nigrostriatal dopaminergic system. Achieved dose levels at 62.5 ppm were 6.4 and 7.6 mg DQ (ion)/kg bw/day for males and females, respectively. A separate group of mice was administered 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) ip as a positive control. The comparative effects of DQ and MPTP on the substantia nigra pars compacta (SNpc) and/or striatum were assessed using neurochemical, neuropathological and stereological endpoints. Morphological and stereological assessments were performed by investigators who were "blinded" to dose group. DQ had no effect on striatal dopamine concentration or dopamine turnover. There was no evidence of neuronal degeneration, astrocytic or microglial activation, or a reduction in the number of tyrosine hydroxylase positive (TH(+)) neurons in the SNpc or neuronal processes in the striatum of DQ-treated mice. These results are consistent with the rapid clearance of DQ from the brain following a single dose of radiolabeled DQ. In contrast, MPTP-treated mice exhibited decreased striatal dopamine concentration, reduced numbers of TH(+) neurons in the SNpc, and neuropathological changes, including neuronal necrosis, as well as astrocytic and microglial activation in the striatum and SNpc. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  10. Neonatal exposure to lipopolysaccharide enhances accumulation of α-synuclein aggregation and dopamine transporter protein expression in the substantia nigra in responses to rotenone challenge in later life

    PubMed Central

    Tien, Lu-Tai; Kaizaki, Asuka; Pang, Yi; Cai, Zhengwei; Bhatt, Abhay J; Fan, Lir-Wan

    2013-01-01

    Brain inflammation in early life may enhance adult susceptibility to develop neurodegenerative disorders triggered by environmental toxins. Our previous studies show that perinatal lipopolysaccharide (LPS) exposure enhances adult susceptibility to rotenone-induced injury to the dopaminergic system in the substantia nigra (SN) of the adult rat brain. To further investigate the enhanced adult susceptibility by neonatal LPS exposure to rotenone neurotoxicity, we used our neonatal rat model of LPS exposure (1 mg/kg, intracerebral injection in postnatal day 5, P5, neonatal rats) to examine the protein levels of α-synuclein and dopamine transporters (DAT) in the adult rat. By P70, rats from the saline- or LPS-exposed group were challenged with rotenone, a commonly used pesticide, through subcutaneous mini-pump infusion at a dose of 1.25 mg/kg per day for 14 days. The accumulation of α-synuclein aggregation and increment of DAT protein content were found in the SN of LPS-exposed rats. Neonatal LPS exposure enhanced rotenone-stimulated accumulation of α-synuclein aggregation and increment in DAT protein expression in the cytoplasmic compartment of the SN, and in the synaptosomal compartment of the striatum of adult rats. Rotenone treatment also resulted in reduction of [3H]dopamine uptake and mitochondrial complex I activity in the striatum of rats with neonatal LPS exposure, but not in those without this exposure. The current study suggests possible roles of α-synuclein aggregate and DAT distribution in the cytoplasm and synaptosome triggered by environmental toxins in later life in the development of neurodegenerative disorders. Our model may be useful in studying mechanisms involved in the pathogenesis of nonfamilial Parkinson's disease and for developing potential therapeutic treatments for this disease. PMID:23567316

  11. Elemental micro-imaging and quantification of human substantia nigra using synchrotron radiation based x-ray fluorescence—in relation to Parkinson’s disease

    NASA Astrophysics Data System (ADS)

    Szczerbowska-Boruchowska, Magdalena; Krygowska-Wajs, Anna; Adamek, Dariusz

    2012-06-01

    Synchrotron radiation based x-ray fluorescence (SRXRF) was applied to the quantitative evaluation of elemental changes in substantia nigra pars compacta (SNc) in Parkinson’s disease (PD) in the framework of a study on the role of chemical elements in the pathophysiology of PD. The analysis was carried out for dopaminergic nerve cells and extraneuronal spaces. The mass fractions of P, S, Cl, K, Ca, Fe, Cu, Zn, Br and Rb were determined. The application of standard samples developed especially for the determination of elemental mass fractions in thin tissue sections using the SRXRF technique is presented. Two-dimensional maps of elemental distribution show that the location of nerve cells in SNc sections is precisely visualized by the high levels of most elements. It was found that statistically significant differences between control and PD neurons are observed for S (p = 0.04), Cl (p = 0.02), Ca (p = 0.08), Fe (p = 0.04) and Zn (p = 0.04). The mass fractions of P (p = 0.08), S (p = 0.07), Cl (p = 0.04), Zn (p = 0.08) and Rb (p = 0.08) in areas outside the nerve cell bodies differed significantly between PD and control groups. A clear cluster separation between the PD nerve cells and neurons representing the control group was noticed. It was found that Cl, Fe, Ca and Zn are the most significant elements in the general discrimination between PD nerve cells and the control. The comparison between the extraneuronal spaces showed that Cl, Fe and Cu differentiate the PD and control group the most. The evident contribution of chemical elements to the pathophysiology of PD was shown.

  12. Dissociable effects of disconnecting amygdala central nucleus from the ventral tegmental area or substantia nigra on learned orienting and incentive motivation

    PubMed Central

    El-Amamy, Heather; Holland, Peter C.

    2010-01-01

    Recent evidence suggests that the amygdala central nucleus (CeA) and midbrain-striatal dopamine systems are critically involved in the alteration of attentional and emotional processing of initially neutral stimuli by associative learning. In rats, the acquisition of learned orienting responses to visual cues paired with food is impaired by lesions of the CeA, and by lesions that disconnect CeA from the dorsolateral striatum, a region traditionally implicated in elevated responsiveness to sensory stimuli. Similarly, the acquisition of emotional significance to cues paired with food also depends on the function of CeA and of the ventral striatal nucleus accumbens, a region often considered crucial to acquired reward and motivation. For example, the ability of a cue previously paired with food to increase the rate of food-reinforced instrumental responding (Pavlovian-instrumental transfer) is eliminated by lesions of the CeA or the accumbens core. In this experiment, we found that lesions that functionally disconnected CeA from the substantia nigra pars compacta impaired the acquisition of conditioned orienting to auditory cues paired with food, but had no effect on their ability to enhance instrumental responding, relative to the effects of unilateral lesions of that region. By contrast, lesions that disconnected CeA from the ventral tegmental area had no effect on the acquisition of conditioned orienting, but facilitated Pavlovian-instrumental transfer relative to unilateral midbrain lesions, rescuing that function to sham-lesion control levels. Otherwise, unilateral lesions of either midbrain region impaired transfer. Implications of these results for circuit models of amygdalo-striatal interactions in associative learning are discussed. PMID:17425582

  13. Nifedipine and nimodipine protect dopaminergic substantia nigra neurons against axotomy-induced cell death in rat vibrosections via modulating inflammatory responses

    PubMed Central

    Daschil, Nina; Humpel, Christian

    2015-01-01

    Neurodegeneration of cholinergic and dopaminergic neurons is a major hallmark in Alzheimer’s or Parkinson’s disease, respectively. A dysregulation in calcium homeostasis may be part of this process and counteracting calcium influx may have neuroprotective properties in both diseases. Therefore, we investigated the putative neuroprotective or neurotoxic activity of L-type calcium channel (LTCC) inhibitors on cholinergic and dopaminergic neurons in a rat organotypic vibrosection model. Sagittal or coronal vibrosections (200 μm thick) of postnatal day 10 rats were cultured on 0.4 μm semipermeable membranes for 2 weeks with 10 ng/ml nerve growth factor (NGF) and/or glial-cell line derived neurotrophic factor (GDNF) to maintain survival of cholinergic or dopaminergic neurons, respectively. Thereafter, sections were incubated with 0.1, 1 or 10 μM isradipine, nicardipine or verapamil for 2 weeks to explore cytotoxicity. Alternatively, in order to explore neuroprotective activity, vibrosections were incubated without growth factors but with isradipine or verapamil or with nicardipine, nimodipine or nifedipine from the beginning for 4 weeks. Our data show that all LTCC inhibitors exhibited no neurotoxic effect on cholinergic and dopaminergic neurons. Further, LTCC inhibitors did not have any neuroprotective activity on cholinergic neurons. However, nimodipine and nifedipine significantly enhanced the survival of dopaminergic substantia nigra (SN) but not ventral tegmental area (VTA) neurons, while nicardipine, isradipine and verapamil had no effect. Nifedipine (and more potently GDNF) reduced inflammatory cytokines (macrophage inflammatory protein-2, tumor necrosis factor-α), but did not influence oxidative stress or caspase-3 activity and did not interfere with iron-mediated overload. Our data show that nifedipine and nimodipine are very potent to enhance the survival of axotomized SN neurons, possibly influencing inflammatory processes. PMID:25038562

  14. Comparative Ultrastructural Analysis of D1 and D5 Dopamine Receptor Distribution in the Substantia Nigra and Globus Pallidus of Monkeys

    PubMed Central

    Kliem, Michele A.; Pare, Jean-Francois; Khan, Zafar U.; Wichmann, Thomas; Smith, Yoland

    2009-01-01

    Dopamine acts through the D1-like (D1, D5) and D2-like (D2, D3, D4) receptor families. Various studies have shown a preponderance of presynaptic dopamine D1 receptors on axons and terminals in the internal globus pallidus (GPi) and substantia nigra reticulata (SNr), but little is known about D5 receptors distribution in these brain regions. In order to further characterize the potential targets whereby dopamine could mediate its effects in basal ganglia output nuclei, we undertook a comparative electron microscopic analysis of D1 and D5 receptors immunoreactivity in the GPi and SNr of rhesus monkeys. At the light microscopic level, D1 receptor labeling was confined to small punctate elements, while D5 receptor immunoreactivity was predominantly expressed in cellular and dendritic processes throughout the SNr and GPi. At the electron microscopic level, 90% of D1 receptor labeling was found in unmyelinated axons or putative GABAergic terminals in both basal ganglia output nuclei. In contrast, D5 receptor labeling showed a different pattern of distribution. Although the majority (65−75%) of D5 receptor immunoreactivity was also found in unmyelinated axons and terminals in GPi and SNr, significant D5 receptor immunolabeling was also located in dendritic and glial processes. Immunogold studies showed that about 50% of D1 receptor immunoreactivity in axons was bound to the plasma membrane providing functional sites for D1 receptor-mediated effects on transmitter release in GPi and SNr. These findings provide evidence for the existence of extrastriatal pre- and post-synaptic targets through which dopamine and drugs acting at D1-like receptors may regulate basal ganglia outflow and possibly exert some of their anti-parkinsonian effects. PMID:19750130

  15. Evaluation of GAD67 immunoreactivity in the region of substantia nigra pars reticulata in resistance to development of convulsive seizure in genetic absence epilepsy rats

    PubMed Central

    Gulcebi, Medine; Akman, Ozlem; Carcak, Nihan; Karamahmutoglu, Tugba; Onat, Filiz

    2016-01-01

    OBJECTIVE: Nonconvulsive absence epilepsy and convulsive epilepsy seizures are rarely seen in the same patient. It has been demonstrated that there is a resistance to development of convulsive seizures in genetic absence epilepsy models. The present study investigated glutamic acid decarboxylase (GAD) immunoreactivity in the brain region related to the interaction of these two seizure types, namely substantia nigra pars reticulata (SNR) subregions, SNRanterior and SNRposterior. METHODS: Nonepileptic adult male Wistar rats and Genetic Absence Epilepsy Rats from Strasbourg (GAERS) were used. Experimental groups of Wistar and GAERS were electrically stimulated for kindling model to induce convulsive epileptic seizures. An electrical stimulation cannula was stereotaxically implanted to the basolateral amygdala and recording electrodes were placed on the cortex. Sagittal sections of SNR were used to evaluate immunohistochemical reaction. Sections were incubated with anti-GAD67 antibody. Densitometric analysis of GAD67 immunoreactive neurons was performed using photographs of stained sections. One-way analysis of variance and post hoc Bonferroni test were used for statistical analysis of the data. RESULTS: There was no difference in GAD67 immunoreactivity of SNR subregions of control Wistar and control GAERS. An increase in GAD67 immunoreactivity was detected in SNRposterior subregion of stimulated Wistar rats, whereas there was a decrease in GAD67 immunoreactivity in SNRposterior of stimulated GAERS. The difference in GAD67 immunoreactivity between these two groups was statistically significant. CONCLUSION: Level of synthetized gamma-aminobutyric acid in SNRposterior subregion plays an important role in the interaction of nonconvulsive absence epilepsy seizures and convulsive epilepsy seizures. PMID:28275746

  16. Embryonic substantia nigra grafts in the mesencephalon send neurites to the host striatum in non-human primate after overexpression of GDNF.

    PubMed

    Redmond, D E; Elsworth, J D; Roth, R H; Leranth, C; Collier, T J; Blanchard, B; Bjugstad, K B; Samulski, R J; Aebischer, P; Sladek, J R

    2009-07-01

    In spite of partial success in treating Parkinson's disease by using ectopically placed grafts of dopamine-producing cells, restoration of the original neuroanatomical circuits, if possible, might work better. Previous evidence of normal anatomic projections from ventral mesencephalic (VM) grafts placed in the substantia nigra (SN) has been limited to neonatal rodents and double grafting or bridging procedures. This study attempted to determine whether injection of a potent growth-promoting factor, glial cell line-derived neurotrophic factor (GDNF), into the target regions or placement of fetal striatal co-grafts in the nigrostriatal pathway might elicit neuritic outgrowth to the caudate nucleus. Four adult St. Kitts green monkeys received embryonic VM grafts into the rostral mesencephalon near the host SN, and injections of adeno-associated virus 2 (AAV2)/GDNF or equine infectious anemia virus (EIAV)/GDNF into the caudate. Three adult monkeys were co-grafted with fetal VM tissue near the SN and fetal striatal grafts (STR) 2.5 mm rostral in the nigrostriatal pathway. Before sacrifice, the striatal target regions were injected with the retrograde tracer Fluoro-Gold (FG). FG label was found in tyrosine hydroxylase-labeled neurons in VM grafts in the SN of only those monkeys that received AAV2/GDNF vector injections into the ipsilateral striatum. All monkeys showed FG labeling in the host SN when FG labeling was injected on the same side. These data show that grafted dopaminergic neurons can extend neurites to a distant target releasing an elevated concentration of GDNF, and suggest that grafted neurons can be placed into appropriate loci for potential tract reconstruction. Copyright 2009 Wiley-Liss, Inc.

  17. Dopamine D4 receptor stimulation in GABAergic projections of the globus pallidus to the reticular thalamic nucleus and the substantia nigra reticulata of the rat decreases locomotor activity.

    PubMed

    Erlij, David; Acosta-García, Jacqueline; Rojas-Márquez, Martín; González-Hernández, Brenda; Escartín-Perez, Erick; Aceves, Jorge; Florán, Benjamín

    2012-02-01

    Dopamine D4 receptors are localized in the GABAergic projections that globus pallidus (GP) neurons send to the reticular nucleus of the thalamus (RTN), the substantia nigra reticulata (SNr) and the subthalamic nucleus (STN). Deficient D4 function in this network could lead to hyperactivity and thus be important in generating some of the symptoms of ADHD (attention deficit hyperactivity disorder), a condition associated with polymorphisms of dopamine D4 receptors. It is then, unexpected that systemic injections of D4 ligands have no significant effects on the motor activity of normal rats. We further examined this issue by microinjecting D4 ligands and psychostimulant drugs in relevant structures. Interstitial dopamine overflow in the RTN was increased by reverse microdialysis of both methylphenidate and methamphetamine. Intranuclear injections in the RTN of methylphenidate, methamphetamine and the selective D4 agonist PD 168,077 reduced motor activity. Intraperitoneal injection of the D4 antagonist L 745,870 blocked the effects of these intranuclear injections. Similarly, intranuclear injections of PD 168,077 in the SNr inhibited motor activity, an effect that was also blocked by intraperitoneal L 745,870. In rats with 6-OHDA induced hemiparkinsonism, intraperitoneal PD 168,077 produced ipsilateral turning behavior that was blocked by L 745,870. Our results suggest that diminished D4 signaling in GP projections could lead to increased traffic through the relay nuclei of the thalamus and hyperactivity. Hence this basal-ganglia-thalamus network may be one of the targets of the beneficial effects that psychostimulant drugs have in disorders associated with D4 receptor abnormalities. This article is part of a Special Issue entitled 'Post-Traumatic Stress Disorder'.

  18. Dopaminergic D2 receptor is a key player in the substantia nigra pars compacta neuronal activation mediated by REM sleep deprivation.

    PubMed

    Proença, Mariana B; Dombrowski, Patrícia A; Da Cunha, Claudio; Fischer, Luana; Ferraz, Anete C; Lima, Marcelo M S

    2014-01-01

    Currently, several studies addresses the novel link between sleep and dopaminergic neurotransmission, focusing most closely on the mechanisms by which Parkinson's disease (PD) and sleep may be intertwined. Therefore, variations in the activity of afferents during the sleep cycles, either at the level of DA cell bodies in the ventral tegmental area (VTA) and/or substantia nigra pars compacta (SNpc) or at the level of dopamine (DA) terminals in limbic areas may impact functions such as memory. Accordingly, we performed striatal and hippocampal neurochemical quantifications of DA, serotonin (5-HT) and metabolites of rats intraperitoneally treated with haloperidol (1.5 mg/kg) or piribedil (8 mg/kg) and submitted to REM sleep deprivation (REMSD) and sleep rebound (REB). Also, we evaluated the effects of REMSD on motor and cognitive parameters and SNpc c-Fos neuronal immunoreactivity. The results indicated that DA release was strongly enhanced by piribedil in the REMSD group. In opposite, haloperidol prevented that alteration. A c-Fos activation characteristic of REMSD was affected in a synergic manner by piribedil, indicating a strong positive correlation between striatal DA levels and nigral c-Fos activation. Hence, we suggest that memory process is severely impacted by both D2 blockade and REMSD and was even more by its combination. Conversely, the activation of D2 receptor counteracted such memory impairment. Therefore, the present evidence reinforce that the D2 receptor is a key player in the SNpc neuronal activation mediated by REMSD, as a consequence these changes may have direct impact for cognitive and sleep abnormalities found in patients with PD. This article is part of the Special Issue entitled 'The Synaptic Basis of Neurodegenerative Disorders'. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. [The effects of lesions in the compact part of the substantia nigra on glutamate and GABA release in the pedunculopontine nucleus].

    PubMed

    Blanco-Lezcano, L; Rocha-Arrieta, L L; Alvarez-González, L; Martínez-Martí, L; Pavón-Fuentes, N; González-Fraguela, M E; Bauzá-Calderín, Y; Coro-Grave de Peralta, Y

    The pedunculopontine nucleus (PPN), co-localized with the mesencephalic locomotor region, has been proposed as a key structure in the physiopathology of Parkinson's disease. The goal of the present study was to assess if the aminoacid neurotransmitter release in the PPN is modified by the degeneration of dopaminergic cells, from substantia nigra pars compacta in 6-hydroxidopamine (6-OHDA)-lesioned rats. In addition, it was studied the aminoacid neurotransmitter release in the PPN of rats with lesion of the subthalamic nucleus by quinolinic acid (QUIN) (100 nmol) intracerebral injection. Rats were assigned to five groups: untreated rats (I) (n = 13), 6-OHDA lesion (II) (n = 11), 6-OHDA + QUIN lesion (III) (n = 9), sham-operated (IV) (n = 10), QUIN, STN (V) lesioned (n = 9). The extracellular concentrations of glutamic acid (GLU) and gamma-aminobutyric acid (GABA) were determined by brain microdialysis and high performance liquid chromatography (HPLC). RESULTS. GLU released in PPN from 6-OHDA lesioned rats (group II), was significantly increased in comparison with the others groups (F(4, 47) = 18.21, p < 0.001). GABA released shows significant differences between experimental groups (F(4, 45) = 12.75, p < 0.001). It was detected a higher valour (p < 0.05) in-group II. The groups III and IV exhibited intermeddle valour (p < 0.001) and groups I and IV (p < 0.001) showed the lower GABA extracellular concentrations. The infusion of artificial cerebrospinal fluid with higher potassium (100 mmol) induced an increase in the GLU and GABA released in all groups, which confirm the neuronal origin of the extracellular content. These results are in agreement with the current model of basal ganglia functioning and suggest the role of STN-PPN projection in the physiopathology of Parkinson's disease.

  20. Mu opioid receptor knockdown in the substantia nigra/ventral tegmental area by synthetic small interfering RNA blocks the rewarding and locomotor effects of heroin

    PubMed Central

    Zhang, Yong; Landthaler, Markus; Schlussman, Stefan D.; Yuferov, Vadim; Ho, Ann; Tuschl, Thomas; Kreek, Mary Jeanne

    2014-01-01

    Mu opioid receptors (MOP-r) play an important role in the rewarding and locomotor stimulatory effects of heroin. The aim of the current study was to determine whether infusion of small interfering RNAs (siRNA) targeting MOP-r into the midbrain could knock down MOP-r mRNA and affect heroin-induced locomotor activity or heroin-induced conditioned place preference. Ten week old male C57BL/6J mice were surgically implanted bilaterally with guide cannulae directed between the substantia nigra and ventral tegmental area. After 4 days recovery, mice were infused bilaterally with siRNAs that target the MOP-r (2mM × 0.75 μl/side/day for 3 days) or control siRNA. Seven days after the last infusion, a procedure for conditioned place preference was begun with four heroin (3mg/kg i.p.) administration sessions alternating with four saline sessions. While heroin induced an increase in locomotor activity in all groups, siRNAs targeting specific regions of MOP-r significantly attenuated this effect. Of particular interest, mice infused with specific siRNAs targeting the MOP-r failed to develop and express conditioned place preference to heroin, or showed a significantly attenuated preference. These alterations in reward related behaviors are likely due to the reduction in MOP-r mRNA and protein, shown in separate studies by in situ hybridization and autoradiography using the same MOP-r- siRNA infusions. Taken together, these studies demonstrate the utility of siRNA in the neurobiological study of specific components of the reward system and should contribute to the study of other complex behaviors. PMID:18938225

  1. Adolescent exposure to MDMA induces dopaminergic toxicity in substantia nigra and potentiates the amyloid plaque deposition in the striatum of APPswe/PS1dE9 mice.

    PubMed

    Abad, Sonia; Ramon, Carla; Pubill, David; Camarasa, Jorge; Camins, Antonio; Escubedo, Elena

    2016-09-01

    MDMA is one of the most used drugs by adolescents and its consumption has been associated with many psychobiological problems, among them psychomotor problems. Moreover, some authors described that early exposure to MDMA may render the dopaminergic neurons more vulnerable to the effects of future neurotoxic insults. Alzheimer disease (AD) is the main cause of dementia in the elderly and a percentage of the patients have predisposition to suffer nigrostriatal alterations, developing extrapyramidal signs. Nigrostriatal dysfunction in the brain of aged APPswe/PS1dE9 (APP/PS1), a mouse model of familiar AD (FAD), has also been described. The aim of the present study was to investigate the consequences of adolescent exposure to MDMA in APP/PS1 mice, on nigrostriatal function on early adulthood. We used a MDMA schedule simulating weekend binge abuse of this substance. Our MDMA schedule produced a genotype-independent decrease in dopaminergic neurons in the substantia nigra that remained at least 3months. Shortly after the injury, wild-type animals showed a decrease in the locomotor activity and apparent DA depletion in striatum, however in the APP/PS1 mice neither the locomotor activity nor the DA levels were modified, but a reduction in dopamine transporter (DAT) expression and a higher levels of oxidative stress were observed. We found that these disturbances are age-related characteristics that this APP/PS1 mice develops spontaneously much later. Therefore, MDMA administration seems to anticipate the striatal dopaminergic dysfunction in this FAD model. The most important outcome lies in a potentiation, by MDMA, of the amyloid beta deposition in the striatum. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. MPTP and DSP-4 susceptibility of substantia nigra and locus coeruleus catecholaminergic neurons in mice is independent of parkin activity

    PubMed Central

    Thomas, Bobby; von Coelln, Rainer; Mandir, Allen S.; Trinkaus, Daniel B.; Farah, Mohamed H.; Lim, Kah Leong; Calingasan, Noel Y.; Beal, M. Flint; Dawson, Valina L.; Dawson, Ted M.

    2007-01-01

    Mutations in the parkin gene cause autosomal recessive familial Parkinson’s disease (PD). Parkin-deficient mouse models fail to recapitulate nigrostriatal dopaminergic neurodegeneration as seen in PD, but produce deficits in dopaminergic neurotransmission and noradrenergic-dependent behavior. Since sporadic PD is thought to be caused by a combination of genetic susceptibilities and environmental factors, we hypothesized that neurotoxic insults from catecholaminergic toxins would render parkin knockout mice more vulnerable to neurodegeneration. Accordingly, we investigated the susceptibility of catecholaminergic neurons in parkin knockout mice to the potent dopaminergic and noradrenergic neurotoxins 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4) respectively. We report that nigrostriatal dopaminergic neurons in parkin knockout mice do not show increased susceptibility to the parkinsonian neurotoxin, MPTP, in acute, subacute and chronic dose regimens of the neurotoxin. Additionally, parkin knockout mice do not show increased vulnerability to the noradrenergic neurotoxin, DSP-4, regarding levels of norepinephrine in cortex, brain stem and spinal cord. These findings suggest that absence of parkin in mice does not increase susceptibility to the loss of catecholaminergic neurons upon exposure to both dopaminergic and noradrenergic neurotoxins. PMID:17336077

  3. Mice lacking the peroxisome proliferator-activated receptor α gene present reduced number of dopamine neurons in the substantia nigra without altering motor behavior or dopamine neuron decline over life.

    PubMed

    Gonzalez-Aparicio, R; Flores, J A; Tasset, I; Tunez, I; Fernandez-Espejo, E

    2011-07-14

    Peroxisome proliferator-activated receptor alpha (PPAR-α), which is expressed by neurons of the nigrostriatal circuit, plays a prominent role in oxidative stress and neuroinflammation. The objectives were: (i) to discern if levels of antioxidant molecules and pro-inflammatory cytokines, along with PPAR-γ expression are modified in the nigrostriatal region of null PPAR-α mice, (ii) to discern whether dopaminergic neuronal features of the substantia nigra pars compacta (SNpc) and dorsal striatum are affected in null mice, and (iii) to establish if aging-induced decline of nigral neurons is different in null PPAR-α mice relative to wild-type littermates. A substantial decrease in antioxidant molecules was found in SNpc of null mice, by using ELISA. The pro-inflammatory factors TNF-α and IL-3 were found to be reduced in the substantia nigra, suggesting dual and opposite effects of PPAR-α deficiency on oxidative and pro-inflammatory molecules. Immunohistological and stereological studies revealed that young null mice present a smaller SNpc (-19.8%; TH downregulation was discarded). Normal locomotion in an open-field was not affected in null mice. Dopamine cell death could be caused by reduced protection against oxidative stress. Old null mice showed a percentage reduction of nigral dopamine neurons similar to that of young null animals, with a rate of decline over life of around 44%, the same value than that of wild-type littermates. These findings suggest that nuclear PPAR-α is necessary for the normal development of the substantia nigra along with normal levels of antioxidant molecules. Lack of PPAR-α does not modify the normal motor behavior of mice or decline of nigral dopamine neurons throughout life. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

  4. Pharmacokinetic, neurochemical, stereological and neuropathological studies on the potential effects of paraquat in the substantia nigra pars compacta and striatum of male C57BL/6J mice.

    PubMed

    Breckenridge, Charles B; Sturgess, Nicholas C; Butt, Mark; Wolf, Jeffrey C; Zadory, Dan; Beck, Melissa; Mathews, James M; Tisdel, Merrill O; Minnema, Daniel; Travis, Kim Z; Cook, Andrew R; Botham, Philip A; Smith, Lewis L

    2013-07-01

    The pharmacokinetics and neurotoxicity of paraquat dichloride (PQ) were assessed following once weekly administration to C57BL/6J male mice by intraperitoneal injection for 1, 2 or 3 weeks at doses of 10, 15 or 25 mg/kg/week. Approximately 0.3% of the administered dose was taken up by the brain and was slowly eliminated, with a half-life of approximately 3 weeks. PQ did not alter the concentration of dopamine (DA), homovanillic acid (HVA) or 3,4-dihydroxyphenylacetic acid (DOPAC), or increase dopamine turnover in the striatum. There was inconsistent stereological evidence of a loss of DA neurons, as identified by chromogenic or fluorescent-tagged antibodies to tyrosine hydroxylase in the substantia nigra pars compacta (SNpc). There was no evidence that PQ induced neuronal degeneration in the SNpc or degenerating neuronal processes in the striatum, as indicated by the absence of uptake of silver stain or reduced immunolabeling of tyrosine-hydroxylase-positive (TH(+)) neurons. There was no evidence of apoptotic cell death, which was evaluated using TUNEL or caspase 3 assays. Microglia (IBA-1 immunoreactivity) and astrocytes (GFAP immunoreactivity) were not activated in PQ-treated mice 4, 8, 16, 24, 48, 96 or 168 h after 1, 2 or 3 doses of PQ. In contrast, mice dosed with the positive control substance, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP; 10mg/kg/dose×4 doses, 2 h apart), displayed significantly reduced DA and DOPAC concentrations and increased DA turnover in the striatum 7 days after dosing. The number of TH(+) neurons in the SNpc was reduced, and there were increased numbers of degenerating neurons and neuronal processes in the SNpc and striatum. MPTP-mediated cell death was not attributed to apoptosis. MPTP activated microglia and astrocytes within 4 h of the last dose, reaching a peak within 48 h. The microglial response ended by 96 h in the SNpc, but the astrocytic response continued through 168 h in the striatum. These results bring into

  5. Assessment of the Effects of MPTP and Paraquat on Dopaminergic Neurons and Microglia in the Substantia Nigra Pars Compacta of C57BL/6 Mice

    PubMed Central

    Smeyne, Richard Jay; Breckenridge, Charles B.; Beck, Melissa; Jiao, Yun; Butt, Mark T.; Wolf, Jeffrey C.; Zadory, Dan; Minnema, Daniel J.; Sturgess, Nicholas C.; Travis, Kim Z.; Cook, Andrew R.; Smith, Lewis L.; Botham, Philip A.

    2016-01-01

    The neurotoxicity of paraquat dichloride (PQ) was assessed in two inbred strains of 9- or 16-week old male C57BL/6 mice housed in two different laboratories and compared to the effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). PQ was administered by intraperitoneal injections; either once (20 mg/kg) or twice (10 mg/kg) weekly for 3 weeks, while MPTP-HCl was injected 4 times on a single day (20 mg/kg/dose). Brains were collected 8, 16, 24, 48, 96 or 168 hours after the last PQ treatment, and 48 or 168 hours after MPTP treatment. Dopamine neurons in the substantia nigra pars compacta (SNpc) were identified by antibodies to tyrosine hydroxylase (TH+) and microglia were identified using Iba-1 immunoreactivity. The total number of TH+ neurons and the number of resting and activated microglia in the SNpc at 168 hours after the last dose were estimated using model- or design-based stereology, with investigators blinded to treatment. In a further analysis, a pathologist, also blinded to treatment, evaluated the SNpc and/or striatum for loss of TH+ neurons (SNpc) or terminals (striatum), cell death (as indicated by amino cupric silver uptake, TUNEL and/or caspase 3 staining) and neuroinflammation (as indicated by Iba-1 and/or GFAP staining). PQ, administered either once or twice weekly to 9- or 16-week old mice from two suppliers, had no effect on the number of TH+ neurons or microglia in the SNpc, as assessed by two groups, each blinded to treatment, using different stereological methods. PQ did not induce neuronal cell loss or degeneration in the SNpc or striatum. Additionally, there was no evidence of apoptosis, microgliosis or astrogliosis. In MPTP-treated mice, the number of TH+ neurons in the SNpc was significantly decreased and the number of activated microglia increased. Histopathological assessment found degenerating neurons/terminals in the SNpc and striatum but no evidence of apoptotic cell death. MPTP activated microglia in the SNpc and increased

  6. Assessment of the Effects of MPTP and Paraquat on Dopaminergic Neurons and Microglia in the Substantia Nigra Pars Compacta of C57BL/6 Mice.

    PubMed

    Smeyne, Richard Jay; Breckenridge, Charles B; Beck, Melissa; Jiao, Yun; Butt, Mark T; Wolf, Jeffrey C; Zadory, Dan; Minnema, Daniel J; Sturgess, Nicholas C; Travis, Kim Z; Cook, Andrew R; Smith, Lewis L; Botham, Philip A

    2016-01-01

    The neurotoxicity of paraquat dichloride (PQ) was assessed in two inbred strains of 9- or 16-week old male C57BL/6 mice housed in two different laboratories and compared to the effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). PQ was administered by intraperitoneal injections; either once (20 mg/kg) or twice (10 mg/kg) weekly for 3 weeks, while MPTP-HCl was injected 4 times on a single day (20 mg/kg/dose). Brains were collected 8, 16, 24, 48, 96 or 168 hours after the last PQ treatment, and 48 or 168 hours after MPTP treatment. Dopamine neurons in the substantia nigra pars compacta (SNpc) were identified by antibodies to tyrosine hydroxylase (TH+) and microglia were identified using Iba-1 immunoreactivity. The total number of TH+ neurons and the number of resting and activated microglia in the SNpc at 168 hours after the last dose were estimated using model- or design-based stereology, with investigators blinded to treatment. In a further analysis, a pathologist, also blinded to treatment, evaluated the SNpc and/or striatum for loss of TH+ neurons (SNpc) or terminals (striatum), cell death (as indicated by amino cupric silver uptake, TUNEL and/or caspase 3 staining) and neuroinflammation (as indicated by Iba-1 and/or GFAP staining). PQ, administered either once or twice weekly to 9- or 16-week old mice from two suppliers, had no effect on the number of TH+ neurons or microglia in the SNpc, as assessed by two groups, each blinded to treatment, using different stereological methods. PQ did not induce neuronal cell loss or degeneration in the SNpc or striatum. Additionally, there was no evidence of apoptosis, microgliosis or astrogliosis. In MPTP-treated mice, the number of TH+ neurons in the SNpc was significantly decreased and the number of activated microglia increased. Histopathological assessment found degenerating neurons/terminals in the SNpc and striatum but no evidence of apoptotic cell death. MPTP activated microglia in the SNpc and increased

  7. Usefulness of Cardiac MIBG Scintigraphy, Olfactory Testing and Substantia Nigra Hyperechogenicity as Additional Diagnostic Markers for Distinguishing between Parkinson’s Disease and Atypical Parkinsonian Syndromes

    PubMed Central

    Fujita, Hiroaki; Numao, Ayaka; Watanabe, Yuji; Uchiyama, Tomoyuki; Miyamoto, Tomoyuki; Miyamoto, Masayuki; Hirata, Koichi

    2016-01-01

    Background We aimed to evaluate the utility of the combined use of cardiac 123I-metaiodobenzylguanidine (MIBG) scintigraphy, olfactory testing, and substantia nigra (SN) hyperechogenicity on transcranial sonography (TCS) in differentiating Parkinson’s disease (PD) from atypical parkinsonian syndromes (APSs), such as multiple system atrophy (MSA) and progressive supranuclear palsy (PSP). Methods Cardiac MIBG scintigraphy, card-type odor identification testing (Open Essence (OE), Wako, Japan), and TCS were performed with 101 patients with PD and 38 patients with APSs (MSA and PSP). Receiver operating characteristic (ROC) curve analysis was used to assess the sensitivity and specificity of these batteries for diagnosing PD from APSs. The diagnostic accuracy of the three tests was also assessed among patients at the early disease stage (drug-naïve patients with a disease duration of 3 years or less). Results In differentiating PD from APSs, the area under the ROC curve was 0.74 (95% CI, 0.65–0.83), 0.8 (95% CI, 0.73–0.87), and 0.75 (95% CI, 0.67–0.82) for TCS, cardiac MIBG scintigraphy, and olfactory testing, respectively. The diagnostic sensitivity and specificity were 53.1% and 91.7%, respectively, for TCS, 70.3% and 86.8%, respectively, for cardiac MIBG scintigraphy, 58.4% and 76.3%, respectively, for OE. Among early-stage patients, sensitivity and specificity were 50.0% and 93.8%, respectively, for TCS, 57.1% and 87.5%, respectively, for cardiac MIBG scintigraphy, and 54.8% and 79.2%, respectively, for OE. At least one positive result from 3 tests improved sensitivity (86.1%) but decreased specificity (63.2%). In contrast, at least 2 positive results from 3 tests had good discrimination for both early-stage patients (50.0% sensitivity and 93.8% specificity) and patients overall (57.8% sensitivity and 95.8% specificity). Positive results for all 3 tests yielded 100% specificity but low sensitivity (25%). Conclusions At least 2 positive results from among

  8. Neurometabolic profiles of the substantia nigra and striatum of MPTP-intoxicated common marmosets: An in vivo proton MRS study at 9.4 T.

    PubMed

    Heo, Hwon; Ahn, Jae-Bum; Lee, Hyeong Hun; Kwon, Euna; Yun, Jun-Won; Kim, Hyeonjin; Kang, Byeong-Cheol

    2017-02-01

    Given the strong coupling between the substantia nigra (SN) and striatum (STR) in the early stage of Parkinson's disease (PD), yet only a few studies reported to date that have simultaneously investigated the neurochemistry of these two brain regions in vivo, we performed longitudinal metabolic profiling in the SN and STR of 1-methyl-1,2,3,6-tetrahydropyridine (MPTP)-intoxicated common marmoset monkey models of PD (n = 10) by using proton MRS ((1) H-MRS) at 9.4 T. T2 relaxometry was also performed in the SN by using MRI. Data were classified into control, MPTP_2weeks, and MPTP_6-10 weeks groups according to the treatment duration. In the SN, T2 of the MPTP_6-10 weeks group was lower than that of the control group (44.33 ± 1.75 versus 47.21 ± 2.47 ms, p < 0.05). The N-acetylaspartate to total creatine ratio (NAA/tCr) and γ-aminobutyric acid to tCr ratio (GABA/tCr) of the MPTP_6-10 weeks group were lower than those of the control group (0.41 ± 0.04 versus 0.54 ± 0.08 (p < 0.01) and 0.19 ± 0.03 versus 0.30 ± 0.09 (p < 0.05), respectively). The glutathione to tCr ratio (GSH/tCr) was correlated with T2 for the MPTP_6-10 weeks group (r = 0.83, p = 0.04). In the STR, however, GABA/tCr of the MPTP_6-10 weeks group was higher than that of the control group (0.25 ± 0.10 versus 0.16 ± 0.05, p < 0.05). These findings may be an in vivo depiction of the altered basal ganglion circuit in PD brain resulting from the degeneration of nigral dopaminergic neurons and disruption of nigrostriatal dopaminergic projections. Given the important role of non-human primates in translational studies, our findings provide better understanding of the complicated evolution of PD.

  9. Altered Expression Patterns of Inflammation-Associated and Trophic Molecules in Substantia Nigra and Striatum Brain Samples from Parkinson's Disease, Incidental Lewy Body Disease and Normal Control Cases

    PubMed Central

    Walker, Douglas G.; Lue, Lih-Fen; Serrano, Geidy; Adler, Charles H.; Caviness, John N.; Sue, Lucia I.; Beach, Thomas G.

    2016-01-01

    Evidence of inflammation has been consistently associated with pathology in Parkinson's disease (PD)-affected brains, and has been suggested as a causative factor. Dopaminergic neurons in the substantia nigra (SN) pars compacta, whose loss results in the clinical symptoms associated with PD, are particularly susceptible to inflammatory damage and oxidative stress. Inflammation in the striatum, where SN dopaminergic neurons project, is also a feature of PD brains. It is not known whether inflammatory changes occur first in striatum or SN. Many animal models of PD have implicated certain inflammatory molecules with dopaminergic cell neuronal loss; however, there have been few studies to validate these findings by measuring the levels of these and other inflammatory factors in human PD brain samples. This study also included samples from incidental Lewy body disease (ILBD) cases, since ILBD is considered a non-symptomatic precursor to PD, with subjects having significant loss of tyrosine hydroxylase-producing neurons. We hypothesized that there may be a progressive change in key inflammatory factors in ILBD samples intermediate between neurologically normal and PD. To address this, we used a quantitative antibody-array platform (Raybiotech-Quantibody arrays) to measure the levels of 160 different inflammation-associated cytokines, chemokines, growth factors, and related molecules in extracts of SN and striatum from clinically and neuropathologically characterized PD, ILBD, and normal control cases. Patterns of changes in inflammation and related molecules were distinctly different between SN and striatum. Our results showed significantly different levels of interleukin (IL)-5, IL-15, monokine induced by gamma interferon, and IL-6 soluble receptor in SN between disease groups. A different panel of 13 proteins with significant changes in striatum, with IL-15 as the common feature, was identified. Although the ability to detect some proteins was limited by sensitivity

  10. Evaluation of the effects of vitamin A supplementation on adult rat substantia nigra and striatum redox and bioenergetic states: mitochondrial impairment, increased 3-nitrotyrosine and alpha-synuclein, but decreased D2 receptor contents.

    PubMed

    de Oliveira, Marcos Roberto; Oliveira, Max William Soares; Behr, Guilherme Antônio; Hoff, Mariana Leivas Muller; da Rocha, Ricardo Fagundes; Moreira, José Cláudio Fonseca

    2009-03-17

    Vitamin A at moderate to high doses is applied in the treatment of some life threatening pathological conditions, for instance cancers. Additionally, vitamin A at low concentrations is a known antioxidant molecule. However, by increasing vitamin A (or its derivatives) concentrations, there is an increase in the levels of oxidative stress markers in several experimental models. Furthermore, it was reported that vitamin A therapy at high doses might induce cognitive decline among the patients, which may become anxious or depressive, for example, depending on vitamin A levels intake. We have previously reported increased levels of oxidative stress markers in rat substantia nigra and striatum. However, the mechanism by which this vitamin altered the redox environment in such rat brain regions remains to be elucidated. In the herein presented work, we have investigated the effects of vitamin A supplementation at clinical doses (1000-9000 IU/kg day(-1)) for 28 days on rat substantia nigra and striatum mitochondrial electron transfer chain (METC) activity, which may produce superoxide anion radical (O(2)(-*)) when impaired. Additionally, the levels of non-enzymatic antioxidant defenses were evaluated, as well as 3-nitrotyrosine, alpha- and beta-synucleins and TNF-alpha levels through ELISA assay. We observed impaired METC in both rat brain regions. Moreover, we found increased O(2)(-*) production and nitrotyrosine content in the nigrostriatal axis of vitamin A-treated rats, suggesting that the use of vitamin A at therapeutic doses may be rethought due to this toxic effects found here.

  11. Can secondary degeneration accelerate the formation of neurofibrillary tangles? A case of hemispheric infarction showing asymmetric degeneration of the substantia nigra, red nuclei, inferior olivary nuclei and dentate nuclei with concomitant changes of progressive supranuclear palsy.

    PubMed

    Matsumoto, R; Oda, M; Arai, N; Shin, T; Hayashi, M

    1999-02-01

    A case of hemispheric infarction involving the territory of the right middle cerebral artery and the thalamus showed conspicuous asymmetric degeneration in the substantia nigra, red nuclei, inferior olivary nuclei and dentate nuclei with concomitant changes of progressive supranuclear palsy (PSP). The right substantia nigra and red nucleus showed loss of neurons and proliferation of astrocytes. The right olivary nucleus was hypertrophic, while the neuronal loss and astrocytosis in the dentate nucleus were predominant on the contralateral side. Modified Gallyas-Braak staining revealed the extensive distribution of neurofibrillary tangles (NFTs), threads and intraglial argyrophilic structures in the globus pallidus, subthalamic nuclei, cerebral cortex and dentate nuclei, as well as in the affected brain stem nuclei, with a distinct predominance on the affected side. In this case, the one-sided predominance of the extended degeneration in these brain stem and cerebellar areas is considered, in addition to the PSP changes, to be due to secondary retrograde degeneration via the nigrostriatal and dentato-rubro-thalamic pathways following the hemispheric infarction, and to also be the result of disruption of the dentato-olivary fiber connections. In addition, because of the predominant distribution of NFTs on the more degenerated side, it is surmised that the formation of NFTs may be accelerated by secondary degeneration.

  12. A primate model of parkinsonism: selective destruction of dopaminergic neurons in the pars compacta of the substantia nigra by N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine.

    PubMed

    Burns, R S; Chiueh, C C; Markey, S P; Ebert, M H; Jacobowitz, D M; Kopin, I J

    1983-07-01

    A syndrome similar to idiopathic parkinsonism developed after intravenous self-administration of an illicit drug preparation in which N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (NMPTP) might have been responsible for the toxicity. In the present study we show that intravenous administration of NMPTP to the rhesus monkey produces a disorder like parkinsonism (akinesia, rigidity, postural tremor, flexed posture, eyelid closure, drooling) that is reversed by the administration of L-dopa. NMPTP treatment decreases the release of dopamine and dopamine accumulates in swollen, distorted axons in the nigrostriatal pathway just above the substantia nigra, followed by severe nerve cell loss in the pars compacta of the substantia nigra and a marked reduction in the dopamine content of the striatum. The pathological and biochemical changes produced by NMPTP are similar to the well-established changes in patients with parkinsonism. Thus, the NMPTP-treated monkey provides a model that can be used to examine mechanisms and explore therapies of parkinsonism.

  13. Iron and cell death in Parkinson's disease: a nuclear microscopic study into iron-rich granules in the parkinsonian substantia nigra of primate models

    NASA Astrophysics Data System (ADS)

    Thong, P. S. P.; Watt, F.; Ponraj, D.; Leong, S. K.; He, Y.; Lee, T. K. Y.

    1999-10-01

    Parkinson's disease is a degenerative brain disease characterised by a loss of cells in the substantia nigra (SN) region of the brain and accompanying biochemical changes such as inhibition of mitochondrial function, increased iron concentrations and decreased glutathione levels in the parkinsonian SN. Though the aetiology of the disease is still unknown, the observed biochemical changes point to the involvement of oxidative stress. In particular, iron is suspected to play a role by promoting free radical production, leading to oxidative stress and cell death. The increase in iron in the parkinsonian SN has been confirmed by several research groups, both in human post-mortem brains and in brain tissue from parkinsonian animal models. However, the question remains as to whether the observed increase in iron is a cause or a consequence of the SN cell death process. Our previous study using unilaterally 1-methyl-4-phenyl-1,2,3,6-tetrahydro-pyridine (MPTP)-lesioned monkeys in a time sequence experiment has shown that the increase in bulk iron concentrations follow rather than precede dopaminergic cell death. However, changes in the localised iron concentrations, which may play a more direct role in SN cell death, may not be reflected at the bulk level. Indeed, we have observed iron-rich granules in parkinsonian SNs. From this time sequence study into the iron content of iron-rich granules in the SNs of an untreated control and unilaterally MPTP-lesioned parkinsonian models, we present the following observations: (1) Iron-rich granules are found in both control and parkinsonian SNs and are variable in size and iron content in any one model. (2) These iron-rich granules may be associated with neuromelanin granules found in the SN and are known to accumulate transition metal ions such as iron. (3) The early onset of bulk SN cell loss (35%) was accompanied by a significant elevation of iron in granules found in the MPTP-injected SN compared to the contra-lateral SN. This

  14. Combining Diffusion Tensor Imaging and Susceptibility Weighted Imaging on the Substantia Nigra of 1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine (MPTP)-induced Rhesus Monkey Model of Parkinson's Disease

    PubMed Central

    Zhang, Q; Li, L; Miao, B; Niu, H

    2015-01-01

    ABSTRACT Objective: The aim of this study was to evaluate whether combining diffusion tensor magnetic resonance imaging (DTI) and susceptibility weighted imaging (SWI) techniques would provide a sensitive method for differentiating between 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced rhesus monkey model of Parkinson's disease (PD) and wild-type controls. Subjects and Methods: Seventeen rhesus monkeys were divided into two groups. A series of intramuscular injections of either saline (control group, n = 8) or MPTP (0.2 mg/kg body weight; PD group, n = 9) were given to the monkeys, twice a week. Then, SWI and DTI scans were obtained from the monkeys with Siemens Magnetom Verio 3.0T superconductive MRI system. Region of interest analysis was performed on substantia nigra pars compacta (SNc) and substantia nigra pars reticulata (SNr). In addition, immunohistochemical staining of tyrosine hydroxylase was applied to assess degeneration of SN dopaminergic neurons. Results: Monkeys in the PD group displayed mild to moderate motor symptoms assessed using Kurlan's scale. With SWI scans, decreased width of SNc but increased width of SNr was found in PD group monkeys compared to controls. Calculation of the ratios of widths of SNc and SNr to the anterior and posterior mesencephalic diameter also reflected narrower SNc but wider SNr than controls. Decreased SWI signal intensity of SNc and SNr suggested iron deposition in both subregions of SN. The DTI scans showed lower fractional anisotropy (FA) values in SNc of the PD group monkeys, while no change of FA values in SNr was detected. Immunohistochemical test displayed generalized loss of dopaminergic neurons in SN of PD group monkeys. Conclusion: Combining the use of DTI and SWI can provide a sensitive method for differentiating between MPTP-induced rhesus monkey model of PD and wild-type controls. This effective imaging modality might provide additional information for characteristic identification of PD at

  15. A glial cell line-derived neurotrophic factor-secreting clone of the Schwann cell line SCTM41 enhances survival and fiber outgrowth from embryonic nigral neurons grafted to the striatum and to the lesioned substantia nigra.

    PubMed

    Wilby, M J; Sinclair, S R; Muir, E M; Zietlow, R; Adcock, K H; Horellou, P; Rogers, J H; Dunnett, S B; Fawcett, J W

    1999-03-15

    We have developed a novel Schwann cell line, SCTM41, derived from postnatal sciatic nerve cultures and have stably transfected a clone with a rat glial cell line-derived neurotrophic factor (GDNF) construct. Coculture with this GDNF-secreting clone enhances in vitro survival and fiber growth of embryonic dopaminergic neurons. In the rat unilateral 6-OHDA lesion model of Parkinson's disease, we have therefore made cografts of these cells with embryonic day 14 ventral mesencephalic grafts and assayed for effects on dopaminergic cell survival and process outgrowth. We show that cografts of GDNF-secreting Schwann cell lines improve the survival of intrastriatal embryonic dopaminergic neuronal grafts and improve neurite outgrowth into the host neuropil but have no additional effect on amphetamine-induced rotation. We next looked to see whether bridge grafts of GDNF-secreting SCTM41 cells would promote the growth of axons to their striatal targets from dopaminergic neurons implanted orthotopically into the 6-OHDA-lesioned substantia nigra. We show that such bridge grafts increase the survival of implanted embryonic dopaminergic neurons and promote the growth of axons through the grafts to the striatum.

  16. Ventral tegmental area/substantia nigra and prefrontal cortex rodent organotypic brain slices as an integrated model to study the cellular changes induced by oxygen/glucose deprivation and reperfusion: effect of neuroprotective agents.

    PubMed

    Colombo, Laura; Parravicini, Chiara; Lecca, Davide; Dossi, Elena; Heine, Claudia; Cimino, Mauro; Wanke, Enzo; Illes, Peter; Franke, Heike; Abbracchio, Maria P

    2014-01-01

    Unveiling the roles of distinct cell types in brain response to insults is a partially unsolved challenge and a key issue for new neuroreparative approaches. In vivo models are not able to dissect the contribution of residential microglia and infiltrating blood-borne monocytes/macrophages, which are fundamentally undistinguishable; conversely, cultured cells lack original tissue anatomical and functional complexity, which profoundly alters reactivity. Here, we tested whether rodent organotypic co-cultures from mesencephalic ventral tegmental area/substantia nigra and prefrontal cortex (VTA/SN-PFC) represent a suitable model to study changes induced by oxygen/glucose deprivation and reperfusion (OGD/R). OGD/R induced cytotoxicity to both VTA/SN and PFC slices, with higher VTA/SN susceptibility. Neurons were highly affected, with astrocytes and oligodendrocytes undergoing very mild damage. Marked reactive astrogliosis was also evident. Notably, OGD/R triggered the activation of CD68-expressing microglia and increased expression of Ym1 and Arg1, two markers of "alternatively" activated beneficial microglia. Treatment with two well-known neuroprotective drugs, the anticonvulsant agent valproic acid and the purinergic P2-antagonist PPADS, prevented neuronal damage. Thus, VTA/SN-PFC cultures are an integrated model to investigate OGD/R-induced effects on distinct cells and easily screen neuroprotective agents. The model is particularly adequate to dissect the microglia phenotypic shift in the lack of a functional vascular compartment.

  17. 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.

  18. Beneficial effects of L-arginine on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced neuronal degeneration in substantia nigra of Balb/c mice

    PubMed Central

    Hami, Javad; Hosseini, Mehran; Nezhad, Saeed Vafaei; Shahi, Sekineh; Lotfi, Nassim; Ehsani, Hossein; Sadeghi, Akram

    2016-01-01

    Background: L-arginine has been recently investigated and proposed to reduce neurological damage after various experimental models of neuronal cellular damage. In this study, we aim to evaluate the beneficial effects of L-arginine administration on the numerical density of dark neurons (DNs) in the substantia nigra pars compacta (SNc) of Balb/c mice subjected to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) administration. Materials and Methods: Male Balb/c mice were randomly divided into 4 groups (n = 7 each): MPTP only; saline only (control); MPTP + L-arginine; and L-arginine only. The animals were infused intranasally with a single intranasal administration of the proneurotoxin MPTP (1 mg/nostril). L-arginine (300 mg/kg) was administrated intraperitoneally once daily for 1-week starting from 3 days after MPTP administration. Cavalieri principle method was used to estimate the numerical density of DNs in the SNc of different studied groups. Results: Twenty days following MPTP administration, the number of DNs was significantly increased when compared to sham-control and L-arginine-control groups (P < 0.05). Nevertheless, our results showed that L-arginine administration significantly decreased the numerical density of DNs in SNc of mice. Conclusion: This investigation provides new insights in experimental models of Parkinson’s disease, indicating that L-arginine represents a potential treatment agent for dopaminergic neuron degeneration in SNc observed in Parkinson’s disease patients. PMID:27656609

  19. Myelinated skin sensory neurons project extensively throughout adult mouse substantia gelatinosa.

    PubMed

    Boada, M Danilo; Woodbury, C Jeffery

    2008-02-27

    The substantia gelatinosa (SG) of the dorsal horn of the spinal cord is a recipient zone for unmyelinated sensory neurons in adults. Recent studies of the central anatomy of physiologically identified skin sensory neurons in neonatal mice have shown that this region also receives substantial inputs from a variety of myelinated afferents. The present experiments were performed to determine whether these neonatal inputs represent a transient phenotype that retracts from the SG. Studies were conducted in an in vivo spinal cord preparation from adult mice; thoracic levels were targeted to facilitate comparisons with previous in vitro findings. We show that the SG continues to receive substantial projections from myelinated skin sensory neurons throughout life. A large population of myelinated nociceptors conducting in the upper A delta and low A beta range maintained extensive projections throughout all areas of the SG well into adulthood; the latter gave rise to dorsally recurving "flame"-shaped arbors extending into the marginal layer that were identical to afferents described in neonates and after nerve injury in adult rats. Furthermore, exquisitely sensitive down hair follicle afferents projected throughout the inner half of the SG (i.e., lamina IIi) and sent dense clusters of terminals well into the outer SG (IIo), where they intermingled with those of unmyelinated nociceptors. Arguments are presented that the SG likely plays a predominant role in tactile processing under normal conditions, but that this role switches rapidly to nociceptive-only during environmental exigencies imposed by temperature extremes.

  20. The role of visual reafferents during a pointing movement: comparative study between open-loop and closed-loop performances in monkeys before and after unilateral electrolytic lesion of the substantia nigra.

    PubMed

    Viallet, F; Trouche, E; Beaubaton, D; Legallet, E

    1987-01-01

    In order to elucidate the compensatory role of visual feedback during movement, two experiments were designed to compare the motor performances of Papio papio baboons depending on whether the animals were able to visually control the limb trajectory (visual closed-loop condition) or not (visual open-loop condition). The visuomotor task used consisted of making trained pointing movements towards a stationary target. In experiment A, the baboons were successively presented with these two experimental conditions. The abolition of visual control was found to cause no change in either reaction time (RT) or movement time (MT), but brought about extensive pointing errors. It was also associated with a conspicuous increase in the mean velocity and the mean length of the trajectories. In experiment B, two groups of baboons were used. The monkeys in the first group were required to perform under closed loop conditions. The second group performed the pointing movement under open loop conditions. Once criterion was reached by each animal, a unilateral electrolytic lesion of the substantia nigra (SN) was performed. A comparison between the post operative performances of the animals in the two groups showed that suppression of visual cues resulted in a lengthening of the RT and a slowing of the movement speed. Moreover when visual feedback was lacking, the amplitude of the movement decreased and the finger fell short of the target. During the last post operative period, suppression of visual feedback brought about a more rapid return of RTs to their preoperative level and a more durable slowing of movement speed than with normal vision. The discussion deals with the role of visual feed-back in the control of movement preparation and execution, and with the change in mode of motor control caused by lesion of the SN. Partial exclusion of the SN might bring about a shift from the feedforward to a feedback mode relying more heavily on visual cues.

  1. A novel use of combined tyrosine hydroxylase and silver nucleolar staining to determine the effects of a unilateral intrastriatal 6-hydroxydopamine lesion in the substantia nigra: a stereological study.

    PubMed

    Healy-Stoffel, Michelle; Ahmad, S Omar; Stanford, John A; Levant, Beth

    2012-09-30

    Neurotoxic lesions of the nigrostriatal pathway model the deficits found in Parkinson's disease. This study used stereology and a novel staining method to examine the effects of a partial unilateral striatal 6-hydroxydopamine (6-OHDA) lesion on substantia nigra pars compacta (SNpc) dopamine neuron number and morphology in rats. Adult male Long-Evans rats were subjected to unilateral lesion of the SNpc by intrastriatal microinjection of 6-OHDA (12.5 μg). Lesions were verified by d-amphetamine-stimulated rotation (2.5 mg/kg, sc) by force-plate rotometry 7 days post-surgery. Seven days after rotation testing, rats were euthanized, and brains were prepared for either histology (n=12) or determination of striatal dopamine content by HPLC-EC (n=20). Brains prepared for histology were stained for tyrosine hydroxylase (TH) combined with a silver nucleolar (AgNOR) stain using a modified protocol developed for stereological assessment. The AgNOR counterstain allowed for precise definition of the nucleolus of the cells, facilitating both counting and qualitative morphometry of TH-positive neurons. Stereological quantitation determined a 54% decrease in TH-positive neuron number (P<0.01), and a 14% decrease in neuron volume (P<0.05) on the lesioned side. Striatal dopamine concentration was decreased by 92% (P<0.01), suggesting that striatal dopamine analysis may overestimate the numbers of SNpc neurons lost. These findings demonstrate that combined use of TH and AgNOR staining provides improved characterization of 6-OHDA-induced pathology. Furthermore, the data suggest that decreased neuronal volume as well as number contributes to the functional deficits observed after unilateral intrastriatal 6-OHDA lesion. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Substantia nigra and Parkinson disease (image)

    MedlinePlus

    ... is a slowly progressive disorder that affects movement, muscle control, and balance. Part of the disease process develops as cells are destroyed in certain parts of the brain stem, particularly the crescent-shaped cell mass known as ...

  3. Minimally invasive microendoscopy system for in vivo functional imaging of deep nuclei in the mouse brain

    PubMed Central

    Bocarsly, Miriam E.; Jiang, Wan-chen; Wang, Chen; Dudman, Joshua T.; Ji, Na; Aponte, Yeka

    2015-01-01

    The ability to image neurons anywhere in the mammalian brain is a major goal of optical microscopy. Here we describe a minimally invasive microendoscopy system for studying the morphology and function of neurons at depth. Utilizing a guide cannula with an ultrathin wall, we demonstrated in vivo two-photon fluorescence imaging of deeply buried nuclei such as the striatum (2.5 mm depth), substantia nigra (4.4 mm depth) and lateral hypothalamus (5.0 mm depth) in mouse brain. We reported, for the first time, the observation of neuronal activity with subcellular resolution in the lateral hypothalamus and substantia nigra of head-fixed awake mice. PMID:26601017

  4. Maternal choline supplementation in a mouse model of Down syndrome: Effects on attention and nucleus basalis/substantia innominata neuron morphology in adult offspring.

    PubMed

    Powers, Brian E; Kelley, Christy M; Velazquez, Ramon; Ash, Jessica A; Strawderman, Myla S; Alldred, Melissa J; Ginsberg, Stephen D; Mufson, Elliott J; Strupp, Barbara J

    2017-01-06

    The Ts65Dn mouse model of Down syndrome (DS) and Alzheimer's disease (AD) exhibits cognitive impairment and degeneration of basal forebrain cholinergic neurons (BFCNs). Our prior studies demonstrated that maternal choline supplementation (MCS) improves attention and spatial cognition in Ts65Dn offspring, normalizes hippocampal neurogenesis, and lessens BFCN degeneration in the medial septal nucleus (MSN). Here we determined whether (i) BFCN degeneration contributes to attentional dysfunction, and (ii) whether the attentional benefits of perinatal MCS are due to changes in BFCN morphology. Ts65Dn dams were fed either a choline-supplemented or standard diet during pregnancy and lactation. Ts65Dn and disomic (2N) control offspring were tested as adults (12-17months of age) on a series of operant attention tasks, followed by morphometric assessment of BFCNs. Ts65Dn mice demonstrated impaired learning and attention relative to 2N mice, and MCS significantly improved these functions in both genotypes. We also found, for the first time, that the number of BFCNs in the nucleus basalis of Meynert/substantia innominata (NBM/SI) was significantly increased in Ts65Dn mice relative to controls. In contrast, the number of BFCNs in the MSN was significantly decreased. Another novel finding was that the volume of BFCNs in both basal forebrain regions was significantly larger in Ts65Dn mice. MCS did not normalize any of these morphological abnormalities in the NBM/SI or MSN. Finally, correlational analysis revealed that attentional performance was inversely associated with BFCN volume, and positively associated with BFCN density. These results support the lifelong attentional benefits of MCS for Ts65Dn and 2N offspring and have profound implications for translation to human DS and pathology attenuation in AD.

  5. Endogenous Parkin Preserves Dopaminergic Substantia Nigral Neurons following Mitochondrial DNA Mutagenic Stress.

    PubMed

    Pickrell, Alicia M; Huang, Chiu-Hui; Kennedy, Scott R; Ordureau, Alban; Sideris, Dionisia P; Hoekstra, Jake G; Harper, J Wade; Youle, Richard J

    2015-07-15

    Parkinson's disease (PD) is a neurodegenerative disease caused by the loss of dopaminergic neurons in the substantia nigra. PARK2 mutations cause early-onset forms of PD. PARK2 encodes an E3 ubiquitin ligase, Parkin, that can selectively translocate to dysfunctional mitochondria to promote their removal by autophagy. However, Parkin knockout (KO) mice do not display signs of neurodegeneration. To assess Parkin function in vivo, we utilized a mouse model that accumulates dysfunctional mitochondria caused by an accelerated generation of mtDNA mutations (Mutator mice). In the absence of Parkin, dopaminergic neurons in Mutator mice degenerated causing an L-DOPA reversible motor deficit. Other neuronal populations were unaffected. Phosphorylated ubiquitin was increased in the brains of Mutator mice, indicating PINK1-Parkin activation. Parkin loss caused mitochondrial dysfunction and affected the pathogenicity but not the levels of mtDNA somatic mutations. A systemic loss of Parkin synergizes with mitochondrial dysfunction causing dopaminergic neuron death modeling PD pathogenic processes.

  6. Dissociation between the panicolytic effect of cannabidiol microinjected into the substantia nigra, pars reticulata, and fear-induced antinociception elicited by bicuculline administration in deep layers of the superior colliculus: The role of CB1-cannabinoid receptor in the ventral mesencephalon.

    PubMed

    da Silva, Juliana Almeida; Biagioni, Audrey Francisco; Almada, Rafael Carvalho; de Souza Crippa, José Alexandre; Cecílio Hallak, Jaime Eduardo; Zuardi, Antônio Waldo; Coimbra, Norberto Cysne

    2015-07-05

    Many studies suggest that the substantia nigra, pars reticulata (SNpr), a tegmental mesencephalic structure rich in γ-aminobutyric acid (GABA)- and cannabinoid receptor-containing neurons, is involved in the complex control of defensive responses through the neostriatum-nigral disinhibitory and nigro-tectal inhibitory GABAergic pathways during imminently dangerous situations. The aim of the present work was to investigate the role played by CB1-cannabinoid receptor of GABAergic pathways terminal boutons in the SNpr or of SNpr-endocannabinoid receptor-containing interneurons on the effect of intra-nigral microinjections of cannabidiol in the activity of nigro-tectal inhibitory pathways. GABAA receptor blockade in the deep layers of the superior colliculus (dlSC) elicited vigorous defensive behaviour. This explosive escape behaviour was followed by significant antinociception. Cannabidiol microinjection into the SNpr had a clear anti-aversive effect, decreasing the duration of defensive alertness, the frequency and duration of defensive immobility, and the frequency and duration of explosive escape behaviour, expressed by running and jumps, elicited by transitory GABAergic dysfunction in dlSC. However, the innate fear induced-antinociception was not significantly changed. The blockade of CB1 endocannabinoid receptor in the SNpr decreased the anti-aversive effect of canabidiol based on the frequency and duration of defensive immobility, the frequency of escape expressed by running, and both the frequency and duration of escape expressed by jumps. These findings suggest a CB1 mediated endocannabinoid signalling in cannabidiol modulation of panic-like defensive behaviour, but not of innate fear-induced antinociception evoked by GABAA receptor blockade with bicuculline microinjection into the superior colliculus, with a putative activity in nigro-collicular GABAergic pathways. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Time-course of SKF-81297-induced increase in glutamic acid decarboxylase 65 and 67 mRNA levels in striatonigral neurons and decrease in GABA(A) receptor alpha1 subunit mRNA levels in the substantia nigra, pars reticulata, in adult rats with a unilateral 6-hydroxydopamine lesion.

    PubMed

    Yamamoto, N; Soghomonian, J-J

    2008-06-26

    Striatal projection neurons use GABA as their neurotransmitter and express the rate-limiting synthesizing enzyme glutamic acid decarboxylase (GAD) and the vesicular GABA transporter vGAT. The chronic systemic administration of an agonist of dopamine D1/D5-preferring receptors is known to alter GAD mRNA levels in striatonigral neurons in intact and dopamine-depleted rats. In the present study, the effects of a single or subchronic systemic administration of the dopamine D1/D5-preferring receptor agonist SKF-81297 on GAD65, GAD67, PPD and vGAT mRNA levels in the striatum and GABA(A) receptor alpha1 subunit mRNA levels in the substantia nigra, pars reticulata, were measured in rats with a unilateral 6-hydroxydopamine (6-OHDA) lesion. After a single injection of SKF-81297, striatal GAD65 mRNA levels were significantly increased at 3 but not 72 h. In contrast, striatal GAD67 mRNA levels were increased and nigral alpha1 mRNA levels were decreased at 72 but not 3 h. Single cell analysis on double-labeled sections indicated that increased GAD or vGAT mRNA levels after acute SKF-81297 occurred in striatonigral neurons identified by their lack of preproenkephalin expression. Subchronic SKF-81297 induced significant increases in striatal GAD67, GAD65, preprodynorphin and vGAT mRNA levels and decreases in nigral alpha1 mRNA levels. In the striatum contralateral to the 6-OHDA lesion, subchronic but not acute SKF-81297 induced a significant increase in GAD65 mRNA levels. The other mRNA levels were not significantly altered. Finally, striatal GAD67 mRNA levels were negatively correlated with nigral alpha1 mRNA levels in the dopamine-depleted but not dopamine-intact side. The results suggest that different signaling pathways are involved in the modulation by dopamine D1/D5 receptors of GAD65 and GAD67 mRNA levels in striatonigral neurons. They also suggest that the down-regulation of nigral GABA(A) receptors is linked to the increase in striatal GAD67 mRNA levels in the dopamine

  8. Multimodal MRI Evaluation of the MitoPark Mouse Model of Parkinson’s Disease

    PubMed Central

    Cong, Linlin; Muir, Eric R.; Chen, Cang; Qian, Yusheng; Liu, Jingwei; Biju, K. C.; Clark, Robert A.; Li, Senlin; Duong, Timothy Q.

    2016-01-01

    The MitoPark mouse, a relatively new genetic model of Parkinson’s disease (PD), has a dopaminergic neuron-specific knock-out that inactivates the mitochondrial transcription factor A (Tfam), a protein essential for mitochondrial DNA expression and maintenance. This study used multimodal MRI to characterize the neuroanatomical correlates of PD-related deficits in MitoPark mice, along with functional behavioral tests. Compared with age-matched wild-type animals, MitoPark mice at 30 weeks showed: i) reduced whole-brain volume and increased ventricular volume, indicative of brain atrophy, ii) reduced transverse relaxation time (T2*) of the substantia nigra and striatum, suggestive of abnormal iron accumulation, iii) reduced apparent diffusion coefficient in the substantia nigra, suggestive of neuronal loss, iv) reduced fractional anisotropy in the corpus callosum and substantia nigra, indicative of white-matter damages, v) cerebral blood flow was not significantly affected, and vi) reduced motor activity in open-field tests, reduced memory in novel object recognition tests, as well as decreased mobility in tail suspension tests, an indication of depression. In sum, MitoPark mice recapitulate changes in many MRI parameters reported in PD patients. Multimodal MRI may prove useful for evaluating neuroanatomical correlates of PD pathophysiology in MitoPark mice, and for longitudinally monitoring disease progression and therapeutic interventions for PD. PMID:27003179

  9. Endogenous Parkin Preserves Dopaminergic Substantia Nigral Neurons following Mitochondrial DNA Mutagenic Stress

    PubMed Central

    Pickrell, Alicia M.; Huang, Chiu-Hui; Kennedy, Scott R.; Ordureau, Alban; Sideris, Dionisia P.; Hoekstra, Jake G.; Harper, J. Wade; Youle, Richard J.

    2016-01-01

    SUMMARY Parkinson's disease (PD) is a neurodegenerative disease caused by the loss of dopaminergic neurons in the substantia nigra. PARK2 mutations cause early-onset forms of PD. PARK2 encodes an E3 ubiquitin ligase, Parkin, that can selectively translocate to dysfunctional mitochondria to promote their removal by autophagy. However, Parkin knockout (KO) mice do not display signs of neurodegeneration. To assess Parkin function in vivo, we utilized a mouse model that accumulates dysfunctional mitochondria caused by an accelerated generation of mtDNA mutations (Mutator mice). In the absence of Parkin, dopaminergic neurons in Mutator mice degenerated causing an L-DOPA reversible motor deficit. Other neuronal populations were unaffected. Phosphorylated ubiquitin was increased in the brains of Mutator mice, indicating PINK1-Parkin activation. Parkin loss caused mitochondrial dysfunction and affected the pathogenicity but not the levels of mtDNA somatic mutations. A systemic loss of Parkin synergizes with mitochondrial dysfunction causing dopaminergic neuron death modeling PD pathogenic processes. PMID:26182419

  10. Neuroprotective effect of silymarin in a MPTP mouse model of Parkinson's disease.

    PubMed

    Pérez-H, Jesús; Carrillo-S, Carlos; García, Esperanza; Ruiz-Mar, Gabriela; Pérez-Tamayo, Ruy; Chavarría, Anahí

    2014-05-07

    Parkinson's disease (PD) is a neurodegenerative disease secondary to the loss of dopaminergic neurons in the substantia nigra. 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) produces in mice and primates histopathological changes similar to PD in humans. A common feature of PD and MPTP models is neuronal death and dopamine depletion. Silymarin is a complex of flavonolignans derived from the seeds of the plant Silybum marianum and has mainly antioxidant, anti-inflammatory, cytoprotective and neuroprotective effects. In order to explore whether silymarin has a neuroprotective effects in a mouse model of PD we determined the concentration of striatal dopamine by HPLC, the number of apoptotic cells by in situ Tunel assay and the number of tyrosine hydroxylase positive neurons by immunohistochemistry in substantia nigra of vehicle-treated, silymarin-treated, MPTP-intoxicated and MPTP-silymarin treated C57BL/6J male mice. MPTP (30 mg/kg) and silymarin doses (25, 50, 100, 200, 250, 300 or 400mg/kg) were administered intraperitoneally once daily for five consecutive days. Silymarin treatment showed a non-monotonic dose-response curve and only 50 and 100mg/kg doses preserved dopamine levels (62% and 69%, respectively) after MPTP intoxication. Additionally, 100mg/kg silymarin treatment significantly diminished the number of apoptotic cells and preserved dopaminergic neurons in the substantia nigra of MPTP-intoxicated mice. These results show the neuroprotective properties of 100mg/kg silymarin and may be of interest in the treatment of PD. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  11. Neuroprotective effects of geniposide in the MPTP mouse model of Parkinson's disease.

    PubMed

    Chen, YiMei; Zhang, Yanfang; Li, Lin; Hölscher, Christian

    2015-12-05

    Parkinson's disease (PD) is a chronic neurodegenerative disease, and there is no cure for it at present. We tested the drug Geniposide, an active component of Gardenia jasminoides Ellis which is used in traditional Chinese medicine. Geniposide has shown neuroprotective and growth-factor like effects in several in vivo and in vitro studies. In the present study, Geniposide had been tested in an acute PD mouse model induced by four 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) intraperitoneal injections. Geniposide treatment (100mg/kg ip.) for 8 days after MPTP treatment (30mg/kg ip.) improved the locomotor and exploratory activity of mice (open field), and improved bradykinesia and movement balance of mice (rotarod, swim test). Geniposide treatment also restored tyrosine hydroxylase (TH) positive dopaminergic neuron numbers in the substantia nigra pars compacta. Drug treatment also increased levels of growth factor signaling molecule Bax and reduced the apoptosis signaling molecule Bcl-2. Caspase 3 activation was also reduced in the substantia nigra. We conclude that Geniposide exerted its neuroprotective effect by enhancing growth factor signaling and the reduction of apoptosis. Geniposide is an ingredient in Chinese traditional medicine with few known side effects and shows potential as a drug treatment for Parkinson's disease. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Glutamate spillover drives endocannabinoid production and inhibits GABAergic transmission in the Substantia Nigra pars compacta.

    PubMed

    Freestone, Peter S; Guatteo, Ezia; Piscitelli, Fabiana; di Marzo, Vincenzo; Lipski, Janusz; Mercuri, Nicola B

    2014-04-01

    Endocannabinoids (eCBs) modulate synaptic transmission in the brain, but little is known of their regulatory role in nigral dopaminergic neurons, and whether transmission to these neurons is tonically inhibited by eCBs as seen in some other brain regions. Using whole-cell recording in midbrain slices, we observed potentiation of evoked IPSCs (eIPSCs) in these neurons after blocking CB1 receptors with rimonabant or LY-320,135, indicating the presence of an eCB tone reducing inhibitory synaptic transmission. Increased postsynaptic calcium buffering and block of mGluR1 or postsynaptic G-protein coupled receptors prevented this potentiation. Increasing spillover of endogenous glutamate by inhibiting uptake attenuated eIPSC amplitude, while enhancing the potentiation by rimonabant. Group I mGluR activation transiently inhibited eIPSCs, which could be prevented by GDP-β-S, increased calcium buffering or rimonabant. We explored the possibility that the dopamine-derived eCB N-arachidonoyl dopamine (NADA) is involved. The eCB tone was abolished by preventing dopamine synthesis, and enhanced by l-DOPA. It was not detected in adjacent non-dopaminergic neurons. Preventing 2-AG synthesis did not affect the tone, while inhibition of NADA production abolished it. Quantification of ventral midbrain NADA suggested a basal level that increased following prolonged depolarization or mGluR activation. Since block of the tone was not always accompanied by attenuation of depolarization-induced suppression of inhibition (DSI) and vice versa, our results indicate DSI and the eCB tone are mediated by distinct eCBs. This study provides evidence that dopamine modulates the activity of SNc neurons not only by conventional dopamine receptors, but also by CB1 receptors, potentially via NADA.

  13. Calcium Homeostatasis and Mitochondrial Dysfunction in Dopaminergic Neurons of the Substantia Nigra

    DTIC Science & Technology

    2010-03-01

    complex I of the electron transport chain (ETC) [18]; this deficit is specific to PD patients [19] and seems to reflect oxidative damage to complex I...the machinery responsible for Ca2+ homeostasis [47]. The ER forms a Figure 1. Ca2+ transport in SNc DA neurons. The steep concentration gradient for Ca2... transported back across the plasma membrane or sequestered in intracellular organelles. Ca2+ is transported across the plasma membrane through either the

  14. Motor Asymmetry and Substantia Nigra Volume Are Related to Spatial Delayed Response Performance in Parkinson Disease

    ERIC Educational Resources Information Center

    Foster, Erin R.; Black, Kevin J.; Antenor-Dorsey, Jo Ann V.; Perlmutter, Joel S.; Hershey, Tamara

    2008-01-01

    Studies suggest motor deficit asymmetry may help predict the pattern of cognitive impairment in individuals with Parkinson disease (PD). We tested this hypothesis using a highly validated and sensitive spatial memory task, spatial delayed response (SDR), and clinical and neuroimaging measures of PD asymmetry. We predicted SDR performance would be…

  15. The Central Amygdala Projection to the Substantia Nigra Reflects Prediction Error Information in Appetitive Conditioning

    ERIC Educational Resources Information Center

    Lee, Hongjoo J.; Gallagher, Michela; Holland, Peter C.

    2010-01-01

    The central amygdala nucleus (CeA) plays a critical role in cognitive processes beyond fear conditioning. For example, intact CeA function is essential for enhancing attention to conditioned stimuli (CSs). Furthermore, this enhanced attention depends on the CeA's connections to the nigrostriatal system. In the current study, we examined the role…

  16. Electrical and Ca2+ signaling in dendritic spines of substantia nigra dopaminergic neurons

    PubMed Central

    Hage, Travis A; Sun, Yujie; Khaliq, Zayd M

    2016-01-01

    Little is known about the density and function of dendritic spines on midbrain dopamine neurons, or the relative contribution of spine and shaft synapses to excitability. Using Ca2+ imaging, glutamate uncaging, fluorescence recovery after photobleaching and transgenic mice expressing labeled PSD-95, we comparatively analyzed electrical and Ca2+ signaling in spines and shaft synapses of dopamine neurons. Dendritic spines were present on dopaminergic neurons at low densities in live and fixed tissue. Uncaging-evoked potential amplitudes correlated inversely with spine length but positively with the presence of PSD-95. Spine Ca2+ signals were less sensitive to hyperpolarization than shaft synapses, suggesting amplification of spine head voltages. Lastly, activating spines during pacemaking, we observed an unexpected enhancement of spine Ca2+ midway throughout the spike cycle, likely involving recruitment of NMDA receptors and voltage-gated conductances. These results demonstrate functionality of spines in dopamine neurons and reveal a novel modulation of spine Ca2+ signaling during pacemaking. DOI: http://dx.doi.org/10.7554/eLife.13905.001 PMID:27163179

  17. Functional upregulation of Ca(2+)-activated K(+) channels in the development of substantia nigra dopamine neurons.

    PubMed

    Ramírez-Latorre, José A

    2012-01-01

    Many connections in the basal ganglia are made around birth when animals are exposed to a host of new affective, cognitive, and sensori-motor stimuli. It is thought that dopamine modulates cortico-striatal synapses that result in the strengthening of those connections that lead to desired outcomes. We propose that there must be a time before which stimuli cannot be processed into functional connections, otherwise it would imply an effective link between stimulus, response, and reward in uterus. Consistent with these ideas, we present evidence that early in development dopamine neurons are electrically immature and do not produce high-frequency firing in response to salient stimuli. We ask first, what makes dopamine neurons immature? and second, what are the implications of this immaturity for the basal ganglia? As an answer to the first question, we find that at birth the outward current is small (3nS-V), insensitive to Ca(2+), TEA, BK, and SK blockers. Rapidly after birth, the outward current increases to 15nS-V and becomes sensitive to Ca(2+), TEA, BK, and SK blockers. We make a detailed analysis of the kinetics of the components of the outward currents and produce a model for BK and SK channels that we use to reproduce the outward current, and to infer the geometrical arrangement of BK and Ca(2+) channels in clusters. In the first cluster, T-type Ca(2+) and BK channels are coupled within distances of ~20 nm (200 Å). The second cluster consists of L-type Ca(2+) and BK channels that are spread over distances of at least 60 nm. As for the second question, we propose that early in development, the mechanism of action selection is in a "locked-in" state that would prevent dopamine neurons from reinforcing cortico-striatal synapses that do not have a functional experiential-based value.

  18. Functional Upregulation of Ca2+ -Activated K+ Channels in the Development of Substantia Nigra Dopamine Neurons

    PubMed Central

    Ramírez-Latorre, José A.

    2012-01-01

    Many connections in the basal ganglia are made around birth when animals are exposed to a host of new affective, cognitive, and sensori-motor stimuli. It is thought that dopamine modulates cortico-striatal synapses that result in the strengthening of those connections that lead to desired outcomes. We propose that there must be a time before which stimuli cannot be processed into functional connections, otherwise it would imply an effective link between stimulus, response, and reward in uterus. Consistent with these ideas, we present evidence that early in development dopamine neurons are electrically immature and do not produce high-frequency firing in response to salient stimuli. We ask first, what makes dopamine neurons immature? and second, what are the implications of this immaturity for the basal ganglia? As an answer to the first question, we find that at birth the outward current is small (3nS-V), insensitive to , TEA, BK, and SK blockers. Rapidly after birth, the outward current increases to 15nS-V and becomes sensitive to , TEA, BK, and SK blockers. We make a detailed analysis of the kinetics of the components of the outward currents and produce a model for BK and SK channels that we use to reproduce the outward current, and to infer the geometrical arrangement of BK and channels in clusters. In the first cluster, T-type and BK channels are coupled within distances of 20 nm (200 Å). The second cluster consists of L-type and BK channels that are spread over distances of at least 60 nm. As for the second question, we propose that early in development, the mechanism of action selection is in a “locked-in” state that would prevent dopamine neurons from reinforcing cortico-striatal synapses that do not have a functional experiential-based value. PMID:23284723

  19. Motor Asymmetry and Substantia Nigra Volume Are Related to Spatial Delayed Response Performance in Parkinson Disease

    ERIC Educational Resources Information Center

    Foster, Erin R.; Black, Kevin J.; Antenor-Dorsey, Jo Ann V.; Perlmutter, Joel S.; Hershey, Tamara

    2008-01-01

    Studies suggest motor deficit asymmetry may help predict the pattern of cognitive impairment in individuals with Parkinson disease (PD). We tested this hypothesis using a highly validated and sensitive spatial memory task, spatial delayed response (SDR), and clinical and neuroimaging measures of PD asymmetry. We predicted SDR performance would be…

  20. The Central Amygdala Projection to the Substantia Nigra Reflects Prediction Error Information in Appetitive Conditioning

    ERIC Educational Resources Information Center

    Lee, Hongjoo J.; Gallagher, Michela; Holland, Peter C.

    2010-01-01

    The central amygdala nucleus (CeA) plays a critical role in cognitive processes beyond fear conditioning. For example, intact CeA function is essential for enhancing attention to conditioned stimuli (CSs). Furthermore, this enhanced attention depends on the CeA's connections to the nigrostriatal system. In the current study, we examined the role…

  1. Selenotranscriptomic Analyses Identify Signature Selenoproteins in Brain Regions in a Mouse Model of Parkinson's Disease.

    PubMed

    Zhang, Xiong; Ye, Yang-Lie; Zhu, Hui; Sun, Sheng-Nan; Zheng, Jing; Fan, Hui-Hui; Wu, Hong-Mei; Chen, Song-Fang; Cheng, Wen-Hsing; Zhu, Jian-Hong

    Genes of selenoproteome have been increasingly implicated in various aspects of neurobiology and neurological disorders, but remain largely elusive in Parkinson's disease (PD). In this study, we investigated the selenotranscriptome (24 selenoproteins in total) in five brain regions (cerebellum, substantia nigra, cortex, pons and hippocampus) by real time qPCR in a two-phase manner using a mouse model of chronic PD. A wide range of changes in selenotranscriptome was observed in a manner depending on selenoproteins and brain regions. While Selv mRNA was not detectable and Dio1& 3 mRNA levels were not affected, 1, 11 and 9 selenoproteins displayed patterns of increase only, decrease only, and mixed response, respectively, in these brain regions of PD mice. In particular, the mRNA expression of Gpx1-4 showed only a decreased trend in the PD mouse brains. In substantia nigra, levels of 17 selenoprotein mRNAs were significantly decreased whereas no selenoprotein was up-regulated in the PD mice. In contrast, the majority of selenotranscriptome did not change and a few selenoprotein mRNAs that respond displayed a mixed pattern of up- and down-regulation in cerebellum, cortex, hippocampus, and/or pons of the PD mice. Gpx4, Sep15, Selm, Sepw1, and Sepp1 mRNAs were most abundant across all these five brain regions. Our results showed differential responses of selenoproteins in various brain regions of the PD mouse model, providing critical selenotranscriptomic profiling for future functional investigation of individual selenoprotein in PD etiology.

  2. Diagnostic value of combined assessment of olfaction and sustantia nigra hyperechogenicity for Parkinson's disease.

    PubMed

    López Hernández, N; García Escrivá, A; Shalabi Benavent, M

    2015-10-01

    Hyposmia and substantia nigra hyperechogenicity (SN+) are characteristic markers of Parkinson's disease (PD), although their diagnostic value in isolation may be limited. We evaluated the combined prevalence of both disorders in patients diagnosed with PD and assessed their diagnostic yield compared to a sample with essential tremor (ET) and another group of healthy subjects. Patients diagnosed with PD and ET and treated in our outpatient clinic were enrolled. Olfaction was assessed using the "Sniffin' Sticks" odour identification test (SS-12) and hyperechogenicity of the substantia nigra (SN+) was assessed by transcranial duplex ultrasound. A total of 98 subjects were analysed, comprising 30 with PD, 21 with ET, and 47 controls. The respective prevalence rates of hyposmia (SS-12 < 8) and SN+ (area > .24cm(2)) were 70% and 83.3% in PD, 33.3% and 9.5% in ET, and 17% and 10.6% in controls. Both markers were present in 63% of patients with PD, none of the patients with ET, and only 2 of the controls. Combined use of substantia nigra sonography and olfactory testing with SS-12, two rapid, safe, and accessible tests, was more specific than each isolated marker for distinguishing patients with PD from patients with ET and control subjects. Since both markers have been described in very early phases of PD, combined use may be helpful in providing early diagnosis of PD. Copyright © 2013 Sociedad Española de Neurología. Published by Elsevier España, S.L.U. All rights reserved.

  3. Phosphodiesterase-10A Inverse Changes in Striatopallidal and Striatoentopeduncular Pathways of a Transgenic Mouse Model of DYT1 Dystonia.

    PubMed

    D'Angelo, Vincenza; Castelli, Valentina; Giorgi, Mauro; Cardarelli, Silvia; Saverioni, Ilaria; Palumbo, Francesca; Bonsi, Paola; Pisani, Antonio; Giampà, Carmela; Sorge, Roberto; Biagioni, Stefano; Fusco, Francesca R; Sancesario, Giuseppe

    2017-02-22

    We report that changes of phosphodiesterase-10A (PDE10A) can map widespread functional imbalance of basal ganglia circuits in a mouse model of DYT1 dystonia overexpressing mutant torsinA. PDE10A is a key enzyme in the catabolism of second messenger cAMP and cGMP, whose synthesis is stimulated by D1 receptors and inhibited by D2 receptors preferentially expressed in striatoentopeducuncular/substantia nigra or striatopallidal pathways, respectively. PDE10A was studied in control mice (NT) and in mice carrying human wild-type torsinA (hWT) or mutant torsinA (hMT). Quantitative analysis of PDE10A expression was assessed in different brain areas by rabbit anti-PDE10A antibody immunohistochemistry and Western blotting. PDE10A-dependent cAMP hydrolyzing activity and PDE10A mRNA were also assessed. Striatopallidal neurons were identified by rabbit anti-enkephalin antibody.In NT mice, PDE10A is equally expressed in medium spiny striatal neurons and in their projections to entopeduncular nucleus/substantia nigra and to external globus pallidus. In hMT mice, PDE10A content selectively increases in enkephalin-positive striatal neuronal bodies; moreover, PDE10A expression and activity in hMT mice, compared with NT mice, significantly increase in globus pallidus but decrease in entopeduncular nucleus/substantia nigra. Similar changes of PDE10A occur in hWT mice, but such changes are not always significant. However, PDE10A mRNA expression appears comparable among NT, hWT, and hMT mice.In DYT1 transgenic mice, the inverse changes of PDE10A in striatoentopeduncular and striatopallidal projections might result over time in an imbalance between direct and indirect pathways for properly focusing movement. The decrease of PDE10A in the striatoentopeduncular/nigral projections might lead to increased intensity and duration of D1-stimulated cAMP/cGMP signaling; conversely, the increase of PDE10A in the striatopallidal projections might lead to increased intensity and duration of D2

  4. Overview of mouse models of Parkinson's disease.

    PubMed

    Bobela, Wojciech; Zheng, Lu; Schneider, Bernard L

    2014-09-03

    Parkinson's disease is a neurodegenerative disorder characterized by the loss of neurons in specific regions of the nervous system, notably in the substantia nigra pars compacta and, in most cases, by the deposition of intraneuronal inclusions named Lewy bodies. These pathological alterations have profound effects on the brain function, leading to the progressive development of various symptoms, the most prominent being the impaired initiation of voluntary movements caused by the loss of dopamine signaling in the basal ganglia. Here, we provide an overview of the mouse models of Parkinson's disease, with the goal of guiding selection of the most appropriate model for studying the question at hand. Pharmacological approaches targeting dopamine signaling and toxins leading to selective degeneration of nigral neurons are used to validate symptomatic treatments that aim at restoring effective dopaminergic function for motor control. Alternative mouse models are based on genetic modifications that are meant to reproduce the inherited alterations associated with familial forms of Parkinson's disease. Although genetic models have most often failed to induce overt degeneration of nigral dopaminergic neurons, they provide essential tools to explore the multifactorial etiology of this complex neurodegenerative disorder. Copyright © 2014 John Wiley & Sons, Inc.

  5. An Anatomically Resolved Mouse Brain Proteome Reveals Parkinson Disease-relevant Pathways.

    PubMed

    Jung, Sung Yun; Choi, Jong Min; Rousseaux, Maxime W C; Malovannaya, Anna; Kim, Jean J; Kutzera, Joachim; Wang, Yi; Huang, Yin; Zhu, Weimin; Maity, Suman; Zoghbi, Huda Yahya; Qin, Jun

    2017-04-01

    Here, we present a mouse brain protein atlas that covers 17 surgically distinct neuroanatomical regions of the adult mouse brain, each less than 1 mm(3) in size. The protein expression levels are determined for 6,500 to 7,500 gene protein products from each region and over 12,000 gene protein products for the entire brain, documenting the physiological repertoire of mouse brain proteins in an anatomically resolved and comprehensive manner. We explored the utility of our spatially defined protein profiling methods in a mouse model of Parkinson's disease. We compared the proteome from a vulnerable region (substantia nigra pars compacta) of wild type and parkinsonian mice with that of an adjacent, less vulnerable, region (ventral tegmental area) and identified several proteins that exhibited both spatiotemporal- and genotype-restricted changes. We validated the most robustly altered proteins using an alternative profiling method and found that these modifications may highlight potential new pathways for future studies. This proteomic atlas is a valuable resource that offers a practical framework for investigating the molecular intricacies of normal brain function as well as regional vulnerability in neurological diseases. All of the mouse regional proteome profiling data are published on line at http://mbpa.bprc.ac.cn/. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  6. RNA Interference of Human α-Synuclein in Mouse

    PubMed Central

    Kim, Young-Cho; Miller, Adam; Lins, Livia C. R. F.; Han, Sang-Woo; Keiser, Megan S.; Boudreau, Ryan L.; Davidson, Beverly L.; Narayanan, Nandakumar S.

    2017-01-01

    α-Synuclein is postulated to play a key role in the pathogenesis of Parkinson’s disease (PD). Aggregates of α-synuclein contribute to neurodegeneration and cell death in humans and in mouse models of PD. Here, we use virally mediated RNA interference to knockdown human α-synuclein in mice. We used an siRNA design algorithm to identify eight siRNA sequences with minimal off-targeting potential. One RNA-interference sequence (miSyn4) showed maximal protein knockdown potential in vitro. We then designed AAV vectors expressing miSyn4 and injected them into the mouse substantia nigra. miSyn4 was robustly expressed and did not detectably change dopamine neurons, glial proliferation, or mouse behavior. We then injected AAV2-miSyn4 into Thy1-hSNCA mice over expressing α-synuclein and found decreased human α-synuclein (hSNCA) in both midbrain and cortex. In separate mice, co-injection of AAV2-hSNCA and AAV2-miSyn4 demonstrated decreased hSNCA expression and rescue of hSNCA-mediated behavioral deficits. These data suggest that virally mediated RNA interference can knockdown hSNCA in vivo, which could be helpful for future therapies targeting human α-synuclein. PMID:28197125

  7. Separation of Dalbergia nigra from Dalbergia spruceana

    Treesearch

    Regis B. Miller; Michael C. Wiemann

    2006-01-01

    The wood anatomical characteristics of Dalbergia nigra and Dalbergia spruceana are too similar to permit reliable species separation, which is sometimes important because D. nigra is a Convention on International Trade in Endangered Species-protected species whereas D. spruceana is not. However, the density, water fluorescence, and ethanol fluorescence of heartwood...

  8. Effects of striatal transplantation of cells transfected with GDNF gene without pre- and pro-regions in mouse model of Parkinson's disease.

    PubMed

    Revishchin, A; Moiseenko, L; Kust, N; Bazhenova, N; Teslia, P; Panteleev, D; Kovalzon, V; Pavlova, G

    2016-06-10

    Previously, we have shown that transgenic cells bearing the GDNF gene with deleted pre- and pro-regions (mGDNF) can release transgenic GDNF. The medium conditioned by transgenic cells with mGDNF induced axonal growth in rat embryonic spinal ganglion in vitro. Here we demonstrate a neurotrophic effect of mGDNF on PC12 cells in vitro as well as its neuroprotective effect on dopaminergic neurons in the substantia nigra pars compacta in vivo as indicated by improved motor coordination and sleep-wakefulness cycle in the MPTP mouse model of Parkinson's disease. HEK293 cells were transfected with a vector encoding an isoform of the human GDNF gene with deleted pre- and pro-regions (mGDNF). This factor in the medium conditioned by the transfected cells was shown to induce axonal growth in PC12 cells. The early Parkinson's disease model was established by injection of the dopaminergic pro-neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) into C57Bl/6 mice. Transgenic HEK293/mGDNF/GFP cells were transplanted into the striatum (caudate-putamen) of experimental mice. The sleep-wakefulness cycle was studied by continuous EEG and motor activity monitoring 1 and 2 weeks after MPTP injection. After the experiment, the motor coordination of experimental animals was evaluated in the rotarod test, and dopaminergic neurons in the substantia nigra pars compacta were counted in cross-sections of the midbrain. MPTP administration lowered the number of tyrosine hydroxylase immunopositive cells in the substantia nigra pars compacta, decreased motor coordination, and increased the total wake time during the dark period. The transplantation of HEK293/mGDNF cells into the caudate-putamen 3 days prior to MPTP injection smoothed these effects, while the control transplantation of HEK293 cells showed no notable impact. Transplantation of transgenic cells with the GDNF gene lacking the pre- and pro-sequences can protect dopaminergic neurons in the mouse midbrain from the subsequent

  9. Erythropoietin is Neuroprotective in a Transgenic Mouse Model of Multiple System Atrophy

    PubMed Central

    Pallua, Anton; Stefanova, Nadia; Poewe, Werner; Wenning, Gregor K.

    2016-01-01

    Multiple system atrophy is a rapidly progressive neurodegenerative disorder with a markedly reduced life expectancy. Failure of symptomatic treatment raises an urgent need for disease-modifying strategies. We have investigated the neuroprotective potential of erythropoietin in (proteolipid protein)-α-synuclein transgenic mice exposed to 3-nitropropionic acid featuring multiple system atrophy-like pathology including oligodendroglial α-synuclein inclusions and selective neuronal degeneration. Mice were treated with erythropoietin starting before (early erythropoietin) and after (late erythropoietin) intoxication with 3-nitropropionic acid. Nonintoxicated animals receiving erythropoietin and intoxicated animals treated with saline served as control groups. Behavioral tests included pole test, open field activity, and motor behavior scale. Immunohistochemistry for tyrosine hydroxylase and dopamine and cyclic adenosine monophosphate-regulated phosphoprotein (DARPP-32) was analyzed stereologically. Animals receiving erythropoietin before and after 3-nitropropionic acid intoxication scored significantly lower on the motor behavior scale and they performed better in the pole test than controls with no significant difference between early and late erythropoietin administration. Similarly, rearing scores were worse in 3-nitropropionic acid-treated animals with no difference between the erythropoietin subgroups. Immunohistochemistry revealed significant attenuation of 3-nitropropionic acid-induced loss of tyrosine hydroxylase and DARPP-32 positive neurons in substantia nigra pars compacta and striatum, respectively, in both erythropoietin-treated groups without significant group difference in the substantia nigra. However, at striatal level, a significant difference between early and late erythropoietin administration was observed. In the combined (proteolipid protein)-α-synuclein 3-nitropropionic acid multiple system atrophy mouse model, erythropoietin appears to rescue

  10. Activin A Inhibits MPTP and LPS-Induced Increases in Inflammatory Cell Populations and Loss of Dopamine Neurons in the Mouse Midbrain In Vivo

    PubMed Central

    Stayte, Sandy; Rentsch, Peggy; Tröscher, Anna R.; Bamberger, Maximilian; Li, Kong M.; Vissel, Bryce

    2017-01-01

    Parkinson’s disease is a chronic neurodegenerative disease characterized by a significant loss of dopaminergic neurons within the substantia nigra pars compacta region and a subsequent loss of dopamine within the striatum. A promising avenue of research has been the administration of growth factors to promote the survival of remaining midbrain neurons, although the mechanism by which they provide neuroprotection is not understood. Activin A, a member of the transforming growth factor β superfamily, has been shown to be a potent anti-inflammatory following acute brain injury and has been demonstrated to play a role in the neuroprotection of midbrain neurons against MPP+-induced degeneration in vitro. We hypothesized that activin A may offer similar anti-inflammatory and neuroprotective effects in in vivo mouse models of Parkinson’s disease. We found that activin A significantly attenuated the inflammatory response induced by both MPTP and intranigral administration of lipopolysaccharide in C57BL/6 mice. We found that administration of activin A promoted survival of dopaminergic and total neuron populations in the pars compacta region both 8 days and 8 weeks after MPTP-induced degeneration. Surprisingly, no corresponding protection of striatal dopamine levels was found. Furthermore, activin A failed to protect against loss of striatal dopamine transporter expression in the striatum, suggesting the neuroprotective action of activin A may be localized to the substantia nigra. Together, these results provide the first evidence that activin A exerts potent neuroprotection and anti-inflammatory effects in the MPTP and lipopolysaccharide mouse models of Parkinson’s disease. PMID:28121982

  11. Tinea nigra masquerading as acral lentiginous melanoma.

    PubMed

    Babel, D E; Pelachyk, J M; Hurley, J P

    1986-05-01

    Tinea nigra is a superficial mycosis that may mimic serious pigmentary lesions. A lesion recently encountered on the foot was suspected of being a malignant melanoma. Histologic and mycologic studies, done after a biopsy was obtained, demonstrated Exophilia werneckii in the stratum corneum. Tinea nigra should be considered in the diagnosis of pigmented lesions of the hands and feet. A KOH examination is a simple and rapid means of demonstrating this entity.

  12. Dermatoscopy in the diagnosis of tinea nigra.

    PubMed

    Xavier, Marcus Henrique de S B; Ribeiro, Lúcia Helena S; Duarte, Hélio; Saraça, Giani; Souza, Angela Cristina L

    2008-08-15

    Tinea nigra is an asymptomatic superficial fungal infection caused by Phaeoannelomyces werneckii, generally affecting the skin of the palms and characterized by deeply pigmented macular non-scaly patches. These lesions are quite characteristic. However, they can be misdiagnosed as a malignant melanoma or a junctional melanocytic nevus and unnecessary biopsies may be performed. Thus, dermoscopy is a fast, useful, clinical adjunctive tool in differentiating tinea nigra from melanocytic lesion.

  13. Antiinflammatory properties of Morus nigra leaves.

    PubMed

    Padilha, Marina M; Vilela, Fabiana C; Rocha, Cláudia Q; Dias, Marcelo J; Soncini, Roseli; dos Santos, Marcelo H; Alves-da-Silva, Geraldo; Giusti-Paiva, Alexandre

    2010-10-01

    The aim of the present study was to investigate antiinflammatory activity of the methylene chloride extract of Morus nigra in animal models. Carrageenan-induced paw edema as well as fibrovascular tissue growth induced by s.c. cotton pellet implantation were used to investigate the antiinflammatory activity of Morus nigra extract (MnE) in rats. A HPLC fingerprint was used for phytochemical analysis of the extracts. The MnE at test doses of 100-300 mg/kg p.o. clearly demonstrated antiinflammatory effects by reduced paw edema induced by carragenan and significantly inhibited the formation of granulomatous tissue. In addition, chemical compounds isolated from Morus nigra, including betulinic acid, β-sitosterol and germanicol, may be responsible for the antiinflammatory effect of the extract.

  14. Scanning electron microscopy of tinea nigra.

    PubMed

    Guarenti, Isabelle Maffei; Almeida, Hiram Larangeira de; Leitão, Aline Hatzenberger; Rocha, Nara Moreira; Silva, Ricardo Marques E

    2014-01-01

    Tinea nigra is a rare superficial mycosis caused by Hortaea werneckii. This infection presents as asymptomatic brown to black maculae mostly in palmo-plantar regions. We performed scanning electron microscopy of a superficial shaving of a tinea nigra lesion. The examination of the outer surface of the sample showed the epidermis with corneocytes and hyphae and elimination of fungal filaments. The inner surface of the sample showed important aggregation of hyphae among keratinocytes, which formed small fungal colonies. The ultrastructural findings correlated with those of dermoscopic examination - the small fungal aggregations may be the dark spicules seen on dermoscopy - and also allowed to document the mode of dissemination of tinea nigra, showing how hyphae are eliminated on the surface of the lesion.

  15. Glutathione Peroxidase 4 is associated with Neuromelanin in Substantia Nigra and Dystrophic Axons in Putamen of Parkinson’s brain

    DTIC Science & Technology

    2011-01-21

    attenuates 6-OHDA induced toxicity to dopamine neurons in rodent models of PD [11, 12]. A recent study showed that GPX1 is present in human microglia and...cortex. J Alzheimers Dis 2008, 15:465-472. 29. Mouton PR, Long JM, Lei DL, Howard V, Jucker M, Calhoun ME, Ingram DK: Age and gender effects on... microglia and astrocyte numbers in brains of mice. Brain Res 2002, 956:30-35. 12 Table 1. Study Subjects. Control (n=11) PD (n=12) Age Range

  16. Neuronal precursors within the adult rat subventricular zone differentiate into dopaminergic neurons after substantia nigra lesion and chromaffin cell transplant.

    PubMed

    Arias-Carrión, Oscar; Hernández-López, Salvador; Ibañez-Sandoval, Osvaldo; Bargas, José; Hernández-Cruz, Arturo; Drucker-Colín, René

    2006-11-15

    Neurogenesis in the adult mammalian brain continues in the subventricular zone (SVZ). Neuronal precursors from the SVZ migrate along the rostral migratory stream to replace olfactory bulb interneurons. After the destruction of the nigro-striatal pathway (SN-lesion), some SVZ precursors begin to express tyrosine hydroxylase (TH) and neuronal markers (NeuN). Grafting of chromaffin cells (CCs) into the denervated striatum increases the number of TH+ cells (SVZ TH+ cells; Arias-Carrión et al., 2004). This study examines the functional properties of these newly differentiating TH+ cells. Under whole-cell patch-clamp, most SVZ cells recorded from lesioned and grafted animals (either TH+ or TH-) were non-excitable. Nevertheless, a small percentage of SVZ TH+ cells had the electrophysiologic phenotype of mature dopaminergic neurons and showed spontaneous postsynaptic potentials. Dopamine (DA) release was measured in SVZ and striatum from both control and SN-lesioned rats. As expected, 12 weeks after SN lesion, DA release decreased drastically. Nevertheless, 8 weeks after CCs graft, release from the SVZ of SN-lesioned rats recovered, and even surpassed that from control SVZ, suggesting that newly formed SVZ TH+ cells release DA. This study shows for the first time that in response to SN-lesions and CC grafts neural precursors within the SVZ change their developmental program, by not only expressing TH, but more importantly by acquiring excitable properties of mature dopaminergic neurons. Additionally, the release of DA in a Ca(2+)-dependent manner and the attraction of synaptic afferents from neighboring neuronal networks gives further significance to the overall findings, whose potential importance is discussed.

  17. Dermoscopy revealing a case of Tinea Nigra*

    PubMed Central

    Criado, Paulo Ricardo; Delgado, Lívia; Pereira, Gustavo Alonso

    2013-01-01

    Dermoscopy has being used over the past twenty years as a noninvasive aid in the diagnosis of innumerable skin conditions, including infectious diseases and infestations (Entodermoscopy).Tinea nigra is a superficial phaeohyfomycosis that affects mainly the glabrous skin of palms and soles. We describe a 14 year-old girl with a three-month history of an enlarging brown patch of her hand diagnosed as Tinea Nigra following clinical and dermoscopy examination.These images emphasize the importance of dermoscopy as a diagnostic tool in the daily routine of dermatologists. PMID:23539019

  18. Effect of microgravity on glial cell line-derived neurotrophic factor and cerebral dopamine neurotrophic factor gene expression in the mouse brain.

    PubMed

    Tsybko, A S; Ilchibaeva, T V; Kulikov, A V; Kulikova, E A; Krasnov, I B; Sychev, V N; Shenkman, B S; Popova, N K; Naumenko, V S

    2015-09-01

    Mice were exposed to 1 month of space flight on the Russian biosatellite BION-M1 to determine its effect on the expression of genes involved in the maintenance of the mouse brain dopamine system. The current article focuses on the genes encoding glial cell line-derived neurotrophic factor (GDNF) and cerebral dopamine neurotrophic factor (CDNF). Space flight reduced expression of the GDNF gene in the striatum and hypothalamus but increased it in the frontal cortex and raphe nuclei area. At the same time, actual space flight reduced expression of the gene encoding CDNF in the substantia nigra but increased it in the raphe nuclei area. To separate the effects of space flight from environmental stress contribution, we analyzed expression of the investigated genes in mice housed for 1 month on Earth in the same shuttle cabins that were used for space flight and in mice of the vivarium control group. Shuttle cabin housing failed to alter the expression of the GDNF and CDNF genes in the brain structures investigated. Thus, actual long-term space flight produced dysregulation in genetic control of GDNF and CDNF genes. These changes may be related to downregulation of the dopamine system after space flight, which we have shown earlier. © 2015 Wiley Periodicals, Inc. Our results provide the first evidence of microgravity effects on expression of the GDNF and CDNF neurotrophic factor genes. A considerable decrease in mRNA level of GDNF and CDNF in the nigrostriatal dopamine system was found. Because both GDNF and CDNF play a significant role in maintenance and survival of brain dopaminergic neurons, we can assume that this dysregulation in genetic control of GDNF and CDNF genes in substantia nigra could be among the reasons for the deleterious effects of space flight on the dopamine system. © 2015 Wiley Periodicals, Inc.

  19. Adventitious shoot regeneration of Fraxinus nigra Marsh

    Treesearch

    Rochelle R. Beasley; Paula M. Pijut

    2010-01-01

    Fraxinus nigra Marsh. (black ash) is a native ash species occurring in Newfoundland west to Manitoba and south to Iowa, Illinois, West Virginia, and Virginia. Although it is not a commercially important species, it has significant ethnobotanical importance to Native American tribes of the eastern United States.

  20. Genetic transformation of black walnut (Juglans nigra)

    Treesearch

    Michael J. Bosela; Gurpreet S. Smagh; Charles H. Michler

    2004-01-01

    Disarmed Agrobacterium tumefaciens strains with binary vectors carrying transgenes for kanamycin resistance (npt II) and β-glucuronidase (GUS, uidA) were used for the genetic transformation of Eastern black walnut (Juglans nigra) somatic embryos. In total, explants from 16 embryo lines...

  1. Tinea nigra: successful treatment with topical butenafine*

    PubMed Central

    Rossetto, André Luiz; Cruz, Rosana Cé Bella

    2012-01-01

    The authors report a case of Tinea nigra in an 8-year-old child, male, from Itajaí, SC, Brazil, with lesions of the macular hyperchromic type, unique, asymptomatic, localized in the right palmar area. The lesion was treated with the topical antifungal butenafine, with remission of symptoms and without recurrence at follow-up for two years. PMID:23197223

  2. Lidocaine Inhibits HCN Currents in Rat Spinal Substantia Gelatinosa Neurons

    PubMed Central

    Hu, Tao; Liu, Nana; Lv, Minhua; Ma, Longxian; Peng, Huizhen; Peng, Sicong

    2016-01-01

    BACKGROUND: Lidocaine, which blocks voltage-gated sodium channels, is widely used in surgical anesthesia and pain management. Recently, it has been proposed that the hyperpolarization-activated cyclic nucleotide (HCN) channel is one of the other novel targets of lidocaine. Substantia gelatinosa in the spinal dorsal horn, which plays key roles in modulating nociceptive information from primary afferents, comprises heterogeneous interneurons that can be electrophysiologically categorized by firing pattern. Our previous study demonstrated that a substantial proportion of substantia gelatinosa neurons reveal the presence of HCN current (Ih); however, the roles of lidocaine and HCN channel expression in different types of substantia gelatinosa neurons remain unclear. METHODS: By using the whole-cell patch-clamp technique, we investigated the effect of lidocaine on Ih in rat substantia gelatinosa neurons of acute dissociated spinal cord slices. RESULTS: We found that lidocaine rapidly decreased the peak Ih amplitude with an IC50 of 80 μM. The inhibition rate on Ih was not significantly different with a second application of lidocaine in the same neuron. Tetrodotoxin, a sodium channel blocker, did not affect lidocaine’s effect on Ih. In addition, lidocaine shifted the half-activation potential of Ih from −109.7 to −114.9 mV and slowed activation. Moreover, the reversal potential of Ih was shifted by −7.5 mV by lidocaine. In the current clamp, lidocaine decreased the resting membrane potential, increased membrane resistance, delayed rebound depolarization latency, and reduced the rebound spike frequency. We further found that approximately 58% of substantia gelatinosa neurons examined expressed Ih, in which most of them were tonically firing. CONCLUSIONS: Our studies demonstrate that lidocaine strongly inhibits Ih in a reversible and concentration-dependent manner in substantia gelatinosa neurons, independent of tetrodotoxin-sensitive sodium channels. Thus, our

  3. Acupuncture promotes mTOR-independent autophagic clearance of aggregation-prone proteins in mouse brain

    PubMed Central

    Tian, Tian; Sun, Yanhong; Wu, Huangan; Pei, Jian; Zhang, Jing; Zhang, Yi; Wang, Lu; Li, Bin; Wang, Lihua; Shi, Jiye; Hu, Jun; Fan, Chunhai

    2016-01-01

    Acupuncture has historically been practiced to treat medical disorders by mechanically stimulating specific acupoints with fine needles. Despite its well-documented efficacy, its biological basis remains largely elusive. In this study, we found that mechanical stimulation at the acupoint of Yanglingquan (GB34) promoted the autophagic clearance of α-synuclein (α-syn), a well known aggregation-prone protein closely related to Parkinson’s disease (PD), in the substantia nigra par compacta (SNpc) of the brain in a PD mouse model. We found the protein clearance arose from the activation of the autophagy-lysosome pathway (ALP) in a mammalian target of rapamycin (mTOR)-independent approach. Further, we observed the recovery in the activity of dopaminergic neurons in SNpc, and improvement in the motor function at the behavior level of PD mice. Whereas acupuncture and rapamycin, a chemical mTOR inhibitor, show comparable α-syn clearance and therapeutic effects in the PD mouse model, the latter adopts a distinctly different, mTOR-dependent, autophagy induction process. Due to this fundamental difference, acupuncture may circumvent adverse effects of the rapamycin treatment. The newly discovered connection between acupuncture and autophagy not only provides a new route to understanding the molecular mechanism of acupuncture but also sheds new light on cost-effective and safe therapy of neurodegenerative diseases. PMID:26792101

  4. Acupuncture promotes mTOR-independent autophagic clearance of aggregation-prone proteins in mouse brain.

    PubMed

    Tian, Tian; Sun, Yanhong; Wu, Huangan; Pei, Jian; Zhang, Jing; Zhang, Yi; Wang, Lu; Li, Bin; Wang, Lihua; Shi, Jiye; Hu, Jun; Fan, Chunhai

    2016-01-21

    Acupuncture has historically been practiced to treat medical disorders by mechanically stimulating specific acupoints with fine needles. Despite its well-documented efficacy, its biological basis remains largely elusive. In this study, we found that mechanical stimulation at the acupoint of Yanglingquan (GB34) promoted the autophagic clearance of α-synuclein (α-syn), a well known aggregation-prone protein closely related to Parkinson's disease (PD), in the substantia nigra par compacta (SNpc) of the brain in a PD mouse model. We found the protein clearance arose from the activation of the autophagy-lysosome pathway (ALP) in a mammalian target of rapamycin (mTOR)-independent approach. Further, we observed the recovery in the activity of dopaminergic neurons in SNpc, and improvement in the motor function at the behavior level of PD mice. Whereas acupuncture and rapamycin, a chemical mTOR inhibitor, show comparable α-syn clearance and therapeutic effects in the PD mouse model, the latter adopts a distinctly different, mTOR-dependent, autophagy induction process. Due to this fundamental difference, acupuncture may circumvent adverse effects of the rapamycin treatment. The newly discovered connection between acupuncture and autophagy not only provides a new route to understanding the molecular mechanism of acupuncture but also sheds new light on cost-effective and safe therapy of neurodegenerative diseases.

  5. Neuroprotective efficacy of aminopropyl carbazoles in a mouse model of amyotrophic lateral sclerosis.

    PubMed

    Tesla, Rachel; Wolf, Hamilton Parker; Xu, Pin; Drawbridge, Jordan; Estill, Sandi Jo; Huntington, Paula; McDaniel, Latisha; Knobbe, Whitney; Burket, Aaron; Tran, Stephanie; Starwalt, Ruth; Morlock, Lorraine; Naidoo, Jacinth; Williams, Noelle S; Ready, Joseph M; McKnight, Steven L; Pieper, Andrew A

    2012-10-16

    We previously reported the discovery of P7C3, an aminopropyl carbazole having proneurogenic and neuroprotective properties in newborn neural precursor cells of the hippocampal dentate gyrus. We have further found that chemicals having efficacy in this in vivo screening assay also protect dopaminergic neurons of the substantia nigra following exposure to the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, a mouse model of Parkinson disease. Here, we provide evidence that an active analog of P7C3, known as P7C3A20, protects ventral horn spinal cord motor neurons from cell death in the G93A-SOD1 mutant mouse model of amyotrophic lateral sclerosis (ALS). P7C3A20 is efficacious in this model when administered at disease onset, and protection from cell death correlates with preservation of motor function in assays of walking gait and in the accelerating rotarod test. The prototypical member of this series, P7C3, delays disease progression in G93A-SOD1 mice when administration is initiated substantially earlier than the expected time of symptom onset. Dimebon, an antihistaminergic drug with significantly weaker proneurogenic and neuroprotective efficacy than P7C3, confers no protection in this ALS model. We propose that the chemical scaffold represented by P7C3 and P7C3A20 may provide a basis for the discovery and optimization of pharmacologic agents for the treatment of ALS.

  6. BCG vaccine-induced neuroprotection in a mouse model of Parkinson's disease.

    PubMed

    Yong, Jing; Lacan, Goran; Dang, Hoa; Hsieh, Terry; Middleton, Blake; Wasserfall, Clive; Tian, Jide; Melega, William P; Kaufman, Daniel L

    2011-01-31

    There is a growing interest in using vaccination with CNS antigens to induce autoreactive T cell responses that home to damaged areas in the CNS and ameliorate neurodegenerative disease. Neuroprotective vaccine studies have focused on administering oligodendrocyte antigens or Copaxone® in complete Freund's adjuvant (CFA). Theoretical considerations, however, suggest that vaccination with a neuronal antigen may induce more robust neuroprotective immune responses. We assessed the neuroprotective potential of vaccines containing tyrosine hydroxylase (a neuronal protein involved in dopamine synthesis) or Copaxone® in CFA in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of Parkinson's disease. Surprisingly, we observed that the main beneficial factor in these vaccines was the CFA. Since the major immunogenic component in CFA is Mycobacterium tuberculosis, which closely related to the bacille Calmette-Guérin (BCG) that is used in human vaccines, we tested BCG vaccination in the MPTP mouse model. We observed that BCG vaccination partially preserved markers of striatal dopamine system integrity and prevented an increase in activated microglia in the substantia nigra of MPTP-treated mice. These results support a new neuroprotective vaccine paradigm in which general (nonself-reactive) immune stimulation in the periphery can limit potentially deleterious microglial responses to a neuronal insult and exert a neurorestorative effect in the CNS. Accordingly, BCG vaccination may provide a new strategy to augment current treatments for a wide range of neuropathological conditions.

  7. BCG Vaccine-Induced Neuroprotection in a Mouse Model of Parkinson's Disease

    PubMed Central

    Yong, Jing; Lacan, Goran; Dang, Hoa; Hsieh, Terry; Middleton, Blake; Wasserfall, Clive; Tian, Jide; Melega, William P.; Kaufman, Daniel L.

    2011-01-01

    There is a growing interest in using vaccination with CNS antigens to induce autoreactive T cell responses that home to damaged areas in the CNS and ameliorate neurodegenerative disease. Neuroprotective vaccine studies have focused on administering oligodendrocyte antigens or Copaxone® in complete Freund's adjuvant (CFA). Theoretical considerations, however, suggest that vaccination with a neuronal antigen may induce more robust neuroprotective immune responses. We assessed the neuroprotective potential of vaccines containing tyrosine hydroxylase (a neuronal protein involved in dopamine synthesis) or Copaxone® in CFA in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of Parkinson's disease. Surprisingly, we observed that the main beneficial factor in these vaccines was the CFA. Since the major immunogenic component in CFA is Mycobacterium tuberculosis, which closely related to the bacille Calmette-Guérin (BCG) that is used in human vaccines, we tested BCG vaccination in the MPTP mouse model. We observed that BCG vaccination partially preserved markers of striatal dopamine system integrity and prevented an increase in activated microglia in the substantia nigra of MPTP-treated mice. These results support a new neuroprotective vaccine paradigm in which general (nonself-reactive) immune stimulation in the periphery can limit potentially deleterious microglial responses to a neuronal insult and exert a neurorestorative effect in the CNS. Accordingly, BCG vaccination may provide a new strategy to augment current treatments for a wide range of neuropathological conditions. PMID:21304945

  8. Myeloperoxidase inhibition ameliorates multiple system atrophy-like degeneration in a transgenic mouse model.

    PubMed

    Stefanova, Nadia; Georgievska, Biljana; Eriksson, Håkan; Poewe, Werner; Wenning, Gregor K

    2012-05-01

    Multiple system atrophy (MSA) is a rare and fatal α-synucleinopathy characterized by a distinctive oligodendrogliopathy with glial cytoplasmic inclusions and associated neuronal multisystem degeneration. The majority of patients presents with a rapidly progressive parkinsonian disorder and atypical features such as early autonomic failure and cerebellar ataxia. We have previously reported that complete MSA pathology can be modeled in transgenic mice overexpressing oligodendroglial α-synuclein under conditions of oxidative stress induced by 3-nitropropionic acid (3-NP) including striatonigral degeneration, olivopontocerebellar atrophy, astrogliosis, and microglial activation. Here, we show that myeloperoxidase (MPO), a key enzyme involved in the production of reactive oxygen species by phagocytic cells, is expressed in both human and mouse MSA brains. We also demonstrate that in the MSA mouse model, MPO inhibition reduces motor impairment and rescues vulnerable neurons in striatum, substantia nigra pars compacta, cerebellar cortex, pontine nuclei, and inferior olives. MPO inhibition is associated with suppression of microglial activation but does not affect 3-NP induced astrogliosis in the same regions. Finally, MPO inhibition results in reduced intracellular aggregates of α-synuclein. This study suggests that MPO inhibition may represent a novel candidate treatment strategy against MSA-like neurodegeneration acting through its anti-inflammatory and anti-oxidative properties. © Springer Science+Business Media, LLC 2011

  9. Functional Analysis of Dopaminergic Systems in a DYT1 Knock-in Mouse Model of Dystonia

    PubMed Central

    Song, Chang-Hyun; Fan, Xueliang; Exeter, Cicely J.; Hess, Ellen J.; Jinnah, H. A.

    2012-01-01

    The dystonias are a group of disorders characterized by involuntary twisting movements and abnormal posturing. The most common of the inherited dystonias is DYT1 dystonia, which is due to deletion of a single GAG codon (ΔE) in the TOR1A gene that encodes torsinA. Since some forms of dystonia have been linked with dysfunction of brain dopamine pathways, the integrity of these pathways was explored in a knock-in mouse model of DYT1 dystonia. In DYT1(ΔE) knock-in mice, neurochemical measures revealed only small changes in the content of dopamine or its metabolites in tissue homogenates from caudoputamen or midbrain, but microdialysis studies revealed robust decreases in baseline and amphetamine-stimulated extracellular dopamine in the caudoputamen. Quantitative stereological methods revealed no evidence for striatal or midbrain atrophy, but substantia nigra neurons immunopositive for tyrosine hydroxylase were slightly reduced in numbers and enlarged in size. Behavioral studies revealed subtle abnormalities in gross motor activity and motor coordination without overt dystonia. Neuropharmacological challenges of dopamine systems revealed normal behavioral responses to amphetamine and a minor increase in sensitivity to haloperidol. These results demonstrate that this DYT1(ΔE) knock-in mouse model of dystonia harbors neurochemical and structural changes of the dopamine pathways, as well as motor abnormalities. PMID:22659308

  10. Inhaled hydrogen sulfide prevents neurodegeneration and movement disorder in a mouse model of Parkinson's disease.

    PubMed

    Kida, Kotaro; Yamada, Marina; Tokuda, Kentaro; Marutani, Eizo; Kakinohana, Manabu; Kaneki, Masao; Ichinose, Fumito

    2011-07-15

    Parkinson's disease is one of the major neurodegenerative disorders. Neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) can cause Parkinson's disease-like symptoms and biochemical changes in humans and animals. Hydrogen sulfide (H(2)S) has been shown to protect neurons. The goal of this study was to examine the effects of inhaled H(2)S in a mouse model of Parkinson's disease induced by MPTP. Male C57BL/6J mice received MPTP at 80 mg/kg and breathed air with or without 40 ppm H(2)S for 8 h/day for 7 days. Administration of MPTP induced movement disorder and decreased tyrosine hydroxylase (TH)-containing neurons in the substantia nigra and striatum in mice that breathed air. Inhalation of H(2)S prevented the MPTP-induced movement disorder and the degeneration of TH-containing neurons. Inhaled H(2)S also prevented apoptosis of the TH-containing neurons and gliosis in nigrostriatal region after administration of MPTP. The neuroprotective effect of inhaled H(2)S after MPTP administration was associated with upregulation of genes encoding antioxidant proteins, including heme oxygenase-1 and glutamate-cysteine ligase. These observations suggest that inhaled H(2)S prevents neurodegeneration in a mouse model of Parkinson's disease induced by MPTP, potentially via upregulation of antioxidant defense mechanisms and inhibition of inflammation and apoptosis in the brain.

  11. Differential regulation of laminin b1 transgene expression in the neonatal and adult mouse brain.

    PubMed

    Sharif, K A; Baker, H; Gudas, L J

    2004-01-01

    Laminins are the major glycoproteins present in basement membrane, a type of extracellular matrix. We showed that the LAMB1 gene, which encodes the laminin beta1 subunit, is transcriptionally activated by retinoic acid in embryonic stem cells. However, little information is available concerning LAMB1 developmental regulation and spatial expression in the adult mouse brain. In this study we used transgenic mice expressing different lengths of LAMB1 promoter driving beta-galactosidase to investigate developmental and adult transcriptional regulation in the regions of the brain in which the laminin beta1 protein is expressed. CNS expression was not observed in transgenic mice carrying a 1.4LAMB1betagal construct. Mice carrying a 2.5LAMB1betagal construct expressed the LAMB1 transgene, as assayed by X-gal staining, only in the molecular layer of the neonatal cerebellum. In contrast, a 3.9LAMB1betagal transgene showed broad regional expression in the adult mouse brain, including the hippocampus, entorhinal cortex, colliculi, striatum, and substantia nigra. Similar expression patterns were observed for the endogenous laminin beta1 protein and for the 3.9LAMB1betagal transgene, analyzed with an antibody against the beta-galactosidase protein. The 3.9LAMB1betagal transgene expression in the hippocampal tri-synaptic circuit suggests a role for the LAMB1 gene in learning and memory.

  12. Neuroprotective efficacy of aminopropyl carbazoles in a mouse model of amyotrophic lateral sclerosis

    PubMed Central

    Tesla, Rachel; Wolf, Hamilton Parker; Xu, Pin; Drawbridge, Jordan; Estill, Sandi Jo; Huntington, Paula; McDaniel, LaTisha; Knobbe, Whitney; Burket, Aaron; Tran, Stephanie; Starwalt, Ruth; Morlock, Lorraine; Naidoo, Jacinth; Williams, Noelle S.; Ready, Joseph M.; McKnight, Steven L.; Pieper, Andrew A.

    2012-01-01

    We previously reported the discovery of P7C3, an aminopropyl carbazole having proneurogenic and neuroprotective properties in newborn neural precursor cells of the hippocampal dentate gyrus. We have further found that chemicals having efficacy in this in vivo screening assay also protect dopaminergic neurons of the substantia nigra following exposure to the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, a mouse model of Parkinson disease. Here, we provide evidence that an active analog of P7C3, known as P7C3A20, protects ventral horn spinal cord motor neurons from cell death in the G93A-SOD1 mutant mouse model of amyotrophic lateral sclerosis (ALS). P7C3A20 is efficacious in this model when administered at disease onset, and protection from cell death correlates with preservation of motor function in assays of walking gait and in the accelerating rotarod test. The prototypical member of this series, P7C3, delays disease progression in G93A-SOD1 mice when administration is initiated substantially earlier than the expected time of symptom onset. Dimebon, an antihistaminergic drug with significantly weaker proneurogenic and neuroprotective efficacy than P7C3, confers no protection in this ALS model. We propose that the chemical scaffold represented by P7C3 and P7C3A20 may provide a basis for the discovery and optimization of pharmacologic agents for the treatment of ALS. PMID:23027932

  13. Ghrelin inhibits LPS-induced release of IL-6 from mouse dopaminergic neurones

    PubMed Central

    2013-01-01

    Background Ghrelin is an orexigenic stomach hormone that acts centrally to increase mid-brain dopamine neurone activity, amplify dopamine signaling and protect against neurotoxin-induced dopamine cell death in the mouse substantia nigra pars compacta (SNpc). In addition, ghrelin inhibits the lipopolysaccharide (LPS)-induced release of pro-inflammatory cytokines from peripheral macrophages, T-cells and from LPS stimulated microglia. Here we sought to determine whether ghrelin attenuates pro-inflammatory cytokine release from dopaminergic neurones. Findings The dopaminergic SN4741 cell-line, which derives from the mouse substantia nigra (SN) and expresses the ghrelin-receptor (growth hormone secretagogue receptor (GHS-R)) and the ghrelin-O-acyl transferase (GOAT) enzyme, was used to determine the neuro-immunomodulatory action of ghrelin. We induced innate immune activation via LPS challenge (1 μg/ml) of SN4741 neurones that had been pre-cultured in the presence or absence of ghrelin (1, 10, 100 nM) for 4 h. After 24 h supernatants were collected for detection of IL-1 beta (IL-1β ), TNF alpha (TNF-α) and IL-6 cytokines via enzyme linked immunosorbent assay (ELISA) analysis. Nuclear translocation of the transcription factor nuclear factor kappa B (NF-κB) was analyzed by Western blotting, and to determine viability of treatments a cell viability assay and caspase-3 immunohistochemistry were performed. We provide evidence that while IL-1β and TNF-α were not detectable under any conditions, SN4741 neurones constitutively released IL-6 under basal conditions and treatment with LPS significantly increased IL-6 secretion. Pre-treatment of neurones with ghrelin attenuated LPS-mediated IL-6 release at 24 h, an affect that was inhibited by the GHS-R antagonist [D-Lys3]-GHRP-6. However, while ghrelin pre-treatment attenuated the LPS-mediated increase in NF-κB, there was no alteration in its nuclear translocation. Cell viability assay and caspase-3 immunocytochemistry

  14. Ghrelin inhibits LPS-induced release of IL-6 from mouse dopaminergic neurones.

    PubMed

    Beynon, Amy L; Brown, M Rowan; Wright, Rhiannon; Rees, Mark I; Sheldon, I Martin; Davies, Jeffrey S

    2013-03-19

    Ghrelin is an orexigenic stomach hormone that acts centrally to increase mid-brain dopamine neurone activity, amplify dopamine signaling and protect against neurotoxin-induced dopamine cell death in the mouse substantia nigra pars compacta (SNpc). In addition, ghrelin inhibits the lipopolysaccharide (LPS)-induced release of pro-inflammatory cytokines from peripheral macrophages, T-cells and from LPS stimulated microglia. Here we sought to determine whether ghrelin attenuates pro-inflammatory cytokine release from dopaminergic neurones. The dopaminergic SN4741 cell-line, which derives from the mouse substantia nigra (SN) and expresses the ghrelin-receptor (growth hormone secretagogue receptor (GHS-R)) and the ghrelin-O-acyl transferase (GOAT) enzyme, was used to determine the neuro-immunomodulatory action of ghrelin. We induced innate immune activation via LPS challenge (1 μg/ml) of SN4741 neurones that had been pre-cultured in the presence or absence of ghrelin (1, 10, 100 nM) for 4 h. After 24 h supernatants were collected for detection of IL-1 beta (IL-1β ), TNF alpha (TNF-α) and IL-6 cytokines via enzyme linked immunosorbent assay (ELISA) analysis. Nuclear translocation of the transcription factor nuclear factor kappa B (NF-κB) was analyzed by Western blotting, and to determine viability of treatments a cell viability assay and caspase-3 immunohistochemistry were performed.We provide evidence that while IL-1β and TNF-α were not detectable under any conditions, SN4741 neurones constitutively released IL-6 under basal conditions and treatment with LPS significantly increased IL-6 secretion. Pre-treatment of neurones with ghrelin attenuated LPS-mediated IL-6 release at 24 h, an affect that was inhibited by the GHS-R antagonist [D-Lys3]-GHRP-6. However, while ghrelin pre-treatment attenuated the LPS-mediated increase in NF-κB, there was no alteration in its nuclear translocation. Cell viability assay and caspase-3 immunocytochemistry demonstrated that the

  15. The RNA-binding protein Celf6 is highly expressed in diencephalic nuclei and neuromodulatory cell populations of the mouse brain.

    PubMed

    Maloney, Susan E; Khangura, Eakta; Dougherty, Joseph D

    2016-05-01

    The gene CUG-BP, Elav-like factor 6 (CELF6) appears to be important for proper functioning of neurocircuitry responsible for behavioral output. We previously discovered that polymorphisms in or near CELF6 may be associated with autism spectrum disorder (ASD) in humans and that the deletion of this gene in mice results in a partial ASD-like phenotype. Here, to begin to understand which circuits might mediate these behavioral disruptions, we sought to establish in what structures, with what abundance, and at which ages Celf6 protein is present in the mouse brain. Using both a knockout-validated antibody to Celf6 and a novel transgenic mouse line, we characterized Celf6 expression in the mouse brain across development. Celf6 gene products were present early in neurodevelopment and in adulthood. The greatest protein expression was observed in distinct nuclei of the diencephalon and neuromodulatory cell populations of the midbrain and hindbrain, with clear expression in dopaminergic, noradrenergic, histaminergic, serotonergic and cholinergic populations, and a variety of presumptive peptidergic cells of the hypothalamus. These results suggest that disruption of Celf6 expression in hypothalamic nuclei may impact a variety of behaviors downstream of neuropeptide activity, while disruption in neuromodulatory transmitter expressing areas such as the ventral tegmental area, substantia nigra, raphe nuclei and locus coeruleus may have far-reaching influences on overall brain activity.

  16. The effect of truncated human alpha-synuclein (1-120) on dopaminergic cells in a transgenic mouse model of Parkinson's disease.

    PubMed

    Michell, A W; Tofaris, G K; Gossage, H; Tyers, P; Spillantini, M G; Barker, R A

    2007-01-01

    Alpha-Synuclein is thought to play an important role in the pathology of Parkinson's disease (PD). Truncated forms of this protein can be found in PD brain extracts, and these species aggregate faster and are more susceptible to oxidative stress than the full-length protein. We investigated the effect of truncated alpha-synuclein on dopaminergic cells using a transgenic mouse expressing alpha-synuclein (1-120) driven by the rat tyrosine hydroxylase promoter on a mouse alpha-synuclein null background. We found a selective reduction in the yield of dopaminergic cells from transgenic embryonic ventral mesencephalic cell cultures. However, in vivo the substantia nigra/ventral tegmentum dopaminergic cell counts were not reduced in transgenics, although these mice are known to have reduced striatal dopamine. When transplanted to the striatum in the unilateral 6-hydroxydopamine-lesioned mouse model of PD, dopaminergic cells derived from transgenic embryonic ventral mesencephala were significantly smaller at 6 weeks, and showed a trend towards being less effective at ameliorating rotational asymmetry than those from control alpha-synuclein null mice. These results suggest that alpha-synuclein (1-120) renders dopaminergic cells more susceptible to stress, which may have important implications as to how this truncated protein might contribute to dopaminergic cell death in sporadic PD.

  17. Ursolic acid attenuates oxidative stress in nigrostriatal tissue and improves neurobehavioral activity in MPTP-induced Parkinsonian mouse model.

    PubMed

    Rai, Sachchida Nand; Yadav, Satyndra Kumar; Singh, Divakar; Singh, Surya Pratap

    2016-01-01

    Parkinson's disease (PD) is characterized by a slow and progressive degeneration of dopaminergic neurons in substantia nigra pars compacta (SNpc) region of brain. Oxidative stress and inflammation plays important role in the neurodegeneration and development of PD. Ursolic Acid (UA: 3β-hydroxy-urs-12-en-28-oic acid) is a natural pentacyclic triterpenoid found in various medicinal plants. Its anti-inflammatory and antioxidant activity is a well-established fact. In this paper, the neuroprotective efficiency of UA in MPTP induced PD mouse model has been explored. For this purpose, we divided 30 mice into 5 different groups; first was control, second was MPTP-treated, third, fourth and fifth were different doses of UA viz., 5 mg/kg, 25 mg/kg, and 50 mg/kg body weight (wt) respectively, along with MPTP. After 21 days of treatment, different behavioral parameters and biochemical assays were conducted. Tyrosine hydroxylase (TH) immunostaining of SN dopaminergic neurons as well as HPLC quantification of dopamine and its metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanilic acid (HVA) were also performed. Our results proved that, UA improves behavioral deficits, restored altered dopamine level and protect dopaminergic neurons in the MPTP intoxicated mouse. Among three different doses, 25 mg/kg body wt was the most effective dose for the PD. This work reveals the potential of UA as a promising drug candidate for PD treatment.

  18. Dermoscopy in the diagnosis of tinea nigra plantaris.

    PubMed

    Smith, S B; Beals, S L; Elston, D M; Meffert, J J

    2001-12-01

    Tinea nigra is a relatively uncommon dermatiaceous fungal infection, usually caused by Phaeoannellomyces werneckii, that may mimic a melanocytic lesion. We describe the value of epiluminescent dermoscopy of tinea nigra plantaris compared with other common diagnostic tools and procedures available (clinical appearance, potassium hydroxide [KOH], culture, culture mount preparation, and biopsy). A case of tinea nigra plantaris was evaluated clinically, microscopically with KOH, and dermatoscopically. Dermatoscopic findings were evaluated according to the Stolz system. Dermoscopy, clinical presentation, and microscopy with KOH all confirmed the diagnosis, with dermoscopy being the fastest and simplest procedure. Dermoscopy is a useful clinical adjuntive tool in differentiating tinea nigra from a melanocytic lesion.

  19. Quantitative mouse brain phenotyping based on single and multispectral MR protocols.

    PubMed

    Badea, Alexandra; Gewalt, Sally; Avants, Brian B; Cook, James J; Johnson, G Allan

    2012-11-15

    Sophisticated image analysis methods have been developed for the human brain, but such tools still need to be adapted and optimized for quantitative small animal imaging. We propose a framework for quantitative anatomical phenotyping in mouse models of neurological and psychiatric conditions. The framework encompasses an atlas space, image acquisition protocols, and software tools to register images into this space. We show that a suite of segmentation tools (Avants, Epstein et al., 2008) designed for human neuroimaging can be incorporated into a pipeline for segmenting mouse brain images acquired with multispectral magnetic resonance imaging (MR) protocols. We present a flexible approach for segmenting such hyperimages, optimizing registration, and identifying optimal combinations of image channels for particular structures. Brain imaging with T1, T2* and T2 contrasts yielded accuracy in the range of 83% for hippocampus and caudate putamen (Hc and CPu), but only 54% in white matter tracts, and 44% for the ventricles. The addition of diffusion tensor parameter images improved accuracy for large gray matter structures (by >5%), white matter (10%), and ventricles (15%). The use of Markov random field segmentation further improved overall accuracy in the C57BL/6 strain by 6%; so Dice coefficients for Hc and CPu reached 93%, for white matter 79%, for ventricles 68%, and for substantia nigra 80%. We demonstrate the segmentation pipeline for the widely used C57BL/6 strain, and two test strains (BXD29, APP/TTA). This approach appears promising for characterizing temporal changes in mouse models of human neurological and psychiatric conditions, and may provide anatomical constraints for other preclinical imaging, e.g. fMRI and molecular imaging. This is the first demonstration that multiple MR imaging modalities combined with multivariate segmentation methods lead to significant improvements in anatomical segmentation in the mouse brain.

  20. Quantitative mouse brain phenotyping based on single and multispectral MR protocols

    PubMed Central

    Badea, Alexandra; Gewalt, Sally; Avants, Brian B.; Cook, James J.; Johnson, G. Allan

    2013-01-01

    Sophisticated image analysis methods have been developed for the human brain, but such tools still need to be adapted and optimized for quantitative small animal imaging. We propose a framework for quantitative anatomical phenotyping in mouse models of neurological and psychiatric conditions. The framework encompasses an atlas space, image acquisition protocols, and software tools to register images into this space. We show that a suite of segmentation tools (Avants, Epstein et al., 2008) designed for human neuroimaging can be incorporated into a pipeline for segmenting mouse brain images acquired with multispectral magnetic resonance imaging (MR) protocols. We present a flexible approach for segmenting such hyperimages, optimizing registration, and identifying optimal combinations of image channels for particular structures. Brain imaging with T1, T2* and T2 contrasts yielded accuracy in the range of 83% for hippocampus and caudate putamen (Hc and CPu), but only 54% in white matter tracts, and 44% for the ventricles. The addition of diffusion tensor parameter images improved accuracy for large gray matter structures (by >5%), white matter (10%), and ventricles (15%). The use of Markov random field segmentation further improved overall accuracy in the C57BL/6 strain by 6%; so Dice coefficients for Hc and CPu reached 93%, for white matter 79%, for ventricles 68%, and for substantia nigra 80%. We demonstrate the segmentation pipeline for the widely used C57BL/6 strain, and two test strains (BXD29, APP/TTA). This approach appears promising for characterizing temporal changes in mouse models of human neurological and psychiatric conditions, and may provide anatomical constraints for other preclinical imaging, e.g. fMRI and molecular imaging. This is the first demonstration that multiple MR imaging modalities combined with multivariate segmentation methods lead to significant improvements in anatomical segmentation in the mouse brain. PMID:22836174

  1. A cadherin-based code for the divisions of the mouse basal ganglia.

    PubMed

    Hertel, Nicole; Krishna-K; Nuernberger, Monique; Redies, Christoph

    2008-06-01

    The expression of 12 different classic cadherins and delta-protocadherins was mapped in consecutive series of sections through the basal ganglia of the postnatal and adult mouse by in situ hybridization. A particular focus was the caudoputamen, which consists of patches (striosomes) and a surrounding matrix that is histologically uniform. The different areas within the caudoputamen are connected specifically to other parts of the basal ganglia and to other brain regions, for example, the substantia nigra. The molecules regulating the morphogenesis and functional connectivity of the basal ganglia are largely unknown. Previous studies suggested that cadherins, a large family of adhesion molecules, are involved in basal ganglia development. In the present work, we study the expression of 12 cadherins and show that the patch and matrix compartments of the caudoputamen express the cadherins differentially, although partial overlap is observed. Moreover, the cadherins are expressed in multiple and diverse gradients within the caudoputamen and other parts of the basal ganglia. The persistence of the expression patterns in the adult basal ganglia suggests the possibility that cadherins also play a role at adult stages. Our results suggest that cadherins provide a code of potentially adhesive cues that specify not only patch and matrix compartments but also multiple molecular gradients within the basal ganglia. This code may relate to patterns of connectivity.

  2. GDNF-Transfected Macrophages Produce Potent Neuroprotective Effects in Parkinson's Disease Mouse Model

    PubMed Central

    Zhao, Yuling; Haney, Matthew J.; Gupta, Richa; Bohnsack, John P.; He, Zhijian; Kabanov, Alexander V.; Batrakova, Elena V.

    2014-01-01

    The pathobiology of Parkinson's disease (PD) is associated with the loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) projecting to the striatum. Currently, there are no treatments that can halt or reverse the course of PD; only palliative therapies, such as replacement strategies for missing neurotransmitters, exist. Thus, the successful brain delivery of neurotrophic factors that promote neuronal survival and reverse the disease progression is crucial. We demonstrated earlier systemically administered autologous macrophages can deliver nanoformulated antioxidant, catalase, to the SNpc providing potent anti-inflammatory effects in PD mouse models. Here we evaluated genetically-modified macrophages for active targeted brain delivery of glial cell-line derived neurotropic factor (GDNF). To capitalize on the beneficial properties afforded by alternatively activated macrophages, transfected with GDNF-encoded pDNA cells were further differentiated toward regenerative M2 phenotype. A systemic administration of GDNF-expressing macrophages significantly ameliorated neurodegeneration and neuroinflammation in PD mice. Behavioral studies confirmed neuroprotective effects of the macrophage-based drug delivery system. One of the suggested mechanisms of therapeutic effects is the release of exosomes containing the expressed neurotropic factor followed by the efficient GDNF transfer to target neurons. Such formulations can serve as a new technology based on cell-mediated active delivery of therapeutic proteins that attenuate and reverse progression of PD, and ultimately provide hope for those patients who are already significantly disabled by the disease. PMID:25229627

  3. 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.

  4. Acupuncture inhibits microglial activation and inflammatory events in the MPTP-induced mouse model.

    PubMed

    Kang, Jun Mo; Park, Hi Joon; Choi, Yeong Gon; Choe, Il Hwan; Park, Jae Hyun; Kim, Yong Sik; Lim, Sabina

    2007-02-02

    Using a mouse model of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease (PD), this study investigated on the neuroprotective effects of acupuncture by examining whether acupuncture contributed to inhibiting microglial activation and inflammatory events. C57BL/6 mice were treated with MPTP (30 mg/kg, i.p.) for 5 consecutive days. Acupuncture was then applied to acupoints Yanglingquan (GB34) and Taichong (LR3) starting 2 h after the first MPTP administration and then at 48 h intervals until the mice were sacrificed for analyses at 1, 3, and 7 days after the last MPTP injection. These experiments demonstrated that acupuncture inhibited the decreased of the tyrosine hydroxylase (TH) immunoreactivity (IR) and generated a neuroprotective effects in the striatum (ST) and the substantia nigra (SN) on days 1, 3, and 7 post-MPTP injections. Acupuncture attenuated the increase of macrophage antigen complex-1 (MAC-1), a marker of microglial activation, at 1 and 3 days and reduced the increases in cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression on days 1, 3, and 7. In MPTP group, striatal dopamine (DA) was measured by 46% at 7 days, whereas DA in the acupuncture group was 78%. On the basis of these results, we suggest that acupuncture could be used as a neuroprotective intervention for the purpose of inhibiting microglial activation and inflammatory events in PD.

  5. Developmental Expression of Orphan G Protein-Coupled Receptor 50 in the Mouse Brain

    PubMed Central

    2012-01-01

    Mental disorders have a complex etiology resulting from interactions between multiple genetic risk factors and stressful life events. Orphan G protein-coupled receptor 50 (GPR50) has been identified as a genetic risk factor for bipolar disorder and major depression in women, and there is additional genetic and functional evidence linking GPR50 to neurite outgrowth, lipid metabolism, and adaptive thermogenesis and torpor. However, in the absence of a ligand, a specific function has not been identified. Adult GPR50 expression has previously been reported in brain regions controlling the HPA axis, but its developmental expression is unknown. In this study, we performed extensive expression analysis of GPR50 and three protein interactors using rt-PCR and immunohistochemistry in the developing and adult mouse brain. Gpr50 is expressed at embryonic day 13 (E13), peaks at E18, and is predominantly expressed by neurons. Additionally we identified novel regions of Gpr50 expression, including brain stem nuclei involved in neurotransmitter signaling: the locus coeruleus, substantia nigra, and raphe nuclei, as well as nuclei involved in metabolic homeostasis. Gpr50 colocalizes with yeast-two-hybrid interactors Nogo-A, Abca2, and Cdh8 in the hypothalamus, amygdala, cortex, and selected brain stem nuclei at E18 and in the adult. With this study, we identify a link between GPR50 and neurotransmitter signaling and strengthen a likely role in stress response and energy homeostasis. PMID:22860215

  6. A disruption mechanism of the molecular clock in a MPTP mouse model of Parkinson's disease.

    PubMed

    Hayashi, Akane; Matsunaga, Naoya; Okazaki, Hiroyuki; Kakimoto, Keisuke; Kimura, Yoshinori; Azuma, Hiroki; Ikeda, Eriko; Shiba, Takeshi; Yamato, Mayumi; Yamada, Ken-Ichi; Koyanagi, Satoru; Ohdo, Shigehiro

    2013-06-01

    Parkinson's disease (PD) is a common neurodegenerative disorder that is characterized by the degeneration of dopaminergic neurons in the substantia nigra and dopamine depletion in the striatum. Although the motor symptoms are still regarded as the main problem, non-motor symptoms in PD also markedly impair the quality of life. Several non-motor symptoms, such as sleep disturbances and depression, are suggested to be implicated in the alteration in circadian clock function. In this study, we investigated circadian disruption and the mechanism in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. MPTP-treated mice exhibited altered 24-h rhythms in body temperature and locomotor activity. In addition, MPTP treatment also affected the circadian clock system at the genetic level. The exposure of human neuroblastoma cells (SH-SY5Y) to 1-metyl-4-phenylpyridinium (MPP(+)) increased or decreased the mRNA levels of several clock genes in a dose-dependent manner. MPP(+)-induced changes in clock genes expression were reversed by Compound C, an inhibitor of AMP-activated protein kinase (AMPK). Most importantly, addition of ATP to the drinking water of MPTP-treated mice attenuated neurodegeneration in dopaminergic neurons, suppressed AMPK activation and prevented circadian disruption. The present findings suggest that the activation of AMPK caused circadian dysfunction, and ATP may be a novel therapeutic strategy based on the molecular clock in PD.

  7. Hsp70 gene transfer by adeno-associated virus inhibits MPTP-induced nigrostriatal degeneration in the mouse model of Parkinson disease.

    PubMed

    Dong, Zhizhong; Wolfer, David P; Lipp, Hans-Peter; Büeler, Hansruedi

    2005-01-01

    Mitochondrial dysfunction and oxidative stress have been implicated in Parkinson disease (PD). In addition, genetic evidence points to an important role of protein misfolding, aggregation, and failure in the proteasomal degradation of specific neuronal proteins in the pathogenesis of PD. The chaperone heat-shock protein 70 (Hsp70) reduces protein misfolding and aggregation and protects cells against a variety of adverse conditions, including oxidative stress. Moreover, Hsp70 exerts antiapoptotic activity by blocking the function of several key proapoptotic factors. Recently, Hsp70 was shown to inhibit alpha-synuclein toxicity in a Drosophila model of inherited PD. Here we tested the potential of Hsp70 (approved gene symbol HSPA1A) for gene therapy in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of idiopathic PD. We show that Hsp70 gene transfer to dopamine neurons by a recombinant adeno-associated virus significantly protects the mouse dopaminergic system against MPTP-induced dopamine neuron loss and the associated decline in striatal dopamine levels and tyrosine hydroxylase-positive fibers. Hsp70 reduced MPTP-induced apoptosis in the substantia nigra, and unilateral protection of the dopaminergic system by Hsp70 was associated with increased amphetamine-induced turning toward the uninjected side. Collectively, these results suggest that increasing chaperone activity may be beneficial for the treatment of idiopathic PD.

  8. Maternal vitamin D deficiency alters fetal brain development in the BALB/c mouse.

    PubMed

    Hawes, Jazmin E; Tesic, Dijana; Whitehouse, Andrew J; Zosky, Graeme R; Smith, Jeremy T; Wyrwoll, Caitlin S

    2015-06-01

    Prenatal exposure to vitamin D is thought to be critical for optimal fetal neurodevelopment, yet vitamin D deficiency is apparent in a growing proportion of pregnant women. The aim of this study was to determine whether a mouse model of vitamin D-deficiency alters fetal neurodevelopment. Female BALB/c mice were placed on either a vitamin D control (2,195 IU/kg) or deficient (0 IU/kg) diet for 5 weeks prior to and during pregnancy. Fetal brains were collected at embryonic day (E) 14.5 or E17.5 for morphological and gene expression analysis. Vitamin D deficiency during pregnancy reduced fetal crown-rump length and head size. Moreover, lateral ventricle volume was reduced in vitamin D-deficient foetuses. Expression of neurotrophin genes brain-derived neurotrophic factor (Bdnf) and transforming growth factor-β1 (Tgf-β1) was altered, with Bdnf reduced at E14.5 and increased at E17.5 following vitamin D deficiency. Brain expression of forkhead box protein P2 (Foxp2), a gene known to be important in human speech and language, was also altered. Importantly, Foxp2 immunoreactive cells in the developing cortex were reduced in vitamin D-deficient female foetuses. At E17.5, brain tyrosine hydroxylase (TH) gene expression was reduced in females, as was TH protein localization (to identify dopamine neurons) in the substantia nigra of vitamin D-deficient female foetuses. Overall, we show that prenatal vitamin D-deficiency leads to alterations in fetal mouse brain morphology and genes related to neuronal survival, speech and language development, and dopamine synthesis. Vitamin D appears to play an important role in mouse neurodevelopment.

  9. Striatal Dysfunctions Associated with Mitochondrial DNA Damage in Dopaminergic Neurons in a Mouse Model of Parkinson’s Disease

    PubMed Central

    Pickrell, Alicia M.; Pinto, Milena; Hida, Aline; Moraes, Carlos T.

    2012-01-01

    Parkinson’s disease (PD) is one of the most common progressive neurodegenerative disorders, characterized by resting tremor, rigidity, bradykinesia, and postural instability. These symptoms are associated with massive loss of tyrosine hydroxylase-positive neurons in the substantia nigra (SN) causing an estimated 70–80% depletion of dopamine (DA) in the striatum, where their projections are located. Although the etiology of PD is unknown, mitochondrial dysfunctions have been associated with the disease pathophysiology. We used a mouse model expressing a mitochondria-targeted restriction enzyme, PstI or mito-PstI, to damage mitochondrial DNA (mtDNA) in dopaminergic neurons. The expression of mito-PstI induces double-strand breaks in the mtDNA, leading to an oxidative phosphorylation deficiency, mostly due to mtDNA depletion. Taking advantage of a dopamine transporter (DAT) promoter-driven tetracycline transactivator protein (tTA), we expressed mito-PstI exclusively in dopaminergic neurons, creating a novel PD transgenic mouse model (PD-mito-PstI mouse). These mice recapitulate most of the major features of PD: they have a motor phenotype that is reversible with l-DOPA treatment, a progressive neurodegeneration of the SN dopaminergic population, and striatal DA depletion. Our results also showed that behavioral phenotypes in PD-mito-PstI mice were associated with striatal dysfunctions preceding SN loss of tyrosine hydroxylase-positive neurons and that other neurotransmitter systems [noradrenaline (NE) and serotonin (5-HT)] were increased after the disruption of DA neurons, potentially as a compensatory mechanism. This transgenic mouse model provides a novel model to study the role of mitochondrial defects in the axonal projections of the striatum in the pathophysiology of PD. PMID:22131425

  10. Acupuncture Enhances the Synaptic Dopamine Availability to Improve Motor Function in a Mouse Model of Parkinson's Disease

    PubMed Central

    Kim, Seung-Nam; Doo, Ah-Reum; Park, Ji-Yeun; Bae, Hyungjin; Chae, Younbyoung; Shim, Insop; Lee, Hyangsook; Moon, Woongjoon; Lee, Hyejung; Park, Hi-Joon

    2011-01-01

    Parkinson's disease (PD) is caused by the selective loss of dopaminergic neurons in the substantia nigra (SN) and the depletion of striatal dopamine (DA). Acupuncture, as an alternative therapy for PD, has beneficial effects in both PD patients and PD animal models, although the underlying mechanisms therein remain uncertain. The present study investigated whether acupuncture treatment affected dopamine neurotransmission in a PD mouse model using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). We found that acupuncture treatment at acupoint GB34 improved motor function with accompanying dopaminergic neuron protection against MPTP but did not restore striatal dopamine depletion. Instead, acupuncture treatment increased dopamine release that in turn, may lead to the enhancement of dopamine availability in the synaptic cleft. Moreover, acupuncture treatment mitigated MPTP-induced abnormal postsynaptic changes, suggesting that acupuncture treatment may increase postsynaptic dopamine neurotransmission and facilitate the normalization of basal ganglia activity. These results suggest that the acupuncture-induced enhancement of synaptic dopamine availability may play a critical role in motor function improvement against MPTP. PMID:22132113

  11. Escin attenuates behavioral impairments, oxidative stress and inflammation in a chronic MPTP/probenecid mouse model of Parkinson's disease.

    PubMed

    Selvakumar, Govindasamy Pushpavathi; Janakiraman, Udaiyappan; Essa, Musthafa Mohamed; Justin Thenmozhi, Arokiasamy; Manivasagam, Thamilarasan

    2014-10-17

    Parkinson's disease (PD) is a progressive neurodegenerative disorder that results mainly due to the death of dopaminergic neurons in the substantia nigra (SN), and subsequently has an effect on one's motor function and coordination. The current investigation explored the neuroprotective potential of escin, a natural triterpene-saponin on chronic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine/probenecid (MPTP/p) induced mouse model of PD. Administration of MPTP led to the depleted striatal dopamine content, impaired patterns of behavior, enhanced oxidative stress and diminished expression of tyrosine hydroxylase (TH), dopamine transporter (DAT) and vesicular monoamine transporter-2 (VMAT-2). The expressions of interleukin-6 and -10, glial fibrillary acidic protein (GFAP), ionized calcium-binding adaptor protein-1 (IBA-1), tumor necrosis factor-α (TNF-α) and inducible nitric oxide synthase (iNOS) in SN were also enhanced. Oral treatment of escin significantly attenuated MPTP/p induced dopaminergic markers depletion, physiological abnormalities, oxidative stress and inhibit neuroinflammatory cytokine expressions in SN. The result of our study confirmed that escin mediated its protection against experimental PD through its antioxidant and anti-inflammatory properties. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. MMP-3 contributes to nigrostriatal dopaminergic neuronal loss, BBB damage, and neuroinflammation in an MPTP mouse model of Parkinson's disease.

    PubMed

    Chung, Young Cheul; Kim, Yoon-Seong; Bok, Eugene; Yune, Tae Young; Maeng, Sungho; Jin, Byung Kwan

    2013-01-01

    The present study examined whether matrix metalloproteinase-3 (MMP-3) participates in the loss of dopaminergic (DA) neurons in the nigrostriatal pathway in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of Parkinson's disease with blood brain barrier (BBB) damage and infiltration of peripheral immune cells. Tyrosine hydroxylase (TH) immunostaining of brain sections from MPTP-treated mice showed that MPTP induced significant degeneration of nigrostriatal DA neurons. Moreover, FITC-labeled albumin detection and immunostaining revealed that MPTP caused damage to the BBB and increased the number of ED-1- and CD-3-immunopositive cells in the substantia nigra (SN). Genetic ablation of MMP-3 reduced the nigrostriatal DA neuron loss and improved motor function. This neuroprotective effect afforded by MMP-3 deletion was associated with the suppression of BBB disruption and a decrease in the number of ED-1- and CD-3-immunopositive cells in the SN. These data suggest that MMP-3 could play a crucial role in neurodegenerative diseases such as PD in which BBB damage and neuroinflammation are implicated.

  13. Ebf2 is required for development of dopamine neurons in the midbrain periaqueductal gray matter of mouse.

    PubMed

    Yang, Qiaoqiao; Liu, Shuxi; Yin, Min; Yin, Yanqing; Zhou, Guomin; Zhou, Jiawei

    2015-11-01

    Dopaminergic (DA) neurons in the midbrain ventral periaqueductal gray matter (PAG) play critical roles in various physiological and pathophysiological processes including sleep-wake rhyme, antinociception, and drug addiction. However, the molecular mechanisms underlying their development are poorly understood. Here, we showed that PAG DA neurons arose as early as E15.5 in mouse embryos. During the prenatal period, the majority of PAG DA neurons was distributed in the intermediate and caudal regions of the PAG. In the postnatal brain, ∼50% of PAG DA neurons were preferentially located in the caudal portion of the PAG. Moreover, transcription factor early B-cell factor 2 (Ebf2) was transiently expressed in a subset of DA neurons in embryonic ventral mesencephalon. Functional analysis revealed that loss of Ebf2 in vivo caused a marked reduction in the number of DA neurons in the midbrain PAG but not in the substantia nigra and ventral tegmental area. Thus, Ebf2 is identified as a novel and important regulator selectively required for midbrain PAG DA neuron development.

  14. Neuroprotective effect of long-term NDI1 gene expression in a chronic mouse model of Parkinson disorder.

    PubMed

    Barber-Singh, Jennifer; Seo, Byoung Boo; Nakamaru-Ogiso, Eiko; Lau, Yuen-Sum; Matsuno-Yagi, Akemi; Yagi, Takao

    2009-08-01

    Previously, we showed that the internal rotenone-insensitive nicotinamide adenine dinucleotide (NADH)-quinone oxidoreductase (NDI1) gene from Saccharomyces cerevisiae (baker's yeast) can be successfully inserted into the mitochondria of mice and rats and the expressed enzyme was found to be fully functional. In this study, we investigated the ability of the Ndi1 enzyme to protect the dopaminergic neurons in a chronic mouse model of Parkinson disorder. After expression of the NDI1 gene in the unilateral substantia nigra of male C57BL/6 mice for 8 months, a chronic Parkinsonian model was created by administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) with probenecid and evaluated using neurochemical and behavioral responses 1-4 weeks post-MPTP/probenecid injection. We showed that expression of Ndi1 was able to significantly prevent the loss of dopamine and tyrosine hydroxylase as well as the dopaminergic transporters in the striatum of the chronic Parkinsonian mice. Behavioral assessment based on a methamphetamine-induced rotation test and spontaneous swing test further supported neurological preservation in the NDI1-treated Parkinsonian mice. The data presented in this study demonstrate a protective effect of the NDI1 gene in dopaminergic neurons, suggesting its therapeutic potential for Parkinson-like disorders.

  15. Protective effect of chinonin in MPTP-induced C57BL/6 mouse model of Parkinson's disease.

    PubMed

    Feng, Guoshuai; Zhang, Zhijian; Bao, Qingqing; Zhang, Zaijun; Zhou, Libing; Jiang, Jie; Li, Sha

    2014-01-01

    The aims of this study were to investigate the effect of chinonin in preventing 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurodegeneration in C57BL/6 mice and to examine the possible mechanisms. The neurotoxin MPTP was employed to create a subacute Parkinson's disease (PD)-like model in C57BL/6 mice. Chinonin (10, 20, 40 mg/kg body weight) was intraperitoneally administered 0.5 h after MPTP (30 mg/kg) injection for 7 d consecutively. Chinonin showed neuroprotective effects in the MPTP-treated mice PD model by ameliorating motor impairment in the catwalk and open-field tests. Consistently, chinonin reduced loss of dopaminergic neurons in the substantia nigra and prevented depletion of dopamine and its metabolites 3-methoxy-4-hydroxy-phenylacetic acid and homovanillic acid in the striatum of mice. Compared with the MPTP group, in the chinonin plus MPTP groups significant increases of superoxide dismutase activity and glutathione levels were observed as well as a distinct reduction of lipid peroxidation product malondialdehyde in the striatum. Taken together, we propose that chinonin exerts neuroprotective effects in C57BL/6 mouse model of PD and these effects may be due to chinonin's antioxidative property.

  16. Transgenic Mouse Lines Subdivide External Segment of the Globus Pallidus (GPe) Neurons and Reveal Distinct GPe Output Pathways

    PubMed Central

    Mastro, Kevin J.; Bouchard, Rachel S.; Holt, Hiromi A. K.

    2014-01-01

    Cell-type diversity in the brain enables the assembly of complex neural circuits, whose organization and patterns of activity give rise to brain function. However, the identification of distinct neuronal populations within a given brain region is often complicated by a lack of objective criteria to distinguish one neuronal population from another. In the external segment of the globus pallidus (GPe), neuronal populations have been defined using molecular, anatomical, and electrophysiological criteria, but these classification schemes are often not generalizable across preparations and lack consistency even within the same preparation. Here, we present a novel use of existing transgenic mouse lines, Lim homeobox 6 (Lhx6)–Cre and parvalbumin (PV)–Cre, to define genetically distinct cell populations in the GPe that differ molecularly, anatomically, and electrophysiologically. Lhx6–GPe neurons, which do not express PV, are concentrated in the medial portion of the GPe. They have lower spontaneous firing rates, narrower dynamic ranges, and make stronger projections to the striatum and substantia nigra pars compacta compared with PV–GPe neurons. In contrast, PV–GPe neurons are more concentrated in the lateral portions of the GPe. They have narrower action potentials, deeper afterhyperpolarizations, and make stronger projections to the subthalamic nucleus and parafascicular nucleus of the thalamus. These electrophysiological and anatomical differences suggest that Lhx6–GPe and PV–GPe neurons participate in different circuits with the potential to contribute to different aspects of motor function and dysfunction in disease. PMID:24501350

  17. Acupuncture enhances the synaptic dopamine availability to improve motor function in a mouse model of Parkinson's disease.

    PubMed

    Kim, Seung-Nam; Doo, Ah-Reum; Park, Ji-Yeun; Bae, Hyungjin; Chae, Younbyoung; Shim, Insop; Lee, Hyangsook; Moon, Woongjoon; Lee, Hyejung; Park, Hi-Joon

    2011-01-01

    Parkinson's disease (PD) is caused by the selective loss of dopaminergic neurons in the substantia nigra (SN) and the depletion of striatal dopamine (DA). Acupuncture, as an alternative therapy for PD, has beneficial effects in both PD patients and PD animal models, although the underlying mechanisms therein remain uncertain. The present study investigated whether acupuncture treatment affected dopamine neurotransmission in a PD mouse model using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). We found that acupuncture treatment at acupoint GB34 improved motor function with accompanying dopaminergic neuron protection against MPTP but did not restore striatal dopamine depletion. Instead, acupuncture treatment increased dopamine release that in turn, may lead to the enhancement of dopamine availability in the synaptic cleft. Moreover, acupuncture treatment mitigated MPTP-induced abnormal postsynaptic changes, suggesting that acupuncture treatment may increase postsynaptic dopamine neurotransmission and facilitate the normalization of basal ganglia activity. These results suggest that the acupuncture-induced enhancement of synaptic dopamine availability may play a critical role in motor function improvement against MPTP.

  18. 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.

  19. Effect of GDNF on depressive-like behavior, spatial learning and key genes of the brain dopamine system in genetically predisposed to behavioral disorders mouse strains.

    PubMed

    Naumenko, Vladimir S; Kondaurova, Elena M; Bazovkina, Daria V; Tsybko, Anton S; Ilchibaeva, Tatyana V; Khotskin, Nikita V; Semenova, Alina A; Popova, Nina K

    2014-11-01

    The effect of glial cell line-derived neurotrophic factor (GDNF) on behavior and brain dopamine system in predisposed to depressive-like behavior ASC (Antidepressant Sensitive Cataleptics) mice in comparison with the parental "nondepressive" CBA mice was studied. In 7days after administration (800ng, i.c.v.) GDNF decreased escape latency time and the path traveled to reach hidden platform in Morris water maze in ASC mice. GDNF enhanced depressive-like behavioral traits in both "nondepressive" CBA and "depressive" ASC mice. In CBA mice, GDNF decreased functional response to agonists of D1 (chloro-APB hydrobromide) and D2 (sumanirole maleate) receptors in tail suspension test, reduced D2 receptor gene expression in the substantia nigra and increased monoamine oxydase A (MAO A) gene expression in the striatum. GDNF increased D1 and D2 receptor genes expression in the nucleus accumbens of ASC mice but failed to alter expression of catechol-O-methyltransferase, dopamine transporter, MAO B and tyrosine hydroxylase genes in both investigated mouse strains. Thus, GDNF produced long-term genotype-dependent effect on behavior and the brain dopamine system. GDNF pretreatment (1) reduced D1 and D2 receptors functional responses and D2 receptor gene expression in s. nigra of CBA mice; (2) increased D1 and D2 receptor genes expression in n. accumbens of ASC mice and (3) improved spatial learning in ASC mice. GDNF enhanced depressive-like behavior both in CBA and ASC mice. The data suggest that genetically defined variance in the cross-talk between GDNF and brain dopamine system contributes to the variability of GDNF-induced responses and might be responsible for controversial GDNF effects. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Broad neuroprotective profile of nicotinamide in different mouse models of MPTP-induced parkinsonism.

    PubMed

    Anderson, D W; Bradbury, K A; Schneider, J S

    2008-08-01

    The factors contributing to substantia nigra pars compacta (SNc) dopamine (DA) neuron death and striatal DA depletion in Parkinson's disease (PD) are still poorly understood. However, mitochondrial dysfunction, cellular energy depletion and oxidative stress appear to play important roles in the pathogenesis of PD. In view of this, the current study examined the potential of nicotinamide, a form of the B-complex vitamin niacin, to protect against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced SNc cell loss and striatal DA depletion in two mouse MPTP models that respond differently to putative neuroprotective agents. Adult male C57Bl/6 mice received nicotinamide (125, 250 or 500 mg/kg i.p.) prior to either acute (four injections in 1 day at 2-h intervals) or sub-acute (two injections per day at 4-h intervals for 5 days) MPTP administration. Striatal DA levels, changes in numbers of tyrosine hydroxylase (TH)- and cresyl violet-stained cells in the SNc at 2 and 6 weeks following the last MPTP exposure were analyzed. Nicotinamide administration resulted in a dose-dependent sparing of striatal DA levels and SNc neurons in acute MPTP-treated animals. Only the highest dose of nicotinamide had similar effects in sub-acute MPTP-treated animals. At 6 weeks after MPTP exposure, there was some spontaneous recovery of striatal DA levels in both models: neuroprotective effects were still apparent in acute but not sub-acute MPTP-treated animals. These results show neuroprotective effects of nicotinamide in different mouse Parkinson models associated with different forms of cell death and suggest that nicotinamide may have broad neuroprotective potential in PD.

  1. Expression of cadherin-8 mRNA in the developing mouse central nervous system.

    PubMed

    Korematsu, K; Redies, C

    1997-10-20

    The expression of cadherin-8 was mapped by in situ hybridization in the embryonic and postnatal mouse central nervous system (CNS). From embryonic day 18 (E18) to postnatal day 6 (P6), cadherin-8 expression is restricted to a subset of developing brain nuclei and cortical areas in all major subdivisions of the CNS. The anlagen of some of the cadherin-8-positive structures also express this molecule at earlier developmental stages (E12.5-E16). The cadherin-8-positive neuroanatomical structures are parts of several functional systems in the brain. In the limbic system, cadherin-8-positive regions are found in the septal region, habenular nuclei, amygdala, interpeduncular nucleus, raphe nuclei, and hippocampus. Cerebral cortex shows expression in several limbic areas at P6. In the basal ganglia and related nuclei, cadherin-8 is expressed by parts of the striatum, globus pallidus, substantia nigra, entopeduncular nucleus, subthalamic nucleus, zona incerta, and pedunculopontine nuclei. A third group of cadherin-8-positive gray matter structures has functional connections with the cerebellum (superior colliculus, anterior pretectal nucleus, red nucleus, nucleus of posterior commissure, inferior olive, pontine, pontine reticular, and vestibular nuclei). The cerebellum itself shows parasagittal stripes of cadherin-8 expression in the Purkinje cell layer. In the hindbrain, cadherin-8 is expressed by several cranial nerve nuclei. Results from this study show that cadherin-8 expression in the embryonic and postnatal mouse brain is restricted to specific developing gray matter structures. These data support the idea that cadherins are a family of molecules whose expression provides a molecular code for the regionalization of the developing vertebrate brain.

  2. Phosphatidylinositol 3-kinase/Akt signaling pathway mediates acupuncture-induced dopaminergic neuron protection and motor function improvement in a mouse model of Parkinson's disease.

    PubMed

    Kim, Seung-Nam; Kim, Seung-Tae; Doo, Ah-Reum; Park, Ji-Yeun; Moon, Woongjoon; Chae, Younbyoung; Yin, Chang Shik; Lee, Hyejung; Park, Hi-Joon

    2011-10-01

    It has been reported that acupuncture treatment reduced dopaminergic neuron degeneration in Parkinson's disease (PD) models. However, the mechanistic pathways underlying, such neuroprotection, are poorly understood. Here, we investigated the effects and the underlying mechanism of acupuncture in a mouse model of PD using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). First, we observed that MPTP-induced impairment of Akt activation, but not MPTP-induced c-Jun activation, was effectively restored by acupuncture treatment in the substantia nigra. Furthermore, we demonstrated for the first time that the brain-specific blockade of phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway, by intranasal administration of LY294002, a specific inhibitor of PI3K/Akt signaling pathway, significantly blocked acupuncture-induced dopaminergic neuron protection and motor function improvement. Our results provide evidence that PI3K/Akt signaling pathway may play a central role in the mechanism underlying acupuncture-induced benefits in Parkinsonian mice.

  3. Delivery of Dual Drug Loaded Lipid Based Nanoparticles across the Blood-Brain Barrier Impart Enhanced Neuroprotection in a Rotenone Induced Mouse Model of Parkinson's Disease.

    PubMed

    Kundu, Paromita; Das, Manasi; Tripathy, Kalpalata; Sahoo, Sanjeeb K

    2016-12-21

    Parkinson's disease (PD) is the most widespread form of dementia where there is an age related degeneration of dopaminergic neurons in the substantia nigra region of the brain. Accumulation of α-synuclein (αS) protein aggregate, mitochondrial dysfunction, oxidative stress, and neuronal cell death are the pathological hallmarks of PD. In this context, amalgamation of curcumin and piperine having profound cognitive properties, and antioxidant activity seems beneficial. However, the blood-brain barrier (BBB) is the major impediment for delivery of neurotherapeutics to the brain. The present study involves formulation of curcumin and piperine coloaded glyceryl monooleate (GMO) nanoparticles coated with various surfactants with a view to enhance the bioavailability of curcumin and penetration of both drugs to the brain tissue crossing the BBB and to enhance the anti-parkinsonism effect of both drugs in a single platform. In vitro results demonstrated augmented inhibition of αS protein into oligomers and fibrils, reduced rotenone induced toxicity, oxidative stress, and apoptosis, and activation of autophagic pathway by dual drug loaded NPs compared to native counterpart. Further, in vivo studies revealed that our formulated dual drug loaded NPs were able to cross BBB, rescued the rotenone induced motor coordination impairment, and restrained dopaminergic neuronal degeneration in a PD mouse model.

  4. Widespread correction of lysosomal storage in the mucopolysaccharidosis type VII mouse brain with a herpes simplex virus type 1 vector expressing beta-glucuronidase.

    PubMed

    Berges, Bradford K; Yellayi, Srikanth; Karolewski, Brian A; Miselis, Richard R; Wolfe, John H; Fraser, Nigel W

    2006-05-01

    We have inoculated a herpes simplex virus type 1 (HSV-1) vector into a variety of sites in the mouse brain and assayed the regions of latency and expression of a beta-glucuronidase (GUSB) cDNA from the latency-associated transcript promoter. Injection sites used were somatosensory cortex, visual cortex, striatum, dorsal hippocampus, and CSF spaces. Latent vector was detected in regions at a distance from the respective injection sites, consistent with axonal transport of vector. Regions of GUSB activity varied by injection site and included cerebral cortex, striatum, thalamus, hypothalamus, substantia nigra, hippocampus, midbrain, pons, medulla, cerebellum, and spinal cord. After a single injection, GUSB enzymatic activity reached wild-type levels in several brain regions. GUSB was found in some areas without any detectable vector, indicative of axonal transport of GUSB enzyme. GUSB-deficient mice, which have the lysosomal storage disease mucopolysaccharidosis (MPS) VII, have lysosomal storage lesions in cells throughout the brain. Adult MPS VII mice treated by injection of vector into a single site on each side of the brain had correction of storage lesions in a large volume of brain. The potential for long-term, widespread correction of lysosomal storage diseases with HSV-1 vectors is discussed.

  5. Neuroprotective Effects of Salidroside in the MPTP Mouse Model of Parkinson's Disease: Involvement of the PI3K/Akt/GSK3β Pathway

    PubMed Central

    He, Hong; Song, Hujie; Zhao, Junjie; Li, Tao; Wu, Leitao

    2016-01-01

    The degenerative loss through apoptosis of dopaminergic neurons in the substantia nigra pars compacta plays a primary role in the progression of Parkinson's disease (PD). Our in vitro experiments suggested that salidroside (Sal) could protect against 1-methyl-4-phenylpyridine-induced cell apoptosis in part by regulating the PI3K/Akt/GSK3β pathway. The current study aims to increase our understanding of the protective mechanisms of Sal in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropypridine- (MPTP-) induced PD mouse model. We found that pretreatment with Sal could protect against MPTP-induced increase of the time of turning downwards and climbing down to the floor. Sal also prevented MPTP-induced decrease of locomotion frequency and the increase of the immobile time. Sal provided a protection of in MPTP-induced loss of tyrosine hydroxylase-positive neurons in SNpc and the level of DA, DOPAC, and HVA in the striatum. Furthermore, Sal could increase the phosphorylation level of Akt and GSK3β, upregulate the ratio of Bcl-2/Bax, and inhibit the activation of caspase-3, caspase-6, and caspase-9. These results show that Sal prevents the loss of dopaminergic neurons and the PI3K/Akt/GSK3β pathway signaling pathway may have mediated the protection of Sal against MPTP, suggesting that Sal may be a potential candidate in neuroprotective treatment for PD. PMID:27738547

  6. Dissociation between dopaminergic response and motor behavior following intrastriatal, but not intravenous, transplant of bone marrow mononuclear stem cells in a mouse model of Parkinson's disease.

    PubMed

    Calice da Silva, Caroline; Azevedo, Bárbara Nunes; Machado, Denise Cantarelli; Zimmer, Eduardo R; Martins, Leo Anderson Meira; da Costa, Jaderson Costa

    2017-05-01

    Parkinson's disease is characterized by the progressive loss of dopaminergic neurons from the substantia nigra, a process that leads to a dopamine deficiency in the striatum. This deficiency is responsible for the development of motor symptoms, including resting tremor, bradykinesia, rigidity and postural instability. Based on the observation of substantial neuronal death, alternatives to Parkinson's disease treatment have been studied, including cell-based therapies. The present study aimed to assess the therapeutic potential of intravenous and intrastriatal transplant of bone marrow mononuclear cells in a mouse model of Parkinson's disease. Animals underwent stereotaxic surgery and received an injection of 6-hydroxydopamine into their medial forebrain bundle. Three weeks later, mice were injected with bone marrow mononuclear cells or saline through the caudal vein or directly into their right striatum. Motor function was assessed using the rotarod and apomorphine-induced rotation tests. Our results showed that intrastriatal bone marrow mononuclear cells, but not intravenous, have a short-term therapeutic effect on dopaminergic response in this mice model of parkinsonism assessed by the apomorphine-induced rotation test. This phenomenon was not identified on the rotarod test, showing dissociation between dopaminergic response and motor behavior. Further experiments are needed to elucidate the precise mechanisms involved in these effects. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Extraction and antioxidant activity of flavonoids of Morus nigra

    PubMed Central

    Feng, Rui-Zhang; Wang, Qin; Tong, Wen-Zhi; Xiong, Juan; Wei, Qin; Zhou, Wan-Hai; Yin, Zhong-Qiong; Yin, Xiao-Ya; Wang, Li-Ying; Chen, Ya-Qin; Lai, Yong-Hong; Huang, Hong-Yan; Luo, Qiao-Li; Wang, Lu; Jia, Ren-Yong; Song, Xu; Zou, Yuan-Feng; Li, Li-Xia

    2015-01-01

    Morus nigra has a long history of medicinal use in Chinese medicine, but the study on it is limited, the flavonoids are one of the main biological active substances. In this study, the Morus nigra flavonoids were extracted by ultrasonic and antioxidant activities both in vitro and in vivo were measured. The results showed that hydroxyl radicals clearance rate and superoxide radical anion clearance rate in vitro increased with the concentration of the total flavonoids in the range of 0-1.05 mg/mL and the maximum clearance rate was 80.33% and 87.69%, respectively. After mice were treated with flavonoids, the content of malonaldehyde (MDA) in serum and liver decreased; the activities of superoxide dismutase (SOD) in serum and liver, catalase (CAT) in liver and glutathione peroxidase (GSH-PX) in blood and liver increased; Langhans cells increased in spleen. These results revealed that the Morus nigra flavonoids possessed strong antioxidant activity. PMID:26885210

  8. Complete mitochondrial genome of the crested black macaque (Macaca nigra).

    PubMed

    Du, Li-Na; Shi, Fang-Lei; Liu, Zhi-Jin; Zhou, Qi-Hai

    2016-11-01

    The complete mitochondrial sequence of the crested black macaque (Macaca nigra) has been determined by mapping the raw data to previously published mitochondrial assemblies of the corresponding species. The total sequence length is 16,564 bp and includes 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and 1 D-loop control region. The base composition of mtDNA genome is 31.76% A, 25.27% T, 30.17% C, and 12.80% G, with an AT content of 57.03%. The arrangement of genes in M. nigra is identical to that of M. mulatta. All genes are encoded on the heavy strand with the exception of ND6 and eight tRNA genes. The mitochondrial genome of M. nigra presented here will contribute to a better understanding of the population genetics, help to protect its genetic diversity and resolve phylogenetic relationships within the family.

  9. Extraction and antioxidant activity of flavonoids of Morus nigra.

    PubMed

    Feng, Rui-Zhang; Wang, Qin; Tong, Wen-Zhi; Xiong, Juan; Wei, Qin; Zhou, Wan-Hai; Yin, Zhong-Qiong; Yin, Xiao-Ya; Wang, Li-Ying; Chen, Ya-Qin; Lai, Yong-Hong; Huang, Hong-Yan; Luo, Qiao-Li; Wang, Lu; Jia, Ren-Yong; Song, Xu; Zou, Yuan-Feng; Li, Li-Xia

    2015-01-01

    Morus nigra has a long history of medicinal use in Chinese medicine, but the study on it is limited, the flavonoids are one of the main biological active substances. In this study, the Morus nigra flavonoids were extracted by ultrasonic and antioxidant activities both in vitro and in vivo were measured. The results showed that hydroxyl radicals clearance rate and superoxide radical anion clearance rate in vitro increased with the concentration of the total flavonoids in the range of 0-1.05 mg/mL and the maximum clearance rate was 80.33% and 87.69%, respectively. After mice were treated with flavonoids, the content of malonaldehyde (MDA) in serum and liver decreased; the activities of superoxide dismutase (SOD) in serum and liver, catalase (CAT) in liver and glutathione peroxidase (GSH-PX) in blood and liver increased; Langhans cells increased in spleen. These results revealed that the Morus nigra flavonoids possessed strong antioxidant activity.

  10. mRNA Transcriptomics of Galectins Unveils Heterogeneous Organization in Mouse and Human Brain

    PubMed Central

    John, Sebastian; Mishra, Rashmi

    2016-01-01

    Background: Galectins, a family of non-classically secreted, β-galactoside binding proteins is involved in several brain disorders; however, no systematic knowledge on the normal neuroanatomical distribution and functions of galectins exits. Hence, the major purpose of this study was to understand spatial distribution and predict functions of galectins in brain and also compare the degree of conservation vs. divergence between mouse and human species. The latter objective was required to determine the relevance and appropriateness of studying galectins in mouse brain which may ultimately enable us to extrapolate the findings to human brain physiology and pathologies. Results: In order to fill this crucial gap in our understanding of brain galectins, we analyzed the in situ hybridization and microarray data of adult mouse and human brain respectively, from the Allen Brain Atlas, to resolve each galectin-subtype’s spatial distribution across brain distinct cytoarchitecture. Next, transcription factors (TFs) that may regulate galectins were identified using TRANSFAC software and the list obtained was further curated to sort TFs on their confirmed transcript expression in the adult brain. Galectin-TF cluster analysis, gene-ontology annotations and co-expression networks were then extrapolated to predict distinct functional relevance of each galectin in the neuronal processes. Data shows that galectins have highly heterogeneous expression within and across brain sub-structures and are predicted to be the crucial targets of brain enriched TFs. Lgals9 had maximal spatial distribution across mouse brain with inferred predominant roles in neurogenesis while LGALS1 was ubiquitously expressed in human. Limbic region associated with learning, memory and emotions and substantia nigra associated with motor movements showed strikingly high expression of LGALS1 and LGALS8 in human vs. mouse brain. The overall expression profile of galectin-8 was most preserved across both these

  11. mRNA Transcriptomics of Galectins Unveils Heterogeneous Organization in Mouse and Human Brain.

    PubMed

    John, Sebastian; Mishra, Rashmi

    2016-01-01

    Background: Galectins, a family of non-classically secreted, β-galactoside binding proteins is involved in several brain disorders; however, no systematic knowledge on the normal neuroanatomical distribution and functions of galectins exits. Hence, the major purpose of this study was to understand spatial distribution and predict functions of galectins in brain and also compare the degree of conservation vs. divergence between mouse and human species. The latter objective was required to determine the relevance and appropriateness of studying galectins in mouse brain which may ultimately enable us to extrapolate the findings to human brain physiology and pathologies. Results: In order to fill this crucial gap in our understanding of brain galectins, we analyzed the in situ hybridization and microarray data of adult mouse and human brain respectively, from the Allen Brain Atlas, to resolve each galectin-subtype's spatial distribution across brain distinct cytoarchitecture. Next, transcription factors (TFs) that may regulate galectins were identified using TRANSFAC software and the list obtained was further curated to sort TFs on their confirmed transcript expression in the adult brain. Galectin-TF cluster analysis, gene-ontology annotations and co-expression networks were then extrapolated to predict distinct functional relevance of each galectin in the neuronal processes. Data shows that galectins have highly heterogeneous expression within and across brain sub-structures and are predicted to be the crucial targets of brain enriched TFs. Lgals9 had maximal spatial distribution across mouse brain with inferred predominant roles in neurogenesis while LGALS1 was ubiquitously expressed in human. Limbic region associated with learning, memory and emotions and substantia nigra associated with motor movements showed strikingly high expression of LGALS1 and LGALS8 in human vs. mouse brain. The overall expression profile of galectin-8 was most preserved across both these

  12. HIF1α is necessary for exercise-induced neuroprotection while HIF2α is needed for dopaminergic neuron survival in the substantia nigra pars compacta.

    PubMed

    Smeyne, M; Sladen, P; Jiao, Y; Dragatsis, I; Smeyne, R J

    2015-06-04

    Exercise reduces the risk of developing a number of neurological disorders and increases the efficiency of cellular energy production. However, overly strenuous exercise produces oxidative stress. Proper oxygenation is crucial for the health of all tissues, and tight regulation of cellular oxygen is critical to balance O2 levels and redox homeostasis in the brain. Hypoxia Inducible Factor (HIF)1α and HIF2α are transcription factors regulated by cellular oxygen concentration that initiate gene regulation of vascular development, redox homeostasis, and cell cycle control. HIF1α and HIF2α contribute to important adaptive mechanisms that occur when oxygen and ROS homeostasis become unbalanced. It has been shown that preconditioning by exposure to a stressor prior to a hypoxic event reduces damage that would otherwise occur. Previously we reported that 3 months of exercise protects SNpc dopaminergic (DA) neurons from toxicity caused by Complex I inhibition. Here, we identify the cells in the SNpc that express HIF1α and HIF2α and show that running exercise produces hypoxia in SNpc DA neurons, and alters the expression of HIF1α and HIF2α. In mice carrying a conditional knockout of Hif1α in postnatal neurons we observe that exercise alone produces SNpc TH+ DA neuron loss. Loss of HIF1α also abolishes exercise-induced neuroprotection. In mice lacking Hif2α in postnatal neurons, the number of TH+ DA neurons in the adult SNpc is diminished, but 3months of exercise rescues this loss. We conclude that HIF1α is necessary for exercise-induced neuroprotection and both HIF1α and HIF2α are necessary for the survival and function of adult SNpc DA neurons.

  13. Degeneration of dopaminergic neurons induced by thrombin injection in the substantia nigra of the rat is enhanced by dexamethasone: role of monoamine oxidase enzyme.

    PubMed

    Argüelles, Sandro; Herrera, Antonio J; Carreño-Müller, Eloisa; de Pablos, Rocío M; Villarán, Ruth F; Espinosa-Oliva, Ana M; Machado, Alberto; Cano, Josefina

    2010-01-01

    Anti-inflammatory strategies receive growing attention for their potential to prevent pathological deterioration in disorders such as Parkinson's disease, which is accompanied by inflammatory reactions that might play a critical role in the degeneration of nigral dopaminergic neurons. We investigated the influence of dexamethasone - a potent synthetic member of the glucocorticoids class of steroid hormones that acts as an anti-inflammatory - on the degeneration of the dopaminergic neurons of rats observed after intranigral injection of thrombin, a serine protease that induces inflammation through microglia proliferation and activation. We evaluated tyrosine hydroxylase (TH)-positive neurons as well as astroglial and microglial populations; dexamethasone prevented the loss of astrocytes but was unable to stop microglial proliferation induced by thrombin. Moreover, dexamethasone produced alterations in the levels of nexin and the thrombin receptor PAR-1, and facilitated accumulation of alpha-synuclein induced by thrombin in dopaminergic neurons. Dexamethasone increased oxidative stress and expression of monoamine oxidase A and B, along with changes on different MAP kinases related to degenerative processes, resulting in a bigger loss of dopaminergic neurons after intranigral injection of thrombin in dexamethasone-treated animals. It is interesting to ascertain that inhibition of monoamine oxidase by tranylcypromine prevented neurodegeneration of dopaminergic neurons, thus suggesting that the deleterious effects of dexamethasone might be mediated by monoamine oxidase.

  14. Striatal patch compartment lesions alter methamphetamine-induced behavior and immediate early gene expression in the striatum, substantia nigra and frontal cortex.

    PubMed

    Murray, Ryan C; Gilbert, Yamiece E; Logan, Anna S; Hebbard, John C; Horner, Kristen A

    2014-07-01

    Methamphetamine (METH) induces stereotypy, which is characterized as inflexible, repetitive behavior. Enhanced activation of the patch compartment of the striatum has been correlated with stereotypy, suggesting that stereotypy may be related to preferential activation of this region. However, the specific contribution of the patch compartment to METH-induced stereotypy is not clear. To elucidate the involvement of the patch compartment to the development of METH-induced stereotypy, we determined if destruction of this sub-region altered METH-induced behaviors. Animals were bilaterally infused in the striatum with the neurotoxin dermorphin-saporin (DERM-SAP; 17 ng/μl) to specifically ablate the neurons of the patch compartment. Eight days later, animals were treated with METH (7.5 mg/kg), placed in activity chambers, observed for 2 h and killed. DERM-SAP pretreatment significantly reduced the number and total area of mu-labeled patches in the striatum. DERM-SAP pretreatment significantly reduced the intensity of METH-induced stereotypy and the spatial immobility typically observed with METH-induced stereotypy. In support of this observation, DERM-SAP pretreatment also significantly increased locomotor activity in METH-treated animals. In the striatum, DERM-SAP pretreatment attenuated METH-induced c-Fos expression in the patch compartment, while enhancing METH-induced c-Fos expression in the matrix compartment. DERM-SAP pretreatment followed by METH administration augmented c-Fos expression in the SNpc and reduced METH-induced c-Fos expression in the SNpr. In the medial prefrontal, but not sensorimotor cortex, c-Fos and zif/268 expression was increased following METH treatment in animals pre-treated with DERM-SAP. These data indicate that the patch compartment is necessary for the expression of repetitive behaviors and suggests that alterations in activity in the basal ganglia may contribute to this phenomenon.

  15. [Lesions in the pars compacta substantiae nigra and the subthalamic nucleus modify the density of muscarinic receptors in different nuclei of the basal ganglia].

    PubMed

    Blanco-Lezcano, L; Rocha-Arrieta, L L; Martínez-Martí, L; Alvarez-González, L; Pavón-Fuentes, N; Macías-González, R; Serrano-Sánchez, T; Rosillo-Martí, J C; Coro-Grave de Peralta, Y; Bauza-Calderín, Y; Briones, M

    Several studies that has focused to the dopaminergic transmission in the basal ganglia in parkinsonian condition, but only a few article has taking into account the imbalance between dopaminergic and cholinergic transmission. To evaluate the muscarinic cholinergic receptors density in SNc and PPN in the 6-OHDA model. Were organized five experimental groups in correspondence to the place of the lesion: I. Non treated rats, II. 6-OHDA lesion in SNc, III. 6-OHDA lesion in SNc + quinolinic acid lesion in NST, IV. Sham operated rats, V. Quinolinic acid in STN. Were obtained coronal sections of 20 microm thickness of SNc and PPN from rats and in these sections was evaluated the muscarinic receptors density through autoradiographic technique with [3H]quinuclidinylbenzilate (QNB) (1.23 nM). The muscarinic antagonist atropine (1 microM) was utilized as non-specific union. The density was evaluated in both hemispheres and the density optical was converted in fentomolas/mg of tissue with base to values obtained from tritium standards. Significant diminution of the muscarinic receptors density was found in the SNc ipsilateral to the 6-OHDA lesion from experimental groups II (t=2.76; p<0.05) and III (t=4.06; p<0.05). In the group V, was seen a significant increase of muscarinic receptor density in the SNc ipsilateral to the 6-OHDA lesion. The comparison between experimental groups evidenced significant differences among them (F=13.13; p<0.001) with a significant decrease in the density from SNc of groups II and III and significant increase in the density from SNc of group V in comparison of the others groups. In relation to PPN, muscarinic receptors density from right PPN ipsilateral to the 6-OHDA lesion, shown significant differences (F=3.93; p<0.01) between the experimental groups with a significant increase of this variable in the group II. These results signal a modification of cholinergic activity after 6-OHDA lesion. The changes in the muscarinic receptors populations located in SNc and PPN could be part of different compensatory mechanisms to attempt ameliorate the imbalance between dopaminergic and cholinergic transmission that it was installed after denervation of nigrostriatal forebrain bundle. The excitotoxic lesion of STN impose a new adjust mechanism for cell from PPN, which could be expressed in the changes of muscarinic cholinergic receptors population at the level of SNc.

  16. Motor dysfunction and alterations in glutathione concentration, cholinesterase activity, and BDNF expression in substantia nigra pars compacta in rats with pedunculopontine lesion.

    PubMed

    Blanco-Lezcano, Lisette; Jimenez-Martin, Javier; Díaz-Hung, Mei-Li; Alberti-Amador, Esteban; Wong-Guerra, Maylin; González-Fraguela, Ma Elena; Estupiñán-Díaz, Bárbara; Serrano-Sánchez, Teresa; Francis-Turner, Liliana; Delgado-Ocaña, Susana; Núñez-Figueredo, Yanier; Vega-Hurtado, Yamilé; Fernández-Jiménez, Isabel

    2017-04-21

    Pedunculopontine nucleus (PPN) has been considered a critically important region in the regulation of some of the physiological functions that fail during the progression of Parkinson's disease (PD). In this paper, the effects of unilateral neurotoxic lesion of the PPN [through the injection of N-methyl-d-aspartate (NMDA) solution (concentration: 0.1M; volume: 0.5µL)] in motor execution and gait disorders and the changes in cellular and molecular indicators in rat nigral tissue were evaluated. The motor execution was assessed using the beam test (BT) and the gait disorders by footprint test. Glutathione (GSH) concentrations, acetyl cholinesterase enzymatic activity (AChE EA), and brain-derived neurotrophic factor (BDNF) mRNA expression in nigral tissue were analyzed. NMDA-lesioned rats showed fine motor dysfunction with a significant increase in the slow (p≤0.01) and fast movement (p≤0.01) time and in path deviation (p≤0.01) on the smaller diameter beams. Moreover, NMDA-lesioned rats exhibited an imprecise path with moments of advances and setbacks, alternating with left and right deviations, suspensions, and inverted positions. Footprint test revealed slight gait disorders, which were manifested by a reduction in the left and right stride lengths, the intra-step distance, and the support area (p≤0.01). Biochemical studies showed that 48h after the PPN neurotoxic injury, the GSH concentrations and BDNF expression were significantly increased (p≤0.01). These variables returned to normal values 7days after the PPN lesion; the AChE EA showed a significant increase at this time. These functional changes in nigral tissue could be a plastic responses associated with early PD.

  17. The novel adaptive rotating beam test unmasks sensorimotor impairments in a transgenic mouse model of Parkinson's disease.

    PubMed

    Gerstenberger, Julia; Bauer, Anne; Helmschrodt, Christin; Richter, Angelika; Richter, Franziska

    2016-05-01

    Development of disease modifying therapeutics for Parkinson's disease (PD), the second most common neurodegenerative disorder, relies on availability of animal models which recapitulate the disease hallmarks. Only few transgenic mouse models, which mimic overexpression of alpha-synuclein, show dopamine loss, behavioral impairments and protein aggregation. Mice overexpressing human wildtype alpha-synuclein under the Thy-1 promotor (Thy1-aSyn) replicate these features. However, female mice do not exhibit a phenotype. This was attributed to a potentially lower transgene expression located on the X chromosome. Here we support that female mice overexpress human wildtype alpha-synuclein only about 1.5 fold in the substantia nigra, compared to about 3 fold in male mice. Since female Thy1-aSyn mice were shown previously to exhibit differences in corticostriatal communication and synaptic plasticity similar to their male counterparts we hypothesized that female mice use compensatory mechanisms and strategies to not show overt motor deficits despite an underlying endophenotype. In order to unmask these deficits we translated recent findings in PD patients that sensory abnormalities can enhance motor dysfunction into a novel behavioral test, the adaptive rotating beam test. We found that under changing sensory input female Thy1-aSyn mice showed an overt phenotype. Our data supports that the integration of sensorimotor information is likely a major contributor to symptoms of movement disorders and that even low levels of overexpression of human wildtype alpha-synuclein has the potential to disrupt processing of these information. The here described adaptive rotating beam test represents a sensitive behavioral test to detect moderate sensorimotor alterations in mouse models.

  18. Squamosamide derivative FLZ protected tyrosine hydroxylase function in a chronic MPTP/probenecid mouse model of Parkinson's disease.

    PubMed

    Bao, Xiu-Qi; Wu, Liang-Yu; Wang, Xiao-Liang; Sun, Hua; Zhang, Dan

    2015-05-01

    Parkinson's disease (PD) is a chronic, progressive neurodegenerative disorder characterized by motor impairments and loss of dopaminergic neurons in the substantia nigra. FLZ (formulated as: N-2-(4-hydroxy-phenyl)-ethyl]-2-(2, 5-dimethoxy-phenyl)-3-(3-methoxy-4-hydroxy-phenyl)-acrylamide) is a novel synthetic derivative of squamosamide from a Chinese herb and has been proven to protect dopaminergic neurons in subacute PD models. However, whether FLZ has a neuroprotective effect on chronic PD model is still unknown. The present study was designed to verify the neuroprotection of FLZ on chronic PD mouse model induced by MPTP combined with probenecid (MPTP/p). The results showed that treatment of mice with FLZ for 9 weeks significantly improved motor behavior and dopaminergic neuronal function of mice injected with MPTP/p. The beneficial effects of FLZ attributed to the elevation of dopaminergic neuron number, dopamine level, and tyrosine hydroxylase (TH) activity, as well as decrease of α-synuclein (α-Syn) expression, α-Syn phosphorylation, nitration, and aggregation. Moreover, FLZ decreased the interaction between α-Syn and TH, which eventually improved dopaminergic neuronal function. Mechanistic study demonstrated that FLZ increased Akt and mTOR phosphorylation, suggesting that FLZ activated Akt/mTOR signaling pathway and this might be involved in the neuroprotection of FLZ. The present results provided more elaborate in vivo evidences to support the neuroprotective effect of FLZ on dopaminergic neurons of chronic PD mouse model and the potential of FLZ to be developed as new drug to treat PD.

  19. TLR4 signaling mediates AP-1 activation in an MPTP-induced mouse model of Parkinson's disease.

    PubMed

    Zhao, Xu-Dong; Wang, Fa-Xiang; Cao, Wen-Fu; Zhang, Yong-Hong; Li, Yan

    2016-03-01

    To evaluate the effects of Toll-like receptor 4 (TLR4) signaling on the activation of the transcription factor activator protein-1 (AP-1) in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of Parkinson's disease (PD). The following groups were evaluated: normal saline (NS)-treated WT mice, NS-treated TLR4-knockout (KO) mice, MPTP-treated WT mice, and MPTP-treated TLR4-KO mice. After establishing the mouse model, behavioral changes were evaluated. AP-1 expression was detected by RT-PCR, Western blotting, immunohistochemistry and immunofluorescence staining. Compared to MPTP-treated WT mice, significantly reduced dyskinesia was observed in MPTP-treated TLR4-KO mice. AP-1 mRNA and protein levels were significantly up-regulated in the substantia nigras (SNs) of MPTP-treated WT mice relative to NS-treated mice (P<0.01); these levels were significantly reduced in MPTP-treated TLR4-KO mice relative to MPTP-treated WT mice (P<0.01). Immunohistochemical staining demonstrated that AP-1 was distributed throughout the SN in MPTP-treated mice, and immunofluorescence further showed that AP-1 was expressed in TH-positive neuronal cells and GFAP-positive astrocytes. In addition, immunofluorescence revealed that AP-1 expression was lower in TH-positive neurons and GFAP-positive astrocytes in the SNs of MPTP-treated TLR4-KO mice relative to MPTP-treated WT mice. The TLR4 pathway may play an important role in regulating AP-1 activation. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Expression of Tgfβ1 and Inflammatory Markers in the 6-hydroxydopamine Mouse Model of Parkinson’s Disease

    PubMed Central

    Haas, Stefan Jean-Pierre; Zhou, Xiaolai; Machado, Venissa; Wree, Andreas; Krieglstein, Kerstin; Spittau, Björn

    2016-01-01

    Parkinson’s disease (PD) is a neurodegenerative disorder that is characterized by loss of midbrain dopaminergic (mDA) neurons in the substantia nigra (SN). Microglia-mediated neuroinflammation has been described as a common hallmark of PD and is believed to further trigger the progression of neurodegenerative events. Injections of 6-hydroxydopamine (6-OHDA) are widely used to induce degeneration of mDA neurons in rodents as an attempt to mimic PD and to study neurodegeneration, neuroinflammation as well as potential therapeutic approaches. In the present study, we addressed microglia and astroglia reactivity in the SN and the caudatoputamen (CPu) after 6-OHDA injections into the medial forebrain bundle (MFB), and further analyzed the temporal and spatial expression patterns of pro-inflammatory and anti-inflammatory markers in this mouse model of PD. We provide evidence that activated microglia as well as neurons in the lesioned SN and CPu express Transforming growth factor β1 (Tgfβ1), which overlaps with the downregulation of pro-inflammatory markers Tnfα, and iNos, and upregulation of anti-inflammatory markers Ym1 and Arg1. Taken together, the data presented in this study suggest an important role for Tgfβ1 as a lesion-associated factor that might be involved in regulating microglia activation states in the 6-OHDA mouse model of PD in order to prevent degeneration of uninjured neurons by microglia-mediated release of neurotoxic factors such as Tnfα and nitric oxide (NO). PMID:26869879

  1. Genetic homogeneity in Juglans nigra(Juglanaceae) at nuclear microsatellites

    Treesearch

    Erin R. Victory; Jeffrey C. Glaubitz; Olin E., Jr. Rhodes; Keith E. Woeste

    2006-01-01

    Broad-scale studies of genetic structure and diversity are indicative of the recent evolutionary history of a species and are relevant to conservation efforts. We have estimated current levels of genetic diversity and population structure for black walnut (Juglans nigra L.), a highly valuable timber species, in the central hardwood region of the...

  2. Regeneration of plants from Fraxinus nigra Marsh. hypocotyls

    Treesearch

    Rochelle R. Beasley; Paula M. Pijut

    2013-01-01

    Fraxinus nigra Marsh. (black ash) is a native North American hardwood tree species that is ecologically important and has ethnobotanical significance to American Indian communities of the eastern United States. Black ash has immature embryos at seed set, combined with complex stratification requirements, making natural regeneration difficult. This,...

  3. [Tinea nigra. 1st clinical case in Uruguay].

    PubMed

    Conti-Díaz, I A; Burgoa, F; Civila, E; Bonasse, J; Miller, A

    1984-08-30

    The first case in Uruguay of 'tinea nigra' is described in a 44-year-old male patient with a maculous pigmented lesion on the right foot. It represents the most meridional case of the disease yet recorded in South America. Exophiala werneckii was isolated in cultures (strain 1905 IHM).

  4. Chemical composition and bioactivity studies of Alpinia nigra essential oils

    USDA-ARS?s Scientific Manuscript database

    Free radical scavenging, bactericidal and bitting deterrent properties of Alpinia nigra essential oils (EOs) were investigated in the present study. Chemical composition of the EOs were analyzed using GC-MS/GC-FID which revealed the presence of 63 constituents including ß-caryophyllene as major comp...

  5. Evaluation of TorsinA as a target for Parkinson disease therapy in mouse models.

    PubMed

    Li, Xinru; Lee, Jenny; Parsons, Dee; Janaurajs, Karen; Standaert, David G

    2012-01-01

    Parkinson disease (PD) is a common and disabling disorder. No current therapy can slow or reverse disease progression. An important aspect of research in this field is target validation, a systematic approach to evaluating the likelihood that modification of a certain molecule, mechanism or biological pathway may be useful for the development of pharmacological or molecular treatments for the disease. TorsinA, a member of the AAA+ family of chaperone proteins, has been proposed as a potential target of neuroprotective therapy. TorsinA is found in Lewy bodies in human PD, and can suppress toxicity in cellular and invertebrate models of PD. Here, we evaluated the neuroprotective properties of torsinA in mouse models of PD based on intoxication with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) as well as recombinant adeno associated virus (rAAV) induced overexpression of alpha-synuclein (α-syn). Using either transgenic mice with overexpression of human torsinA (hWT mice) or mice in which torsinA expression was induced using an rAAV vector, we found no evidence for protection against acute MPTP intoxication. Similarly, genetic deletion of the endogenous mouse gene for torsinA (Dyt1) using an rAAV delivered Cre recombinase did not enhance the vulnerability of dopaminergic neurons to MPTP. Overexpression of α-syn using rAAV in the mouse substantia nigra lead to a loss of TH positive neurons six months after administration, and no difference in the degree of loss was observed between transgenic animals expressing forms of torsinA and wild type controls. Collectively, we did not observe evidence for a protective effect of torsinA in the mouse models we examined. Each of these models has limitations, and there is no single model with established predictive value with respect to the human disease. Nevertheless, these data do seem to support the view that torsinA is unlikely to be successfully translated as a target of therapy for human PD.

  6. Dissection and culture of mouse dopaminergic and striatal explants in three-dimensional collagen matrix assays.

    PubMed

    Schmidt, Ewoud R E; Morello, Francesca; Pasterkamp, R Jeroen

    2012-03-23

    Midbrain dopamine (mdDA) neurons project via the medial forebrain bundle towards several areas in the telencephalon, including the striatum(1). Reciprocally, medium spiny neurons in the striatum that give rise to the striatonigral (direct) pathway innervate the substantia nigra(2). The development of these axon tracts is dependent upon the combinatorial actions of a plethora of axon growth and guidance cues including molecules that are released by neurites or by (intermediate) target regions(3,4). These soluble factors can be studied in vitro by culturing mdDA and/or striatal explants in a collagen matrix which provides a three-dimensional substrate for the axons mimicking the extracellular environment. In addition, the collagen matrix allows for the formation of relatively stable gradients of proteins released by other explants or cells placed in the vicinity (e.g. see references 5 and 6). Here we describe methods for the purification of rat tail collagen, microdissection of dopaminergic and striatal explants, their culture in collagen gels and subsequent immunohistochemical and quantitative analysis. First, the brains of E14.5 mouse embryos are isolated and dopaminergic and striatal explants are microdissected. These explants are then (co)cultured in collagen gels on coverslips for 48 to 72 hours in vitro. Subsequently, axonal projections are visualized using neuronal markers (e.g. tyrosine hydroxylase, DARPP32, or βIII tubulin) and axon growth and attractive or repulsive axon responses are quantified. This neuronal preparation is a useful tool for in vitro studies of the cellular and molecular mechanisms of mesostriatal and striatonigral axon growth and guidance during development. Using this assay, it is also possible to assess other (intermediate) targets for dopaminergic and striatal axons or to test specific molecular cues.

  7. Neuroprotective efficacy of aminopropyl carbazoles in a mouse model of Parkinson disease

    PubMed Central

    De Jesús-Cortés, Héctor; Xu, Pin; Drawbridge, Jordan; Estill, Sandi Jo; Huntington, Paula; Tran, Stephanie; Britt, Jeremiah; Tesla, Rachel; Morlock, Lorraine; Naidoo, Jacinth; Melito, Lisa M.; Wang, Gelin; Williams, Noelle S.; Ready, Joseph M.; McKnight, Steven L.; Pieper, Andrew A.

    2012-01-01

    We previously reported the discovery of P7C3, an aminopropyl carbazole having proneurogenic and neuroprotective properties in newborn neural precursor cells of the dentate gyrus. Here, we provide evidence that P7C3 also protects mature neurons in brain regions outside of the hippocampus. P7C3 blocks 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-mediated cell death of dopaminergic neurons in the substantia nigra of adult mice, a model of Parkinson disease (PD). Dose–response studies show that the P7C3 analog P7C3A20 blocks cell death with even greater potency and efficacy, which parallels the relative potency and efficacy of these agents in blocking apoptosis of newborn neural precursor cells of the dentate gyrus. P7C3 and P7C3A20 display similar relative effects in blocking 1-methyl-4-phenylpyridinium (MPP+)-mediated death of dopaminergic neurons in Caenorhabditis elegans, as well as in preserving C. elegans mobility following MPP+ exposure. Dimebon, an antihistaminergic drug that is weakly proneurogenic and neuroprotective in the dentate gyrus, confers no protection in either the mouse or the worm models of PD. We further demonstrate that the hippocampal proneurogenic efficacy of eight additional analogs of P7C3 correlates with their protective efficacy in MPTP-mediated neurotoxicity. In vivo screening of P7C3 analogs for proneurogenic efficacy in the hippocampus may thus provide a reliable means of predicting neuroprotective efficacy. We propose that the chemical scaffold represented by P7C3 and P7C3A20 provides a basis for optimizing and advancing pharmacologic agents for the treatment of patients with PD. PMID:23027934

  8. Paraoxonase 2 (PON2) in the mouse central nervous system: A neuroprotective role?

    SciTech Connect

    Giordano, Gennaro; Cole, Toby B.; Furlong, Clement E.; Costa, Lucio G.

    2011-11-15

    The aims of this study were to characterize the expression of paraoxonase 2 (PON2) in mouse brain and to assess its antioxidant properties. PON2 levels were highest in the lung, intestine, heart and liver, and lower in the brain; in all tissues, PON2 expression was higher in female than in male mice. PON2 knockout [PON2{sup -/-}] mice did not express any PON2, as expected. In the brain, the highest levels of PON2 were found in the substantia nigra, the nucleus accumbens and the striatum, with lower levels in the cerebral cortex, hippocampus, cerebellum and brainstem. A similar regional distribution of PON2 activity (measured by dihydrocoumarin hydrolysis) was also found. PON3 was not detected in any brain area, while PON1 was expressed at very low levels, and did not show any regional difference. PON2 levels were higher in astrocytes than in neurons isolated from all brain regions, and were highest in cells from the striatum. PON2 activity and mRNA levels followed a similar pattern. Brain PON2 levels were highest around birth, and gradually declined. Subcellular distribution experiments indicated that PON2 is primarily expressed in microsomes and in mitochondria. The toxicity in neurons and astrocytes of agents known to cause oxidative stress (DMNQ and H{sub 2}O{sub 2}) was higher in cells from PON2{sup -/-} mice than in the same cells from wild-type mice, despite similar glutathione levels. These results indicate that PON2 is expressed in the brain, and that higher levels are found in dopaminergic regions such as the striatum, suggesting that this enzyme may provide protection against oxidative stress-mediated neurotoxicity.

  9. Immunostaining of Oxidized DJ-1 in Human and Mouse Brains

    PubMed Central

    Saito, Yoshiro; Miyasaka, Tomohiro; Hatsuta, Hiroyuki; Takahashi-Niki, Kazuko; Hayashi, Kojiro; Mita, Yuichiro; Kusano-Arai, Osamu; Iwanari, Hiroko; Ariga, Hiroyoshi; Hamakubo, Takao; Yoshida, Yasukazu; Niki, Etsuo; Murayama, Shigeo; Ihara, Yasuo; Noguchi, Noriko

    2014-01-01

    Abstract DJ-1, the product of a causative gene of a familial form of Parkinson disease, undergoes preferential oxidation of Cys106 (cysteine residue at position 106) under oxidative stress. Using specific monoclonal antibodies against Cys106 oxidized DJ-1 (oxDJ-1), we examined oxDJ-1 immunoreactivity in brain sections from DJ-1 knockout and wild-type mice and in human brain sections from cases classified into different Lewy body stages of Parkinson disease and Parkinson disease with dementia. Oxidized DJ-1 immunoreactivity was prominently observed in neuromelanin-containing neurons and neuron processes of the substantia nigra; Lewy bodies also showed oxDJ-1 immunoreactivity. Oxidized DJ-1 was also detected in astrocytes in the striatum, in neurons and glia in the red nucleus, and in the inferior olivary nucleus, all of which are related to regulation of movement. These observations suggest the relevance of DJ-1 oxidation to homeostasis in multiple brain regions, including neuromelanin-containing neurons of the substantia nigra, and raise the possibility that oxDJ-1 levels might change during the progression of Lewy body–associated neurodegenerative diseases. PMID:24918637

  10. Tinea nigra presenting speckled or "salt and pepper" pattern.

    PubMed

    Rossetto, André Luiz; Cruz, Rosana Cé Bella; Haddad, Vidal Junior

    2014-06-01

    A 7-year-old Caucasian female resident of the southern coast of Brazil presented dark spots on the left palm that converged to a unique macule with speckled pattern at about 1 month. The mycological exam and the fungi culture were typical of Hortaea werneckii, the agent of the superficial mycosis Tinea nigra. The patient received butenafine hydrochloride 1% for 30 days, resulting in a complete remission of the lesion. At a follow-up visit 12 months after treatment, there was no lesion recurrence. We describe a form of rare geographical Tinea nigra with a speckled pattern. The "salt and pepper" aspect should be taken into consideration when the mycosis was suspected.

  11. Polymorphism and divergence at three duplicate genes in Brassica nigra.

    PubMed

    Sjödin, Per; Hedman, Harald; Kruskopf Osterberg, Marita; Gustafsson, Susanne; Lagercrantz, Ulf; Lascoux, Martin

    2008-06-01

    The CONSTANS-like gene family has been shown to evolve exceptionally fast in Brassicaceae. In the present study we analyzed sequence polymorphism and divergence of three genes from this family: COL1 (CONSTANS-LIKE 1) and two copies of CO (CONSTANS), COa and COb, in B. nigra. There was a significant fourfold difference in overall nucleotide diversity among the three genes, with BniCOb having twice as much variation as BniCOL1, which in turn was twice as variable as BniCOa. The ratio of nonsynonymous-to-synonymous substitutions (dN/dS) was high for all three genes, confirming previous studies. While we did not detect evidence of selection at BniCOa and BniCOb, there was a significant excess of polymorphic synonymous mutations in a McDonald-Kreitman test comparing COL1 in B. nigra and A. thaliana. This is apparently the result of an increase in selective constraint on COL1 in B. nigra combined with a decrease in A. thaliana. In conclusion, a complex scenario involving both demography and selection seems to have shaped the pattern of polymorphism at the three genes.

  12. (G2019S) LRRK2 causes early-phase dysfunction of SNpc dopaminergic neurons and impairment of corticostriatal long-term depression in the PD transgenic mouse.

    PubMed

    Chou, Jun-Shiao; Chen, Chu-Yu; Chen, Ying-Ling; Weng, Yi-Hsin; Yeh, Tu-Hsueh; Lu, Chin-Song; Chang, Ya-Ming; Wang, Hung-Li

    2014-08-01

    Twelve- to sixteen-month-old (G2019S) LRRK2 transgenic mice prepared by us displayed progressive neuronal death of substantia nigra pars compacta (SNpc) dopaminergic cells. In the present study, we hypothesized that prior to a late-phase death of SNpc dopaminergic neurons, (G2019S) LRRK2 also causes an early-phase neuronal dysfunction of SNpc dopaminergic cells in the (G2019S) LRRK2 mouse. Eight to nine-month-old (G2019S) LRRK2 transgenic mice exhibited the symptom of hypoactivity in the absence of the degeneration of SNpc dopaminergic neurons or nigrostriatal dopaminergic terminals. Whole-cell current-clamp recordings of SNpc dopaminergic cells in brain slices demonstrated a significant decrease in spontaneous firing frequency of SNpc dopaminergic neurons of 8-month-old (G2019S) LRRK2 mice. Carbon fiber electrode amperometry recording using striatal slices showed that (G2019S) LRRK2 transgenic mice at the age of 8 to 9months display an impaired evoked dopamine release in the dorsolateral striatum. Normal nigrostriatal dopaminergic transmission is required for the induction of long-term synaptic plasticity expressed at corticostriatal glutamatergic synapses of striatal medium spiny neurons. Whole-cell voltage-clamp recordings showed that in contrast to medium spiny neurons of 8 to 9-month-old wild-type mice, high-frequency stimulation of corticostriatal afferents failed to induce long-term depression (LTD) of corticostriatal EPSCs in medium spiny neurons of (G2019S) LRRK2 mice at the same age. Our study provides the evidence that mutant (G2019S) LRRK2 causes early-phase dysfunctions of SNpc dopaminergic neurons, including a decrease in spontaneous firing rate and a reduction in evoked dopamine release, and impairment of corticostriatal LTD in the (G2019S) LRRK2 transgenic mouse.

  13. D-Ala2-GIP-glu-PAL is neuroprotective in a chronic Parkinson's disease mouse model and increases BNDF expression while reducing neuroinflammation and lipid peroxidation.

    PubMed

    Li, Yanwei; Liu, WeiZhen; Li, Lin; Hölscher, Christian

    2017-02-15

    Type 2 diabetes mellitus (T2DM) is a risk factor for Parkinson's disease (PD). Therefore, treatment to improve insulin resistance in T2DM may be useful for PD patients. Glucose dependent insulinotropic polypeptide (GIP) is a member of the incretin hormone family that can promote insulin release and improve insulin resistance. Several GIP analogues have been developed as potential treatments for T2DM. We had shown previously that D-Ala2-GIP-glu-PAL, a novel long-acting GIP analogue, can play a neuroprotective role in the PD mouse model induced by acute MPTP injection. The drug reduced damage to the dopaminergic neurons and increased CREB-mediated Bcl-2 expression to prevent apoptosis and reduced chronic inflammation in the brain. In the present study, we further tested the effects of chronic treatment by D-Ala2-GIP-glu-PAL in a chronic PD mouse model induced by MPTP (25mg/kg ip.) combination with probenecid (250mg/kg ip.) injection for 5 weeks. The results demonstrated that chronic treatment with D-Ala2-GIP-glu-PAL inhibits MPTP -induced Parkinsonism-like motor disorders in mice, and that the drug prevents dopaminergic neuronal loss in the substantia nigra pars compacta (SNpc). Moreover, D-Ala2-GIP-glu-PAL also inhibited the increased levels of expression of α-synuclein in the SNpc and striatum induced by MPTP. Furthermore, drug treatment reduced chronic neuroinflammation, oxidative stress and lipid peroxidation, and increased the expression of BDNF. These findings show that GIP signaling is neuroprotective and holds promise as a novel treatment of PD.

  14. A novel α-synuclein-GFP mouse model displays progressive motor impairment, olfactory dysfunction and accumulation of α-synuclein-GFP.

    PubMed

    Hansen, Christian; Björklund, Tomas; Petit, Geraldine H; Lundblad, Martin; Murmu, Reena Prity; Brundin, Patrik; Li, Jia-Yi

    2013-08-01

    Compelling evidence suggests that accumulation and aggregation of alpha-synuclein (α-syn) contribute to the pathogenesis of Parkinson's disease (PD). Here, we describe a novel Bacterial Artificial Chromosome (BAC) transgenic model, in which we have expressed wild-type human α-syn fused to green fluorescent protein (GFP), under control of the mouse α-syn promoter. We observed a widespread and high expression of α-syn-GFP in multiple brain regions, including the dopaminergic neurons of the substantia nigra pars compacta (SNpc) and the ventral tegmental area, the olfactory bulb as well as in neocortical neurons. With increasing age, transgenic mice exhibited reductions in amphetamine-induced locomotor activity in the open field, impaired rotarod performance and a reduced striatal dopamine release, as measured by amperometry. In addition, they progressively developed deficits in an odor discrimination test. Western blot analysis revealed that α-syn-GFP and phospho-α-syn levels increased in multiple brain regions, as the mice grew older. Further, we observed, by immunohistochemical staining for phospho-α-syn and in vivo by two-photon microscopy, the formation of α-syn aggregates as the mice aged. The latter illustrates that the model can be used to track α-syn aggregation in vivo. In summary, this novel BAC α-syn-GFP model mimics a unique set of aspects of PD progression combined with the possibility of tracking α-syn aggregation in neocortex of living mice. Therefore, this α-syn-GFP-mouse model can provide a powerful tool that will facilitate the study of α-syn biology and its involvement in PD pathogenesis. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Effects of (-)-sesamin on motor and memory deficits in an MPTP-lesioned mouse model of Parkinson's disease treated with l-DOPA.

    PubMed

    Zhao, T T; Shin, K S; Kim, K S; Park, H J; Kim, H J; Lee, K E; Lee, M K

    2016-12-17

    The present study investigated the effects of (-)-sesamin on motor and memory deficits in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned mouse model of Parkinson's disease (PD) with l-3,4-dihydroxyphenylalanine (l-DOPA). MPTP-lesioned (30mg/kg/day, 5days) mice showed deficits in memory including habit learning memory and spatial memory, which were further aggravated by daily treatment with 25mg/kg l-DOPA for 21days. However, daily treatment with (-)-sesamin (25 and 50mg/kg) for 21days ameliorated memory deficits in an MPTP-lesioned mouse model of PD treated with l-DOPA (25mg/kg). Both (-)-sesamin doses reduced decreases in the retention latency time in the passive avoidance test, latency to fall of rotarod test and distance traveled in the open field test, and attenuated decreases in tyrosine hydroxylase (TH)-immunopositive cells, dopamine, and its metabolites in the substantia nigra-striatum. (-)-Sesamin reduced increases in the retention transfer latency time in the elevated plus-maze test and N-methyl-d-aspartate receptor (NMDAR) expression and reduced decreases in the phosphorylation of extracellular signal-regulated kinase (ERK1/2) and cyclic AMP-response element binding protein (CREB) in the hippocampus. In contrast, daily treatment with 10mg/kg l-DOPA for 21days ameliorated memory deficits in MPTP-lesioned mice, and this effect was further improved by treatment with (-)-sesamin (25 and 50mg/kg). These results suggest that (-)-sesamin protects against habit learning memory deficits by activating the dopamine neuronal system, while spatial memory deficits are decreased by its modulatory effects on the NMDAR-ERK1/2-CREB system. Accordingly, (-)-sesamin may act as an adjuvant phytonutrient for motor and memory deficits in patients with PD receiving l-DOPA.

  16. 14-3-3 inhibition promotes dopaminergic neuron loss and 14-3-3θ overexpression promotes recovery in the MPTP mouse model of Parkinson's disease

    PubMed Central

    Ding, Huiping; Underwood, Rachel; Lavalley, Nicholas; Yacoubian, Talene A.

    2015-01-01

    14-3-3s are a highly conserved protein family that plays important roles in cell survival and interact with several proteins implicated in Parkinson's disease (PD). Disruption of 14-3-3 expression and function has been implicated in the pathogenesis of PD. We have previously shown that increasing the expression level of 14-3-3θ is protective against rotenone and 1-methyl-4-phenylpyridinium (MPP+) in cultured cells. Here, we extend our studies to examine the effects of 14-3-3s in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. We first investigated whether targeted nigral 14-3-3θ overexpression mediated by adeno-associated virus offers neuroprotection against MPTP-induced toxicity. 14-3-3θ overexpression using this approach did not reduce MPTP-induced dopaminergic cell loss in the substantia nigra nor the depletion of dopamine and its metabolites in the striatum at three weeks after MPTP administration. However, 14-3-3θ-overexpressing mice showed a later partial recovery in striatal dopamine metabolites at eight weeks after MPTP administration compared to controls, suggesting that 14-3-3θ overexpression may help in the functional recovery of those dopaminergic neurons that survive. Conversely, we investigated whether disrupting 14-3-3 function in transgenic mice expressing the pan 14-3-3 inhibitor difopein exacerbates MPTP-induced toxicity. We found that difopein expression promoted dopaminergic cell loss in response to MPTP treatment. Together, these findings suggest that 14-3-3θ overexpression promotes recovery of dopamine metabolites whereas 14-3-3 inhibition exacerbates neuron loss in the MPTP mouse model of PD. PMID:26314634

  17. Extracts of Morus nigra L. Leaves Standardized in Chlorogenic Acid, Rutin and Isoquercitrin: Tyrosinase Inhibition and Cytotoxicity

    PubMed Central

    Fontes, Pedro Ribeiro; Souza, Paula Monteiro; William Fagg, Christopher; Neves Silva Guerra, Eliete; de Medeiros Nóbrega, Yanna Karla; Silveira, Damaris; Fonseca-Bazzo, Yris; Simeoni, Luiz Alberto; Homem-de-Mello, Maurício; Oliveira Magalhães, Pérola

    2016-01-01

    Melanogenesis is a process responsible for melanin production, which is stored in melanocytes containing tyrosinase. Inhibition of this enzyme is a target in the cosmetics industry, since it controls undesirable skin conditions such as hyperpigmentation due to the overproduction of melanin. Species of the Morus genus are known for the beneficial uses offered in different parts of its plants, including tyrosinase inhibition. Thus, this project aimed to study the inhibitory activity of tyrosinase by extracts from Morus nigra leaves as well as the characterization of its chromatographic profile and cytotoxicity in order to become a new therapeutic option from a natural source. M. nigra leaves were collected, pulverized, equally divided into five batches and the standardized extract was obtained by passive maceration. There was no significant difference between batches for total solids content, yield and moisture content, which shows good reproducibility of the extraction process. Tyrosinase enzymatic activity was determined for each batch, providing the percentage of enzyme inhibition and IC50 values obtained by constructing dose-response curves and compared to kojic acid, a well-known tyrosinase inhibitor. High inhibition of tyrosinase activity was observed (above 90% at 15.625 μg/mL). The obtained IC50 values ranged from 5.00 μg/mL ± 0.23 to 8.49 μg/mL ± 0.59 and were compared to kojic acid (3.37 μg/mL ± 0.65). High Performance Liquid Chromatography analysis revealed the presence of chlorogenic acid, rutin and, its major compound, isoquercitrin. The chromatographic method employed was validated according to ICH guidelines and the extract was standardized using these polyphenols as markers. Cytotoxicity, assessed by MTT assay, was not observed on murine melanomas, human keratinocytes and mouse fibroblasts in tyrosinase IC50 values. This study demonstrated the potential of M. nigra leaf extract as a promising whitening agent of natural source against skin

  18. Intervention with exercise restores motor deficits but not nigrostriatal loss in a progressive MPTP mouse model of Parkinson's disease.

    PubMed

    Sconce, M D; Churchill, M J; Greene, R E; Meshul, C K

    2015-07-23

    Many studies have investigated exercise therapy in Parkinson's disease (PD) and have shown benefits in improving motor deficits. However, exercise does not slow down the progression of the disease or induce the revival of lost nigrostriatal neurons. To examine the dichotomy of behavioral improvement without the slowing or recovery of dopaminergic cell or terminal loss, we tested exercise therapy in an intervention paradigm where voluntary running wheels were installed half-way through our progressive PD mouse model. In our model, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is administered over 4 weeks with increased doses each week (8, 16, 24, 32-kg/mg). We found that after 4 weeks of MPTP treatment, mice that volunteered to exercise had behavioral recovery in several measures despite the loss of 73% and 53% tyrosine hydroxylase (TH) within the dorsolateral (DL) striatum and the substantia nigra (SN), respectively which was equivalent to the loss seen in the mice that did not exercise but were also administered MPTP for 4 weeks. Mice treated with 4 weeks of MPTP showed a 41% loss of vesicular monoamine transporter II (VMAT2), a 71% increase in the ratio of glycosylated/non-glycosylated dopamine transporter (DAT), and significant increases in glutamate transporters including VGLUT1, GLT-1, and excitatory amino acid carrier 1. MPTP mice that exercised showed recovery of all these biomarkers back to the levels seen in the vehicle group and showed less inflammation compared to the mice treated with MPTP for 4 weeks. Even though we did not measure tissue dopamine (DA) concentration, our data suggest that exercise does not alleviate motor deficits by sparing nigrostriatal neurons, but perhaps by stabilizing the extraneuronal neurotransmitters, as evident by a recovery of DA and glutamate transporters. However, suppressing inflammation could be another mechanism of this locomotor recovery. Although exercise will not be a successful treatment alone, it could

  19. Identification of Multiple QTLs Linked to Neuropathology in the Engrailed-1 Heterozygous Mouse Model of Parkinson’s Disease

    PubMed Central

    Kurowska, Zuzanna; Jewett, Michael; Brattås, Per Ludvik; Jimenez-Ferrer, Itzia; Kenéz, Xuyian; Björklund, Tomas; Nordström, Ulrika; Brundin, Patrik; Swanberg, Maria

    2016-01-01

    Motor symptoms in Parkinson’s disease are attributed to degeneration of midbrain dopaminergic neurons (DNs). Heterozygosity for Engrailed-1 (En1), one of the key factors for programming and maintenance of DNs, results in a parkinsonian phenotype featuring progressive degeneration of DNs in substantia nigra pars compacta (SNpc), decreased striatal dopamine levels and swellings of nigro-striatal axons in the SwissOF1-En1+/− mouse strain. In contrast, C57Bl/6-En1+/− mice do not display this neurodegenerative phenotype, suggesting that susceptibility to En1 heterozygosity is genetically regulated. Our goal was to identify quantitative trait loci (QTLs) that regulate the susceptibility to PD-like neurodegenerative changes in response to loss of one En1 allele. We intercrossed SwissOF1-En1+/− and C57Bl/6 mice to obtain F2 mice with mixed genomes and analyzed number of DNs in SNpc and striatal axonal swellings in 120 F2-En1+/− 17 week-old male mice. Linkage analyses revealed 8 QTLs linked to number of DNs (p = 2.4e-09, variance explained = 74%), 7 QTLs linked to load of axonal swellings (p = 1.7e-12, variance explained = 80%) and 8 QTLs linked to size of axonal swellings (p = 7.0e-11, variance explained = 74%). These loci should be of prime interest for studies of susceptibility to Parkinson’s disease-like damage in rodent disease models and considered in clinical association studies in PD. PMID:27550741

  20. The soluble isoform of CX3CL1 is necessary for neuroprotection in a mouse model of Parkinson's disease.

    PubMed

    Morganti, Josh M; Nash, Kevin R; Grimmig, Bethany A; Ranjit, Sonali; Small, Brent; Bickford, Paula C; Gemma, Carmelina

    2012-10-17

    The chemokine CX3CL1/fractalkine is expressed by neurons as a transmembrane-anchored protein that can be cleaved to yield a soluble isoform. However, the roles for these two types of endogenous CX3CL1 in neurodegenerative pathophysiology remain elusive. As such, it has been difficult to delineate the function of the two isoforms of CX3CL1, as both are natively present in the brain. In this study we examined each isoform's ability to regulate neuroinflammation in a mouse model of Parkinson's disease initiated by the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). We were able to delineate the function of both CX3CL1 isoforms by using adeno-associated virus-mediated gene therapy to selectively express synthetic variants of CX3CL1 that remain either permanently soluble or membrane bound. In the present study we injected each CX3CL1 variant or a GFP-expressing vector directly into the substantia nigra of CX3CL1(-/-) mice. Our results show that only the soluble isoform of CX3CL1 is sufficient for neuroprotection after exposure to MPTP. Specifically, we show that the soluble CX3CL1 isoform reduces impairment of motor coordination, decreases dopaminergic neuron loss, and ameliorates microglial activation and proinflammatory cytokine release resulting from MPTP exposure. Furthermore, we show that the membrane-bound isoform provides no neuroprotective capability to MPTP-induced pathologies, exhibiting similar motor coordination impairment, dopaminergic neuron loss, and inflammatory phenotypes as MPTP-treated CX3CL1(-/-) mice, which received the GFP-expressing control vector. Our results reveal that the neuroprotective capacity of CX3CL1 resides solely upon the soluble isoform in an MPTP-induced model of Parkinson's disease.

  1. Brain catecholamine depletion and motor impairment in a Th knock-in mouse with type B tyrosine hydroxylase deficiency.

    PubMed

    Korner, Germaine; Noain, Daniela; Ying, Ming; Hole, Magnus; Flydal, Marte I; Scherer, Tanja; Allegri, Gabriella; Rassi, Anahita; Fingerhut, Ralph; Becu-Villalobos, Damasia; Pillai, Samyuktha; Wueest, Stephan; Konrad, Daniel; Lauber-Biason, Anna; Baumann, Christian R; Bindoff, Laurence A; Martinez, Aurora; Thöny, Beat

    2015-10-01

    Tyrosine hydroxylase catalyses the hydroxylation of L-tyrosine to l-DOPA, the rate-limiting step in the synthesis of catecholamines. Mutations in the TH gene encoding tyrosine hydroxylase are associated with the autosomal recessive disorder tyrosine hydroxylase deficiency, which manifests phenotypes varying from infantile parkinsonism and DOPA-responsive dystonia, also termed type A, to complex encephalopathy with perinatal onset, termed type B. We generated homozygous Th knock-in mice with the mutation Th-p.R203H, equivalent to the most recurrent human mutation associated with type B tyrosine hydroxylase deficiency (TH-p.R233H), often unresponsive to l-DOPA treatment. The Th knock-in mice showed normal survival and food intake, but hypotension, hypokinesia, reduced motor coordination, wide-based gate and catalepsy. This phenotype was associated with a gradual loss of central catecholamines and the serious manifestations of motor impairment presented diurnal fluctuation but did not improve with standard l-DOPA treatment. The mutant tyrosine hydroxylase enzyme was unstable and exhibited deficient stabilization by catecholamines, leading to decline of brain tyrosine hydroxylase-immunoreactivity in the Th knock-in mice. In fact the substantia nigra presented an almost normal level of mutant tyrosine hydroxylase protein but distinct absence of the enzyme was observed in the striatum, indicating a mutation-associated mislocalization of tyrosine hydroxylase in the nigrostriatal pathway. This hypomorphic mouse model thus provides understanding on pathomechanisms in type B tyrosine hydroxylase deficiency and a platform for the evaluation of novel therapeutics for movement disorders with loss of dopaminergic input to the striatum. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Application of a blood-brain-barrier-penetrating form of GDNF in a mouse model for Parkinson's disease.

    PubMed

    Dietz, Gunnar P H; Valbuena, Paoloa C; Dietz, Birgit; Meuer, Katrin; Müeller, Patrick; Weishaupt, Jachen H; Bähr, Mathias

    2006-04-12

    Glial-cell-line-derived neurotrophic factor (GDNF) promotes mesencephalic dopaminergic neuronal survival in several in vitro and in vivo models. As the demise of dopaminergic neurons is the cause for Parkinson's disease (PD) symptoms, GDNF is a promising agent for its treatment. However, this neurotrophin is unable to cross the blood-brain barrier, which has complicated its clinical use. Therefore, ways to deliver GDNF into the central nervous system in an effective manner are needed. The HIV-1-Tat-derived cell-penetrating peptide (CPP) provides a means to deliver fusion proteins into the brain. We generated a fusion protein between the 11 amino acid CPP of Tat and the rat GDNF mature protein to deliver GDNF across the blood-brain barrier. We showed previously that Tat-GDNF enhances the neuroprotective effect of GDNF in in vivo models for nerve trauma and ischemia. Here, we tested its effect in a subchronic scheme of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) application into the mouse as a model for PD to evaluate the effect of Tat-GDNF fusion protein in dopaminergic neuron survival. We showed that the fusion protein did indeed reach the dopaminergic neurons. However, the in vivo application of Tat-GDNF did not provide neuroprotection of dopaminergic neurons, as revealed by immunohistochemistry and counting of the number of tyrosine-hydroxylase-immunoreactive neurons in the substantia nigra pars compacta. Possibly, GDNF does protect nigro-striatal projections of those neurons that survive MPTP treatment but does not increase the number of surviving dopaminergic neurons. A concomitant treatment of Tat-GDNF with an anti-apoptotic Tat-fusion protein might be beneficial.

  3. Identification of Multiple QTLs Linked to Neuropathology in the Engrailed-1 Heterozygous Mouse Model of Parkinson's Disease.

    PubMed

    Kurowska, Zuzanna; Jewett, Michael; Brattås, Per Ludvik; Jimenez-Ferrer, Itzia; Kenéz, Xuyian; Björklund, Tomas; Nordström, Ulrika; Brundin, Patrik; Swanberg, Maria

    2016-08-23

    Motor symptoms in Parkinson's disease are attributed to degeneration of midbrain dopaminergic neurons (DNs). Heterozygosity for Engrailed-1 (En1), one of the key factors for programming and maintenance of DNs, results in a parkinsonian phenotype featuring progressive degeneration of DNs in substantia nigra pars compacta (SNpc), decreased striatal dopamine levels and swellings of nigro-striatal axons in the SwissOF1-En1+/- mouse strain. In contrast, C57Bl/6-En1+/- mice do not display this neurodegenerative phenotype, suggesting that susceptibility to En1 heterozygosity is genetically regulated. Our goal was to identify quantitative trait loci (QTLs) that regulate the susceptibility to PD-like neurodegenerative changes in response to loss of one En1 allele. We intercrossed SwissOF1-En1+/- and C57Bl/6 mice to obtain F2 mice with mixed genomes and analyzed number of DNs in SNpc and striatal axonal swellings in 120 F2-En1+/- 17 week-old male mice. Linkage analyses revealed 8 QTLs linked to number of DNs (p = 2.4e-09, variance explained = 74%), 7 QTLs linked to load of axonal swellings (p = 1.7e-12, variance explained = 80%) and 8 QTLs linked to size of axonal swellings (p = 7.0e-11, variance explained = 74%). These loci should be of prime interest for studies of susceptibility to Parkinson's disease-like damage in rodent disease models and considered in clinical association studies in PD.

  4. Therapeutic immunization protects dopaminergic neurons in a mouse model of Parkinson's disease

    PubMed Central

    Benner, Eric J.; Mosley, R. Lee; Destache, Chris J.; Lewis, Travis B.; Jackson-Lewis, Vernice; Gorantla, Santhi; Nemachek, Craig; Green, Steven R.; Przedborski, Serge; Gendelman, Howard E.

    2004-01-01

    Degeneration of the nigrostriatal dopaminergic pathway, the hallmark of Parkinson's disease, can be recapitulated in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-intoxicated mice. Herein, we demonstrate that adoptive transfer of copolymer-1 immune cells to MPTP recipient mice leads to T cell accumulation within the substantia nigra pars compacta, suppression of microglial activation, and increased local expression of astrocyte-associated glial cell line-derived neurotrophic factor. This immunization strategy resulted in significant protection of nigrostriatal neurons against MPTP-induced neurodegeneration that was abrogated by depletion of donor T cells. Such vaccine treatment strategies may provide benefit for Parkinson's disease. PMID:15197276

  5. Neuropeptide localisation in the substantia innominata and adjacent regions of the human brain.

    PubMed Central

    Candy, J M; Perry, R H; Thompson, J E; Johnson, M; Oakley, A E

    1985-01-01

    A dense peptidergic innervation has been demonstrated in the substantia innominata region in postmortem specimens of human brain using immunocytochemical techniques. A peptidergic innervation of the nucleus of Meynert - the prominent nucleus of this area containing the cholinergic cell bodies which innervate the cerebral cortex - has been demonstrated by immunostaining with antisera against the following eight neuropeptides: somatostatin, substance P, cholecystokinin octapeptide, vasoactive intestinal polypeptide, met-enkephalin, ACTH, alpha-MSH and oxytocin. Other immunocytochemical features of the substantia innominata region include a dense band of peptide immunoreactivity beneath the medial aspect of the anterior commissure and islands of somatostatin and substance P terminal immunoreactivity in the rostral part of the substantia innominata. Somatostatin immunostained cell bodies have been located in a discrete area of the bed nucleus of the stria terminalis and in the rostral portion of the substantia innominata, nucleus accumbens and the ventral part of the putamen. The dense band of peptide immunoreactivity beneath the medial aspect of the anterior commissure consists of ribbon-like processes stained with antisera against somatostatin, substance P, cholecystokinin octapeptide, vasoactive intestinal polypeptide and met-enkephalin. Less intense immunostaining of ribbon-like elements is also present in the globus pallidus. The presence of a peptidergic innervation to the nucleus of Meynert suggests a possible important modulatory role in cortical cholinergic function. Images Fig. 1 (cont.) Fig. 1 Fig. 3 (cont.) Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 PMID:2416723

  6. Tinea versicolor, tinea nigra, white piedra, and black piedra.

    PubMed

    Bonifaz, Alexandro; Gómez-Daza, Fernando; Paredes, Vanessa; Ponce, Rosa María

    2010-03-04

    Superficial mycoses are fungal infections limited to the stratum corneum and its adnexal structures. The most frequent types are dermatophytoses or tineas. Tinea versicolor involves the skin in the form of hypochromic or hyperchromic plaques, and tinea nigra affects the skin of the palms with dark plaques. White piedra and black piedra are parasitic infections of scalp hairs in the form of concretions caused by fungal growth. Diagnosis of these mycoses is made from mycologic studies, direct examination, stains, and isolation, and identification of the fungi. Treatment includes systemic antifungals, topical antifungals, and keratolytics.

  7. Phenolic acids in the flowers of Althaea rosea var. nigra.

    PubMed

    Dudek, Marlena; Matławska, Irena; Szkudlarek, Maurycy

    2006-01-01

    Distribution of phenolic acids in the flowers of Althaea rosea var. nigra has been studied by 2D-TLC and HPLC methods. The phenolic acids occurring in these fractions have been identified as ferulic, vanillic, syringic, p-coumaric, p-hydroxybenzoic, p-hydroxyphenylacetic and caffeic acids. By means of the HPLC methods the contents of major phenolic acids were estimated. From among the phenolic acids analyzed the syringic, p-hydroxybenzoic and p-coumaric acids are dominant. Total content of phenolic acids was determined by the Arnov's method.

  8. Bacillus Calmette-Guerin vaccine-mediated neuroprotection is associated with regulatory T-cell induction in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mouse model of Parkinson's disease.

    PubMed

    Laćan, Goran; Dang, Hoa; Middleton, Blake; Horwitz, Marcus A; Tian, Jide; Melega, William P; Kaufman, Daniel L

    2013-10-01

    We previously showed that, in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of Parkinson's disease (PD), vaccination with bacillus Calmette-Guerin (BCG) prior to MPTP exposure limited the loss of striatal dopamine (DA) and dopamine transporter (DAT) and prevented the activation of nigral microglia. Here, we conducted BCG dose studies and investigated the mechanisms underlying BCG vaccination's neuroprotective effects in this model. We found that a dose of 1 × 10(6) cfu BCG led to higher levels of striatal DA and DAT ligand binding (28% and 42%, respectively) in BCG-vaccinated vs. unvaccinated MPTP-treated mice, but without a significant increase in substantia nigra tyrosine hydroxylase-staining neurons. Previous studies showed that BCG can induce regulatory T cells (Tregs) and that Tregs are neuroprotective in models of neurodegenerative diseases. However, MPTP is lymphotoxic, so it was unclear whether Tregs were maintained after MPTP treatment and whether a relationship existed between Tregs and the preservation of striatal DA system integrity. We found that, 21 days post-MPTP treatment, Treg levels in mice that had received BCG prior to MPTP were threefold greater than those in MPTP-only-treated mice and elevated above those in saline-only-treated mice, suggesting that the persistent BCG infection continually promoted Treg responses. Notably, the magnitude of the Treg response correlated positively with both striatal DA levels and DAT ligand binding. Therefore, BCG vaccine-mediated neuroprotection is associated with Treg levels in this mouse model. Our results suggest that BCG-induced Tregs could provide a new adjunctive therapeutic approach to ameliorating pathology associated with PD and other neurodegenerative diseases.

  9. Transcript expression levels of full-length alpha-synuclein and its three alternatively spliced variants in Parkinson’s disease brain regions and in a transgenic mouse model of alpha-synuclein overexpression

    PubMed Central

    McLean, Jesse R.; Hallett, Penelope J.; Cooper, Oliver; Stanley, Michael; Isacson, Ole

    2012-01-01

    Alternative splicing is a complex post-transcriptional process that can be regulated by cis-acting elements located within genomic non-coding regions. Recent studies have identified that polymorphic variations in non-coding regions of the α-synuclein gene (SNCA) locus are associated with an increased risk for developing Parkinson’s disease (PD). The underlying mechanism(s) for this susceptibility may involve changes in α-synuclein mRNA expression and alternative splicing. As a first step towards understanding the biology of α-synuclein splice variants in PD, we characterized the levels of the full-length SNCA-140 mRNA transcript and SNCA-126, -112, and -98 alternatively spliced variants in different neuronal regions from PD patients or transgenic mice overexpressing human α-synuclein (ASO). In human post-mortem tissue, α-synuclein spliced transcripts were expressed in a region-specific manner in cortex, substantia nigra, and cerebellum. We observed increased nigral SNCA-140 and SNCA-126 transcript levels in PD patients when compared to neurologically unaffected cases. Human α-synuclein splicing changes were also found to occur in a region-specific manner in ASO mice. Here, SNCA-126, -112, and -98 transcript levels did not increase proportionally with SNCA-140 levels, or parallel the region-specific mouse transcript ratios seen in wild-type (WT) littermates. While most transcripts were elevated in ASO mice when compared to WT mice, the most prominent increase was found in the ventral midbrain of 15-month-old ASO mice. These results demonstrate region-specific human α-synuclein transcript level abnormalities in PD patients and in a transgenic mouse model of α-synucleinopathy. This study is relevant to understanding the normal, adaptive, or pathological role(s) of α-synuclein splice variants. PMID:22155155

  10. Diversity in tree species in southeastern Ohio Betula nigra L. communities

    Treesearch

    Larry D. Cribben; Dina D. Scacchetti

    1976-01-01

    Quantitative data were obtained for arboreal species within 50 lowland forests in southeastern Ohio. Thirty-seven communities were dominated by Betula nigra L. and 13 were dominated by Acer saccharinum L. The acidic soils collected from B. nigra communities contained toxic concentrations of exchangeable aluminum...

  11. Adventitious shoot regeneration from in vitro leaf explants of Fraxinus nigra

    Treesearch

    Jun Hyung Lee; Paula M. Pijut

    2017-01-01

    Black ash (Fraxinus nigra) is an endangered hardwood tree species under threat of extirpation by the emerald ash borer (EAB), an aggressive exotic phloemfeeding beetle. We have developed an efficient regeneration system through adventitious shoot organogenesis in F. nigra using in vitro-derived leaf explants. Two types of leaf...

  12. Fraxinus nigra (black ash) dieback in Minnesota: Regional variation and potential contributing factors

    Treesearch

    Brian J. Palik; Michael E. Ostry; Robert C. Venette; Ebrahim Abdela

    2011-01-01

    Extensive tree dieback is a recurrent issue in many regions. Crown dieback of Fraxinus nigra Marsh. (black ash; brown ash) in the northeastern and north central United States is an example. F. nigra is a widely distributed hardwood that is often the dominant species in wetland forests from Manitoba to Newfoundland and West...

  13. G-protein coupled receptor 6 deficiency alters striatal dopamine and cAMP concentrations and reduces dyskinesia in a mouse model of Parkinson's disease.

    PubMed

    Oeckl, Patrick; Hengerer, Bastian; Ferger, Boris

    2014-07-01

    The orphan G-protein coupled receptor 6 (GPR6) is a constitutively active receptor which is positively coupled to the formation of cyclic adenosine-3',5'-monophosphate (cAMP). GPR6 is predominantly expressed in striatopallidal neurons. Here, we investigated neurochemical and behavioural effects of Gpr6 deficiency in mice. Gpr6 depletion decreased in vivo cAMP tissue concentrations (20%) in the striatum. An increase of striatal tissue dopamine concentrations (10%) was found in Gpr6(-/-) mice, whereas basal extracellular dopamine levels were not changed compared with Gpr6(+/+) mice, as shown by in vivo microdialysis. Western blot analyses revealed no alteration in the expression and subcellular localisation of the dopamine D2 receptor in the striatum of Gpr6(-/-) mice, and the number of tyrosine hydroxylase positive neurons in the substantia nigra was unchanged. DARPP-32 (dopamine and cAMP-regulated phosphoprotein of 32kDa) expression in the striatum of Gpr6(-/-) mice was not altered, however, a twofold increase in the phosphorylation of DARPP-32 at Thr34 was detected in Gpr6(-/-) compared with Gpr6(+/+) mice. Gpr6(-/-) mice showed higher locomotor activity in the open field, which persisted after treatment with the dopamine D2 receptor antagonist haloperidol. They also displayed reduced abnormal involuntary movements after apomorphine and quinpirole treatment in the mouse dyskinesia model of Parkinson's disease. In conclusion, the depletion of Gpr6 reduces cAMP concentrations in the striatum and alters the striatal dopaminergic system. Gpr6 deficiency causes an interesting behavioural phenotype in the form of enhanced motor activity combined with reduced abnormal involuntary movements. These findings could offer an opportunity for the treatment of Parkinson's disease beyond dopamine replacement.

  14. High density of benzodiazepine binding sites in the substantia innominata of the rat

    SciTech Connect

    Sarter, M.; Schneider, H.H.

    1988-07-01

    In order to study the neuronal basis of the pharmacological interactions between benzodiazepine receptor ligands and cortical cholinergic turnover, we examined the regional distribution of specific benzodiazepine binding sites using in vitro autoradiography. In the basal forebrain, the substantia innominata contained a high density of (/sup 3/H)lormetazepam (LMZ) binding sites (Bmax = 277 fmol/mg tissue; Kd = 0.55 nM). The label could be displaced by diazepam (IC50 = 100 nM), the benzodiazepine receptor antagonist beta-carboline ZK 93426 (45 nM) and the partial inverse agonist beta-carboline FG 7142 (540 nM). It is hypothesized that the amnesic effects of benzodiazepine receptor agonists are exerted through benzodiazepine receptors which are situated on cholinergic neurons in the substantia innominata and are involved in a tonic inhibition of cortical acetylcholine release. The benzodiazepine receptor antagonist ZK 93426 may exert its nootropic effects via benzodiazepine receptors in the substantia innominata and, consequently, by disinhibiting cortical acetylcholine release.

  15. [Application of Populus Nigra preparations at experimental parodontitis].

    PubMed

    Kipiani, N V; Kuchukhidze, Dzh K; Chichua, Z Dzh; Kipiani, V A; Datunashvili, I V

    2007-09-01

    Severe oxidative stress, developed under experimental periodontitis is accompanied by disturbances in mitochondrial respiration in tissue cells of gingiva, membrane damage and release of Fe(2+) and Mn(2+), leading to the worsening of inflammation process and gingival tissue necrosis. Reduction of free nitric oxide in gingival tissue appeared to be characteristic for experimental parodontitis: decreases local immunity, antimicrobial resistance, and tissue regeneration, disturbs blood supply and tissue trophism, which forwards important role in deepening of inflammation process and wasting of gingival tissue. Application of preparations derived from black poplar (Populus Nigra) gemma standardizes mitochondrial respiration, reduces presentation of inflammation, and considerably improves EPR-spectrum of gingival tissue. Though the complete normalization is not achieved--hazard of peroxidation still remains, the applied preparations, due to their strong anti- oxidative and anti-inflammatory activities is as an effective and rehabilitative means to tackle gingivitis and peiodontitis.

  16. Tinea corporis, tinea cruris, tinea nigra, and piedra.

    PubMed

    Gupta, Aditya K; Chaudhry, Maria; Elewski, Boni

    2003-07-01

    Tinea infections are among the most common dermatologic conditions throughout the world. To avoid a misdiagnosis, identification of dermatophyte infections requires both a fungal culture on Sabouraud's agar media, and a light microscopic mycologic examination from skin scrapings. Topical antifungals may be sufficient for treatment of tinea corporis and cruris and tinea nigra, and the shaving of hair infected by piedra may also be beneficial. Systemic therapy, however, may be required when the infected areas are large, macerated with a secondary infection, or in immunocompromised individuals. Preventative measures of tinea infections include practicing good personal hygiene; keeping the skin dry and cool at all times; and avoiding sharing towels, clothing, or hair accessories with infected individuals.

  17. Two new lignans and melanogenesis inhibitors from Schisandra nigra.

    PubMed

    Narukawa, Yuji; Komatsu, Chihiro; Yamauchi, Rina; Shibayama, Sakiko; Hachisuka, Mayuko; Kiuchi, Fumiyuki

    2016-07-01

    An acetone extract from the stems of Schisandra nigra MAX. (Schisandraceae) exhibited significant inhibition of 3-isobutyl-1-methylxanthine (IBMX)-stimulated melanogenesis in murine B16 melanoma F10 cells. Fractionation and purification of the extract led to the isolation of two new tetrahydrofuran-type lignans, (+)-5-methoxyzuonin A (2) and kadlongirin C (3), along with eight known compounds (1, 4-10). The structures of the new compounds were determined by spectroscopic analyses. Of the isolated compounds (1, 3 -10), (+)-zuonin A (1) showed remarkable inhibition of melanogenesis at concentrations without cytotoxicity in B16 melanoma F10 cells. (+)-Zuonin A (1) did not inhibit tyrosinase; however, Western blot analysis revealed that it decreased protein levels of tyrosinase and tyrosinase-related proteins (TRP)-1 and TRP-2 without changing phosphorylation level of cAMP response element-binding protein.

  18. Effects of photooxidation on membrane integrity in Salix nigra seeds

    PubMed Central

    Roqueiro, Gonzalo; Facorro, Graciela B.; Huarte, Mónica G.; Rubín de Celis, Emilio; García, Fernando; Maldonado, Sara; Maroder, Horacio

    2010-01-01

    Background and Aims Salix nigra seeds are desiccation-tolerant, as are orthodox seeds, although in contrast to other orthodox seeds they lose viability in a few weeks at room temperature. They also differ in that the chloroplasts of the embryo tissues conserve their chlorophyll and endomembranes. The aim of this paper was to investigate the role of chlorophyll in seed deterioration. Methods Seeds were aged at different light intensities and atmospheric conditions. Mean germination time and normal and total germination were evaluated. The formation of free radicals was assessed using electronic spin resonance spectroscopy, and changes in the fatty acid composition from phospholipids, galactolipids and triglycerides using gas–liquid chromatography. Membrane integrity was studied with electronic spin resonance spin probe techniques, electrolyte leakage and transmission electron microscopy. Key Results Light and oxygen played an important role in free-radical generation, causing a decrease in normal germination and an increase in mean germination time. Both indices were associated with a decrease in polyunsaturated fatty acids derived from membrane lipids as phospholipids and galactolipids. The detection of damage in thylakoid membranes and an increase in plasmalemma permeability were consistent with the decrease in both types of lipids. Triglycerides remained unchanged. Light-induced damage began in outermost tissues and spread inwards, decreasing normal germination. Conclusions Salix nigra seeds were very susceptible to photooxidation. The thylakoid membranes appeared to be the first target of the photooxidative process since there were large decreases in galactolipids and both these lipids and the activated chlorophyll are contiguous in the structure of that membrane. Changes in normal germination and mean germination time could be explained by the deteriorative effects of oxidation. PMID:20338949

  19. Dalnigrin, a neoflavonoid marker for the identification of Brazilian rosewood (Dalbergia nigra) in CITES enforcement.

    PubMed

    Kite, Geoffrey C; Green, Paul W C; Veitch, Nigel C; Groves, Madeleine C; Gasson, Peter E; Simmonds, Monique S J

    2010-07-01

    International trade in Brazilian rosewood, Dalbergia nigra (Vell.) Allemão ex Benth., is regulated by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). One problem in enforcing these regulations is the difficulty in distinguishing the wood of D. nigra from that of a closely-related but unregulated species, Dalbergia spruceana Benth. Using LC-MS to analyse methanol extracts of xylaria specimens, we identified a chemical marker for D. nigra heartwood, and determined its structure as the neoflavonoid 6-hydroxy-7-methoxy-4-(4-methoxyphenyl)-2H-1-benzopyran-2-one (4'-O-methylmelanettin; dalnigrin), using spectroscopic techniques. Dalnigrin was present in all nine available heartwood specimens of D. nigra, but it was not detected in extracts of 59 other heartwood samples representing 15 species of Dalbergia, including D. spruceana. Five other phenolic compounds were also isolated from D. nigra heartwood and similarly identified as the neoflavonoids 3'-hydroxymelanettin, melanettin, melannein and dalbergin, and the isoflavone caviunin. In extracts of D. spruceana heartwood, pseudobaptigenin was identified by LC-MS to be a major phenolic component that was not detected in wood extracts of D. nigra. We conclude that chemical analysis, in combination with anatomical investigation, can provide persuasive evidence to support the positive identification of untreated heartwood of D. nigra.

  20. Manganese Superoxide Dismutase Protects against 6-Hydroxydopamine Injury in Mouse Brains*

    PubMed Central

    Callio, Jason; Oury, Tim D.; Chu, Charleen T.

    2007-01-01

    Dopaminergic neurons of the substantia nigra are susceptible to toxin-based insults. Intrastriatal injection of 6-hydroxydopamine results in selective toxicity to these neurons. A mechanistic role for reactive oxygen species is supported by observations that antioxidants confer protection from 6-hydroxydopamine. Although cell culture studies have suggested extracellular or nonmitochondrial mechanisms in 6-hydroxydopamine toxicity, the compartmentalization of oxidative injury mechanisms is incompletely defined in vivo. Transgenic mice overexpressing mitochondrial manganese superoxide dismutase or extracellular superoxide dismutase received unilateral intrastriatal injections of 6-hydroxydopamine. Mice that overexpress manganese superoxide dismutase showed significantly smaller striatal lesions than littermate controls. There were no differences in nonspecific striatal injury associated with contralateral vehicle injection. Manganese superoxide dismutase overexpression also protected against loss of neuronal cell bodies in the substantia nigra. In contrast, mice overexpressing extracellular superoxide dismutase showed no protection from 6-hydroxydopamine toxicity in either brain region. Protection of the nigrostriatal system by overexpression of manganese super-oxide dismutase supports a role for mitochondrially derived superoxide in 6-hydroxydopamine toxicity. Mitochondrial oxidative stress appears to be a common mechanism among diverse models of Parkinson disease, whether involving toxins, mutated genes, or cybrid cells containing patient mitochondria. Antioxidant therapies that target this subcellular compartment may prove promising. PMID:15755737

  1. Electrophysiological Properties of Catecholaminergic Neurons in the Norepinephrine-Deficient Mouse

    PubMed Central

    Beckstead, Michael J.; Weinshenker, David

    2007-01-01

    To determine how norepinephrine affects the basic physiological properties of catecholaminergic neurons, brain slices containing the Substantia Nigra Pars Compacta and Locus Coeruleus were studied with cell-attached and whole-cell recordings in control and dopamine β-hydroxylase knockout (Dbh −/−) mice that lack norepinephrine. In the cell-attached configuration, the spontaneous firing rate and pattern of Locus Coeruleus neurons recorded from Dbh −/− mice was the same as the firing rate and pattern recorded from heterozygous littermates (Dbh +/−). During whole-cell recordings, synaptic stimulation produced an α-2 receptor-mediated outward current in the Locus Coeruleus of control mice that was absent in Dbh −/− mice. Normal α-2 mediated outward currents were restored in Dbh −/− slices after pre-incubation with norepinephrine. Locus Coeruleus neurons also displayed similar changes in holding current in response to bath application of norepinephrine, UK 14304, and methionine-enkephalin. Dopamine neurons recorded in the Substantia Nigra Pars Compacta similarly showed no differences between slices harvested from Dbh −/− and control mice. These results indicate that endogenous norepinephrine is not necessary for the expression of catecholaminergic neuron firing properties or responses to direct agonists, but is necessary for auto-inhibition mediated by indirect α-2 receptor stimulation. PMID:17156935

  2. Dermoscopy improves diagnosis of tinea nigra: a study of 50 cases.

    PubMed

    Piliouras, Peter; Allison, Scott; Rosendahl, Cliff; Buettner, Petra G; Weedon, David

    2011-08-01

    Tinea nigra is a relatively uncommon dematiaceous fungal infection of the palms and soles, which clinically may mimic a melanocytic lesion. We sought to ascertain how frequently misdiagnosis of this infection occurred and whether the use of dermoscopy helped in its diagnosis. Fifty consecutive cases of tinea nigra diagnosed at a dermatopathology laboratory were examined with regard to the clinical diagnosis, use of dermoscopy and the mode of management. Of the 50 cases, 21 (42.0%) were treated by shave or surgical excision. The clinical diagnosis of tinea nigra was made in five cases (10.0%) and suggested along with other diagnoses in a further two cases (4.0%). The dermatologists (n = 9) gave the correct diagnosis in four patients (44.4%), the general practitioners (n = 38) gave the correct diagnosis in one patient (2.6%) and the three surgeons involved did not give the correct diagnosis. When dermoscopy was used, in seven of 13 (53.8%) cases tinea nigra was suggested as a probable diagnosis but when dermoscopy was not used (n = 37) tinea nigra was not clinically diagnosed (P < 0.001). The diagnosis of tinea nigra is significantly improved by dermoscopy, the disease should be considered as a cause of palmar or plantar pigmentation. © 2011 The Authors; Australasian Journal of Dermatology © 2011 The Australasian College of Dermatologists.

  3. Oscillatory activity within rat substantia gelatinosa in vitro: a role for chemical and electrical neurotransmission

    PubMed Central

    Asghar, Aziz UR; Cilia La Corte, Paul F; LeBeau, Fiona EN; Dawoud, Mutaz Al; Reilly, Siobhan C; Buhl, Eberhard H; Whittington, Miles A; King, Anne E

    2005-01-01

    Although rhythmic behaviour of mammalian spinal ventral horn networks has been extensively studied little is known about oscillogenesis in the spinal dorsal horn. The aims of this in vitro study were to record and determine the underlying mechanisms of potassium-evoked network field oscillations in the substantia gelatinosa of the neonatal rat dorsal horn, a lamina involved in nociceptive processing. Transient pressure ejection of a potassium solution evoked reproducible rhythmic activity in discrete areas of the substantia gelatinosa which lasted for 5–15 s with a single prominent peak in the 4–12 Hz frequency band (7.7 ± 0.1 Hz, n = 60). Oscillations of similar frequency and amplitude were also observed in isolated dorsal horn quadrants. Application of CNQX (10 μm) reduced peak power amplitude and integrated power area (from 4 to 12 Hz) of the power spectrum, whereas d-AP5 (50 μm) had no effect on the potassium-evoked rhythm. Bicuculline (30 μm) or strychnine (10 μm) reduced the power amplitude and area. On combination of bicuculline (30 μm) and strychnine (10 μm) the reductions in power amplitude and area were not significantly different (P > 0.05) when compared with application of either drug alone. The gap junction blockers carbenoxolone (100 μm) or octanol (1 mm) significantly reduced power amplitude and area. Although TTX (1 μm) or a calcium-free perfusate both caused reductions in the power amplitude and area, potassium-evoked rhythmic activity persisted. However, this persistent rhythm was further reduced on combination of calcium-free perfusate with octanol (1 mm) and was abolished using a cocktail of drugs. Blockade of the potassium delayed rectifier current by tetraethylammonium (5 mm) or the hyperpolarization-activated current (Ih) by ZD7288 (10 μm) disrupted the synchronization of the potassium-induced oscillation. The frequency of potassium-induced rhythms was unaffected by any of the drugs tested. These novel findings demonstrate that

  4. [Introduction trial of medicine mulberry (Morus nigra) in Chongqing].

    PubMed

    Zeng, Qi-Wei; Zhang, Chao; Chen, Hong-Yu; Ding, Tian-Long; Zhao, Ai-Chun; Xiang, Zhong-Huai; He, Ning-Jia

    2016-04-01

    Medicine mulberry (Morus nigra) mainly distributed in southern areas of Xinjiang Uighur Autonomous Region and introduced by grafting, is a unique Morus species, whose plant number is little. As a traditional herbal medicine, medicine mulberry with high levels of secondary metabolites has important values of scientific research and utilization. In order to solve the introduction problems for medicine mulberry, we have established its rapid propagation system through tissue culture since 2011. The shoots of medicine mulberry through tissue culture were transplanted into the field to carry out an introduction experiment. Here, we firstly reported that the growth status and pest and disease occurrence of medicine mulberry in the field of Chongqing and found that the medicine mulberry through tissue culture had well-developed root system, it showed better growth than medicine mulberry by grafting technique, and Pseudodendrothrips moil was a major pest of medicine mulberry. The introduction technique for medicine mulberry established successfully in this study could lay the foundation for large-scale cultivation and high efficiency utilization of medicine mulberry. Copyright© by the Chinese Pharmaceutical Association.

  5. Personality of Wild Male Crested Macaques (Macaca nigra)

    PubMed Central

    Neumann, Christof; Agil, Muhammad; Widdig, Anja; Engelhardt, Antje

    2013-01-01

    Animal personalities, i.e. consistent differences in behavior across time and/or context, have received increased attention of behavioral biologists over the last years. Recent research shows that personalities represent traits on which natural and sexual selection work and which can have substantial fitness consequences. The aim of this study is to establish the personality structure of crested macaque (Macaca nigra) males as foundation for future studies on its adaptive value. We collected behavioral data through focal animal sampling and additionally conducted two sets of playback experiments. Results of a factor analysis on the behavioral data revealed a four factor structure with components we labeled Anxiety, Sociability, Connectedness and Aggressiveness. Results from the experiments revealed an additional and independent Boldness factor but the absence of Neophilia. Overall, this structure resembles other macaque and animal species with the exception of Connectedness, which might be a consequence of the species' tolerant social style. Our results thus not only form the basis for future studies on the adaptive value of personality in crested macaques but also contribute an important data point for investigating the evolution of personality structure from a comparative perspective by refining, for example, which personality factors characterized the last common ancestor of hominids and macaques. PMID:23940517

  6. In vitro regeneration of Salix nigra from adventitious shoots.

    PubMed

    Lyyra, Satu; Lima, Amparo; Merkle, Scott A

    2006-07-01

    Black willow (Salix nigra Marsh.) is the largest and only commercially important willow species in North America. It is a candidate for phytoremediation of polluted soils because it is fast-growing and thrives on floodplains throughout eastern USA. Our objective was to develop a protocol for the in vitro regeneration of black willow plants that could serve as target material for gene transformation. Unexpanded inflorescence explants were excised from dormant buds collected from three source trees and cultured on woody plant medium (WPM) supplemented with one of: (1) 0.1 mg l(-1) thidiazuron (TDZ); (2) 0.5 mg l(-1) 6-benzoaminopurine (BAP); or (3) 1 mg l(-1) BAP. All plant growth regulator (PGR) treatments induced direct adventitious bud formation from the genotypes. The percentage of explants producing buds ranged from 20 to 92%, depending on genotype and treatment. Although most of the TDZ-treated inflorescences produced buds, these buds failed to elongate into shoots. Buds on explants treated with BAP elongated into shoots that were easily rooted in vitro and further established in potting mix in high humidity. The PGR treatments significantly affected shoot regeneration frequency (P < 0.01). The highest shoot regeneration frequency (36%) was achieved with Genotype 3 cultured on 0.5 mg l(-1) BAP. Mean number of shoots per explant varied from one to five. The ability of black willow inflorescences to produce adventitious shoots makes them potential targets for Agrobacterium-mediated transformation with heavy-metal-resistant genes for phytoremediation.

  7. Antiplasmodial alkaloids from the bark of Cryptocarya nigra (Lauraceae).

    PubMed

    Nasrullah, Ayu Afiqah; Zahari, Azeana; Mohamad, Jamaludin; Awang, Khalijah

    2013-07-08

    A dichloromethane extract of the stem bark of Cryptocarya nigra showed strong in vitro inhibition of Plasmodium falciparum growth, with an IC50 value of 2.82 μg/mL. The phytochemical study of this extract has led to the isolation and characterization of four known alkaloids: (+)-N-methylisococlaurine (1), atherosperminine (2), 2-hydroxyathersperminine (3), and noratherosperminine (4). Structural elucidation of all alkaloids was accomplished by means of high field 1D- and 2D-NMR, IR, UV and LCMS spectral data. The isolated extract constituents (+)-N-methylisococlaurine (1), atherosperminine (2) and 2-hydroxy-atherosperminine (3) showed strong antiplasmodial activity, with IC50 values of 5.40, 5.80 and 0.75 μM, respectively. In addition, (+)-N-methylisocolaurine (1) and atherosperminine (2) showed high antioxidant activity in a DPPH assay with IC50 values of 29.56 ug/mL and 54.53 ug/mL respectively. Compounds 1 and 2 also both showed high antioxidant activity in the FRAP assay, with percentages of 78.54 and 70.66 respectively and in the metal chelating assay, with IC50 values of 50.08 ug/mL and 42.87 ug/mL, respectively.

  8. Pseudonocardia nigra sp. nov., isolated from Atacama Desert rock.

    PubMed

    Trujillo, Martha E; Idris, Hamidah; Riesco, Raúl; Nouioui, Imen; Igual, José M; Bull, Alan T; Goodfellow, Michael

    2017-08-01

    Eleven actinobacterial strains were isolated from a rock sample collected in the Atacama Desert. Molecular typing by BOX-PCR divided the strains into three clusters and showed that, although very similar, they were not clones. Three strains, ATK01, ATK03T and ATK17, each representing one of the defined BOX clusters, were chosen for further characterization. Phylogenetic analysis indicated that the strains were related to the genus Pseudonocardia and were recovered in a cluster together with Pseudonocardia bannensis YIM 63101T and Pseudonocardia xinjiangensis AS 4.1538T. Chemotaxonomic analyses confirmed their affiliation to the genus Pseudonocardia but differences were found between the new strains and their closest phylogenetic relatives. Physiological and fatty acid analyses also revealed differences between these strains and their phylogenetic neighbours supporting their status as a distinct species. Based on the overall data, it is proposed that strains ATK01, ATK03T and ATK17 represent a novel species of the genus Pseudonocardia for which the name Pseudonocardia nigra sp. nov. is proposed (type strain ATK03T=DSM 104088T=CECT 9183T).

  9. Protective effects of 2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside in the MPTP-induced mouse model of Parkinson's disease: Involvement of reactive oxygen species-mediated JNK, P38 and mitochondrial pathways.

    PubMed

    He, Hong; Wang, Songhai; Tian, Jiyu; Chen, Lei; Zhang, Wei; Zhao, Junjie; Tang, Haifeng; Zhang, Xiaojun; Chen, Jianzong

    2015-11-15

    Parkinson's disease (PD) is characterized by the selective death of dopaminergic neurons in the substantia nigra pars compacta. Oxidative stress-induced neuron loss is thought to play a crucial role in the pathogenesis of PD. Previous work from our group suggests that 2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside (TSG), an active component extracted from a traditional Chinese herb, Polygonum multiflorum thunb, can attenuate 1-methyl-4-phenyl pyridium-induced apoptosis in the neuronal cell line PC12, by inhibiting reactive oxygen species generation and modulating c-Jun N-terminal kinases (JNK) activation. Here, we investigated the protective effects of TSG against 1-methyl-4-phenyl-1,2,3,6-tetrahydropypridine (MPTP)-induced loss of tyrosine hydroxylase positive cells in mice and the underlying mechanisms. The results showed that MPTP-induced loss of tyrosine hydroxylase positive cells and reactive oxygen species generation were prevented by TSG in a dose-dependent manner. The reactive oxygen species scavenger N-acetylcysteine could also mitigate reactive oxygen species generation. Moreover, JNK and P38 were activated by MPTP, but extracellular signal-regulated protein kinases phosphorylation did not change after MPTP treatment. TSG at different doses blocked the activation of JNK and P38. The protective effect of TSG was also associated with downregulation of the bax/bcl-2 ratio, reversed the release of cytochrome c and smac, and inhibited the activation of caspase-3, -6, and -9 induced by MPTP. In conclusion, our studies demonstrated that the protective effects of TSG in the MPTP-induced mouse model of PD are involved, at least in part, in controlling reactive oxygen species-mediated JNK, P38, and mitochondrial pathways.

  10. Progressive nigrostriatal terminal dysfunction and degeneration in the engrailed1 heterozygous mouse model of Parkinson's disease.

    PubMed

    Nordströma, Ulrika; Beauvais, Geneviève; Ghosh, Anamitra; Pulikkaparambil Sasidharan, Baby Chakrapani; Lundblad, Martin; Fuchs, Julia; Joshi, Rajiv L; Lipton, Jack W; Roholt, Andrew; Medicetty, Satish; Feinstein, Timothy N; Steiner, Jennifer A; Escobar Galvis, Martha L; Prochiantz, Alain; Brundin, Patrik

    2015-01-01

    Current research on Parkinson's disease (PD) pathogenesis requires relevant animal models that mimic the gradual and progressive development of neuronal dysfunction and degeneration that characterizes the disease. Polymorphisms in engrailed 1 (En1), a homeobox transcription factor that is crucial for both the development and survival of mesencephalic dopaminergic neurons, are associated with sporadic PD. This suggests that En1 mutant mice might be a promising candidate PD model. Indeed, a mouse that lacks one En1 allele exhibits decreased mitochondrial complex I activity and progressive midbrain dopamine neuron degeneration in adulthood, both features associated with PD. We aimed to further characterize the disease-like phenotype of these En1(+/-) mice with a focus on early neurodegenerative changes that can be utilized to score efficacy of future disease modifying studies. We observed early terminal defects in the dopaminergic nigrostriatal pathway in En1(+/-) mice. Several weeks before a significant loss of dopaminergic neurons in the substantia nigra could be detected, we found that striatal terminals expressing high levels of dopaminergic neuron markers TH, VMAT2, and DAT were dystrophic and swollen. Using transmission electron microscopy, we identified electron dense bodies consistent with abnormal autophagic vacuoles in these terminal swellings. In line with these findings, we detected an up-regulation of the mTOR pathway, concurrent with a downregulation of the autophagic marker LC3B, in ventral midbrain and nigral dopaminergic neurons of the En1(+/-) mice. This supports the notion that autophagic protein degradation is reduced in the absence of one En1 allele. We imaged the nigrostriatal pathway using the CLARITY technique and observed many fragmented axons in the medial forebrain bundle of the En1(+/-) mice, consistent with axonal maintenance failure. Using in vivo electrochemistry, we found that nigrostriatal terminals in the dorsal striatum were severely

  11. Loss of Homeostasis in the Direct Pathway in a Mouse Model of Asymptomatic Parkinson's Disease.

    PubMed

    Escande, Mariela V; Taravini, Irene R E; Zold, Camila L; Belforte, Juan E; Murer, M Gustavo

    2016-05-25

    The characteristic slowness of movement in Parkinson's disease relates to an imbalance in the activity of striatal medium spiny neurons (MSNs) of the direct (dMSNs) and indirect (iMSNs) pathways. However, it is still unclear whether this imbalance emerges during the asymptomatic phase of the disease or if it correlates with symptom severity. Here, we have used in vi