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Substantia nigra

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https://www.readbyqxmd.com/read/28924693/phosphodiesterase-4-inhibition-affects-both-the-direct-and-indirect-pathway-an-electrophysiological-study-examining-the-tri-phasic-response-in-the-substantia-nigra-pars-reticulata
#1
P R A Heckman, J V Schweimer, T Sharp, J Prickaerts, A Blokland
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...
September 18, 2017: Brain Structure & Function
https://www.readbyqxmd.com/read/28924005/nigral-glutamatergic-neurons-control-the-speed-of-locomotion
#2
Dimitri Ryczko, Swantje Grätsch, Laura Schläger, Avo Keuyalian, Zakaria Boukhatem, Claudia Garcia, François Auclair, Ansgar Büschges, Réjean Dubuc
The Mesencephalic Locomotor Region (MLR) plays a crucial role in locomotor control. In vertebrates, stimulation of the MLR at increasing intensities elicits locomotion of growing speed. This effect has been presumed to result from higher brain inputs activating the MLR like a dimmer switch. Here, we show in lampreys (Petromyzon marinus) of either sex that incremental stimulation of a region homologous to the mammalian substantia nigra pars compacta (SNc) evokes increasing activation of MLR cells with a graded increase in the frequency of locomotor movements...
September 18, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28920936/dopamine-induces-soluble-%C3%AE-synuclein-oligomers-and-nigrostriatal-degeneration
#3
Danielle E Mor, Elpida Tsika, Joseph R Mazzulli, Neal S Gould, Hanna Kim, Malcolm J Daniels, Shachee Doshi, Preetika Gupta, Jennifer L Grossman, Victor X Tan, Robert G Kalb, Kim A Caldwell, Guy A Caldwell, John H Wolfe, Harry Ischiropoulos
Parkinson's disease (PD) is defined by the loss of dopaminergic neurons in the substantia nigra and the formation of Lewy body inclusions containing aggregated α-synuclein. Efforts to explain dopamine neuron vulnerability are hindered by the lack of dopaminergic cell death in α-synuclein transgenic mice. To address this, we manipulated both dopamine levels and α-synuclein expression. Nigrally targeted expression of mutant tyrosine hydroxylase with enhanced catalytic activity increased dopamine levels without damaging neurons in non-transgenic mice...
September 18, 2017: Nature Neuroscience
https://www.readbyqxmd.com/read/28919537/neuroprotective-effect-of-curcumin-i-in-copper-induced-dopaminergic-neurotoxicity-in-rats-a-possible-link-with-parkinson-s-disease
#4
Abdellatif Abbaoui, Hicham Chatoui, Omar El Hiba, Halima Gamrani
Numerous findings indicate an involvement of heavy metals in the neuropathology of several neurodegenerative disorders, especially Parkinson's disease (PD). Previous studies have demonstrated that Copper (Cu) exhibits a potent neurotoxic effect on dopaminergic neurons and triggers profound neurobehavioral alterations. Curcumin is a major component of Curcuma longa rhizomes and a powerful medicinal plant that exerts many pharmacological effects. However, the neuroprotective action of curcumin on Cu-induced dopaminergic neurotoxicity is yet to be investigated...
September 14, 2017: Neuroscience Letters
https://www.readbyqxmd.com/read/28918943/vagus-nerve-stimulation-improves-locomotion-and-neuronal-populations-in-a-model-of-parkinson-s-disease
#5
Ariana Q Farrand, Kristi L Helke, Rebecca A Gregory, Monika Gooz, Vanessa K Hinson, Heather A Boger
BACKGROUND: Parkinson's disease (PD) is a progressive, neurodegenerative disorder with no disease-modifying therapies, and symptomatic treatments are often limited by debilitating side effects. In PD, locus coeruleus noradrenergic (LC-NE) neurons degenerate prior to substantia nigra dopaminergic (SN-DA) neurons. Vagus nerve stimulation (VNS) activates LC neurons, and decreases pro-inflammatory markers, allowing improvement of LC targets, making it a potential PD therapeutic. OBJECTIVE: To assess therapeutic potential of VNS in a PD model...
August 24, 2017: Brain Stimulation
https://www.readbyqxmd.com/read/28918332/control-of-absence-epilepsy-seizures-in-specific-relay-nuclei-of-thalamus
#6
Bing Hu, Xiaoqiang Zou, Yu Guo, Zhejia Yang, Feng Shi, Wangyuan Dong
In this paper, we used a classic basal ganglia-corticothalamic model(BGCT) to study the onset and control mechanism of absence epilepsy in specific relay nuclei (SRN) of thalamus. It was found that the seizure state may appear in SRN by turning the coupling strength -vsr and signal transmission delay τ on the route "Thalamic reticular nuclei (TRN) of thalamus ⟶ SRN ". With increasing of -vsr, the seizure state appeared two times, and its onset mechanism has not been discussed in previous studies. The seizure activity can be well controlled by adjusting the activation level of the substantia nigra pars reticulata (SNr) in basal ganglia, which is a main output tissue to the corticothalamic system through two direct inhibitory pathways "SNr ⟶ SRN" and "SNr ⟶ TRN " in our model...
September 13, 2017: Journal of Theoretical Biology
https://www.readbyqxmd.com/read/28918091/opposed-effects-of-dityrosine-formation-in-soluble-and-aggregated-%C3%AE-synuclein-on-fibril-growth
#7
Michael M Wördehoff, Hamed Shaykhalishahi, Luca Groß, Lothar Gremer, Matthias Stoldt, Alexander K Buell, Dieter Willbold, Wolfgang Hoyer
Parkinson's disease (PD) is the second most common neurodegenerative disease. It is characterized by aggregation of the protein α-synuclein (α-syn) in Lewy bodies, mitochondrial dysfunction, and increased oxidative stress in the substantia nigra. Oxidative stress leads to several modifications of biomolecules including dityrosine (DiY)-crosslinking in proteins, which has recently been detected in α-syn in Lewy bodies from PD patients. Here we report that α-syn is highly susceptible to UV-induced DiY formation...
September 13, 2017: Journal of Molecular Biology
https://www.readbyqxmd.com/read/28916503/altered-serotonergic-and-gabaergic-neurotransmission-in-a-mice-model-of-obsessive-compulsive-disorder
#8
Christine Winter, Dana M Greene, Paraskevi Mavrogiorgou, Helge Schaper, Reinhard Sohr, Abel Bult-Ito, Georg Juckel
There is ample evidence that obsessive-compulsive disorder (OCD) is based on reduced serotonergic function. Replicated bidirectional selection for thermoregulatory nest-building behavior in the laboratory house mouse (Mus musculus) resulted in compulsive-like, non-compulsive-like and randomly bred control mice that represent a non-induced animal model of OCD. The present study aimed at investigating the neurochemical patterns in specific brain regions of compulsive-like (HA) versus non-compulsive-like (LA) and normal (CA) mice...
September 12, 2017: Behavioural Brain Research
https://www.readbyqxmd.com/read/28912676/chemical-exchange-saturation-transfer-mri-signal-loss-of-the-substantia-nigra-as-an-imaging-biomarker-to-evaluate-the-diagnosis-and-severity-of-parkinson-s-disease
#9
Chunmei Li, Min Chen, Xuna Zhao, Rui Wang, Haibo Chen, Wen Su, Shuhua Li, Baohui Lou, Guodong Song, Shuai Zhang, Jintao Zhang, Jinyuan Zhou
The early diagnosis of Parkinson's disease (PD) and the accurate evaluation of disease severity are crucial for intervention and treatment in PD patients. In this study, we applied chemical exchange saturation transfer (CEST) imaging to patients at different stages of PD and explored the clinical value of the CEST signal loss of the substantia nigra as an imaging biomarker of PD. The measured CEST signal intensities (including amide proton transfer-weighted or APTw, and total CEST or CESTtotal) of the substantia nigra in PD patients showed a significantly decreased tendency with PD progression...
2017: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/28912019/a-nigro-vagal-pathway-controls-gastric-motility-and-is-affected-in-a-rat-model-of-parkinsonism
#10
Laura Anselmi, Luca Toti, Cecilia Bove, Jessica Hampton, R Alberto Travagli
BACKGROUND & AIMS: In most patients with Parkinson's disease, gastrointestinal (GI) dysfunctions, such as gastroparesis and constipation, are prodromal to the cardinal motor symptoms of the disease. Sporadic Parkinson's disease has been proposed to develop following ingestion of neurotoxicants that affect the brain-gut axis via the vagus nerve, and then travel to higher centers compromising the substantia nigra pars compacta (SNpc), and, later, the cerebral cortex. We aimed to identify the pathway that connects the brainstem vagal nuclei and the SNpc, and to determine whether this pathway is compromised in a rat model of Parkinsonism...
September 11, 2017: Gastroenterology
https://www.readbyqxmd.com/read/28904388/protective-efficacy-of-phosphodiesterase-1-inhibition-against-alpha-synuclein-toxicity-revealed-by-compound-screening-in-luhmes-cells
#11
Matthias Höllerhage, Claudia Moebius, Johannes Melms, Wei-Hua Chiu, Joachim N Goebel, Tasnim Chakroun, Thomas Koeglsperger, Wolfgang H Oertel, Thomas W Rösler, Marc Bickle, Günter U Höglinger
α-synuclein-induced neurotoxicity is a core pathogenic event in neurodegenerative synucleinopathies such as Parkinson's disease, dementia with Lewy bodies, or multiple system atrophy. There is currently no disease-modifying therapy available for these diseases. We screened 1,600 FDA-approved drugs for their efficacy to protect LUHMES cells from degeneration induced by wild-type α-synuclein and identified dipyridamole, a non-selective phosphodiesterase inhibitor, as top hit. Systematic analysis of other phosphodiesterase inhibitors identified a specific phosphodiesterase 1 inhibitor as most potent to rescue from α-synuclein toxicity...
September 13, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28900002/modeling-parkinson-s-disease-pathology-by-combination-of-fibril-seeds-and-%C3%AE-synuclein-overexpression-in-the-rat-brain
#12
Poonam Thakur, Ludivine S Breger, Martin Lundblad, Oi Wan Wan, Bengt Mattsson, Kelvin C Luk, Virginia M Y Lee, John Q Trojanowski, Anders Björklund
Although a causative role of α-synuclein (α-syn) is well established in Parkinson's disease pathogenesis, available animal models of synucleinopathy do not replicate the full range of cellular and behavioral changes characteristic of the human disease. This study was designed to generate a more faithful model of Parkinson's disease by injecting human α-syn fibril seeds into the rat substantia nigra (SN), in combination with adenoassociated virus (AAV)-mediated overexpression of human α-syn, at levels that, by themselves, are unable to induce acute dopamine (DA) neurodegeneration...
September 12, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28899020/progression-marker-of-parkinson-s-disease-a-4-year-multi-site-imaging-study
#13
Roxana G Burciu, Edward Ofori, Derek B Archer, Samuel S Wu, Ofer Pasternak, Nikolaus R McFarland, Michael S Okun, David E Vaillancourt
Progression markers of Parkinson's disease are crucial for successful therapeutic development. Recently, a diffusion magnetic resonance imaging analysis technique using a bitensor model was introduced allowing the estimation of the fractional volume of free water within a voxel, which is expected to increase in neurodegenerative disorders such as Parkinson's disease. Prior work demonstrated that free water in the posterior substantia nigra was elevated in Parkinson's disease compared to controls across single- and multi-site cohorts, and increased over 1 year in Parkinson's disease but not in controls at a single site...
August 1, 2017: Brain: a Journal of Neurology
https://www.readbyqxmd.com/read/28895489/effects-of-mild-running-on-substantia-nigra-during-early-neurodegeneration
#14
Michael F Almeida, Carolliny M Silva, Rodrigo S Chaves, Nathan C R Lima, Renato S Almeida, Karla P Melo, Marilene Demasi, Tiago Fernandes, Edilamar M Oliveira, Luis E S Netto, Sandra M Cardoso, Merari F R Ferrari
Moderate physical exercise acts at molecular and behavioural levels, such as interfering in neuroplasticity, cell death, neurogenesis, cognition and motor functions. Therefore, the aim of this study is to analyse the cellular effects of moderate treadmill running upon substantia nigra during early neurodegeneration. Aged male Lewis rats (9-month-old) were exposed to rotenone 1mg/kg/day (8 weeks) and 6 weeks of moderate treadmill running, beginning 4 weeks after rotenone exposure. Substantia nigra was extracted and submitted to proteasome and antioxidant enzymes activities, hydrogen peroxide levels and Western blot to evaluate tyrosine hydroxylase (TH), alpha-synuclein, Tom-20, PINK1, TrkB, SLP1, CRMP-2, Rab-27b, LC3II and Beclin-1 level...
September 12, 2017: Journal of Sports Sciences
https://www.readbyqxmd.com/read/28892570/dnajc12-and-dopa-responsive-non-progressive-parkinsonism
#15
Letizia Straniero, Ilaria Guella, Roberto Cilia, Laura Parkkinen, Valeria Rimoldi, Alexander Young, Rosanna Asselta, Giulia Soldà, Vesna Sossi, A Jon Stoessl, Alberto Priori, Kenya Nishioka, Nobutaka Hattori, Jordan Follett, Alex Rajput, Nenad Blau, Gianni Pezzoli, Matthew J Farrer, Stefano Goldwurm, Ali H Rajput, Stefano Duga
Biallelic DNAJC12 mutations were described in children with hyperphenylalaninemia, neurodevelopmental delay, and dystonia. We identified DNAJC12 homozygous null variants (c.187A>T;p.K63*and c.79-2A>G;p.V27Wfs*14) in two kindreds with early-onset parkinsonism. Both probands had mild intellectual disability, mild non-progressive, motor symptoms, sustained benefit from small dose of levodopa and substantial worsening of symptoms after levodopa discontinuation. Neuropathology (Proband-A) revealed no alpha-synuclein pathology and substantia nigra depigmentation with moderate cell loss DNAJC12 transcripts were reduced in both patients...
September 11, 2017: Annals of Neurology
https://www.readbyqxmd.com/read/28892024/stereological-estimation-of-dopaminergic-neuron-number-in-the-mouse-substantia-nigra-using-the-optical-fractionator-and-standard-microscopy-equipment
#16
Chi Wang Ip, David Cheong, Jens Volkmann
In pre-clinical Parkinson's disease research, analysis of the nigrostriatal tract, including quantification of dopaminergic neuron loss within the substantia nigra, is essential. To estimate the total dopaminergic neuron number, unbiased stereology using the optical fractionator method is currently considered the gold standard. Because the theory behind the optical fractionator method is complex and because stereology is difficult to achieve without specialized equipment, several commercially available complete stereology systems that include the necessary software do exist, purely for cell counting reasons...
September 1, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/28890053/intrastriatal-chromospheres-transplant-reduces-nociception-in-hemiparkinsonian-rats
#17
Alejandra Gómez-Paz, René Drucker-Colín, Diana Milán-Aldaco, Marcela Palomero-Rivero, Mónica Ambriz-Tututi
The present study evaluates the possible antinociceptive effect of chromosphere transplants in rats injected with 6-hydroxydopamine (6-OHDA), a model of Parkinson's disease. Male adult Wistar rats received 40μg/0.5μl of 6-OHDA or 0.5μl of vehicle into the left substantia nigra (SNc). Rats were evaluated for mechanical allodynia, cold allodynia, thermal hyperalgesia and formalin. Rats with altered nociceptive threshold were transplanted with chromospheres. After transplant, rats were evaluated every week...
September 8, 2017: Neuroscience
https://www.readbyqxmd.com/read/28887991/superparamagnetic-iron-oxide-nanoparticles-modified-with-dimyristoylphosphatidylcholine-and-their-distribution-in-the-brain-after-injection-in-the-rat-substantia-nigra
#18
Lichao Su, Baolin Zhang, Yinping Huang, Hao Zhang, Qin Xu, Jie Tan
The subcellular distributions of nanoparticles in the brain are important for their biological application. We synthesized and characterized the superparamagnetic iron oxide nanoparticles (SPIONs) modified with poly (ethylene glycol) (PEG) and polyethylenimine (PEI) (PEG/PEI-SPIONs), and with dimyristoylphosphatidylcholine (DMPC) (DMPC-SPIONs). The nanoparticles were unilaterally injected into the left substantia nigra of rat brains. The distributions of the nanoparticles in the left brains of the rats were examined by ICP-OES (inductively coupled plasma optical emission spectrometer) and TEM (transmission electron microscopy) at 24h after the injection...
December 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28887803/psychosis-in-spinocerebellar-ataxias-a-case-series-and-study-of-tyrosine-hydroxylase-in-substantia-nigra
#19
Katherine W Turk, Margaret E Flanagan, Samuel Josephson, C Dirk Keene, Suman Jayadev, Thomas D Bird
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...
September 8, 2017: Cerebellum
https://www.readbyqxmd.com/read/28887769/%C3%AE-synuclein-interacts-with-lipoproteins-in-plasma
#20
Fatemeh Nouri Emamzadeh, David Allsop
Parkinson's disease (PD) is an age-related neurodegenerative disorder characterized by dopaminergic neural cell death in the substantia nigra of the brain and α-synuclein (α-syn) accumulation in Lewy bodies. α-Syn can be detected in blood and is a potential biomarker for PD. It has been shown recently that α-syn can pass through the blood-brain barrier (BBB), but the mechanism is not yet understood. We hypothesized that α-syn could interact with lipoproteins, and in association with these particles, could pass through the BBB...
September 8, 2017: Journal of Molecular Neuroscience: MN
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