Parkinson disease, substantia nigra vulnerability, and calbindin expression: Enlightening the darkness?

2019 ◽  
Vol 34 (2) ◽  
pp. 161-163 ◽  
Author(s):  
Javier Blesa ◽  
Miquel Vila
Keyword(s):  
Substantia Nigra ◽  
Parkinson Disease

scholarly journals Substantia nigra neuromelanin magnetic resonance imaging in patients with different subtypes of Parkinson disease

2021 ◽  
Author(s):  
Lu Wang ◽  
Yayun Yan ◽  
Liyao Zhang ◽  
Yan Liu ◽  
Ruirui Luo ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Substantia Nigra ◽  
Parkinson Disease ◽  
Clinical Symptoms ◽  
Dopamine Neurons ◽  
Substantia Nigra Pars Compacta ◽  
Resonance Imaging ◽  
Mean Values

AbstractNeuromelanin (NM) is a dark pigment that mainly exists in neurons of the substantia nigra pars compacta (SNc). In Parkinson disease (PD) patients, NM concentration decreases gradually with degeneration and necrosis of dopamine neurons, suggesting potential use as a PD biomarker. We aimed to evaluate associations between NM concentration in in vivo SN and PD progression and different motor subtypes using NM magnetic resonance imaging (NM-MRI). Fifty-four patients with idiopathic PD were enrolled. Patients were divided into groups by subtypes with different clinical symptoms: tremor dominant (TD) group and postural instability and gait difficulty (PIGD) group. Fifteen healthy age-matched volunteers were enrolled as controls. All subjects underwent clinical assessment and NM-MRI examination. PD patients showed significantly decreased contrast-to-noise ratio (CNR) values in medial and lateral SN (P < 0.05) compared to controls. CNR values in lateral SN region decreased linearly with PD progression (P = 0.001). PIGD patients showed significant decreases in CNR mean values in lateral SN compared to TD patients (P = 0.004). Diagnostic accuracy of using lateral substantia nigra (SN) in TD and PIGD groups was 79% (sensitivity 76.5%, specificity 78.6%). NM concentration in PD patients decreases gradually during disease progression and differs significantly between PD subtypes. NM may be a reliable biomarker for PD severity and subtype identification.

scholarly journals Utility of manual fractional anisotropy measurements in the management of patients with Parkinson disease: a feasibility study with a 1.5-T magnetic resonance imaging system

2021 ◽  
Vol 10 (2) ◽  
pp. 205846012199347
Author(s):  
Romulo V de Oliveira ◽  
João S Pereira
Keyword(s):  
Diffusion Tensor Imaging ◽  
Substantia Nigra ◽  
Parkinson Disease ◽  
Fractional Anisotropy ◽  
Diffusion Tensor ◽  
Neuronal Damage ◽  
Magnetic Resonance Imaging System ◽  
Healthy Controls ◽  
Clinical Variables ◽  
Severity Scores

Background Diffusion tensor imaging has emerged as a promising tool for quantitative analysis of neuronal damage in Parkinson disease, with potential value for diagnostic and prognostic evaluation. Purpose The aim of this study was to examine Parkinson disease-associated alterations in specific brain regions revealed by diffusion tensor imaging and how such alterations correlate with clinical variables. Material and Methods Diffusion tensor imaging was performed on 42 Parkinson disease patients and 20 healthy controls with a 1.5-T scanner. Manual fractional anisotropy measurements were performed for the ventral, intermediate, and dorsal portions of the substantia nigra, as well as for the cerebral peduncles, putamen, thalamus, and supplementary motor area. The correlation analysis between these measurements and the clinical variables was performed using χ2 variance and multiple linear regression. Results Compared to healthy controls, Parkinson disease patients had significantly reduced fractional anisotropy values in the substantia nigra ( P < .05). Some fractional anisotropy measurements in the substantia nigra correlated inversely with duration of Parkinson disease and Parkinson disease severity scores. Reduced fractional anisotropy values in the substantia nigra were also correlated inversely with age variable. fractional anisotropy values obtained for the right and left putamen varied significantly between males and females in both groups. Conclusion Manual fractional anisotropy measurements in the substantia nigra were confirmed to be feasible with a 1.5-T scanner. Diffusion tensor imaging data can be used as a reliable biomarker of Parkinson disease that can be used to support diagnosis, prognosis, and progression/treatment monitoring.

Bursting in Substantia Nigra Pars Reticulata Neurons In Vitro: Possible Relevance for Parkinson Disease

2007 ◽  
Vol 98 (4) ◽  
pp. 2311-2323 ◽  
Author(s):  
Osvaldo Ibáñez-Sandoval ◽  
Luis Carrillo-Reid ◽  
Elvira Galarraga ◽  
Dagoberto Tapia ◽  
Ernesto Mendoza ◽  
...  
Keyword(s):  
Substantia Nigra ◽  
Parkinson Disease ◽  
Temporal Structure ◽  
Projection Neurons ◽  
Rate Model ◽  
Indirect Pathway ◽  
Bath Application ◽  
Pattern Generators ◽  
Oscillatory Model

Projection neurons of the substantia nigra reticulata (SNr) convey basal ganglia (BG) processing to thalamocortical and brain stem circuits responsible for movement. Two models try to explain pathological BG performance during Parkinson disease (PD): the rate model, which posits an overexcitation of SNr neurons due to hyperactivity in the indirect pathway and hypoactivity of the direct pathway, and the oscillatory model, which explains PD as the product of pathological pattern generators disclosed by dopamine reduction. These models are, apparently, incompatible. We tested the predictions of the rate model by increasing the excitatory drive and reducing the inhibition on SNr neurons in vitro. This was done pharmacologically with bath application of glutamate agonist N-methyl-d-aspartate and GABAA receptor blockers, respectively. Both maneuvers induced bursting behavior in SNr neurons. Therefore synaptic changes forecasted by the rate model induce the electrical behavior predicted by the oscillatory model. In addition, we found evidence that CaV3.2 Ca2+ channels are a critical step in generating the bursting firing pattern in SNr neurons. Other ion channels involved are: hyperpolarization-activated cation channels, high-voltage-activated Ca2+ channels, and Ca2+-activated K+ channels. However, although these channels shape the temporal structure of bursting, only CaV3.2 Ca2+ channels are indispensable for the initiation of the bursting pattern.

scholarly journals Glucocerebrosidase deficiency in substantia nigra of parkinson disease brains

2012 ◽  
Vol 72 (3) ◽  
pp. 455-463 ◽  
Author(s):  
Matthew E. Gegg ◽  
Derek Burke ◽  
Simon J. R. Heales ◽  
J. Mark Cooper ◽  
John Hardy ◽  
...  
Keyword(s):  
Substantia Nigra ◽  
Parkinson Disease

Hypokinetic Movement Disorders: Parkinson Disease

2021 ◽  
pp. 576-582
Author(s):  
Sarah M. Tisel ◽  
Bryan T. Klassen
Keyword(s):  
Cell Death ◽  
Substantia Nigra ◽  
Parkinson Disease ◽  
Movement Disorder ◽  
Movement Disorders ◽  
Dopaminergic Neurons ◽  
Microscopic Level ◽  
Rest Tremor ◽  
Macroscopic Level ◽  
Progressive Degeneration

Parkinson disease (PD) is the classic hypokinetic movement disorder and one of the most common and widely recognized neurodegenerative conditions. PD is distinct from parkinsonism, a term that refers to a syndrome of rest tremor, bradykinesia, rigidity, and postural instability. The mechanism behind the progressive degeneration and cell death that result in PD is not precisely understood. Substantia nigra depigmentation occurs on a macroscopic level and loss of dopaminergic neurons and gliosis on a microscopic level.

scholarly journals Substantia Nigra Volumetry with 3-T MRI in De Novo and Advanced Parkinson Disease

Radiology ◽  
2020 ◽  
Vol 296 (2) ◽  
pp. 401-410
Author(s):  
Paolo Vitali ◽  
Marina I. Pan ◽  
Fulvia Palesi ◽  
Giancarlo Germani ◽  
Arianna Faggioli ◽  
...  
Keyword(s):  
Substantia Nigra ◽  
Parkinson Disease ◽  
De Novo

scholarly journals Earliest Mechanisms of Dopaminergic Neurons Sufferance in a Novel Slow Progressing Ex Vivo Model of Parkinson Disease in Rat Organotypic Cultures of Substantia Nigra

2019 ◽  
Vol 20 (9) ◽  
pp. 2224 ◽  
Author(s):  
Matteo Dal Ben ◽  
Rosario Bongiovanni ◽  
Simone Tuniz ◽  
Emanuela Fioriti ◽  
Claudio Tiribelli ◽  
...  
Keyword(s):  
Substantia Nigra ◽  
Parkinson Disease ◽  
Dopaminergic Neurons ◽  
Molecular Mechanisms ◽  
Ex Vivo ◽  
Ex Vivo Model ◽  
Redox Imbalance ◽  
Clinical Phase ◽  
Protein Clearance ◽  
Persistent Inflammation

The current treatments of Parkinson disease (PD) are ineffective mainly due to the poor understanding of the early events causing the decline of dopaminergic neurons (DOPAn). To overcome this problem, slow progressively degenerating models of PD allowing the study of the pre-clinical phase are crucial. We recreated in a short ex vivo time scale (96 h) all the features of human PD (needing dozens of years) by challenging organotypic culture of rat substantia nigra with low doses of rotenone. Thus, taking advantage of the existent knowledge, the model was used to perform a time-dependent comparative study of the principal possible causative molecular mechanisms undergoing DOPAn demise. Alteration in the redox state and inflammation started at 3 h, preceding the reduction in DOPAn number (pre-diagnosis phase). The number of DOPAn declined to levels compatible with diagnosis only at 12 h. The decline was accompanied by a persistent inflammation and redox imbalance. Significant microglia activation, apoptosis, a reduction in dopamine vesicle transporters, and the ubiquitination of misfolded protein clearance pathways were late (96 h, consequential) events. The work suggests inflammation and redox imbalance as simultaneous early mechanisms undergoing DOPAn sufferance, to be targeted for a causative treatment aimed to stop/delay PD.

High levels of mitochondrial DNA deletions in substantia nigra neurons in aging and Parkinson disease

2006 ◽  
Vol 38 (5) ◽  
pp. 515-517 ◽  
Author(s):  
Andreas Bender ◽  
Kim J Krishnan ◽  
Christopher M Morris ◽  
Geoffrey A Taylor ◽  
Amy K Reeve ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Substantia Nigra ◽  
Parkinson Disease ◽  
Dna Deletions

scholarly journals Methylation Status and Neurodegenerative Markers in Parkinson Disease

2009 ◽  
Vol 55 (10) ◽  
pp. 1852-1860 ◽  
Author(s):  
Rima Obeid ◽  
Achim Schadt ◽  
Ulrich Dillmann ◽  
Panagiotis Kostopoulos ◽  
Klaus Fassbender ◽  
...  
Keyword(s):  
Substantia Nigra ◽  
Parkinson Disease ◽  
Platelet Rich Plasma ◽  
Methylation Status ◽  
Amyloid Β ◽  
Brain Parenchyma ◽  
Serum Concentrations ◽  
Cell Extracts ◽  
Age Related ◽  
Adenosyl Methionine

Abstract Background: Increased concentrations of plasma total homocysteine (tHcy) have been associated with age-related diseases, including dementia, stroke, and Parkinson disease (PD). Methylation status might link Hcy metabolism to neurodegenerative proteins in patients with PD. Methods: We tested blood samples from 87 patients with PD (median age 68 years; 35 men) for tHcy, methylmalonic acid (MMA), vitamin B12, vitamin B6, folate, S-adenosyl methionine (SAM), S-adenosyl homocysteine (SAH), and amyloid-β(1–42). We collected citrate blood from a subset of 45 patients to prepare platelet-rich plasma, and we used washed platelets to prepare cell extracts for amyloid precursor protein (APP) and α-synuclein assays. We used brain parenchyma sonography to estimate the substantia nigra echogenic area in a subset of 59 patients. Results: Serum concentrations of tHcy were increased in PD patients (median 14.8 μmol/L). tHcy (β coefficient = −0.276) and serum creatinine (β = −0.422) were significant predictors of the ratio of SAM/SAH in plasma (P &lt; 0.01). The plasma SAM/SAH ratio was a significant determinant for DemTect scores (β = 0.612, P = 0.004). Significant negative correlations were found between concentrations of SAH in plasma and platelet APP and between SAM and platelet α-synuclein. A larger echogenic area of the substantia nigra was related to higher serum concentrations of MMA (P = 0.016). Conclusions: Markers of neurodegeneration (APP, α-synuclein) are related to markers of methylation (SAM, SAH) in patients with PD. Better cognitive function was related to higher methylation potential (SAM/SAH ratio).

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