scholarly journals Three-dimensional reconstruction of substantia nigra pars compacta of human brain

2018 ◽  
Vol 26 (2) ◽  
pp. 175-183
Author(s):  
Dmitriy N. Voronkov ◽  
Vladimir N. Salkov ◽  
Rudolf M. Khudoerkov
Keyword(s):  
Tyrosine Hydroxylase ◽  
Substantia Nigra ◽  
Human Brain ◽  
Spatial Organization ◽  
Three Dimensional ◽  
Spatial Differentiation ◽  
Dopamine Neurons ◽  
Immunohistochemical Method ◽  
Substantia Nigra Pars Compacta ◽  
Dimensional Reconstruction

Background. Up to the moment there is no universally accepted scheme of spatial organization of the groups of neurons of substantia nigra pars compacta of the human midbrain. A detailed study of the architectonics of this structure is necessary for pathomorphological analysis of agerelated changes in the nervous tissue and the associated neurodegenerative diseases with selective death of dopamine neurons. Aim. To clarify the peculiarities of the morphochemical organization of the substantia nigra (SN) of a human brain and to create a threedimensional model of pars compacta. Materials and Methods. Threedimensional reconstruction of substantia nigra pars compacta was performed on the brain autopsy material of individuals without neurological pathology (n=10, between 52 to 84 years of age) using a method of computed morphometry. Sections of the midbrain were stained by Nissl method and by an immunohistochemical method for localization of tyrosine hydroxylase – a marker of dopamine. Results. In the SN pars compacta accumulations of neurons were identified in the form of 9 bands oriented in the rostrocaudal direction and including four areas: medial, lateral, dorsal and ventral. Morphometric analysis detected significant differences in the density of neurons and in expression of tyrosine hydroxylase between the areas of SN. Conclusion. A model of cellular organization of SN pars compacta proposed by us on the basis of threedimensional reconstruction is characterized by a high degree of detalization as compared to similar works, and shows expressed spatial differentiation of the groups of neurons of SN which should be taken into consideration in pathomorphological examinations.

scholarly journals Threedimensional reconstruction of substantia nigra pars compacta of human brain

2018 ◽  
Vol 26 (2) ◽  
pp. 175-183
Author(s):  
Dmitriy N. Voronkov ◽  
Vladimir N. Salkov ◽  
Rudolf M. Khudoerkov
Keyword(s):  
Tyrosine Hydroxylase ◽  
Substantia Nigra ◽  
Human Brain ◽  
Spatial Organization ◽  
Spatial Differentiation ◽  
Dopamine Neurons ◽  
Immunohistochemical Method ◽  
Substantia Nigra Pars Compacta ◽  
Selective Death ◽  
The Moment

Background. Up to the moment there is no universally accepted scheme of spatial organization of the groups of neurons of substantia nigra pars compacta of the human midbrain. A detailed study of the architectonics of this structure is necessary for pathomorphological analysis of agerelated changes in the nervous tissue and the associated neurodegenerative diseases with selective death of dopamine neurons. Aim. To clarify the peculiarities of the morphochemical organization of the substantia nigra (SN) of a human brain and to create a threedimensional model of pars compacta. Materials and Methods. Threedimensional reconstruction of substantia nigra pars compacta was performed on the brain autopsy material of individuals without neurological pathology (n=10, between 52 to 84 years of age) using a method of computed morphometry. Sections of the midbrain were stained by Nissl method and by an immunohistochemical method for localization of tyrosine hydroxylase – a marker of dopamine. Results. In the SN pars compacta accumulations of neurons were identified in the form of 9 bands oriented in the rostrocaudal direction and including four areas: medial, lateral, dorsal and ventral. Morphometric analysis detected significant differences in the density of neurons and in expression of tyrosine hydroxylase between the areas of SN. Conclusion. A model of cellular organization of SN pars compacta proposed by us on the basis of threedimensional reconstruction is characterized by a high degree of detalization as compared to similar works, and shows expressed spatial differentiation of the groups of neurons of SN which should be taken into consideration in pathomorphological examinations.

scholarly journals The Spatial Organization of the Intranuclear Structures of Human Brain Dopaminergic Neurons

Acta Naturae ◽  
2017 ◽  
Vol 9 (3) ◽  
pp. 81-88 ◽  
Author(s):  
D. E. Korzhevskii ◽  
V. V. Gusel’nikova ◽  
O. V. Kirik ◽  
E. G. Sukhorukova ◽  
I. P. Grigorev
Keyword(s):  
Substantia Nigra ◽  
Dopaminergic Neurons ◽  
Spatial Organization ◽  
Molecular Mechanisms ◽  
Three Dimensional ◽  
Selective Vulnerability ◽  
Confocal Laser ◽  
Double Labeling ◽  
Dimensional Reconstruction ◽  
Marinesco Bodies

We studied the intranuclear localization of protein nucleophosmin (B23) and ubiquitin in the dopaminergic neurons of human substantia nigra (n = 6, age of 25-87 years) using immunohistochemistry and confocal laser microscopy. Intranuclear ubiquitin-immunopositive bodies that morphologically correspond to Marinesco bodies were found to be present in substantia nigra dopaminergic (tyrosine hydroxylase-immunopositive) neurons but absent in non-dopaminergic neurons. The number of bodies varied from 0 to 6 per cell nucleus. Nucleophosmin (B23) was found in the neuronal nucleolus, with the nucleolus size being constant in the nigral neurons of each individual brain. All the observed neurons had only one large nucleolus with intense nucleophosmin immunoreactivity and a lightly stained region (1-2 m in diameter) that apparently represents the giant fibrillar center (GFC). An intensely immunostained nucleophosmin-containing granule was often observed at the GFC periphery. Double labeling demonstrated that nucleophosmin-immunoreactive nucleolus and ubiquitin-immunoreactive Marinesco bodies can occur both closely to and remotely from each other. Three-dimensional reconstruction indicates that rounded Marinesco bodies are polymorphic and often have a complex shape, with some flattening and concavities, which may be associated with contact not only with the nucleolus, but also, presumably, with other intranuclear structures free of ubiquitin or nucleophosmin. Ubiquitin-immunoreactive structures with a relatively small size (up to 1 m in length) and various clastosome-like shapes (Lafarga et al., 2002) often occur near Marinesco bodies. There were no cases of detection of ubiquitin in the nucleoli of dopaminergic neurons and nucleophosmin/B23 in typical Marinesco bodies. The obtained information may be helpful in unraveling the molecular mechanisms of the selective vulnerability of substantia nigra dopaminergic neurons to damaging factors.

scholarly journals The tectonigral pathway regulates appetitive locomotion in predatory hunting in mice

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Meizhu Huang ◽  
Dapeng Li ◽  
Xinyu Cheng ◽  
Qing Pei ◽  
Zhiyong Xie ◽  
...  
Keyword(s):  
Substantia Nigra ◽  
Superior Colliculus ◽  
Dopamine Release ◽  
Dorsal Striatum ◽  
Dopamine Neurons ◽  
Substantia Nigra Pars Compacta ◽  
Neuronal Circuitry ◽  
Locomotion Speed ◽  
Brain Circuit ◽  
Goal Directed Behavior

AbstractAppetitive locomotion is essential for animals to approach rewards, such as food and prey. The neuronal circuitry controlling appetitive locomotion is unclear. In a goal-directed behavior—predatory hunting, we show an excitatory brain circuit from the superior colliculus (SC) to the substantia nigra pars compacta (SNc) to enhance appetitive locomotion in mice. This tectonigral pathway transmits locomotion-speed signals to dopamine neurons and triggers dopamine release in the dorsal striatum. Synaptic inactivation of this pathway impairs appetitive locomotion but not defensive locomotion. Conversely, activation of this pathway increases the speed and frequency of approach during predatory hunting, an effect that depends on the activities of SNc dopamine neurons. Together, these data reveal that the SC regulates locomotion-speed signals to SNc dopamine neurons to enhance appetitive locomotion in mice.

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 Effect of various extracts of Tabernaemontana divaricata on haloperidol induced catalepsy in rats

2014 ◽  
Vol 3 (3) ◽  
pp. 240-242 ◽  
Author(s):  
Chanchal N. Raj ◽  
A. Balasubramaniam ◽  
Sayyed Nadeem
Keyword(s):  
Animal Model ◽  
Substantia Nigra ◽  
Neurodegenerative Diseases ◽  
Pharmaceutical Journal ◽  
Dopamine Neurons ◽  
Substantia Nigra Pars Compacta ◽  
Selective Loss ◽  
Tabernaemontana Divaricata ◽  
Medicinal Use ◽  
Different Doses

Parkinson’s disease (PD) is one of the neurodegenerative diseases with selective loss of dopamine neurons of the substantia nigra pars compacta. In the present study, anti-cataleptic activity of Tabernaemontana divaricata leaves extracts viz. aqueous and ethanolic at different doses (50, 100 and 150 mg/kg i.p.) were studied using haloperidol (1 mg/kg, i.p.) induced catalepsy in rats which is a useful animal model for screening drugs for Parkinson’s disease. Both the extracts were found to reduce catalepsy significantly (P<0.001) as compared to the haloperidol treated rats showing greater effect at 150 mg/kg i.p. dose. Thus the present study reveals the anti-cataleptic activity of Tabernaemontana divaricata evaluating the traditional folklore medicinal use of the plant.DOI: http://dx.doi.org/10.3329/icpj.v3i3.17891 International Current Pharmaceutical Journal, February 2014, 3(3): 240-242

scholarly journals A pH-eQTL interaction at the RIT2-SYT4 Parkinson's disease risk locus in the substantia nigra

2020 ◽  
Author(s):  
Sejal Patel ◽  
Derek Howard ◽  
Leon French
Keyword(s):  
Gene Expression ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Substantia Nigra ◽  
Human Brain ◽  
Disease Risk ◽  
Brain Regions ◽  
Dopamine Neurons ◽  
Postmortem Human Brain ◽  
Increased Risk

BACKGROUND: Parkinson's disease (PD) causes severe motor and cognitive disabilities that result from the progressive loss of dopamine neurons in the substantia nigra. The rs12456492 variant in the RIT2 gene has been repeatedly associated with increased risk for Parkinson's disease. From a transcriptomic perspective, a meta-analysis found that RIT2 gene expression is correlated with pH in the human brain. OBJECTIVE: To assess pH associations at the RIT2-SYT4 locus. METHODS: Linear models to examine two datasets that assayed rs12456492, gene expression, and pH in the postmortem human brain. RESULTS: Using the BrainEAC dataset, we replicate the positive correlation between RIT2 gene expression and pH in the human brain. Furthermore, we found that the relationship between expression and pH is influenced by rs12456492. When tested across ten brain regions, this interaction is specifically found in the substantia nigra. A similar association was found for the co-localized SYT4 gene. In addition, SYT4 associations are stronger in a combined model with both genes, and the SYT4 interaction appears to be specific to males. In the GTEx dataset, the pH associations involving rs12456492 and expression of either SYT4 and RIT2 was not seen. This null finding may be due to the short postmortem intervals (PMI) of the GTEx tissue samples. In the BrainEAC data, we tested the effect of PMI and only observed the interactions in the longer PMI samples. CONCLUSIONS: These previously unknown associations suggest novel mechanistic roles for rs12456492, RIT2, and SYT4 in the regulation of pH in the substantia nigra.

scholarly journals Transient dopamine neuron activity precedes and encodes the vigor of contralateral movements

2021 ◽  
Author(s):  
Marcelo D Mendonça ◽  
Joaquim Alves da Silva ◽  
Ledia F. Hernandez ◽  
Ivan Castela ◽  
José Obeso ◽  
...  
Keyword(s):  
Substantia Nigra ◽  
Dopamine Neurons ◽  
Substantia Nigra Pars Compacta ◽  
Neuron Activity ◽  
Similar Proportion ◽  
List Type ◽  
Dopamine Depletion ◽  
Movement Initiation ◽  
Transient Activity ◽  
Forelimb Movement

SummaryDopamine neurons (DANs) in the substantia nigra pars compacta (SNc) have been related to movement vigor, and loss of these neurons leads to bradykinesia in Parkinson’s disease. However, it remains unclear whether DANs encode a general motivation signal or modulate movement kinematics. We imaged activity of SNc DANs in mice trained in a novel operant task which relies on individual forelimb movement sequences. We uncovered that a similar proportion of SNc DANs increased their activity before ipsi- vs. contralateral forelimb movements. However, the magnitude of this activity was higher for contralateral actions, and was related to contralateral but not ipsilateral action vigor. In contrast, the activity of reward-related DANs, largely distinct from those modulated by movement, was not lateralized. Finally, unilateral dopamine depletion impaired contralateral, but not ipsilateral, movement vigor. These results indicate that movement-initiation DANs encode more than a general motivation signal, and invigorate kinematic aspects of contralateral movements.HighlightsDeveloped a freely-moving task where mice learn rapid individual forelimb sequences.Movement-related DANs encode contralateral but not ipsilateral action vigor.The activity of reward-related DANs is not lateralized.Unilateral dopamine depletion impaired contralateral, but not ipsilateral, movement vigor.eTOC summary: Mendonça et al. show that transient activity in movement-related dopamine neurons in substantia nigra pars compacta encodes contralateral, but not ipsilateral action vigor. Consistently, unilateral dopamine depletion impaired contralateral, but not ipsilateral, movement vigor.

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