Search results for "substantia nigra"
showing 10 items of 90 documents
[18F]PR04.MZ PET/CT Imaging for Evaluation of Nigrostriatal Neuron Integrity in Patients With Parkinson Disease.
2020
Introduction Degeneration of dopaminergic, nigrostriatal neurons is the hallmark of Parkinson disease (PD), and PET quantification of dopamine transporters is a widely accepted method for differential diagnosis between idiopathic PD and essential tremor. [18F]PR04.MZ is a new PET tracer with excellent imaging properties allowing for precise quantification of striatal and extrastriatal dopamine transporter. Here we describe our initial experience with [18F]PR04.MZ PET/CT in a larger cohort of healthy controls and PD patients as a proof-of-concept study for this tracer. Methods Eighteen healthy subjects, 19 early PD patients (Hoehn-Yahr I–II), and 13 moderate-advanced PD patients (Hoehn-Yahr …
Effects of scopolamine on dopamine neurons in the substantia nigra : role of the pedunculopontine tegmental nucleus
2009
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…
Regional distribution of the leucine-rich glioma inactivated (LGI) gene family transcripts in the adult mouse brain
2009
25 p., figuras y bibliografía
Involvement of Nitric Oxide in Nigrostriatal Dopaminergic System Degeneration : A Neurochemical Study.
2009
The present study was undertaken to explore the involvement of nitric oxide (NO) in the 6-hydroxydopamine (6-OHDA) experimental model of Parkinson's disease (PD) in rats. The effect of pharmacological manipulation of the NO system was evaluated on striatal dopamine (DA) level decrease produced by the toxin. 7-nitroindazole (7-NI, 50 mg/kg i.p.; n= 5) pretreatment significantly restored the striatal DA contents. Conversely, 40 mg/kg i.p. of molsidomine (MOL, n= 5), an NO donor, significantly worsened the neurodegeneration (n= 5) and completely counteracted the neuroprotective effect of 7-NI (n= 5). Thus, a crucial role for NO in 6-OHDA induced neurodegeneration is suggested together with a p…
7-nitroindazole protects striatal dopaminergic neurons against MPP+-induced degeneration: an in vivo microdialysis study.
2007
The neuropathological hallmark of Parkinson's disease (PD) is the selective degeneration of dopaminergic (DAergic) neurons in the substantia nigra pars compacta (SNc). In this study, using a microdialysis technique, we investigated whether an inhibitor of neuronal nitric oxide synthase (nNOS), 7-nitrindazole (7-NI), could protect against DAergic neuronal damage induced by in vivo infusion of 1-methyl-4-phenylpiridinium iodide (MPP(+)) in freely moving rats. Experiments were performed over 2 days in three groups of rats: (a) nonlesioned, (b) MPP(+)-lesioned, and (c) 7-NI pretreated MPP(+)-lesioned rats. On day 1, control rats were perfused with an artificial CSF, while 1 mM MPP(+) was infuse…
Critical role of nitric oxide on nicotine-induced hyperactivation of dopaminergic nigrostriatal system: electrophysiological and neurochemical eviden…
2010
Nicotine, the main psychoactive ingredient in tobacco, stimulates dopamine (DA) function, increasing DA neuronal activity and DA release. DA is involved in both motor control and in the rewarding and reinforcing effects of nicotine; however, the complete understanding of its molecular mechanisms is yet to be attained. Substantial evidence indicates that the reinforcing properties of drugs of abuse, including nicotine, can be affected by the nitric oxide (NO) system, which may act by modulating central dopaminergic function. In this study, using single cell recordings in vivo coupled with microiontophoresis and microdialysis in freely moving animals, the role of NO signaling on the hyperacti…
Neuroprotective Properties of Mildronate, a Small Molecule, in a Rat Model of Parkinson’s Disease
2010
Previously, we have found that mildronate [3-(2,2,2-trimethylhydrazinium) propionate dihydrate], a small molecule with charged nitrogen and oxygen atoms, protects mitochondrial metabolism that is altered by inhibitors of complex I and has neuroprotective effects in an azidothymidine-neurotoxicity mouse model. In the present study, we investigated the effects of mildronate in a rat model of Parkinson’s disease (PD) that was generated via a unilateral intrastriatal injection of the neurotoxin 6-hydroxydopamine (6‑OHDA). We assessed the expression of cell biomarkers that are involved in signaling cascades and provide neural and glial integration: the neuronal marker TH (tyrosine hydroxylase); …
Effects of Substantia Nigra pars compacta lesion on the behavioral sequencing in the 6-OHDA model of Parkinson’s disease
2019
The basal ganglia circuitry plays a crucial role in the sequential organization of behavior. Here we studied the behavioral structure of the animals after 21 days of 6-OHDA-induced lesion of the dopaminergic nigrostriatal system. Frequencies and durations of individual components of the behavioral repertoire were calculated; moreover, whether a temporal organization of the activity was present, it was investigated by using T-pattern analysis, a multivariate approach able to detect the real-time sequential organization of behavior. Six sham-depleted and six rats with unilateral 6−OHDA-lesion of the Substantia Nigra pars compacta were used. As to quantitative evaluations, the comparison betwe…
Sox-2 Positive Neural Progenitors in the Primate Striatum Undergo Dynamic Changes after Dopamine Denervation.
2013
The existence of endogenous neural progenitors in the nigrostriatal system could represent a powerful tool for restorative therapies in Parkinson's disease. Sox-2 is a transcription factor expressed in pluripotent and adult stem cells, including neural progenitors. In the adult brain Sox-2 is expressed in the neurogenic niches. There is also widespread expression of Sox-2 in other brain regions, although the neurogenic potential outside the niches is uncertain. Here, we analyzed the presence of Sox-2(+) cells in the adult primate (Macaca fascicularis) brain in naïve animals (N = 3) and in animals exposed to systemic administration of 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine to render th…
Transgenic expression and activation of PGC-1α protect dopaminergic neurons in the MPTP mouse model of Parkinson’s disease
2011
Mitochondrial dysfunction and oxidative stress occur in Parkinson’s disease (PD), but little is known about the molecular mechanisms controlling these events. Peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α) is a transcriptional coactivator that is a master regulator of oxidative stress and mitochondrial metabolism. We show here that transgenic mice overexpressing PGC-1α in dopaminergic neurons are resistant against cell degeneration induced by the neurotoxin MPTP. The increase in neuronal viability was accompanied by elevated levels of mitochondrial antioxidants SOD2 and Trx2 in the substantia nigra of transgenic mice. PGC-1α overexpression also protected against MP…