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sites of dopamine concentration

Francesca Romana Rizzo, Mauro Federici, Nicola Biagio Mercuri
An increase of extracellular dopamine (DA) has been implicated in the psychostimulant properties of 3,4-methylenedioxymethamphetamine (MDMA). Although this drug has been reported to affect the DA uptake transporter (DAT), it might activate other mechanisms to regulate the outflow of DA in the brain. Our aim was to examine the overall effects of MDMA on the release of DA in the striatum. We studied the effect of MDMA on stimulus-evoked synaptic DA release in dorsal striatal slices of mice using in vitro amperometric techniques...
March 3, 2018: Neuroscience
David S Goldstein, Courtney Holmes, Grisel J Lopez, Tianxia Wu, Yehonatan Sharabi
BACKGROUND: Consistent with nigrostriatal dopamine depletion, low cerebrospinal fluid (CSF) concentrations of 3,4-dihydroxyphenylacetic acid (DOPAC), the main neuronal metabolite of dopamine, characterize Parkinson's disease (PD) even in recently diagnosed patients. Whether low CSF levels of DOPAC or DOPA, the precursor of dopamine, identify pre-clinical PD in at-risk healthy individuals has been unknown. METHODS: Participants in the intramural NINDS PDRisk study entered information about family history of PD, olfactory dysfunction, dream enactment behavior, and orthostatic hypotension at a protocol-specific website...
February 15, 2018: Parkinsonism & related Disorders
Alessandra Porcu, Miriam Melis, Rostislav Turecek, Celine Ullrich, Ignazia Mocci, Bernhard Bettler, Gian Luigi Gessa, M Paola Castelli
Rimonabant is a potent and selective cannabinoid CB1 receptor antagonist widely used in animal and clinical studies. Besides its antagonistic properties, numerous studies have shown that, at micromolar concentrations rimonabant behaves as an inverse agonist at CB1 receptors. The mechanism underpinning this activity is unclear. Here we show that micromolar concentrations of rimonabant inhibited Gαi/o-type G proteins, resulting in a receptor-independent block of G protein signaling. Accordingly, rimonabant decreased basal and agonist stimulated [35S]GTPγS binding to cortical membranes of CB1- and GABAB-receptor KO mice and Chinese Hamster Ovary (CHO) cell membranes stably transfected with GABAB or D2 dopamine receptors...
January 27, 2018: Neuropharmacology
G Ibáñez-Redín, D Wilson, D Gonçalves, O N Oliveira
A green approach for the preparation of carbon black (CB) and electrochemically reduced graphene oxide composite (ERGO) is described based on screen printed carbon electrodes (SPCEs) fabricated on poly(ethylene terephthalate) (PET) as electrochemical sensors. This approach leads to a heterogeneous hydrophilic surface with high concentration of defect sites according to scanning electron microscopy, contact angle and Raman spectroscopy measurements. The SPCE/CB-ERGO sensor was tested with dopamine (DA), epinephrine (EP) and paracetamol (PCM), exhibiting an enhanced electrocatalytic performance compared to the bare SPCE...
December 30, 2017: Journal of Colloid and Interface Science
Tzu-Yen Huang, Chung-Wei Kung, Yu-Te Liao, Sheng-Yuan Kao, Mingshan Cheng, Ting-Hsiang Chang, Joel Henzie, Hatem R Alamri, Zeid A Alothman, Yusuke Yamauchi, Kuo-Chuan Ho, Kevin C-W Wu
With the aim of a reliable biosensing exhibiting enhanced sensitivity and selectivity, this study demonstrates a dopamine (DA) sensor composed of conductive poly(3,4-ethylenedioxythiophene) nanotubes (PEDOT NTs) conformally coated with porphyrin-based metal-organic framework nanocrystals (MOF-525). The MOF-525 serves as an electrocatalytic surface, while the PEDOT NTs act as a charge collector to rapidly transport the electron from MOF nanocrystals. Bundles of these particles form a conductive interpenetrating network film that together: (i) improves charge transport pathways between the MOF-525 regions and (ii) increases the electrochemical active sites of the film...
November 2017: Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
Helen N Schwerdt, Hideki Shimazu, Ken-Ichi Amemori, Satoko Amemori, Patrick L Tierney, Daniel J Gibson, Simon Hong, Tomoko Yoshida, Robert Langer, Michael J Cima, Ann M Graybiel
Many debilitating neuropsychiatric and neurodegenerative disorders are characterized by dopamine neurotransmitter dysregulation. Monitoring subsecond dopamine release accurately and for extended, clinically relevant timescales is a critical unmet need. Especially valuable has been the development of electrochemical fast-scan cyclic voltammetry implementing microsized carbon fiber probe implants to record fast millisecond changes in dopamine concentrations. Nevertheless, these well-established methods have only been applied in primates with acutely (few hours) implanted sensors...
December 12, 2017: Proceedings of the National Academy of Sciences of the United States of America
Ankur Choubey, Ritu Gilhotra, Santosh Kumar Singh, Gopal Garg
Background: Nanotechnology has given the likelihood of conveying medications to particular cells utilizing nanoparticles. Nanosystems can convey the dynamic constituent at an adequate fixation amid the whole treatment time frame, guiding it to the fancied site of activity. Traditional medications do not meet these necessities. The fundamental motivation behind creating elective medication conveyance advancements is to expand effectiveness of medication conveyance and security during the time spent medication conveyance and give more accommodation to the patient...
October 2017: Asian Journal of Neurosurgery
Kisho Obi, Izuki Amano, Yusuke Takatsuru
Functional recovery after a stroke is important for patients' quality of life. Not only medical care during the acute phase, but also rehabilitation during the chronic phase after a stroke is important. However, the mechanisms underlying functional recovery, particularly the chronic phase after stroke, are still not fully understood. Thus, further basic study on brain after focal stroke is necessary. In this study, we found that the concentration of dopamine (DA) increased during first week after a stroke in the hemisphere contralateral in the site of stroke by in vivo microdialysis...
January 1, 2018: Brain Research
Moritz Schübler, Bassem Sadek, Tim Kottke, Lilia Weizel, Holger Stark
Neurleptic drugs, e.g., aripiprazole, targeting the dopamine D2S and D3 receptors (D2SR and D3R) in the central nervous system are widely used in the treatment of several psychotic and neurodegenerative diseases. Therefore, a new series of benzothiazole-based ligands (3-20) was synthesized by applying the bioisosteric approach derived from the selective D3Rs ligand BP-897 (1) and its structurally related benz[d]imidazole derivative (2). Herein, introduction of the benzothiazole moiety was well tolerated by D2SR and D3R binding sites leading to antagonist affinities in the low nanomolar concentration range at both receptor subtypes...
2017: Frontiers in Chemistry
Qing Guo, Huihui You, Xu Yang, Bencheng Lin, Zhihong Zhu, Zhisong Lu, Xiaoxiao Li, Yun Zhao, Lin Mao, Shiping Shen, Haoyan Cheng, Jiting Zhang, Lingfu Deng, Jianhua Fan, Zhuge Xi, Rui Li, Chang Ming Li
Current treatments for Parkinson's disease (PD) are limited, partly due to the difficulties posed by the blood brain barrier (BBB) when delivering drugs to the brain. Herein, we explore the feasibility and efficacy of functional single-walled carbon nanotubes 'CAR' (SWCNT-PEGs-Lf) which carry and target-deliver dopamine (DA) to the brain in PD mice for treatment. SWCNTs can penetrate the cell-membrane remarkably, with the characteristics including high drug-loading and pH-dependent therapeutic unloading capacities...
August 3, 2017: Nanoscale
Franziska Wedekind, Angela Oskamp, Markus Lang, Alexander Hawlitschka, Karl Zilles, Andreas Wree, Andreas Bauer
Cerebral administration of botulinum neurotoxin A (BoNT-A) has been shown to improve disease-specific motor behavior in a rat model of Parkinson disease (PD). Since the dopaminergic system of the basal ganglia fundamentally contributes to motor function, we investigated the impact of BoNT-A on striatal dopamine receptor expression using in vitro and in vivo imaging techniques (positron emission tomography and quantitative autoradiography, respectively). Seventeen male Wistar rats were unilaterally lesioned with 6-hydroxydopamine (6-OHDA) and assigned to two treatment groups 7 weeks later: 10 rats were treated ipsilaterally with an intrastriatal injection of 1 ng BoNT-A, while the others received vehicle (n = 7)...
July 11, 2017: Journal of Neuroscience Research
David J Heal, Michelle Hallam, Michael Prow, Jane Gosden, Sharon Cheetham, Yong K Choi, Frank Tarazi, Peter Hutson
Adult, female rats given irregular, limited access to chocolate develop binge-eating behaviour with normal bodyweight and compulsive/perseverative and impulsive behaviours similar to those in binge-eating disorder. We investigated whether (a) dysregulated central nervous system dopaminergic and opioidergic systems are part of the psychopathology of binge-eating and (b) these neurotransmitter systems may mediate the actions of drugs ameliorating binge-eating disorder psychopathology. Binge-eating produced a 39% reduction of striatal D1 receptors with 22% and 23% reductions in medial and lateral caudate putamen and a 22% increase of striatal μ-opioid receptors...
June 2017: Journal of Psychopharmacology
Yuehua Zhang, Wu Lei, Yujuan Xu, Xifeng Xia, Qingli Hao
A novel, simple and selective electrochemical method was investigated for the simultaneous detection of dopamine (DA) and uric acid (UA) on a poly(l-lysine)/graphene oxide (GO) modified glassy carbon electrode (PLL/GO/GCE) by differential pulse voltammetry (DPV). The electrochemically prepared PLL/GO sensory platform toward the oxidation of UA and DA exhibited several advantages, including high effective surface area, more active sites and enhanced electrochemical activity. Compared to the PLL-modified GCE (PLL/GCE), GO-modified GCE and bare GCE, the PLL/GO/GCE exhibited an increase in the anodic potential difference and a remarkable enhancement in the current responses for both UA and DA...
September 28, 2016: Nanomaterials
Brian O'Neill, Jyoti C Patel, Margaret E Rice
Fast-scan cyclic voltammetry (FCV) is an established method to monitor increases in extracellular dopamine (DA) concentration ([DA]o) in the striatum, which is densely innervated by DA axons. Ex vivo brain slice preparations provide an opportunity to identify endogenous modulators of DA release. For these experiments, local electrical stimulation is often used to elicit release of DA, as well as other transmitters, in the striatal microcircuitry; changes in evoked increases in [DA]o after application of a pharmacological agent (e...
February 15, 2017: ACS Chemical Neuroscience
Luis J Jara, Gabriela Medina, Miguel A Saavedra, Olga Vera-Lastra, Honorio Torres-Aguilar, Carmen Navarro, Monica Vazquez Del Mercado, Luis R Espinoza
Prolactin, a 23-kDa peptide hormone, is produced by the anterior pituitary gland and extrapituitary sites including the immune cells. Prolactin (PRL) participates in innate and adaptive immune response. PRL stimulates the immune cells by binding to receptor (PRL-R). Binding of PRL to its receptor activates the Janus kinase-signal transducer (JAK-STAT). Activation of these cascades results in endpoints such as immunoestimulator and immunosupressor action. Prolactin belongs to the network of immune-neuroendocrine interaction...
April 2017: Immunologic Research
Yang Li, Felix P Mayer, Peter S Hasenhuetl, Verena Burtscher, Klaus Schicker, Harald H Sitte, Michael Freissmuth, Walter Sandtner
The human dopamine transporter (DAT) has a tetrahedral Zn(2+)-binding site. Zn(2+)-binding sites are also recognized by other first-row transition metals. Excessive accumulation of manganese or of copper can lead to parkinsonism because of dopamine deficiency. Accordingly, we examined the effect of Mn(2+), Co(2+), Ni(2+), and Cu(2+) on transport-associated currents through DAT and DAT-H193K, a mutant with a disrupted Zn(2+)-binding site. All transition metals except Mn(2+) modulated the transport cycle of wild-type DAT with affinities in the low micromolar range...
March 10, 2017: Journal of Biological Chemistry
Auwal Bello Hassan, Tahamina Begum, Mohammed Faruque Reza, Nasir Yusoff
BACKGROUND: Previous studies have revealed that self-related tasks (items) receive more attention than non-self-related, and that they elicit event-related potential (ERP) components with larger amplitudes. Since personality has been reported as one of the biological correlates influencing these components, as well as our behavioural differences, it is important to examine how it affects our self-consciousness in relation to tasks of varied relevance and the neurological basis. METHODS: A total of 33 male and female undergraduate Malaysian medical students of Universiti Sains Malaysia (USM) participated in the study...
November 2016: Malaysian Journal of Medical Sciences: MJMS
Aleksandra Maršavelski, Robert Vianello
Monoamine oxidase (MAO) enzymes catalyze the degradation of a very broad range of biogenic and dietary amines including many neurotransmitters in the brain, whose imbalance is extensively linked with the biochemical pathology of various neurological disorders. Although sharing around 70 % sequence identity, both MAO A and B isoforms differ in substrate affinities and inhibitor sensitivities. Inhibitors that act on MAO A are used to treat depression, due to their ability to raise serotonin concentrations, whereas MAO B inhibitors decrease dopamine degradation and improve motor control in patients with Parkinson disease...
February 24, 2017: Chemistry: a European Journal
Annika Pienimaeki-Roemer, Tatiana Konovalova, Melina M Musri, Alexander Sigruener, Alfred Boettcher, Gunter Meister, Gerd Schmitz
BACKGROUND: Platelets (PLTs) are derived from megakaryocytes during PLT shedding. Senescent or activated PLTs are expanded in vascular and neurological diseases and release PLT extracellular vesicles (PL-EVs). A systematic analysis of regular messenger RNA (mRNA) and small RNA composition in PLTs and PL-EVs during in vitro PLT senescence has not yet been published. STUDY DESIGN AND METHODS: We isolated PLTs, total PL-EVs, and PL-EV subsets on Days 0 and 5 from human stored donor platelet concentrates...
January 2017: Transfusion
Michelle A Sahai, Colin Davidson, George Khelashvili, Vincenzo Barrese, Neelakshi Dutta, Harel Weinstein, Jolanta Opacka-Juffry
Novel psychoactive substances (NPS) are increasingly prevalent world-wide although their pharmacological characteristics are largely unknown; those with stimulant properties, due to interactions with the dopamine transporter (DAT), have addictive potential which their users may not realise. We evaluated the binding of 1-(1-benzofuran-5-yl)-N-methylpropan-2-amine (5-MAPB) to rat striatal DAT by means of quantitative autoradiography with [(125)I]RTI-121, and the effects of 5-MAPB on electrically-evoked dopamine efflux by fast-cyclic voltammetry in rat brain slices...
April 3, 2017: Progress in Neuro-psychopharmacology & Biological Psychiatry
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