Read by QxMD icon Read

raclopride AND

Y Kimura, J Maeda, M Yamada, K Takahata, K Yokokawa, Y Ikoma, C Seki, H Ito, M Higuchi, T Suhara
RATIONALE: The beneficial effects of psychostimulant drugs in the treatment of psychiatric disorders occur because they increase the extracellular dopamine concentration by inhibiting re-uptake of extracellular dopamine at dopamine transporters. However, the psychological effects at low dopamine transporter occupancy have not been well demonstrated. OBJECTIVES: The purpose of the study was to evaluate the psychological effects, dopamine transporter occupancy, and dopamine release induced by a single oral administration of a clinical dose of mazindol...
October 20, 2016: Psychopharmacology
David Mathar, Leonora Wilkinson, Anna K Holl, Jane Neumann, Lorenz Deserno, Arno Villringer, Marjan Jahanshahi, Annette Horstmann
Incidental learning of appropriate stimulus-response associations is crucial for optimal functioning within our complex environment. Positive and negative prediction errors (PEs) serve as neural teaching signals within distinct ('direct'/'indirect') dopaminergic pathways to update associations and optimize subsequent behavior. Using a computational reinforcement learning model, we assessed learning from positive and negative PEs on a probabilistic task (Weather Prediction Task - WPT) in three populations that allow different inferences on the role of dopamine (DA) signals: (1) Healthy volunteers that repeatedly underwent [(11)C]raclopride Positron Emission Tomography (PET), allowing for assessment of striatal DA release during learning, (2) Parkinson's disease (PD) patients tested both on and off L-DOPA medication, (3) early Huntington's disease (HD) patients, a disease that is associated with hyper-activation of the 'direct' pathway...
September 19, 2016: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
Tarek K Rajji, Benoit H Mulsant, Shinichiro Nakajima, Fernando Caravaggio, Takefumi Suzuki, Hiroyuki Uchida, Philip Gerretsen, Wanna Mar, Bruce G Pollock, David C Mamo, Ariel Graff-Guerrero
OBJECTIVES: To assess the impact of reducing the dose of antipsychotics on cognition and dopaminergic D2 receptor availability in the whole striatum, and identify their relationship in patients with schizophrenia aged 50 years or older. DESIGN: Open-label prospective PET [(11)C]-raclopride study. SETTING: A tertiary care center outpatient setting. PARTICIPANTS: Thirty-seven clinically stable participants with schizophrenia or schizoaffective disorder, aged 50 years or greater, and having been treated with olanzapine or risperidone monotherapy at the same dose for at least 6 months...
August 2, 2016: American Journal of Geriatric Psychiatry
Martin J Bobak, Matthew W Weber, Melissa A Doellman, Douglas R Schuweiler, Jeana M Athens, Steven A Juliano, Paul A Garris
Modafinil (MOD) exhibits therapeutic efficacy for treating sleep and psychiatric disorders, but its mechanism is incompletely understood. Compared to other psychostimulants inhibiting dopamine (DA) uptake, MOD weakly interacts with the dopamine transporter (DAT) and modestly elevates striatal dialysate DA, suggesting additional targets besides DAT. However, the ability of MOD to induce wakefulness is abolished with DAT knockout, conversely suggesting that DAT is necessary for MOD action. Another psychostimulant target, but one not established for MOD, is activation of phasic DA signaling...
October 12, 2016: Journal of Pharmacology and Experimental Therapeutics
Irene Sebastianutto, Natallia Maslava, Corey R Hopkins, M Angela Cenci
Rodent models of l-DOPA-induced dyskinesia (LID) are essential to investigate pathophysiological mechanisms and treatment options. Ratings of abnormal involuntary movements (AIMs) are used to capture both qualitative and quantitative features of dyskinetic behaviors. Thus far, validated rating scales for the mouse have anchored the definition of severity to the time during which AIMs are present. Here we have asked whether the severity of axial, limb, and orolingual AIMs can be objectively assessed with scores based on movement amplitude...
September 2, 2016: Neurobiology of Disease
Jieqing Jiao, Alexandre Bousse, Kris Thielemans, Ninon Burgos, Philip Weston, Pawel Markiewicz, Jonathan Schott, David Atkinson, Simon Arridge, Brian Hutton, Sebastien Ourselin
Direct reconstruction of parametric images from raw photon counts has been shown to improve the quantitative analysis of dynamic positron emission tomography (PET) data. However it suffers from subject motion which is inevitable during the typical acquisition time of 1-2 hours. In this work we propose a framework to jointly estimate subject head motion and reconstruct the motion-corrected parametric images directly from raw PET data, so that the effects of distorted tissue-to-voxel mapping due to subject motion can be reduced in reconstructing the parametric images with motion-compensated attenuation correction and spatially aligned temporal PET data...
August 24, 2016: IEEE Transactions on Medical Imaging
Gagan Fervaha, Fernando Caravaggio, David C Mamo, Benoit H Mulsant, Bruce G Pollock, Shinichiro Nakajima, Philip Gerretsen, Tarek K Rajji, Wanna Mar, Yusuke Iwata, Eric Plitman, Jun Ku Chung, Gary Remington, Ariel Graff-Guerrero
RATIONALE: Several pre-clinical studies suggest that antipsychotic medications cause secondary negative symptoms. However, direct evidence for a relationship among antipsychotic medications, their direct effects on neurotransmitter systems, and negative symptoms in schizophrenia remains controversial. OBJECTIVE: The objective of this study was to examine the relationship between antipsychotic-related dopamine D2/3 receptor occupancy and negative symptoms in patients with schizophrenia...
October 2016: Psychopharmacology
Hiroyuki Takuwa, Yoko Ikoma, Eiji Yoshida, Hideaki Tashima, Hidekatsu Wakizaka, Tetsuya Shinaji, Taiga Yamaya
Simultaneous measurements of multiple physiological parameters are essential for the study of brain disease mechanisms and the development of suitable therapies to treat them. In this study, we developed a measurement system for simultaneous optical imaging and PET for awake mice. The key elements of this system are the OpenPET, optical imaging and fixation apparatus for an awake mouse. The OpenPET is our original open-type PET geometry, which can be used in combination with another device because of the easily accessible open space of the former...
September 7, 2016: Physics in Medicine and Biology
S Montagud-Romero, M D Reguilon, C Roger-Sanchez, M Pascual, M A Aguilar, C Guerri, J Miñarro, M Rodríguez-Arias
Numerous studies report that social defeat stress alters dopamine (DA) neurotransmission in several areas of the brain. Alterations of the mesolimbic dopaminergic pathway are believed to be responsible for the increased vulnerability to drug use observed as a result of social stress. In the present study, we evaluated the influence of DA receptors on the long-term effect of repeated social defeat (RSD) on the conditioned rewarding and reinstating effects of cocaine. For this purpose, the D1R antagonist SCH 23390 and the D1R antagonist raclopride were administered 30min before each social defeat and a cocaine-induced CPP procedure was initiated three weeks later...
November 3, 2016: Progress in Neuro-psychopharmacology & Biological Psychiatry
Aviv Malkiel Weinstein, Nanette Freedman, Joel Greif, Zipi Yemini, Eyal Mishani, Edythe London, Roland Chisin, Moshe Bocher
BACKGROUND AND OBJECTIVES: In an effort to help identify factors that maintain heavy smoking, this study tested the association of pretreatment cigarette use (cigarettes per day) with striatal dopamine release during smoking-cessation treatment. METHODS: Thirteen regular smokers (≥10 cigarettes per day) were evaluated on parameters of smoking behavior, and they entered a smoking cessation treatment protocol, including bupropion administration and individual counseling for 2 months...
September 2016: American Journal on Addictions
Brandon G Oberlin, Mario Dzemidzic, Jaroslaw Harezlak, Maria A Kudela, Stella M Tran, Christina M Soeurt, Karmen K Yoder, David A Kareken
BACKGROUND: Cue-evoked drug-seeking behavior likely depends on interactions between frontal activity and ventral striatal (VST) dopamine (DA) transmission. Using [(11) C]raclopride (RAC) positron emission tomography (PET), we previously demonstrated that beer flavor (absent intoxication) elicited VST DA release in beer drinkers, inferred by RAC displacement. Here, a subset of subjects from this previous RAC-PET study underwent a similar paradigm during functional magnetic resonance imaging (fMRI) to test how orbitofrontal cortex (OFC) and VST blood oxygenation level-dependent (BOLD) responses to beer flavor are related to VST DA release and motivation to drink...
September 2016: Alcoholism, Clinical and Experimental Research
Miguel Pérez de la Mora, Diana Pérez-Carrera, Minerva Crespo-Ramírez, Alexander Tarakanov, Kjell Fuxe, Dasiel O Borroto-Escuela
Dopamine D2 receptor (D2R)-Oxytocin receptor (OTR) interactions exist within heterocomplexes with facilitatory effects on D2R recognition and Gi/o coupling. In this work the hypothesis is tested using cotransfected HEK293 cells whether allosteric reciprocal D2R-OTR interactions can enhance signaling of D2R-OTR heterocomplexes along the CREB, MAPK and PLC pathways and whether the anxiolytic effects of OT may involve facilitatory D2R-OTR interactions within the central amygdaloid nucleus (CeA). Oxytocin enhanced the D2-like agonist quinpirole induced inhibition of the AC-PKA-pCREB signaling cascade and increased its signaling over the RAS-MAPK-pELK pathway...
July 14, 2016: Biochimica et Biophysica Acta
Molly M McGinnis, Cody A Siciliano, Sara R Jones
Cocaine is a commonly abused central nervous system stimulant that enhances dopamine (DA) neurotransmission through its ability to block dopamine transporters (DATs). Recent evidence suggests there may be an interaction between DATs and D2/D3 autoreceptors that modulates cocaine's effects. The purpose of this study was to explore how D2/D3 autoreceptors modulate the ability of cocaine to inhibit DA uptake through DATs on pre-synaptic DA terminals. Using fast-scan cyclic voltammetry in brain slices containing the nucleus accumbens core from male and female C57BL/6J mice, we first sought to examine the effects of global autoreceptor blockade using the non-selective D2/D3 autoreceptor antagonist, raclopride...
September 2016: Journal of Neurochemistry
Lars Nyberg, Nina Karalija, Alireza Salami, Micael Andersson, Anders Wåhlin, Neda Kaboovand, Ylva Köhncke, Jan Axelsson, Anna Rieckmann, Goran Papenberg, Douglas D Garrett, Katrine Riklund, Martin Lövdén, Ulman Lindenberger, Lars Bäckman
D1 and D2 dopamine receptors (D1DRs and D2DRs) may contribute differently to various aspects of memory and cognition. The D1DR system has been linked to functions supported by the prefrontal cortex. By contrast, the role of the D2DR system is less clear, although it has been hypothesized that D2DRs make a specific contribution to hippocampus-based cognitive functions. Here we present results from 181 healthy adults between 64 and 68 y of age who underwent comprehensive assessment of episodic memory, working memory, and processing speed, along with MRI and D2DR assessment with [(11)C]raclopride and PET...
July 12, 2016: Proceedings of the National Academy of Sciences of the United States of America
Jarkko Johansson, Kati Alakurtti, Juho Joutsa, Jussi Tohka, Ulla Ruotsalainen, Juha O Rinne
BACKGROUND: The striatum is the primary target in regional C-raclopride-PET studies, and despite its small volume, it contains several functional and anatomical subregions. The outcome of the quantitative dopamine receptor study using C-raclopride-PET depends heavily on the quality of the region-of-interest (ROI) definition of these subregions. The aim of this study was to evaluate subregional analysis techniques because new approaches have emerged, but have not yet been compared directly...
October 2016: Nuclear Medicine Communications
D Tomasi, G-J Wang, N D Volkow
Sleep deprivation (SD) disrupts dopamine (DA) signaling and impairs attention. However, the interpretation of these concomitant effects requires a better understanding of dopamine's role in attention processing. Here we test the hypotheses that D2/D3 receptors (D2/D3R) in dorsal and ventral striatum would distinctly regulate the activation of attention regions and that, by decreasing D2/D3, SD would disrupt these associations. We measured striatal D2/D3R using positron emission tomography with [(11)C]raclopride and brain activation to a visual attention (VA) task using 4-Tesla functional magnetic resonance imaging...
2016: Translational Psychiatry
Wen Li, Elisabet Englund, Håkan Widner, Bengt Mattsson, Danielle van Westen, Jimmy Lätt, Stig Rehncrona, Patrik Brundin, Anders Björklund, Olle Lindvall, Jia-Yi Li
Clinical trials using cells derived from embryonic ventral mesencephalon have shown that transplanted dopaminergic neurons can survive and function in the long term, as demonstrated by in vivo brain imaging using (18)F-fluorodopa and (11)C-raclopride positron emission tomography. Here we report the postmortem analysis of a patient with Parkinson's disease who 24 y earlier underwent unilateral transplantation of embryonic dopaminergic neurons in the putamen and subsequently exhibited major motor improvement and recovery of striatal dopaminergic function...
June 7, 2016: Proceedings of the National Academy of Sciences of the United States of America
Kenji Hashimoto, Takeharu Kakiuchi, Hiroyuki Ohba, Shingo Nishiyama, Hideo Tsukada
R-ketamine appears to be a potent, long-lasting and safer antidepressant, relative to esketamine (S-ketamine), since it might be free of psychotomimetic side effects. Using [(11)C]raclopride and positron emission tomography (PET), we investigated whether esketamine and R-ketamine can affect dopamine D2/3 receptor binding in the conscious monkey brain. A single infusion of esketamine (0.5 mg/kg), but not R-ketamine (0.5 mg/kg), caused a reduction of binding availability of dopamine D2/3 receptor in the monkey striatum...
April 18, 2016: European Archives of Psychiatry and Clinical Neuroscience
Margarida Dourado, Helder Cardoso-Cruz, Clara Monteiro, Vasco Galhardo
Testing the clinical efficacy of drugs that also have important side effects on locomotion needs to be properly designed in order to avoid erroneous identification of positive effects when the evaluation depends on motor-related tests. One such example is the evaluation of analgesic role of drugs that act on dopaminergic receptors, since the pain perception tests used in animal models are based on motor responses that can also be compromised by the same substances. The apparent analgesic effect obtained by modulation of the dopaminergic system is still a highly disputed topic...
2016: Journal of Experimental Neuroscience
Isadora L Alves, Antoon Tm Willemsen, Rudi A Dierckx, Ana Maria M da Silva, Michel Koole
Receptor occupancy studies performed with PET often require time-consuming dynamic imaging for baseline and post-dose scans. Shorter protocol approximations based on standard uptake value ratios have been proposed. However, such methods depend on the time-point chosen for the quantification and often lead to overestimation and bias. The aim of this study was to develop a shorter protocol for the quantification of post-dose scans using a dual time-point approximation, which employs kinetic parameters from the baseline scan...
April 12, 2016: Journal of Cerebral Blood Flow and Metabolism
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"