Background: Although the incidence of cannabis abuse/dependence in Americans is rising, the neurobiology of cannabis addiction is not well understood. Imaging studies have demonstrated deficits in striatal D(2)/D(3) receptor availability in several substance-dependent populations. However, this has not been studied in currently using chronic cannabis users.
Objective: The purpose of this study was to compare striatal D(2)/D(3) receptor availability between currently using chronic cannabis users and healthy controls.
Methods: Eighteen right-handed males age 18-34 were studied. Ten subjects were chronic cannabis users; eight were demographically matched controls. Subjects underwent a [(11)C]raclopride (RAC) PET scan. Striatal RAC binding potential (BP(ND)) was calculated on a voxel-wise basis. Prior to scanning, urine samples were obtained from cannabis users for quantification of urine Δ-9-tetrahydrocannabinol (THC) and THC metabolites (11-nor-Δ-9-THC-9-carboxylic acid; THC-COOH and 11-hydroxy-THC;OH-THC).
Results: There were no differences in D(2)/D(3) receptor availability between cannabis users and controls. Voxel-wise analyses revealed that RAC BP(ND) values were negatively associated with both urine levels of cannabis metabolites and self-report of recent cannabis consumption.
Conclusions: In this sample, current cannabis use was not associated with deficits in striatal D(2)/D(3) receptor availability. There was an inverse relationship between chronic cannabis use and striatal RAC BP(ND). Additional studies are needed to identify the neurochemical consequences of chronic cannabis use on the dopamine system.
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http://dx.doi.org/10.1016/j.drugalcdep.2012.07.016 | DOI Listing |
Cells
December 2024
Department of Physiology, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea.
Injured or atrophied adult skeletal muscles are regenerated through terminal differentiation of satellite cells to form multinucleated muscle fibers. Transplantation of satellite cells or cultured myoblasts has been used to improve skeletal muscle regeneration. Some of the limitations observed result from the limited number of available satellite cells that can be harvested and the efficiency of fusion of cultured myoblasts with mature muscle fibers (i.
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November 2024
Department of Psychiatry, Firat University School of Medicine, Elazig, Turkey.
Objectives: Clozapine is an atypical antipsychotic crucial for treatment-resistant schizophrenia, characterised by its multi-receptor targeting, including serotonin (5-HT2A, 5-HT2C) and dopamine (D1, D2, D3, D4) receptors, among others. This broad mechanism is effective against positive symptoms of schizophrenia with a lower incidence of extrapyramidal side effects. However, clozapine poses significant haematological risks, notably agranulocytosis, necessitating stringent blood monitoring protocols.
View Article and Find Full Text PDFFront Psychiatry
September 2024
School of Medicine, University of Belgrade, Belgrade, Serbia.
Major depressive disorder (MDD) is among the most prevalent psychiatric conditions and a leading cause of disability worldwide. MDD presents a diverse range of symptoms that significantly impact personal, societal, and economic dimensions. Despite the availability of numerous antidepressant treatments (ADTs) targeting different molecular mechanisms, a substantial proportion of patients experience inadequate response, presenting a considerable challenge in MDD management.
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September 2024
II Department of Psychiatry and Psychiatric Rehabilitation, Faculty of Medicine, Medical University of Lublin, Lublin, Poland.
Int J Mol Sci
August 2024
Division of Behavioral Neuropharmacology, International Center for Brain Science (ICBS), Fujita Health University, Toyoake 470-1192, Aichi, Japan.
In patients with Parkinson's disease (PD), dopamine replacement therapy with dopamine D2/D3 receptor agonists induces impairments in decision-making, including pathological gambling. The neurobiological mechanisms underlying these adverse effects remain elusive. Here, in a mouse model of PD, we investigated the effects of the dopamine D3 receptor (D3R)-preferring agonist pramipexole (PPX) on decision-making.
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