Accumulating evidence indicates that dopamine and D1 receptor ligands modulate N-methyl D-aspartate (NMDA) receptors through a variety of D1 receptor-dependent mechanisms. In this study, we reveal a distinct D1 receptor-independent mechanism by which NMDA receptors are modulated. Using the human embryonic kidney (HEK) cell recombinant system and dissociated neurons, we have discovered that dopamine and several D1 ligands act as voltage-dependent, open-channel blockers for NMDA receptors, regardless of whether they are agonists or antagonists for D1 receptors. Analysis of structural and functional relationships of D1 ligands revealed the elements that are critical for their binding to NMDA receptors. Furthermore, using D1 receptor knockout mice, we verified that this channel-blocking effect was independent of D1 receptors. Finally, we demonstrated that D1 ligands functionally interact with Mg(2+) block through multiple sites, implying a possible role of the direct channel block under physiological conditions. Our results suggest that the direct inhibition of NMDA receptors by dopamine D1 receptor ligands is due to the channel pore block rather than receptor-receptor interactions.
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http://dx.doi.org/10.1124/mol.106.028332 | DOI Listing |
Curr Neuropharmacol
January 2025
Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section, University of Genoa, Viale Cembrano 4, 16148, Genoa, Italy.
The central nervous system (CNS) is not an immune-privileged compartment, but it is intimately intertwined with the immune system. Among the components shared by the two compartments is the complement, a main constituent of innate immunity, which is also produced centrally and controls the development and organization of synaptic connections. Complement is considered a doubled-faced system that, besides controlling the physiological development of the central network, also subserves synaptic engulfment pivotal to the progression of neurodegenerative diseases.
View Article and Find Full Text PDFJ Pain Res
January 2025
Programa de Pós-Graduação em Medicina (Cirurgia Geral), Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
Introduction: Diabetes mellitus (DM) has become a public health problem, which is associated with high morbidity and mortality, due to the chronic complications, such as diabetic neuropathy. Current recommendations for the treatment of neuropathic pain achieve a reduction of 30% in only 30% of cases. Therefore, it is necessary to identify new therapeutic approaches to improve the quality of life of diabetic patients.
View Article and Find Full Text PDFRegen Ther
March 2025
Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan.
Introduction: Tau protein plays a pivotal role in the pathogenesis of Alzheimer's disease (AD) and in regulating neuronal excitability. Among tau-coding microtubule associated protein tau () gene mutations, the A152T mutation is reported to increase the risk of AD and neuronal excitability in mouse models.
Methods: To investigate the effects of gene expression and its mutations on neuronal activity in human neurons, we employed genome editing technology to introduce the A152T or P301S mutations into induced pluripotent stem cells (iPSCs).
Am J Psychiatry
January 2025
Biobehavioral Imaging and Molecular Neuropsychopharmacology Section, NIDA, Baltimore (Levinstein, Budinich, Michaelides); Department of Pathology and Experimental Therapeutics, Institute of Neurosciences, University of Barcelona, L'Hospitalet de Llobregat, Barcelona (Bonaventura); Neuropharmacology and Pain Group, Neuroscience Program, IDIBELL-Bellvitge Biomedical Research Institute, L'Hospitalet de Llobregat, Barcelona (Bonaventura); Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford (Schatzberg); Experimental Therapeutics and Pathophysiology Branch, NIMH, Bethesda (Zarate); Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore (Michaelides).
Ketamine is a racemic compound and medication comprised of ()-ketamine and ()-ketamine enantiomers and its metabolites. It has been used for decades as a dissociative anesthetic, analgesic, and recreational drug. More recently, ketamine, its enantiomers, and its metabolites have been used or are being investigated for the treatment of refractory depression, as well as for comorbid disorders such as anxiety, obsessive-compulsive, and opioid use disorders.
View Article and Find Full Text PDFAlzheimers Res Ther
January 2025
Department of Neuroscience "Rita Levi Montalcini", University of Turin, Via Cherasco 15, Turin, 10126, Italy.
Background: Alzheimer's disease (AD) is a progressive neurodegenerative disorder with both genetic and environmental factors contributing to its pathogenesis. While early-onset AD has well-established genetic determinants, the genetic basis for late-onset AD remains less clear. This study investigates a large Italian family with late-onset autosomal dominant AD, identifying a novel rare missense variant in GRIN2C gene associated with the disease, and evaluates the functional impact of this variant.
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