Background: Synaptic and extrasynaptic distribution of N-methyl-D-aspartate receptors (NMDARs) has not been addressed in the brain from Alzheimer´s disease (AD) subjects, despite their contribution to neurodegeneration.
Methods: We have developed a protocol to isolate synaptic and extrasynaptic membranes from controls and AD frontal cortex. We characterized the distribution of the NMDAR subunits GluN2B, GluN2A, GluN1, and GluN3A, as well as post-translational modifications, such as phosphorylation and glycosylation.
Results: Lower levels of synaptic GluN2B and GluN2A were found in AD fractions, while extrasynaptic GluN2B and GluN1 levels were significantly higher; GluN3A distribution remained unaffected in AD. We also identified different glycoforms of GluN2B and GluN2A in extrasynaptic membranes. Synaptic Tyr1472 GluN2B phosphorylation was significantly lower in AD fractions.
Discussion: Reduction of synaptic NMDAR subunits, particularly for GluN2B, is likely to contribute to synaptic transmission failure in AD. Additionally, the increment of extrasynaptic NMDAR subunits could favor the activation of excitotoxicity in AD.
Highlights: New protocol to isolate synaptic and extrasynaptic membranes from the human cortex. Low GluN2B and GluN2A levels in Alzheimer´s disease (AD) synaptic membranes. High GluN2B and GluN1 levels in AD extrasynaptic membranes. Specific glycoforms of extrasynaptic GluN2B and GluN2A. Low phosphorylation at Tyr1472 in synaptic GluN2B in AD.
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http://dx.doi.org/10.1002/alz.14125 | DOI Listing |
Food Chem Toxicol
January 2025
Department of Occupational and Environmental Health, School of Public Health, Jinzhou Medical University, Jinzhou, Liaoning, PR China. Electronic address:
Flame retardant polybrominated diphenyl ethers (PBDEs) accumulate in human bodies through food and dust ingestion, and cause neurobehavioral deficits with obscure mechanism. We aimed to investigate NMDAR-CaMKⅡγ-mediated synapse-to-nuclear communication involved in BDE-209-induced cognitive impairment, and alleviation from exogenous melatonin. Decreased NMDAR subunits GluN2A and 2B, autophosphorylation of CaMKⅡα, and postsynaptic GluA1 trafficking were observed in the hippocampus of juvenile rats after maternal BDE-209 exposure.
View Article and Find Full Text PDFIt is well known that activation of NMDA receptors can trigger long-term synaptic depression (LTD) and that a morphological correlate of this functional plasticity is spine retraction and elimination. Recent studies have led to the surprising conclusion that NMDA-induced spine shrinkage proceeds independently of ion flux and requires the initiation of protein synthesis, highlighting an unappreciated contribution of mRNA translation to non-ionotropic NMDAR signaling. Here we used NMDA-induced spine shrinkage in slices of mouse hippocampus as a readout to investigate this novel modality of synaptic transmission.
View Article and Find Full Text PDFAlzheimers Res Ther
January 2025
MMDN, Univ Montpellier, EPHE, INSERM, Montpellier, France.
Background: Fluoroethylnormemantine (FENM), a new Memantine (MEM) derivative, prevented amyloid-β[25-35] peptide (Aβ)-induced neurotoxicity in mice, a pharmacological model of Alzheimer's disease (AD) with high predictive value for drug discovery. Here, as drug infusion is likely to better reflect drug bioavailability due to the interspecies pharmacokinetics variation, we analyzed the efficacy of FENM after chronic subcutaneous (SC) infusion, in comparison with IP injections in two AD mouse models, Aβ-injected mice and the transgenic APP/PSEN1 (APP/PS1) line.
Methods: In Aβ-treated mice, FENM was infused at 0.
Neurosci Lett
December 2024
School of Biomedical Engineering and Sciences, Virginia Tech, Blacksburg, VA, USA; Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, USA; Veterans Affairs Medical Center, Salem, VA, USA. Electronic address:
Regulation of glutamate through glutamate-glutamine cycling is critical for mediating nervous system plasticity. Blast-induced traumatic brain injury (bTBI) has been linked to glutamate-dependent excitotoxicity, which may be potentiating chronic disorders such as post-traumatic epilepsy. The purpose of this study was to measure changes in the expression of astrocytic and neuronal proteins responsible for glutamatergic regulation at 4-, 12-, and 24 h in the cortex and hippocampus following single blast exposure in a rat model for bTBI.
View Article and Find Full Text PDFEcotoxicol Environ Saf
December 2024
Department of Pediatrics, The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang 550001, China; Department of Chinese Medicine, Jinan Geriatric/Rehabilitation Hospital, Jinan 250013, China; Graduate School of Guangzhou University of Chinese Medicine; Guangzhou 510006, China; Department of Proctology, The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang 550001, China. Electronic address:
Subchronic exposure to cyanuric acid (CA) and its structural analogue melamine induces long-term effects on brain and behavior in male rodents. To examine if this exposure induced negative effects on cognitive function in females, we examined the behavioral performance and further attempted to investigate synaptic and neuronal function. CA was intraperitoneal treated with 20 or 40 mg/kg/day to adolescent female rats for 4 consecutive weeks.
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