N-Methyl-d-aspartate receptors (NMDARs) control synaptic plasticity and brain development in a manner determined by receptor subunit composition. Pathogenic variants in GRIN2A gene, encoding the NMDAR GluN2A subunit, can cause gain or loss of function of receptors containing the affected subunit and are associated with intellectual disability and epilepsy in patients. While in vitro studies of recombinant receptors have yielded some insights, animal experimental models are essential to better understand the relationship between the molecular pathology of the variants and the disease. Here we introduce a zebrafish model of GluN2A loss of function to study system-level effects of zebrafish grin2Aa and grin2Ab gene deletion. Our electrophysiological analysis revealed functional differences between receptors containing zebrafish GluN2Aa/b and GluN2Bb paralogs comparable with mammalian receptors containing GluN2A versus GluN2B subunits. Both grin2Aa-/- and grin2Ab-/- as well as double-knock-out grin2A-/- zebrafish larvae showed increased locomotor activity in a novel environment. Proteomic analysis suggested that the relative proportion of GluN2B-containing NMDARs may be increased in grin2A mutant fish. Our results highlight fundamental similarities between zebrafish and mammalian NMDAR signaling and validate the use of zebrafish as a model organism to study the neurodevelopmental role of NMDARs. The newly created transgenic zebrafish strains complement the rodent models of GluN2A loss of function and can be used for high-throughput testing of pharmacological or genetic treatment strategies for patients with GRIN2A gene variants.

• Klíčová slova
• CRISPR-Cas9, Grin genes, channelopathy, glutamate receptors, zebrafish,
• MeSH
• dánio pruhované MeSH
• epilepsie * genetika   patofyziologie   MeSH
• geneticky modifikovaná zvířata MeSH
• modely nemocí na zvířatech MeSH
• plavání * fyziologie   MeSH
• proteiny dánia pruhovaného * genetika   MeSH
• receptory N-methyl-D-aspartátu * genetika   nedostatek   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• N-methyl D-aspartate receptor subtype 2A MeSH Prohlížeč
• NR2B NMDA receptor MeSH Prohlížeč
• proteiny dánia pruhovaného * MeSH
• receptory N-methyl-D-aspartátu * MeSH

N-Methyl-d-aspartate receptors (NMDARs), encoded by GRIN genes, are ionotropic glutamate receptors playing a critical role in synaptic transmission, plasticity, and synapse development. Genome sequence analyses have identified variants in GRIN genes in patients with neurodevelopmental disorders, but the underlying disease mechanisms are not well understood. Here, we have created and evaluated a transgenic mouse line carrying a missense variant Grin2bL825V , corresponding to a de novo GRIN2B variant encoding GluN2B(L825V) found in a patient with intellectual disability (ID) and autism spectrum disorder (ASD). We used HEK293T cells expressing recombinant receptors and primary hippocampal neurons prepared from heterozygous Grin2bL825V/+ (L825V/+) and wild-type (WT) Grin2b+/+ (+/+) male and female mice to assess the functional impact of the variant. Whole-cell NMDAR currents were reduced in neurons from L825V/+ compared with +/+ mice. The peak amplitude of NMDAR-mediated evoked excitatory postsynaptic currents (NMDAR-eEPSCs) was unchanged, but NMDAR-eEPSCs in L825V/+ neurons had faster deactivation compared with +/+ neurons and were less sensitive to a GluN2B-selective antagonist ifenprodil. Together, these results suggest a decreased functional contribution of GluN2B subunits to synaptic NMDAR currents in hippocampal neurons from L825V/+ mice. The analysis of the GluN2B(L825V) subunit surface expression and synaptic localization revealed no differences compared with WT GluN2B. Behavioral testing of mice of both sexes demonstrated hypoactivity, anxiety, and impaired sensorimotor gating in the L825V/+ strain, particularly affecting males, as well as cognitive symptoms. The heterozygous L825V/+ mouse offers a clinically relevant model of GRIN2B-related ID/ASD, and our results suggest synaptic-level functional changes that may contribute to neurodevelopmental pathology.

• Klíčová slova
• GluN2B, NMDA receptors, autism spectrum disorder, mouse model, synaptic transmission,
• MeSH
• excitační postsynaptické potenciály fyziologie   MeSH
• HEK293 buňky MeSH
• hipokampus metabolismus   MeSH
• lidé MeSH
• missense mutace MeSH
• myši inbrední C57BL MeSH
• myši transgenní * MeSH
• myši MeSH
• neurony metabolismus   MeSH
• neurovývojové poruchy * genetika   patofyziologie   metabolismus   MeSH
• receptory N-methyl-D-aspartátu * genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• NR2B NMDA receptor MeSH Prohlížeč
• receptory N-methyl-D-aspartátu * MeSH

Glutamate is the major excitatory neurotransmitter in the mammalian central nervous system. There are three distinct subtypes of ionotropic glutamate receptors (GluRs) that have been identified including 2-amino-3-(5-methyl-3-oxo-1,2-oxazol-4-yl)propanoic acid receptors (AMPARs), N-methyl-D-aspartate receptors (NMDARs) and kainate receptors. The most common GluRs in mature synapses are AMPARs that mediate the fast excitatory neurotransmission and NMDARs that mediate the slow excitatory neurotransmission. There have been large numbers of recent reports studying how a single neuron regulates synaptic numbers and types of AMPARs and NMDARs. Our current research is centered primarily on NMDARs and, therefore, we will focus in this review on recent knowledge of molecular mechanisms occurring (1) early in the biosynthetic pathway of NMDARs, (2) in the transport of NMDARs after their release from the endoplasmic reticulum (ER); and (3) at the plasma membrane including excitatory synapses. Because a growing body of evidence also indicates that abnormalities in NMDAR functioning are associated with a number of human psychiatric and neurological diseases, this review together with other chapters in this issue may help to enhance research and to gain further knowledge of normal synaptic physiology as well as of the etiology of many human brain diseases.

• Klíčová slova
• excitatory neurotransmission, glutamate receptor, internalization, intracellular trafficking, ion channel, subcellular compartment,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

There is accumulating evidence that methamphetamine (MA) is a widely abused drug popular among pregnant women. MA exposure is associated with changes in the function of neurotransmitter systems, namely the dopaminergic, serotonergic and glutamatergic systems. Since N-methyl-D-aspartate receptors (NMDA) are affected by MA-induced glutamate release, we assessed the expression of NMDAR subunits (NR1, NR2A, and NR2B) and postsynaptic density protein 95 (PSD-95), which is connected with NMDAR. We measured the expression of these proteins in adolescent (30 days old) and adult (60 days old) rat males exposed to MA during the entire prenatal period and compared them with the same parameters in age matched saline-exposed rats. There was a significant increase in the NR1 and NR2B subunits in the hippocampus of adult males, but not in adolescent males. We identified a significant change in adult MA-induced rats when compared to adult controls for NR2A and NR2B, while in adolescent MA rats this change was close to the boundary of significance. In summary, our study suggests that prenatal MA exposure is connected with changes in NMDAR subunit expression in adult rats but not in adolescent rats.

• MeSH
• hipokampus účinky léků   metabolismus   MeSH
• methamfetamin toxicita   MeSH
• novorozená zvířata MeSH
• podjednotky proteinů metabolismus   MeSH
• potkani Sprague-Dawley MeSH
• receptory N-methyl-D-aspartátu metabolismus   MeSH
• signální transdukce účinky léků   MeSH
• stárnutí MeSH
• těhotenství MeSH
• zpožděný efekt prenatální expozice metabolismus   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• methamfetamin MeSH
• podjednotky proteinů MeSH
• receptory N-methyl-D-aspartátu MeSH