Glutamate neurotoxicity mediated by NMDA and non-NMDA receptors of cultured cortical neurons

1991 ◽  
Vol 16 ◽  
pp. 88
Author(s):  
Akinori Akaike ◽  
Yutaka Tamura ◽  
Yuko Sato
Keyword(s):  
Nmda Receptors ◽  
Cortical Neurons ◽  
Glutamate Neurotoxicity ◽  
Cultured Cortical Neurons

scholarly journals Characterization of Neuroprotection from Excitotoxicity by Moderate and Profound Hypothermia in Cultured Cortical Neurons Unmasks a Temperature-Insensitive Component of Glutamate Neurotoxicity

1998 ◽  
Vol 18 (8) ◽  
pp. 848-867 ◽  
Author(s):  
Michael Tymianski ◽  
Rita Sattler ◽  
Joseph M. Zabramski ◽  
Robert F. Spetzler
Keyword(s):  
Nmda Receptors ◽  
Cortical Neurons ◽  
Underlying Mechanism ◽  
The Other ◽  
Glutamate Toxicity ◽  
Protective Effects ◽  
Profound Hypothermia ◽  
Glutamate Neurotoxicity ◽  
Cultured Cortical Neurons

Although profound hypothermia has been used for decades to protect the human brain from hypoxic or ischemic insults, little is known about the underlying mechanism. We therefore report the first characterization of the effects of moderate (30°C) and profound hypothermia (12° to 20°C) on excitotoxicity in cultured cortical neurons exposed to excitatory amino acids (EAA; glutamate, N-methyl-D-aspartate [NMDA], AMPA, or kainate) at different temperatures (12° to 37°C). Cooling neurons to 30°C and 20°C was neuroprotective, but cooling to 12°C was toxic. The extent of protection depended on the temperature, the EAA receptor agonist employed, and the duration of the EAA challenge. Neurons challenged briefly (5 minutes) with all EAA were protected, as were neurons challenged for 60 minutes with NMDA, AMPA, or kainate. The protective effects of hypothermia (20° and 30°C) persisted after rewarming to 37°C, but rewarming from 12°C was deleterious. Surprisingly, however, prolonged (60 minutes) exposures to glutamate unmasked a temperature-insensitive component of glutamate neurotoxicity that was not seen with the other, synthetic EAA; this component was still mediated via NMDA receptors, not by ionotropic or metabotropic non-NMDA receptors. The temperature-insensitivity of glutamate toxicity was not explained by effects of hypothermia on EAA-evoked [Ca2+]i increases measured using high- and low-affinity Ca2+ indicators, nor by effects on mitochondrial production of reactive oxygen species. This first characterization of excitotoxicity at profoundly hypothermic temperatures reveals a previously unnoticed feature of glutamate neurotoxicity unseen with the other EAA, and also suggests that hypothermia protects the brain at the level of neurons by blocking, rather than slowing, excitotoxicity.

Trapping Channel Block of NMDA-Activated Responses By Amantadine and Memantine

1997 ◽  
Vol 77 (1) ◽  
pp. 309-323 ◽  
Author(s):  
Thomas A. Blanpied ◽  
Faye A. Boeckman ◽  
Elias Aizenman ◽  
Jon W. Johnson
Keyword(s):  
Nmda Receptor ◽  
Nmda Receptors ◽  
Cortical Neurons ◽  
Chinese Hamster ◽  
Therapeutic Effects ◽  
Channel Block ◽  
Cultured Cortical Neurons ◽  
Simple Kinetic Model ◽  
Rat Cortical Neurons ◽  
Partial Trapping

Blanpied, Thomas A., Faye Boeckman, Elias Aizenman, and Jon W. Johnson. Trapping channel block of NMDA-activated responses by amantadine and memantine. J. Neurophysiol. 77: 309–323, 1997. We investigated the mechanisms by which the antiparkinsonian and neuroprotective agents amantadine and memantine inhibit responses to N-methyl-d-aspartic acid (NMDA). Whole cell recordings were performed using cultured rat cortical neurons or Chinese hamster ovary (CHO) cells expressing NMDA receptors. Both amantadine and memantine blocked NMDA-activated channels by binding to a site at which they could be trapped after channel closure and agonist unbinding. For neuronal receptors, the IC50s of amantadine and memantine at −67 mV were 39 and 1.4 μM, respectively. When memantine and agonists were washed off after steady-state block, one-sixth of the blocked channels released rather than trapped the blocker; memantine exhibited “partial trapping.” Thus memantine appears to have a lesser tendency to be trapped than do phencyclidine or (5R,10S)-(+)-5m e t h y l - 1 0 , 1 1 - d i h y d r o - 5 H - d i b e n z o [ 1 , d ] c y c l i h e p t e n - 5 , 1 0 - i m i n e(MK-801). We next investigated mechanisms that might underlie partial trapping. Memantine blocked and could be trapped by recombinant NMDA receptors composed of NR1 and either NR2A or NR2B subunits. In these receptors, as in the native receptors, the drug was released from one-sixth of blocked channels rather than being trapped in all of them. The partial trapping we observed therefore was not due to variability in the action of memantine on a heterogeneous population of NMDA receptors in cultured cortical neurons. Amantadine and memantine each noncompetitively inhibited NMDA-activated responses by binding at a second site with roughly 100-fold lower affinity, but this form of inhibition had little effect on the extent to which memantine was trapped. A simple kinetic model of blocker action was used to demonstrate that partial trapping can result if the presence of memantine in the channel affects the gating transitions or agonist affinity of the NMDA receptor. Partial trapping guarantees that during synaptic communication in the presence of blocker, some channels will release the blocker between synaptic responses. The extent to which amantadine and memantine become trapped after channel block thus may influence their therapeutic effects and their modulation of NMDA-receptor-mediated excitatory postsynaptic potentials.

Serofendic acid prevents acute glutamate neurotoxicity in cultured cortical neurons

2003 ◽  
Vol 477 (3) ◽  
pp. 195-203 ◽  
Author(s):  
Ryota Taguchi ◽  
Hiroyuki Nishikawa ◽  
Toshiaki Kume ◽  
Taro Terauchi ◽  
Shuji Kaneko ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Glutamate Neurotoxicity ◽  
Cultured Cortical Neurons

scholarly journals Effect of Conantokin G on NMDA Receptor–Mediated Spontaneous EPSCs in Cultured Cortical Neurons

2006 ◽  
Vol 96 (3) ◽  
pp. 1084-1092 ◽  
Author(s):  
Anitha B. Alex ◽  
Anthony J. Baucum ◽  
Karen S. Wilcox
Keyword(s):  
Nmda Receptor ◽  
Nmda Receptors ◽  
Binding Site ◽  
Cortical Neurons ◽  
Dependent Manner ◽  
Patch Clamp Technique ◽  
Concentration Dependent Manner ◽  
Whole Cell ◽  
Cultured Cortical Neurons

Conantokin G (Con G), derived from the venom of Conus geographus, is the most characterized natural peptide antagonist targeted to N-methyl-d-aspartate (NMDA) receptors. Although Con G is known to bind to the glutamate binding site on the NR2 subunit of the receptor, it is unclear whether it can allosterically modulate the function of the receptor through the glycine binding site on the NR1 subunit. This study was designed to evaluate the action of Con G on NMDA receptor–mediated spontaneous excitatory postsynaptic currents (sEPSCs) and its modulation by glycine in cultured cortical neurons (13–19 days in vitro) using the whole cell patch-clamp technique. Con G inhibited NMDA receptor–mediated sEPSCs in a concentration-dependent manner. Also, the potency of Con G decreased as a function of time in culture. The inhibition of EPSCs observed after application of Con G in the presence of high (10 μM) and nominal (no added) concentrations of glycine was not different at 13 days in vitro (DIV). Furthermore, similar results were obtained with experiments on Con G–induced inhibition of NMDA-evoked whole cell currents. These results indicate that glycine concentrations do not have a direct effect on Con G–induced inhibition of NMDA currents. In addition, age dependency in the action of Con G on cortical neurons in vitro suggests that this model system would be useful in examining the effects of different agonists/antagonists on native synaptic NMDA receptors.

Cholecystokinin-induced protection of cultured cortical neurons against glutamate neurotoxicity

1991 ◽  
Vol 557 (1-2) ◽  
pp. 303-307 ◽  
Author(s):  
Akinori Akaike ◽  
Yutaka Tamura ◽  
Yuko Sato ◽  
Kumi Ozaki ◽  
Rika Matsuoka ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Glutamate Neurotoxicity ◽  
Cultured Cortical Neurons

scholarly journals Bi-directional regulation of CaMKIIα phosphorylation at Thr286 by NMDA receptors in cultured cortical neurons

2012 ◽  
Vol 122 (2) ◽  
pp. 295-307 ◽  
Author(s):  
Xianju Zhou ◽  
Fei Zheng ◽  
Changjong Moon ◽  
Oliver M. Schlüter ◽  
Hongbing Wang
Keyword(s):  
Nmda Receptors ◽  
Cortical Neurons ◽  
Cultured Cortical Neurons

Changes in the Effect of Isoflurane on N -methyl-d-aspartic Acid-gated Currents in Cultured Cerebral Cortical Neurons with Time in Culture

2002 ◽  
Vol 97 (4) ◽  
pp. 856-867 ◽  
Author(s):  
Zhen Ming ◽  
Benjamin L. Griffith ◽  
George R. Breese ◽  
Robert A. Mueller ◽  
Hugh E. Criswell
Keyword(s):  
Nmda Receptors ◽  
Cortical Neurons ◽  
Splice Variants ◽  
Cell Voltage ◽  
Hek 293 ◽  
Hek 293 Cells ◽  
293 Cells ◽  
Cerebral Cortical Neurons ◽  
Cultured Cortical Neurons ◽  
Nr2 Subunits

Background Developmental changes in NR1 splice variants and NR2 subunits of the N-methyl-D-aspartate (NMDA) receptor have been associated with changes in the sensitivity of NMDA receptors to agonists, antagonists, and pharmacologic modulators. The authors have investigated changes in the effect of isoflurane on NMDA-gated currents from cultured cortical neurons with time in culture and related these changes to the subunit composition of the NMDA receptors. Methods N-methyl-D-aspartate-gated currents were measured using whole-cell voltage clamp recording in cortical neurons cultured for 1-4 weeks and HEK 293 cells transiently expressing NR1-1a + NR2A or NR1-1a + NR2B subunit-containing receptors. NMDA alone or NMDA with treatment agents (isoflurane or ifenprodil) was applied to cells using a U tube. Results The effect of isoflurane and the NR2B selective antagonist ifenprodil on NMDA-gated currents from cortical neurons decreased significantly with time in culture. NMDA-gated currents mediated by NR2A-containing receptors were less sensitive to isoflurane than those mediated by NR2B-containing receptors. Tachyphylaxis to repeated application of isoflurane was found in cortical neurons and HEK 293 cells with recombinant NMDA receptors. Hooked tail currents were induced by isoflurane in cultured cortical neurons and HEK 293 cells with expressed NMDA receptors. Conclusions Isoflurane inhibits NMDA-gated currents at concentrations well below 1 minimum alveolar concentration (MAC). This effect of isoflurane was subunit dependent with the NR2B-containing receptors more sensitive to isoflurane than the NR2A-containing receptors. A potent tachyphylaxis occurred after brief exposure to isoflurane.

scholarly journals The Bacterial Enzyme Cas13 Interferes with Neurite Outgrowth from Cultured Cortical Neurons

Toxins ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 262
Author(s):  
Qin-Wei Wu ◽  
Josef P. Kapfhammer
Keyword(s):  
Rna Editing ◽  
Cortical Neurons ◽  
High Efficiency ◽  
Primary Cultures ◽  
Cultured Neurons ◽  
Therapeutic Tool ◽  
Bacterial Enzyme ◽  
Rna Targeting ◽  
Cultured Cortical Neurons ◽  
New Generation

The CRISPR-Cas13 system based on a bacterial enzyme has been explored as a powerful new method for RNA manipulation. Due to the high efficiency and specificity of RNA editing/interference achieved by this system, it is currently being developed as a new therapeutic tool for the treatment of neurological and other diseases. However, the safety of this new generation of RNA therapies is still unclear. In this study, we constructed a vector expressing CRISPR-Cas13 under a constitutive neuron-specific promoter. CRISPR-Cas13 from Leptotrichia wadei was expressed in primary cultures of mouse cortical neurons. We found that the presence of CRISPR-Cas13 impedes the development of cultured neurons. These results show a neurotoxic action of Cas13 and call for more studies to test for and possibly mitigate the toxic effects of Cas13 enzymes in order to improve CRISPR-Cas13-based tools for RNA targeting.

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