scholarly journals Regulation of spontaneous Ca2+ spikes by metabotropic glutamate receptors in primary cultures of rat cortical neurons

2010 ◽  
Vol 88 (10) ◽  
pp. 2252-2262 ◽  
Author(s):  
Kazumi Koga ◽  
Yuki Iwahori ◽  
Satoshi Ozaki ◽  
Hisashi Ohta
Keyword(s):  
Glutamate Receptors ◽  
Cortical Neurons ◽  
Metabotropic Glutamate Receptors ◽  
Primary Cultures ◽  
Metabotropic Glutamate ◽  
Rat Cortical Neurons

scholarly journals Early Effects of the Soluble Amyloid β25-35 Peptide in Rat Cortical Neurons: Modulation of Signal Transduction Mediated by Adenosine and Group I Metabotropic Glutamate Receptors

2021 ◽  
Vol 22 (12) ◽  
pp. 6577
Author(s):  
Carlos Alberto Castillo ◽  
Inmaculada Ballesteros-Yáñez ◽  
David Agustín León-Navarro ◽  
José Luis Albasanz ◽  
Mairena Martín
Keyword(s):  
Gene Expression ◽  
Glutamate Receptors ◽  
Adenosine Receptors ◽  
Cortical Neurons ◽  
Metabotropic Glutamate Receptors ◽  
Fine Tuning ◽  
Amyloid Β Peptide ◽  
Metabotropic Glutamate ◽  
Group I ◽  
Rat Cortical Neurons

The amyloid β peptide (Aβ) is a central player in the neuropathology of Alzheimer’s disease (AD). The alteration of Aβ homeostasis may impact the fine-tuning of cell signaling from the very beginning of the disease, when amyloid plaque is not deposited yet. For this reason, primary culture of rat cortical neurons was exposed to Aβ25-35, a non-oligomerizable form of Aβ. Cell viability, metabotropic glutamate receptors (mGluR) and adenosine receptors (AR) expression and signalling were assessed. Aβ25-35 increased mGluR density and affinity, mainly due to a higher gene expression and protein presence of Group I mGluR (mGluR1 and mGluR5) in the membrane of cortical neurons. Intriguingly, the main effector of group I mGluR, the phospholipase C β1 isoform, was less responsive. Also, the inhibitory action of group II and group III mGluR on adenylate cyclase (AC) activity was unaltered or increased, respectively. Interestingly, pre-treatment of cortical neurons with an antagonist of group I mGluR reduced the Aβ25-35-induced cell death. Besides, Aβ25-35 increased the density of A1R and A2AR, along with an increase in their gene expression. However, while A1R-mediated AC inhibition was increased, the A2AR-mediated stimulation of AC remained unchanged. Therefore, one of the early events that takes place after Aβ25-35 exposure is the up-regulation of adenosine A1R, A2AR, and group I mGluR, and the different impacts on their corresponding signaling pathways. These results emphasize the importance of deciphering the early events and the possible involvement of metabotropic glutamate and adenosine receptors in AD physiopathology.

scholarly journals Evidence that Functional Glutamate Receptors are not Expressed on Rat or Human Cerebromicrovascular Endothelial Cells

1998 ◽  
Vol 18 (4) ◽  
pp. 396-406 ◽  
Author(s):  
Paul Morley ◽  
Daniel L. Small ◽  
Christine L. Murray ◽  
Geoffrey A. Mealing ◽  
Michael O. Poulter ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Nmda Receptor ◽  
Glutamate Receptors ◽  
Glutamate Receptor ◽  
Ampa Receptor ◽  
Cortical Neurons ◽  
Cerebral Vessels ◽  
Rt Pcr ◽  
Metabotropic Glutamate ◽  
Rat Cortical Neurons

Excitatory amino acids can modify the tone of cerebral vessels and permeability of the blood-brain barrier (BBB) by acting directly on endothelial cells of cerebral vessels or indirectly by activating receptors expressed on other brain cells. In this study we examined whether rat or human cerebromicrovascular endothelial cells (CEC) express ionotropic and metabotropic glutamate receptors. Glutamate and the glutamate receptor agonists N-methyl-d-aspartate (NMDA), α-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA), and kainate failed to increase [Ca2+]i in either rat or human microvascular and capillary CEC but elicited robust responses in primary rat cortical neurons, as measured by fura-2 fluorescence. The absence of NMDA and AMPA receptors in rat and human CEC was further confirmed by the lack of immunocytochemical staining of cells by antibodies specific for the AMPA receptor subunits GluR1, GluR2/3, and GluR4 and the NMDA receptor subunits NR1, NR2A, and NR2B. We failed to detect mRNA expression of the AMPA receptor subunits GluR1 to GluR4 or the NMDA receptor subunits NR11XX, NR10XX, and NR2A to NR2C in both freshly isolated rat and human microvessels and cultured CEC using reverse transcriptase polymerase chain reaction (RT-PCR). Cultured rat CEC expressed mRNA for KA1 or KA2 and GluR5 subunits. Primary rat cortical neurons were found to express GluR1 to GluR3 and NR1, NR2A, and NR2B by both immunocytochemistry and RT-PCR and KA1, KA2, GluR5, GluR6, and GluR7 by RT-PCR. Moreover, the metabotropic glutamate receptor agonist 1-amino-cyclopentyl-1 S, 3 R-dicorboxylate (1 S,3 R-trans-ACPD), while eliciting both inositol trisphosphate and [Ca2+]i increases and inhibiting forskolin-stimulated cyclic AMP in cortical neurons, was unable to induce either of these responses in rat or human CEC. These results strongly suggest that both rat and human CEC do not express functional glutamate receptors. Therefore, excitatory amino acid-induced changes in the cerebral microvascular tone and BBB permeability must be affected indirectly, most likely by mediators released from the adjacent glutamate-responsive cells.

Estrogen Receptors and Type 1 Metabotropic Glutamate Receptors Are Interdependent in Protecting Cortical Neurons against β-Amyloid Toxicity

2011 ◽  
Vol 81 (1) ◽  
pp. 12-20 ◽  
Author(s):  
Simona Federica Spampinato ◽  
Gemma Molinaro ◽  
Sara Merlo ◽  
Luisa Iacovelli ◽  
Filippo Caraci ◽  
...  
Keyword(s):  
Estrogen Receptors ◽  
Glutamate Receptors ◽  
Cortical Neurons ◽  
Metabotropic Glutamate Receptors ◽  
Metabotropic Glutamate ◽  
Amyloid Toxicity ◽  
Β Amyloid

β-Amyloid Peptides Impair PKC-Dependent Functions of Metabotropic Glutamate Receptors in Prefrontal Cortical Neurons

2005 ◽  
Vol 93 (6) ◽  
pp. 3102-3111 ◽  
Author(s):  
Joanna P. Tyszkiewicz ◽  
Zhen Yan
Keyword(s):  
Nmda Receptor ◽  
Glutamate Receptors ◽  
Cortical Neurons ◽  
Metabotropic Glutamate Receptors ◽  
Pyramidal Neurons ◽  
Amyloid Peptide ◽  
Metabotropic Glutamate ◽  
Prefrontal Cortical ◽  
Group I ◽  
Β Amyloid

The metabotropic glutamate receptors (mGluRs) have been implicated in cognition, memory, and some neurodegenerative disorders, including the Alzheimer's disease (AD). To understand how the dysfunction of mGluRs contributes to the pathophysiology of AD, we examined the β-amyloid peptide (Aβ)-induced alterations in the physiological functions of mGluRs in prefrontal cortical pyramidal neurons. Two potential targets of mGluR signaling involved in cognition, the GABAergic system and the N-methyl-d-aspartate (NMDA) receptor, were examined. Activation of group I mGluRs with (S)-3,5-dihydroxyphenylglycine (DHPG) significantly increased the spontaneous inhibitory postsynaptic current (sIPSC) amplitude, and this effect was protein kinase C (PKC) sensitive. Treatment with Aβ abolished the DHPG-induced enhancement of sIPSC amplitude. On the other hand, activation of group II mGluRs with (2R,4R)-4-aminopyrrolidine-2,4-dicarboxylate (APDC) significantly increased the NMDA receptor (NMDAR)-mediated currents via a PKC-dependent mechanism, and Aβ treatment also diminished the APDC-induced potentiation of NMDAR currents. In Aβ-treated slices, both DHPG and APDC failed to activate PKC. These results indicate that the mGluR regulation of GABA transmission and NMDAR currents is impaired by Aβ treatment probably due to the Aβ-mediated interference of mGluR activation of PKC. This study provides a framework within which the role of mGluRs in normal cognitive functions and AD can be better understood.

scholarly journals Glutamate Stimulates Local Protein Synthesis in the Axons of Rat Cortical Neurons by Activating α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid (AMPA) Receptors and Metabotropic Glutamate Receptors

2015 ◽  
Vol 290 (34) ◽  
pp. 20748-20760 ◽  
Author(s):  
Wei-Lun Hsu ◽  
Hui-Wen Chung ◽  
Chih-Yueh Wu ◽  
Huei-Ing Wu ◽  
Yu-Tao Lee ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Ampa Receptors ◽  
Cortical Neurons ◽  
Metabotropic Glutamate Receptors ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Local Protein Synthesis ◽  
Metabotropic Glutamate ◽  
Rat Cortical Neurons ◽  
Local Protein

Glutamate is the principal excitatory neurotransmitter in the mammalian CNS. By analyzing the metabolic incorporation of azidohomoalanine, a methionine analogue, in newly synthesized proteins, we find that glutamate treatments up-regulate protein translation not only in intact rat cortical neurons in culture but also in the axons emitting from cortical neurons before making synapses with target cells. The process by which glutamate stimulates local translation in axons begins with the binding of glutamate to the ionotropic AMPA receptors and metabotropic glutamate receptor 1 and members of group 2 metabotropic glutamate receptors on the plasma membrane. Subsequently, the activated mammalian target of rapamycin (mTOR) signaling pathway and the rise in Ca2+, resulting from Ca2+ influxes through calcium-permeable AMPA receptors, voltage-gated Ca2+ channels, and transient receptor potential canonical channels, in axons stimulate the local translation machinery. For comparison, the enhancement effects of brain-derived neurotrophic factor (BDNF) on the local protein synthesis in cortical axons were also studied. The results indicate that Ca2+ influxes via transient receptor potential canonical channels and activated the mTOR pathway in axons also mediate BDNF stimulation to local protein synthesis. However, glutamate- and BDNF-induced enhancements of translation in axons exhibit different kinetics. Moreover, Ca2+ and mTOR signaling appear to play roles carrying different weights, respectively, in transducing glutamate- and BDNF-induced enhancements of axonal translation. Thus, our results indicate that exposure to transient increases of glutamate and more lasting increases of BDNF would stimulate local protein synthesis in migrating axons en route to their targets in the developing brain.

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