Membrane-tethered AKT kinase regulates basal synaptic transmission and early phase LTP expression by modulation of post-synaptic AMPA receptor level

Hippocampus ◽  
2016 ◽  
Vol 26 (9) ◽  
pp. 1149-1167 ◽  
Author(s):  
Y. Pen ◽  
N. Borovok ◽  
M. Reichenstein ◽  
A. Sheinin ◽  
I. Michaelevski
Keyword(s):  
Synaptic Transmission ◽  
Ampa Receptor ◽  
Early Phase ◽  
Akt Kinase ◽  
Receptor Level ◽  
Basal Synaptic Transmission

Lack of AMPA Receptor Desensitization During Basal Synaptic Transmission in the Hippocampal Slice

1999 ◽  
Vol 81 (6) ◽  
pp. 3096-3099 ◽  
Author(s):  
Gregory O. Hjelmstad ◽  
John T. R. Isaac ◽  
Roger A. Nicoll ◽  
Robert C. Malenka
Keyword(s):  
Synaptic Transmission ◽  
Ampa Receptor ◽  
Ampa Receptors ◽  
Hippocampal Slice ◽  
Hippocampal Slices ◽  
Release Site ◽  
Pyramidal Cells ◽  
Receptor Desensitization ◽  
Synaptic Receptors ◽  
Basal Synaptic Transmission

Lack of AMPA receptor desensitization during basal synaptic transmission in the hippocampal slice. Excitatory postsynaptic currents in the CA1 region of rat hippocampal slices are mediated primarily by α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in response to synaptically released glutamate. Outside-out patches from pyramidal cells in this region have shown that AMPA receptors are desensitized by short (1 ms) pulses of glutamate. We have taken a number of approaches to ask whether synaptic receptors desensitize in response to synaptically released glutamate in the slice. Recordings with paired pulses and minimal stimulation conditions that are presumably activating only a single release site do not show evidence for desensitization. Furthermore, cyclothiazide, a drug that blocks desensitization, does not alter paired-pulse ratios even under conditions of high probability of release, which should maximize desensitization. These results suggest that synaptic receptors do not desensitize in response to synaptically released glutamate during basal synaptic transmission.

scholarly journals Reduced Effect of Anticonvulsants on AMPA Receptor Palmitoylation-Deficient Mice

2021 ◽  
Vol 12 ◽  
Author(s):  
Madoka Iizumi ◽  
Akiko Oota-Ishigaki ◽  
Mariko Yamashita ◽  
Takashi Hayashi
Keyword(s):  
Synaptic Transmission ◽  
Ampa Receptor ◽  
Ampa Receptors ◽  
Receptor Expression ◽  
Mammalian Brain ◽  
Model Animal ◽  
Channel Blocking ◽  
Gabaergic Synapses ◽  
Novel Target ◽  
Basal Synaptic Transmission

AMPA receptors are responsible for fast excitatory synaptic transmission in the mammalian brain. Post-translational protein S-palmitoylation of AMPA receptor subunits GluA1-4 reversibly regulates synaptic AMPA receptor expression, resulting in long-lasting changes in excitatory synaptic strengths. Our previous studies have shown that GluA1 C-terminal palmitoylation-deficient (GluA1C811S) mice exhibited hyperexcitability in the cerebrum and elevated seizure susceptibility without affecting brain structure or basal synaptic transmission. Moreover, some inhibitory GABAergic synapses-targeting anticonvulsants, such as valproic acid, phenobarbital, and diazepam, had less effect on these AMPA receptor palmitoylation-deficient mutant mice. This work explores pharmacological effect of voltage-gated ion channel-targeted anticonvulsants, phenytoin and trimethadione, on GluA1C811S mice. Similar to GABAergic synapses-targeting anticonvulsants, anticonvulsive effects were also reduced for both sodium channel- and calcium channel-blocking anticonvulsants, which suppress excess excitation. These data strongly suggest that the GluA1C811S mice generally underlie the excessive excitability in response to seizure-inducing stimulation. AMPA receptor palmitoylation site could be a novel target to develop unprecedented type of anticonvulsants and GluA1C811S mice are suitable as a model animal for broadly evaluating pharmacological effectiveness of antiepileptic drugs.

Rapidly Deactivating AMPA Receptors Determine Excitatory Synaptic Transmission to Interneurons in the Nucleus Tractus Solitarius From Rat

1997 ◽  
Vol 78 (1) ◽  
pp. 82-91 ◽  
Author(s):  
Stefan Titz ◽  
Bernhard U. Keller
Keyword(s):  
Synaptic Transmission ◽  
Ampa Receptor ◽  
Decay Time ◽  
Ampa Receptors ◽  
Time Course ◽  
Nucleus Tractus Solitarius ◽  
Synaptic Cleft ◽  
Excitatory Synaptic Transmission ◽  
Membrane Properties ◽  
Time Constants

Titz, Stefan and Bernhard U. Keller. Rapidly deactivating AMPA receptors determine excitatory synaptic transmission to interneurons in the nucleus tractus solitarius from rat. J. Neurophysiol. 78: 82–91, 1997. Excitatory synaptic transmission was investigated in interneurons of the parvocellular nucleus tractus solitarius (pNTS) by performing patch-clamp experiments in thin slice preparations from rat brain stem. Stimulation of single afferent fibers evoked excitatory postsynaptic currents (EPSCs) mediated by glutamate receptors of the dl-α-amino-3-hydroxy-5-methylisoxazole-propionic acid (AMPA) and N-methyl-d-aspartate types. AMPA-receptor-mediated EPSCs displayed decay time constants of 3.5 ± 1.2 (SD) ms (13 cells), which were slow compared with EPSC decay time constants in neurons of the cerebellum or hippocampus. Slow EPSC decay was not explained by dendritic filtering, because the passive membrane properties of pNTS interneurons provided favorable voltage-clamp conditions. Also, the slowness of EPSC decay did not result from slow deactivation of AMPA receptors (0.7 ± 0.2 ms, 5 cells), which was investigated during rapid application of agonist to outside-out patches. Comparison of AMPA receptor kinetics with EPSC decay time constants suggested that the slow time course of EPSCs resulted from the prolonged presence of glutamate in the synaptic cleft.

scholarly journals Basal Synaptic Transmission: Astrocytes Rule!

Cell ◽  
2011 ◽  
Vol 146 (5) ◽  
pp. 675-677 ◽  
Author(s):  
Marta Navarrete ◽  
Alfonso Araque
Keyword(s):  
Synaptic Transmission ◽  
Basal Synaptic Transmission

Kainate receptor-mediated synaptic transmissions in the adult rodent insular cortex

2012 ◽  
Vol 108 (7) ◽  
pp. 1988-1998 ◽  
Author(s):  
Kohei Koga ◽  
Su-Eon Sim ◽  
Tao Chen ◽  
Long-Jun Wu ◽  
Bong-Kiun Kaang ◽  
...  
Keyword(s):  
Synaptic Transmission ◽  
Receptor Antagonist ◽  
Ampa Receptor ◽  
Time Course ◽  
Insular Cortex ◽  
Nmda Receptor Antagonist ◽  
Functional Roles ◽  
Adult Rat ◽  
Whole Cell Patch Clamp ◽  
The Central Nervous System

Kainate (KA) receptors are expressed widely in the central nervous system and regulate both excitatory and inhibitory synaptic transmission. KA receptors play important roles in fear memory, anxiety, and pain. However, little is known about their function in synaptic transmission in the insular cortex (IC), a critical region for taste, memory, and pain. Using whole cell patch-clamp recordings, we have shown that KA receptors contribute to fast synaptic transmission in neurons in all layers of the IC. In the presence of the GABAA receptor antagonist picrotoxin, the NMDA receptor antagonist AP-5, and the selective AMPA receptor antagonist GYKI 53655, KA receptor-mediated excitatory postsynaptic currents (KA EPSCs) were revealed. We found that KA EPSCs are ∼5–10% of AMPA/KA EPSCs in all layers of the adult mouse IC. Similar results were found in adult rat IC. KA EPSCs had a significantly slower rise time course and decay time constant compared with AMPA receptor-mediated EPSCs. High-frequency repetitive stimulations at 200 Hz significantly facilitated the summation of KA EPSCs. In addition, genetic deletion of GluK1 or GluK2 subunit partially reduced postsynaptic KA EPSCs, and exposure of GluK2 knockout mice to the selective GluK1 antagonist UBP 302 could significantly reduce the KA EPSCs. These data suggest that both GluK1 and GluK2 play functional roles in the IC. Our study may provide the synaptic basis for the physiology and pathology of KA receptors in the IC-related functions.

Synaptic activation of a presynaptic kainate receptor facilitates AMPA receptor-mediated synaptic transmission at hippocampal mossy fibre synapses.

2001 ◽  
Vol 41 (8) ◽  
pp. 907-915 ◽  
Author(s):  
Sari E. Lauri ◽  
Caroline Delany ◽  
Vernon R. J. Clarke ◽  
Zuner A. Bortolotto ◽  
Paul L. Ornstein ◽  
...  
Keyword(s):  
Synaptic Transmission ◽  
Ampa Receptor ◽  
Kainate Receptor ◽  
Mossy Fibre ◽  
Synaptic Activation

Postnatal aniracetam treatment improves prenatal ethanol induced attenuation of AMPA receptor-mediated synaptic transmission

2007 ◽  
Vol 26 (3) ◽  
pp. 696-706 ◽  
Author(s):  
Nayana Wijayawardhane ◽  
Brian C. Shonesy ◽  
Julia Vaglenova ◽  
Thirumalini Vaithianathan ◽  
Mark Carpenter ◽  
...  
Keyword(s):  
Synaptic Transmission ◽  
Ampa Receptor
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