scholarly journals Postsynaptic Density 95 controls AMPA Receptor Incorporation during Long-Term Potentiation and Experience-Driven Synaptic Plasticity

2004 ◽  
Vol 24 (4) ◽  
pp. 916-927 ◽  
Author(s):  
I. Ehrlich
Proteomes ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 40 ◽  
Author(s):  
Joongkyu Park

Synaptic plasticity has been considered a key mechanism underlying many brain functions including learning, memory, and drug addiction. An increase or decrease in synaptic activity of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) complex mediates the phenomena as shown in the cellular models of synaptic plasticity, long-term potentiation (LTP), and depression (LTD). In particular, protein phosphorylation shares the spotlight in expressing the synaptic plasticity. This review summarizes the studies on phosphorylation of the AMPAR pore-forming subunits and auxiliary proteins including transmembrane AMPA receptor regulatory proteins (TARPs) and discusses its role in synaptic plasticity.


2003 ◽  
Vol 358 (1432) ◽  
pp. 715-720 ◽  
Author(s):  
Fabrice Duprat ◽  
Michael Daw ◽  
Wonil Lim ◽  
Graham Collingridge ◽  
John Isaac

AMPA-type glutamate receptors mediate most fast excitatory synaptic transmissions in the mammalian brain. They are critically involved in the expression of long-term potentiation and long-term depression, forms of synaptic plasticity that are thought to underlie learning and memory. A number of synaptic proteins have been identified that interact with the intracellular C-termini of AMPA receptor subunits. Here, we review recent studies and present new experimental data on the roles of these interacting proteins in regulating the AMPA receptor function during basal synaptic transmission and plasticity.


2019 ◽  
Author(s):  
Mason L. Yeh ◽  
Jessica R. Yasko ◽  
Eric S. Levine ◽  
Betty A. Eipper ◽  
Richard E. Mains

AbstractKalirin-7 (Kal7) is a Rac1/RhoG GEF and multidomain scaffold localized to the postsynaptic density which plays an important role in synaptic plasticity. Behavioral and physiological phenotypes observed in the Kal7 knockout mouse are quite specific: genetics of breeding, growth, strength and coordination are normal; Kal7 knockout animals self-administer cocaine far more than normal mice, show exaggerated locomotor responses to cocaine, but lack changes in dendritic spine morphology seen in wildtype mice; Kal7 knockout mice have depressed surface expression of GluN2B receptor subunits and exhibit marked suppression of long-term potentiation and depression in hippocampus, cerebral cortex, and spinal cord; and Kal7 knockout mice have dramatically blunted perception of pain. To address the underlying cellular and molecular mechanisms which are deranged by loss of Kal7, we administered intracellular blocking peptides to acutely change Kal7 function at the synapse, to determine if plasticity deficits in Kal7-/-mice are the product of developmental processes since conception, or could be detected on a much shorter time scale. We found that specific disruption of the interactions of Kal7 with PSD-95 or GluN2B resulted in significant suppression of long-term potentiation and long-term depression. Biochemical approaches indicated that Kal7 interacted with PSD-95 at multiple sites within Kal7.Graphical Table of ContentsThe postsynaptic density is an integral player in receiving, interpreting and storing signals transmitted by presynaptic terminals. The correct molecular composition is crucial for successful expression of synaptic plasticity. Key components of the postsynaptic density include ligand-gated ion channels, structural and binding proteins, and multidomain scaffolding plus enzymatic proteins. These studies address whether the multiple components of the synaptic density bind together in a static or slowly adapting molecular complex, or whether critical interactions are fluid on a minute-to-minute basis.


2019 ◽  
Author(s):  
Xiaojun Yu ◽  
Wei Li ◽  
Tong Wang

AbstractNMDA receptors (NMDAR) are key players in the initiation of synaptic plasticity that underlies learning and memory. Long-term potentiation (LTP) of synapses require an increased calcium current via NMDA channels to trigger modifications in postsynaptic density (PSD). It is generally believed that the amount of NMDARs on the postsynaptic surface remains stationary, whereas their subunit composition is dynamically fluctuated during this plasticity process. However, the molecular machinery underlying this subunit-specific regulation remains largely elusive. Here, by detecting the time-lapse changes of surface GluN2A and GluN2B subunit levels using biochemical approaches, surface immunostaining, live-imaging and super-resolution microscopy, we uncovered a transient increase of surface GluN2A-type NMDARs shortly after the induction of chemical long term potentiation (cLTP). These augmented sub-diffraction-limited GluN2A clusters predominantly exist in extrasynaptic domains. We also showed that the spine-enriched SNARE associated protein SNAP-23, and to a minor extent its homologue SNAP-25, control both the basal and regulated surface level of GluN2A receptors. Using a total internal reflection fluorescence microscopy (TIRFM) based live-imaging assay, we resolved and analyzed individual exocytic events of NMDARs in live neurons and found that cLTP raised the frequency of NMDAR exocytosis at extrasynaptic regions, without altering the duration or the package size of these events. Our study thereby provides direct evidence that synaptic plasticity controls the postsynaptic exocytosis machinery, which induces the insertion of more GluN2A receptors into the extrasynaptic area.Significance StatementMemory formation involves the long-term modification of synapses, which is called synaptic plasticity. In the postsynaptic density (PSD) of excited neurons, this modification process occurs on a minute timescale, initiated by the opening of NMDARs that trigger downstream cascades to fix the potentiation (LTP) at specific synapses for longer timescales. Here, using a novel live-imaging assay we resolved the dynamic delivery of NMDARs to the cell surface, and found that only the insertion frequency, not the duration of individual insertion or number of GluN2A subunits each of these NMDAR vesicles contains, was altered during the synaptic potentiation process. We also identified SNAP-23 as the key molecule mediating this activity dependent NMDAR surface delivery. This study provides a novel mechanism of how NMDARs are regulated in the short window to initiate the long-lasting synaptic modifications.


2020 ◽  
Vol 17 (4) ◽  
pp. 354-360 ◽  
Author(s):  
Yu-Xing Ge ◽  
Ying-Ying Lin ◽  
Qian-Qian Bi ◽  
Yu-Juan Chen

Background: Patients with temporal lobe epilepsy (TLE) usually suffer from cognitive deficits and recurrent seizures. Brivaracetam (BRV) is a novel anti-epileptic drug (AEDs) recently used for the treatment of partial seizures with or without secondary generalization. Different from other AEDs, BRV has some favorable properties on synaptic plasticity. However, the underlying mechanisms remain elusive. Objective: The aim of this study was to explore the neuroprotective mechanism of BRV on synaptic plasticity in experimental TLE rats. Methods: The effect of chronic treatment with BRV (10 mg/kg) was assessed on Pilocarpine induced TLE model through measurement of the field excitatory postsynaptic potentials (fEPSPs) in vivo. Differentially expressed synaptic vesicle protein 2A (SV2A) were identified with immunoblot. Then, fast phosphorylation of synaptosomal-associated protein 25 (SNAP-25) during long-term potentiation (LTP) induction was performed to investigate the potential roles of BRV on synaptic plasticity in the TLE model. Results: An increased level of SV2A accompanied by a depressed LTP in the hippocampus was shown in epileptic rats. Furthermore, BRV treatment continued for more than 30 days improved the over-expression of SV2A and reversed the synaptic dysfunction in epileptic rats. Additionally, BRV treatment alleviates the abnormal SNAP-25 phosphorylation at Ser187 during LTP induction in epileptic ones, which is relevant to the modulation of synaptic vesicles exocytosis and voltagegated calcium channels. Conclusion: BRV treatment ameliorated the over-expression of SV2A in the hippocampus and rescued the synaptic dysfunction in epileptic rats. These results identify the neuroprotective effect of BRV on TLE model.


2006 ◽  
Vol 16 ◽  
pp. S52
Author(s):  
S. Salomon ◽  
Y. Nachum-Biala ◽  
Y. Bogush ◽  
M. Lineal ◽  
H. Matzner ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yire Jeong ◽  
Hye-Yeon Cho ◽  
Mujun Kim ◽  
Jung-Pyo Oh ◽  
Min Soo Kang ◽  
...  

AbstractMemory is supported by a specific collection of neurons distributed in broad brain areas, an engram. Despite recent advances in identifying an engram, how the engram is created during memory formation remains elusive. To explore the relation between a specific pattern of input activity and memory allocation, here we target a sparse subset of neurons in the auditory cortex and thalamus. The synaptic inputs from these neurons to the lateral amygdala (LA) are not potentiated by fear conditioning. Using an optogenetic priming stimulus, we manipulate these synapses to be potentiated by the learning. In this condition, fear memory is preferentially encoded in the manipulated cell ensembles. This change, however, is abolished with optical long-term depression (LTD) delivered shortly after training. Conversely, delivering optical long-term potentiation (LTP) alone shortly after fear conditioning is sufficient to induce the preferential memory encoding. These results suggest a synaptic plasticity-dependent competition rule underlying memory formation.


eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Javier Díaz-Alonso ◽  
Wade Morishita ◽  
Salvatore Incontro ◽  
Jeffrey Simms ◽  
Julia Holtzman ◽  
...  

We tested the proposal that the C-terminal domain (CTD) of the AMPAR subunit GluA1 is required for LTP. We found that a knock-in mouse lacking the CTD of GluA1 expresses normal LTP and spatial memory, assayed by the Morris water maze. Our results support a model in which LTP generates synaptic slots, which capture passively diffusing AMPARs.


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