scholarly journals PIP3 Regulates Spinule Formation in Dendritic Spines during Structural Long-Term Potentiation

2013 ◽  
Vol 33 (27) ◽  
pp. 11040-11047 ◽  
Author(s):  
Y. Ueda ◽  
Y. Hayashi
PLoS ONE ◽  
2009 ◽  
Vol 4 (6) ◽  
pp. e6021 ◽  
Author(s):  
Amadou T. Corera ◽  
Guy Doucet ◽  
Edward A. Fon

2019 ◽  
Vol 400 (9) ◽  
pp. 1129-1139 ◽  
Author(s):  
Iryna Hlushchenko ◽  
Pirta Hotulainen

Abstract Synaptic plasticity underlies central brain functions, such as learning. Ca2+ signaling is involved in both strengthening and weakening of synapses, but it is still unclear how one signal molecule can induce two opposite outcomes. By identifying molecules, which can distinguish between signaling leading to weakening or strengthening, we can improve our understanding of how synaptic plasticity is regulated. Here, we tested gelsolin’s response to the induction of chemical long-term potentiation (cLTP) or long-term depression (cLTD) in cultured rat hippocampal neurons. We show that gelsolin relocates from the dendritic shaft to dendritic spines upon cLTD induction while it did not show any relocalization upon cLTP induction. Dendritic spines are small actin-rich protrusions on dendrites, where LTD/LTP-responsive excitatory synapses are located. We propose that the LTD-induced modest – but relatively long-lasting – elevation of Ca2+ concentration increases the affinity of gelsolin to F-actin. As F-actin is enriched in dendritic spines, it is probable that increased affinity to F-actin induces the relocalization of gelsolin.


Nature ◽  
2004 ◽  
Vol 429 (6993) ◽  
pp. 761-766 ◽  
Author(s):  
Masanori Matsuzaki ◽  
Naoki Honkura ◽  
Graham C. R. Ellis-Davies ◽  
Haruo Kasai

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Joshua J. W. Paulin ◽  
Peter Haslehurst ◽  
Alexander D. Fellows ◽  
Wenfei Liu ◽  
Joshua D. Jackson ◽  
...  

The laying down of memory requires strong stimulation resulting in specific changes in synaptic strength and corresponding changes in size of dendritic spines. Strong stimuli can also be pathological, causing a homeostatic response, depressing and shrinking the synapse to prevent damage from too much Ca2+influx. But do all types of dendritic spines serve both of these apparently opposite functions? Using confocal microscopy in organotypic slices from mice expressing green fluorescent protein in hippocampal neurones, the size of individual spines along sections of dendrite has been tracked in response to application of tetraethylammonium. This strong stimulus would be expected to cause both a protective homeostatic response and long-term potentiation. We report separation of these functions, with spines of different sizes reacting differently to the same strong stimulus. The immediate shrinkage of large spines suggests a homeostatic protective response during the period of potential danger. In CA1, long-lasting growth of small spines subsequently occurs consolidating long-term potentiation but only after the large spines return to their original size. In contrast, small spines do not change in dentate gyrus where potentiation does not occur. The separation in time of these changes allows clear functional differentiation of spines of different sizes.


PLoS ONE ◽  
2014 ◽  
Vol 9 (1) ◽  
pp. e85367 ◽  
Author(s):  
Toshiyuki Mizui ◽  
Yuko Sekino ◽  
Hiroyuki Yamazaki ◽  
Yuta Ishizuka ◽  
Hideto Takahashi ◽  
...  

2020 ◽  
Author(s):  
Paul G Donlin-Asp ◽  
Claudio Polisseni ◽  
Robin Klimek ◽  
Alexander Heckel ◽  
Erin M Schuman

AbstractDecades of work have demonstrated that mRNAs are localized and translated within neuronal dendrites and axons to provide proteins for remodeling and maintaining growth cones or synapses. It remains unknown, however, whether specific forms of plasticity differentially regulate the dynamics and translation of individual mRNA species. To address these issues, we targeted three individual synaptically-localized mRNAs, CamkIIa, Beta actin, Psd95, and used molecular beacons to track endogenous mRNA movements and reporters and Crispr-Cas9 gene editing to track their translation. We found widespread alterations in mRNA behavior during two forms of synaptic plasticity, long-term potentiation (LTP) and depression (LTD). Changes in mRNA dynamics following plasticity resulted in an enrichment of mRNA in the vicinity of dendritic spines. Both the reporters and tagging of endogenous proteins revealed the transcript-specific stimulation of protein synthesis following LTP or LTD. The plasticity-induced enrichment of mRNA near synapses could be uncoupled from its translational status. The enrichment of mRNA in the proximity of spines allows for localized signaling pathways to decode plasticity milieus and stimulate a specific translational profile, resulting in a customized remodeling of the synaptic proteome.


2018 ◽  
Author(s):  
Gaurang Mahajan ◽  
Suhita Nadkarni

ABSTRACTLong-term plasticity mediated by NMDA receptors supports input-specific, Hebbian forms of learning at excitatory CA3-CA1 connections in the hippocampus. An additional layer of stabilizing mechanisms that act globally as well as locally over multiple time scales may be in place to ensure that plasticity occurs in a constrained manner. Here, we investigate the potential role of calcium (Ca2+) stores associated with the endoplasmic reticulum (ER) in the local regulation of plasticity dynamics at individual CA1 synapses. Our study is spurred by (1) the curious observation that ER is sparsely distributed in dendritic spines, but over-represented in large spines that are likely to have undergone activity-dependent strengthening, and (2) evidence suggesting that ER motility within synapses can be rapid, and accompany activity-regulated spine remodeling. Based on a physiologically realistic computational model for ER-bearing CA1 spines, we characterize the contribution of IP3-sensitive Ca2+ stores to spine Ca2+ dynamics during activity patterns mimicking the induction of long-term potentiation (LTP) and depression (LTD). Our results suggest graded modulation of the NMDA receptor-dependent plasticity profile by ER, which selectively enhances LTD induction. We propose that spine ER can locally tune Ca2+-based plasticity on an as-needed basis, providing a braking mechanism to mitigate runaway strengthening at potentiated synapses. Our model suggests that the presence of ER in the CA1 spine may promote re-use of synapses with saturated strengths.


2020 ◽  
Author(s):  
Yanrui Yang ◽  
Jiang Chen ◽  
Xue Chen ◽  
Di Li ◽  
Jianfeng He ◽  
...  

AbstractDendritic spines of excitatory neurons undergo activity-dependent structural and functional plasticity, which are cellular correlates of learning and memory. However, mechanisms underlying the rapid morphological changes immediately after NMDAR-mediated Ca2+ influx into spines remain poorly understood. Here we report that endophilin A1, a neuronal N-BAR protein, orchestrates membrane dynamics with actin polymerization to initiate spine enlargement in the induction phase of long-term potentiation (LTP). Upon LTP induction, Ca2+/calmodulin enhances its binding to both membrane and p140Cap, a cytoskeleton regulator. As a result, endophilin A1 rapidly associates with the relaxed plasma membrane and promotes actin polymerization, leading to acute expansion of spine head. Moreover, not only the p140Cap-binding, but also calmodulin- and membrane-binding capacities of endophilin A1 are required for LTP and long-term memory. Thus, endophilin A1 functions as calmodulin effector to drive spine enlargement in response to Ca2+ influx in the initial phase of structural plasticity.


2021 ◽  
Vol 220 (6) ◽  
Author(s):  
Yanrui Yang ◽  
Jiang Chen ◽  
Xue Chen ◽  
Di Li ◽  
Jianfeng He ◽  
...  

Induction of long-term potentiation (LTP) in excitatory neurons triggers a large transient increase in the volume of dendritic spines followed by decays to sustained size expansion, a process termed structural LTP (sLTP) that contributes to the cellular basis of learning and memory. Although mechanisms regulating the early and sustained phases of sLTP have been studied intensively, how the acute spine enlargement immediately after LTP stimulation is achieved remains elusive. Here, we report that endophilin A1 orchestrates membrane dynamics with actin polymerization to initiate spine enlargement in NMDAR-mediated LTP. Upon LTP induction, Ca2+/calmodulin enhances binding of endophilin A1 to both membrane and p140Cap, a cytoskeletal regulator. Consequently, endophilin A1 rapidly localizes to the plasma membrane and recruits p140Cap to promote local actin polymerization, leading to spine head expansion. Moreover, its molecular functions in activity-induced rapid spine growth are required for LTP and long-term memory. Thus, endophilin A1 serves as a calmodulin effector to drive acute structural plasticity necessary for learning and memory.


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