Different Rho GTPase–dependent signaling pathways initiate sequential steps in the consolidation of long-term potentiation
Open accessAbstract
The releasable factor adenosine blocks the formation of long-term potentiation (LTP). These experiments used this observation to uncover the synaptic processes that stabilize the potentiation effect. Brief adenosine infusion blocked stimulation-induced actin polymerization within dendritic spines along with LTP itself in control rat hippocampal slices but not in those pretreated with the actin filament stabilizer jasplakinolide. Adenosine also blocked activity-driven phosphorylation of synaptic cofilin but not of synaptic p21-activated kinase (PAK). A search for the upstream origins of these effects showed that adenosine suppressed RhoA activity but only modestly affected Rac and Cdc42. A RhoA kinase (ROCK) inhibitor reproduced adenosine's effects on cofilin phosphorylation, spine actin polymerization, and LTP, whereas a Rac inhibitor did not. However, inhibitors of Rac or PAK did prolong LTP's vulnerability to reversal by latrunculin, a toxin which blocks actin filament assembly. Thus, LTP induction initiates two synaptic signaling cascades: one (RhoA-ROCK-cofilin) leads to actin polymerization, whereas the other (Rac-PAK) stabilizes the newly formed filaments.
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Each theta-burst stimulus led to actin filament polymerization in spines, which is important for stabilization of LTP.
“Each theta-burst stimulus led to actin filament polymerization in spines, which is known to be important for the stabilization of LTP49.”
From The right time to learn: Mechanisms and optimization of spaced learning (2016) · cites this paper as [49]
The mechanism underlying this phenomenon involves local spreading of signaling cascades from the activated spine to its neighbors, and some of these spreading signals are potent drivers of F-actin dynamics.
“The mechanism underlying this phenomenon involves local spreading of signaling cascades from the activated spine to its neighbors, and some of these spreading signals are potent drivers of F-actin dynamics (24–26).”
From Synaptic evidence for the efficacy of spaced learning (2012) · cites this paper as [26]
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- Authors
- Rex, C. S., Chen, L. Y., Sharma, A., Liu, J., Babayan, A. H., Gall, C. M., & Lynch, G.
- Affiliations
- University of California, Irvine (US)
- Corresponding author
- Rex, Christopher S.
- Venue
- Journal of Cell Biology
- Publisher
- Rockefeller University Press
- Published
- 2009-07-13
- Volume
- 186
- Issue
- 1
- Pages
- 85-97
- ISSN
- 0021-9525 (ISSN-L)
- 1540-8140
- PMC
- PMC2712993
- OpenAlex
- W2151843908
- Cited by
- 293
- References
- 53
- Citations by year
- 2026: 3 · 2025: 3 · 2024: 16 · 2023: 17 · 2022: 12 · 2021: 14 · 2020: 11 · 2019: 13 · 2018: 11 · 2017: 19 · 2016: 19 · 2015: 20 · 2014: 37 · 2013: 30 · 2012: 24
- FWCI
- 9.40
- Type
- journal article
- Language
- en
- Open access
- hybrid
- doi.org
- Licence
- cc-by-nc-sa
- Locations
- The Journal of Cell Biology (publishedVersion, cc-by-nc-sa)
- PubMed Central (publishedVersion, cc-by-nc-sa)
- PubMed (publishedVersion)
- eScholarship (California Digital Library) (submittedVersion, cc-by)
- Funders
- National Institute of Mental Health (MH083396, F31MH083396)
- National Institute of Neurological Disorders and Stroke (P01NS045260, NS 37799, NS-45260, NS 045540, R01NS037799, T32NS045540)
- Topics
- Life Sciences › Neuroscience › Cellular and Molecular Neuroscience › Neuroscience and Neuropharmacology Research
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Protein Kinase Regulation and GTPase Signaling
- Life Sciences › Neuroscience › Cognitive Neuroscience › Memory and Neural Mechanisms
- Keywords
- long-term potentiation, adenosine, RhoA, Rho kinase, cofilin phosphorylation, Rac, p21-activated kinase, actin polymerization, dendritic spines, hippocampus, actin filament stabilization, latrunculin, jasplakinolide
- MeSH terms
- Actins, Adenosine, Animals, Fluorescent Antibody Technique, Male, Actin Cytoskeleton, Models, Biological, Phosphorylation, Time Factors, Signal Transduction, Rats, Sprague-Dawley, Long-Term Potentiation, rho GTP-Binding Proteins, rhoA GTP-Binding Protein, rac1 GTP-Binding Protein, Dendritic Spines, Actin Depolymerizing Factors, Rats, p21-Activated Kinases
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