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Cited by 565Neuroscience and Neuropharmacology ResearchProtein Kinase Regulation and GTPase SignalingMemory and Neural Mechanisms

Local, persistent activation of Rho GTPases during plasticity of single dendritic spines

Open access
Murakoshi, Hideji, Wang, Hong, Yasuda, Ryohei·2011·Nature
DOI 10.1038/nature09823PMC PMC3105377
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Abstract

The Rho family of GTPases have important roles in the morphogenesis of the dendritic spines of neurons in the brain and synaptic plasticity by modulating the organization of the actin cytoskeleton. Here we used two-photon fluorescence lifetime imaging microscopy to monitor the activity of two Rho GTPases-RhoA and Cdc42-in single dendritic spines undergoing structural plasticity associated with long-term potentiation in CA1 pyramidal neurons in cultured slices of rat hippocampus. When long-term volume increase was induced in a single spine using two-photon glutamate uncaging, RhoA and Cdc42 were rapidly activated in the stimulated spine. These activities decayed over about five minutes, and were then followed by a phase of persistent activation lasting more than half an hour. Although active RhoA and Cdc42 were similarly mobile, their activity patterns were different. RhoA activation diffused out of the stimulated spine and spread over about 5 µm along the dendrite. In contrast, Cdc42 activation was restricted to the stimulated spine, and exhibited a steep gradient at the spine necks. Inhibition of the Rho-Rock pathway preferentially inhibited the initial spine growth, whereas the inhibition of the Cdc42-Pak pathway blocked the maintenance of sustained structural plasticity. RhoA and Cdc42 activation depended on Ca(2+)/calmodulin-dependent kinase (CaMKII). Thus, RhoA and Cdc42 relay transient CaMKII activation to synapse-specific, long-term signalling required for spine structural plasticity.

AI snapshot

Written from the paper’s full text.

TL;DR

Using 2pFLIM in single dendritic spines, this study shows that RhoA and Cdc42 are rapidly activated after glutamate uncaging, decay over ~5 min, and then remain active for more than 30 min during LTP-associated structural plasticity. RhoA activity spreads along dendrites, whereas Cdc42 activity stays spine-restricted, and the two GTPases support distinct phases of spine enlargement through Rho-Rock and Cdc42-Pak signaling downstream of CaMKII.

Key findings

  • In stimulated spines, RhoA and Cdc42 activated within ~30 s, decayed over ~5 min, and showed persistent activity lasting more than 30 min; spine volume rose by ~300% transiently and relaxed to a sustained 70–80% increase for >30 min.
  • RhoA activation spread into dendrites with a length constant of 4.5 μm and invaded ~25% of surrounding spines, while Cdc42 activation was restricted to the stimulated spine with a dendritic length constant of ~1.9 μm.
  • AP5 abolished RhoA/Cdc42 activation and spine enlargement; KN62 and AIP2 inhibited activation more strongly in the sustained phase, indicating CaMKII dependence.
  • Rho/Rock inhibition suppressed both transient and sustained volume changes, whereas Cdc42/Pak inhibition selectively decreased the sustained phase, suggesting distinct roles in spine structural plasticity.

Methods

  • Cultured hippocampal slices from postnatal day 6–7 rats; CA1 pyramidal neurons were ballistically transfected with RhoA or Cdc42 FRET sensors at days in vitro 10–14 and imaged 2–4 days later.
  • Rho GTPase activity was measured with 2-photon fluorescence lifetime imaging microscopy (2pFLIM), and spine volume was monitored from mCherry-RBD-mCherry fluorescence; structural plasticity was induced by 30 two-photon glutamate uncaging pulses at 0.5 Hz in zero extracellular Mg2+.
  • Pharmacological inhibitors, shRNA knockdown, rescue constructs, and photoactivatable GFP diffusion measurements were used; most imaging was at room temperature (25–27°C), with similar results also obtained at 32–34°C.

Limitations

  • The paper notes that shRNA-mediated protein downregulation is partial and requires relatively long expression (4 days), and that most imaging experiments were performed at room temperature, although near-physiological temperature gave similar results.
  • Evident from the text: experiments use cultured hippocampal slices and sparse transfection/overexpression of FRET sensors, and conclusions from pharmacological inhibitors such as AP5, KN62, GH1152, and IPA3 may be limited by potential off-target effects.
  • The paper does not include a dedicated limitations section beyond these points.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1038/nature09823

Cites

43 of 43 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

16 of 28 cited sources checked · 8 supported · 0 flagged · accuracy not yet measured

  • Interpretationreasoning

    RhoA and Cdc42 relay transient CaMKII activation to synapse-specific, long-term signalling required for spine structural plasticity.

    “Thus, RhoA and Cdc42 relay transient CaMKII activation13 to synapse-specific, long-term signalling required for spine structural plasticity.”
    • Also stated in: § Abstract · plain
      “Localized, persistent activation of RhoA and Cdc42, which peaks in between CaMKII activation and the volume change (Fig. 4l), relays the transient CaMKII signalling13 to long-term spine structural plasticity (Fig. 4k).”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites [13] Lee, S. J., Escobedo-Lozoya, Y., Szatmari, E. M. & Yasuda, R. Activation of CaMKII in single dendritic spines during long-term potentiation. Nature 458, 299–304 (2009) source
    • Rests on an assumption: Long-lasting, spine-specific plasticity requires signalling pathways that relay compartmentalized signalling on the time scale of minutes to hours.
  • Findingown data

    The length constant of RhoA activity spread along the dendrite was 4.5 μm.

    “The length constant of spread along the dendrite was 4.5 μm (Fig. 3a, b), a value similar to that for HRas (~10 μm)12.”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites [12] Harvey, C. D., Yasuda, R., Zhong, H. & Svoboda, K. The spread of Ras activity triggered by activation of a single dendritic spine. Science 321, 136–140 (2008) source
  • Findingown data

    When long-term volume increase was induced in a single spine using 2-photon glutamate uncaging, RhoA and Cdc42 were rapidly activated in the stimulated spine.

    “When long-term volume increase was induced in a single spine using 2-photon glutamate uncaging14,15, RhoA and Cdc42 were rapidly activated in the stimulated spine.”
    • Also stated in: § Abstract · plain
      “When spine structural plasticity was induced, both RhoA (Fig. 1a, b) and Cdc42 (Fig. 2a, b) were activated rapidly within ~30 s in the stimulated spines.”
    Quote in the paperSubstantial claim1 of 2 sources checked
    • cites [14] Matsuzaki, M., Honkura, N., Ellis-Davies, G. C. & Kasai, H. Structural basis of long-term potentiation in single dendritic spines. Nature 429, 761–766 (2004) source
    • cites [15] Honkura, N., Matsuzaki, M., Noguchi, J., Ellis-Davies, G. C. & Kasai, H. The subspine organization of actin fibers regulates the structure and plasticity of dendritic spines. Neuron 57, 719–729 (2008) source
  • Interpretationreasoning

    The NMDA receptor-CaMKII-Cdc42-Pak pathway constitutes the spine-specific signal transduction spanning the time scale from sub-second to more than 30 min to cause sustained structural and functional spine plasticity.

    “the NMDA receptor-CaMKII-Cdc42-Pak pathway (red line in Fig. 4k) constitutes the spine specific signal transduction spanning the time scale from sub-second to more than 30 min to cause sustained structural and functional spine plasticity”
    Quote in the paperSubstantial claim1 of 2 sources checked
    • cites [13] Lee, S. J., Escobedo-Lozoya, Y., Szatmari, E. M. & Yasuda, R. Activation of CaMKII in single dendritic spines during long-term potentiation. Nature 458, 299–304 (2009) source

      The section ‘CaMKII activation during structural plasticity of dendritic spines’ (page unavailable) reports NMDA-receptor-dependent, spine-restricted CaMKII activation and spine enlargement lasting more than 30 minutes. It does not establish a Cdc42–Pak pathway, a sub-second-to-30-minute signaling cascade, or that this pathway causes sustained functional as well as structural plasticity. (LLM, conf=0.88)

      Experimental — accuracy not yet measured
    • cites [14] Matsuzaki, M., Honkura, N., Ellis-Davies, G. C. & Kasai, H. Structural basis of long-term potentiation in single dendritic spines. Nature 429, 761–766 (2004) source
    • Rests on an assumption: Long-lasting, spine-specific plasticity requires signalling pathways that relay compartmentalized signalling on the time scale of minutes to hours.
  • Interpretationcitation

    Cdc42 activation showed a spatial pattern similar to that of CaMKII.

    “In contrast, Cdc42 activation was restricted to the stimulated spines (Fig. 3c, d), showing a spatial pattern similar to that of CaMKII13.”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [13] Lee, S. J., Escobedo-Lozoya, Y., Szatmari, E. M. & Yasuda, R. Activation of CaMKII in single dendritic spines during long-term potentiation. Nature 458, 299–304 (2009) source
  • Classified as probably not a substantial claim. 2
  • May combine two claims. 22

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    Rock and Pak are two kinases that can be activated respectively by Rho and Cdc42.

    “Amongst known effectors of Rho and Cdc42, Rock and Pak are two kinases that can be activated repsectively by these GTPases24–26.”
    Quote in the paperSubstantial claim1 of 3 sources checked
    • cites [24] Nikolić, M. The Pak1 kinase: an important regulator of neuronal morphology and function in the developing forebrain. Mol. Neurobiol. 37, 187–202 (2008) source
    • cites [25] Kreis, P. et al. The p21-activated kinase 3 implicated in mental retardation regulates spine morphogenesis through a Cdc42-dependent pathway. J. Biol. Chem. 282, 21497–21506 (2007) source

      The section “R67C Mutation Impairs Kinase Activation by Cdc42” reports that PAK3 is activated by the intersectin–Cdc42 module, supporting the Pak–Cdc42 part of the claim. The passages found in our copy do not establish that ROCK is activated by Rho (searched: “ROCK” and “ROCK Rho kinase activated by Rho”). (LLM, conf=0.85)

      Experimental — accuracy not yet measured
    • cites [26] Iden, S. & Collard, J. G. Crosstalk between small GTPases and polarity proteins in cell polarization. Nature Rev. Mol. Cell Biol. 9, 846–859 (2008) source

  • May combine two claims.

    Findingown data

    The paGFP-Rho GTPase decay time constants were ~10 times larger than that of cytosolic paGFP (~0.4 s) and similar to that of a constitutively active HRas mutant (~6 s).

    “These values are ~10 times larger than the decay time constant of cytosolic paGFP (~0.4 s) and similar to that of a constitutively active HRas mutant (~6 s) (Fig. 3e–h)12.”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites [12] Harvey, C. D., Yasuda, R., Zhong, H. & Svoboda, K. The spread of Ras activity triggered by activation of a single dendritic spine. Science 321, 136–140 (2008) source

      The mobility results (p. 2) report that paGFP-Ras decayed more than ten times slower than cytosolic paGFP and that constitutively active Ras G12V diffused similarly to wild-type Ras. Figure 3B’s caption (p. 8) identifies the cytosolic and Ras G12V comparisons, but our copy does not give the cited numerical estimates of ~0.4 s and ~6 s. The Rho GTPase values appear to be the citing authors’ own results, not a finding attributed to this source. (LLM, conf=0.83)

      Experimental — accuracy not yet measured

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    HRas activity spreads from stimulated spines along dendrites and into surrounding spines over ~10 μm.

    “In contrast, HRas activity spreads from the stimulated spines along dendrites and into surrounding spines over ~10 μm12.”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [12] Harvey, C. D., Yasuda, R., Zhong, H. & Svoboda, K. The spread of Ras activity triggered by activation of a single dendritic spine. Science 321, 136–140 (2008) source

  • May combine two claims.

    Premisecitation

    CaMKII activation is restricted to spines and decays rapidly with a time constant of ~10 s.

    “CaMKII activation is restricted to spines, and decays rapidly with a time constant of ~10 s13.”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites [13] Lee, S. J., Escobedo-Lozoya, Y., Szatmari, E. M. & Yasuda, R. Activation of CaMKII in single dendritic spines during long-term potentiation. Nature 458, 299–304 (2009) source

      The Discussion says CaMKII activation is largely restricted to the stimulated spine during LTP. However, the Mechanisms of spine specific CaMKII activation section reports two inactivation time constants, 6 and 45 s, rather than a single time constant of approximately 10 s. The claim captures rapid, spine-specific activation but oversimplifies its decay kinetics. (LLM, conf=0.88)

      Experimental — accuracy not yet measured

  • May combine two claims.

    Interpretationown data

    C3 and Wasp inhibited synaptic potentiation induced by pairing postsynaptic depolarization (0 mV) and 2-photon glutamate uncaging, suggesting Rho and Cdc42 are important for functional plasticity as well as structural plasticity of spines.

    “C3 and Wasp also inhibited synaptic potentiation induced by pairing postsynaptic depolarization (0 mV) and 2-photon glutamate uncaging (Supplementary Fig. 10)13,14, suggesting that Rho and Cdc42 are important for the functional plasticity as well as the structural plasticity of spines.”
    Quote in the paperSubstantial claim1 of 2 sources checked
    • cites [13] Lee, S. J., Escobedo-Lozoya, Y., Szatmari, E. M. & Yasuda, R. Activation of CaMKII in single dendritic spines during long-term potentiation. Nature 458, 299–304 (2009) source

      The section “CaMKII activation during pairing-induced LTP” (page unavailable) reports synaptic potentiation induced by pairing 0 mV postsynaptic depolarization with two-photon glutamate uncaging. Our copy does not report that C3 or Wasp inhibited this potentiation, or draw the claimed conclusion about Rho and Cdc42. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
    • cites [14] Matsuzaki, M., Honkura, N., Ellis-Davies, G. C. & Kasai, H. Structural basis of long-term potentiation in single dendritic spines. Nature 429, 761–766 (2004) source

  • May combine two claims.

    Findingown data

    Inhibition of Pak with IPA3 decreased the sustained volume change selectively without changing the transient volume change, similarly to inhibition of Cdc42 signalling.

    “In contrast, inhibition of Pak with IPA3 (100 μM)28 decreased the sustained volume change selectively without changing the transient volume change (Fig. 4h, i, j) similarly to inhibition of Cdc42 signalling (Fig. 4e, g).”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites [28] Deacon, S. W. et al. An isoform-selective, small-molecule inhibitor targets the autoregulatory mechanism of p21-activated kinase. Chem. Biol. 15, 322–331 (2008) source

  • May combine two claims.

    Findingown data

    The spine volume increased rapidly by ~300% following glutamate uncaging (transient phase) and relaxed to an elevated level of 70-80% for more than 30 min (sustained phase).

    “The spine volume increased rapidly by ~300% following glutamate uncaging (transient phase) and relaxed to an elevated level of 70–80% for more than 30 min (sustained phase) (Figs. 1d, 2d)12–14.”
    Quote in the paperSubstantial claim2 of 3 sources checked
    • cites [12] Harvey, C. D., Yasuda, R., Zhong, H. & Svoboda, K. The spread of Ras activity triggered by activation of a single dendritic spine. Science 321, 136–140 (2008) source

      The paper reports that glutamate uncaging caused sustained enlargement of the stimulated spine (p. 1). Its Figure 1 caption (p. 6) describes spine-volume measurements, but the text does not give a rapid ~300% increase or a sustained 70–80% increase for more than 30 minutes; it defines the sustained measurement at 15.5–19.5 minutes. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
    • cites [13] Lee, S. J., Escobedo-Lozoya, Y., Szatmari, E. M. & Yasuda, R. Activation of CaMKII in single dendritic spines during long-term potentiation. Nature 458, 299–304 (2009) source

      The section “CaMKII activation during structural plasticity of dendritic spines” (page not provided) supports a rapid increase after glutamate uncaging followed by enlargement lasting more than 30 minutes. It reports 376 ± 68% initially and 104 ± 21% afterward, rather than the claimed ~300% and 70–80%. (LLM, conf=0.88)

      Experimental — accuracy not yet measured
    • cites [14] Matsuzaki, M., Honkura, N., Ellis-Davies, G. C. & Kasai, H. Structural basis of long-term potentiation in single dendritic spines. Nature 429, 761–766 (2004) source

  • May combine two claims.

    Premisecitation

    Rho GTPases play important roles in regulating the actin cytoskeleton, which is essential for spine-specific, long-term structural and functional plasticity.

    “Rho GTPases may constitute such signalling, because they play important roles in regulating actin cytoskeleton3,16, which is essential for spine-specific, long-term structural and functional plasticity14,17.”
    Quote in the paperSubstantial claim1 of 4 sources checked
    • cites [3] Saneyoshi, T., Fortin, D. A. & Soderling, T. R. Regulation of spine and synapse formation by activity-dependent intracellular signaling pathways. Curr. Opin. Neurobiol. 20, 108–115 (2009) source
    • cites [16] Heasman, S. J. & Ridley, A. J. Mammalian Rho GTPases: new insights into their functions from in vivo studies. Nature Rev. Mol. Cell Biol. 9, 690–701 (2008) source
    • cites [14] Matsuzaki, M., Honkura, N., Ellis-Davies, G. C. & Kasai, H. Structural basis of long-term potentiation in single dendritic spines. Nature 429, 761–766 (2004) source
    • cites [17] Okamoto, K., Nagai, T., Miyawaki, A. & Hayashi, Y. Rapid and persistent modulation of actin dynamics regulates postsynaptic reorganization underlying bidirectional plasticity. Nature Neurosci. 7, 1104–1112 (2004) source

  • May combine two claims.

    Interpretationreasoning

    The inactivation time constant is ~6 s for Cdc42 and ~30 s for RhoA, compared to 200-300 s for HRas.

    “The short length constant of Cdc42 in the dendrites (1.9 μm, Fig. 3) also supports the fast inactivation of Cdc42 in the dendrite: the inactivation time constant τ is related to the length constant L and the diffusion constant D~0.6 μm2 (Ref 12) as τ = L2/D, and thus is ~6 s for Cdc42 and ~30 s for RhoA, compared to 200–300 s for HRas12.”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites [12] Harvey, C. D., Yasuda, R., Zhong, H. & Svoboda, K. The spread of Ras activity triggered by activation of a single dendritic spine. Science 321, 136–140 (2008) source

  • May combine two claims.

    Findingown data

    Cdc42 activation was restricted to the stimulated spine and exhibited a steep gradient at the spine necks.

    “In contrast, Cdc42 activation was restricted to the stimulated spine, and exhibited a steep gradient at the spine necks.”
    • Also stated in: § Abstract · plain
      “In contrast, Cdc42 activation was restricted to the stimulated spines (Fig. 2a–c, 3c, d).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    RhoA and Cdc42 activities decayed over ~5 min and were followed by persistent activation lasting more than 30 min.

    “These activities decayed over ~5 min, and were then followed by a phase of persistent activation lasting more than 30 min.”
    • Also stated in: § Abstract · plain
      “The activation decayed over ~5 min, followed by sustained activity lasting more than 30 min.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    shRNA against Cdc42 decreased the sustained volume change but not the transient volume change.

    “In contrast, shRNA against Cdc42 decreased the sustained volume change, but not the transient volume change (Fig. 4e, i, j).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Downregulation of RhoA and RhoB with shRNA decreased the transient volume change but did not appreciably affect the sustained volume change.

    “Downregulation of RhoA and RhoB with short-hairpin RNA (shRNA) decreased the transient volume change, but did not appreciably affect the sustained volume change (Fig. 4a, i, j).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    Inhibition of the Rho-Rock pathway preferentially inhibited the initial spine growth, whereas inhibition of the Cdc42-Pak pathway blocked the maintenance of sustained structural plasticity.

    “Inhibition of the Rho-Rock pathway preferentially inhibited the initial spine growth, whereas the inhibition of the Cdc42-Pak pathway blocked the maintenance of sustained structural plasticity.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    There was only a small fraction (10-20%) of fluorescence remaining at 20 s after photoactivation, suggesting no major immobile fraction of RhoA or Cdc42 exists in spines.

    “There was only a small fraction (10–20 %) of fluorescence remaining at 20 s after photoactivation (Fig. 3e–h), suggesting that no major immobile fraction of RhoA or Cdc42 exists in spines.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Study design and conductown data

    The phenotypes caused by the shRNAs were rescued by co-expressing shRNA-resistant mEGFP-Rho GTPases, indicating the shRNA effects are specific and the mEGFP-RhoA and mEGFP-Cdc42 used in the FRET sensors are functional as endogenous proteins.

    “The phenotypes caused by these shRNAs were rescued by co-expressing shRNA-resistant mEGFP-Rho GTPases (Fig. 4b, f, i, j), indicating that the effect of the shRNAs are specific and the mEGFP-RhoA and mEGFP-Cdc42 used in the FRET sensors are functional as endogenous proteins.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    Rho signalling is required for the transient phase and likely the sustained phase of spine enlargement, while Cdc42 signalling is required for the sustained phase.

    “Thus, our data suggest that Rho signalling is required for the transient phase and likely the sustained phase of spine enlargement, while Cdc42 signalling is required for the sustained phase.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Study design and conductown data

    The time course of spine enlargement in neurons expressing the FRET sensor was similar to that in neurons expressing only EGFP, suggesting overexpression of FRET sensors causes almost no effects on spine structural plasticity.

    “The time course of spine enlargement in neurons expressing the FRET sensor was similar to that in neurons expressing only EGFP (Fig. 4)14, suggesting that the overexpression of FRET sensors causes almost no effects on spine structural plasticity (Supplementary note).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [14] Matsuzaki, M., Honkura, N., Ellis-Davies, G. C. & Kasai, H. Structural basis of long-term potentiation in single dendritic spines. Nature 429, 761–766 (2004) source

  • May combine two claims.

    Study design and conductown data

    The FRET sensors were verified to be specific and sensitive under 2pFLIM.

    “These sensors were verified to be specific and sensitive under 2pFLIM (Supplementary note).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    The Rho-Rock pathway is required for both transient and sustained phase, while the Cdc42-Pak pathway is required for the sustained phase of structural plasticity but not the transient phase.

    “Taken together with the results from Rho/Cdc42 inhibition (Fig. 4a–j), our data implies that the Rho-Rock pathway is required for both transient and sustained phase, while the Cdc42-Pak pathway is required for the sustained phase of the structural plasticity but not for the transient phase (Fig. 4k).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    Cdc42 must be continuously activated at the stimulated spines during plasticity and inactivated immediately after diffusing out of the spines.

    “Since the high spatial gradient of Cdc42 between the stimulated spines and dendrite was maintained for more than 20–30 min (Fig. 2b, c, 3d), Cdc42 must be continuously activated at the stimulated spines during plasticity, and inactivated immediately after diffusing out of the spines.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    Cdc42 is as mobile as RhoA and HRas, yet only Cdc42 shows compartmentalized activity.

    “Thus, Cdc42 is as mobile as RhoA and HRas, yet only Cdc42 shows the compartmentalized activity.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    Neither C3 nor Wasp affected CaMKII activation, indicating no feedback signalling from Rho and Cdc42 to upstream Ca2+ and CaMKII.

    “Neither C3 nor Wasp affected CaMKII activation (Supplementary Fig. 9), indicating that there is no feedback signalling from Rho and Cdc42 to upstream Ca2+ and CaMKII.”
    Quote in the paperSubstantial claim
23 of 23

  • The paper relies on this without support.

    Long-lasting, spine-specific plasticity requires signalling pathways that relay compartmentalized signalling on the time scale of minutes to hours.

    “However, in order to achieve long-lasting, spine-specific plasticity, there should also exist signalling pathways that relay compartmentalized signalling in the time scale of minutes to hours.”
1 of 1

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • The diffusion kinetics of both Cdc42 and Rho were comparable and similar to Ras diffusion and showed no immobile fraction left in the spine.

    “Also the diffusion kinetics of both molecules were comparable and similar to Ras diffusion and showed no immobile fraction left in the spine.”

    From Barriers in the brain: resolving dendritic spine morphology and compartmentalization (2014) · cites this paper as Murakoshi et al., 2011

    The diffusion-coupling passage reports that RhoA and Cdc42 were similarly mobile, with decay times comparable to a constitutively active HRas mutant. But it says 10–20% of fluorescence remained after 20 seconds, suggesting no *major* immobile fraction—not that no immobile fraction was left in the spine. (LLM, conf=0.88)

    Experimental — accuracy not yet measured

  • Ras activity was shown to invade typically 10-20 neighboring spines in a range of 10 μm along the dendrite, whereas RhoA activity only spread 5 μm and rarely invaded neighboring spines.

    “Ras activity was shown to invade typically 10–20 neighboring spines in a range of 10 μm along the dendrite, whereas RhoA activity only spread 5 μm and rarely invaded neighboring spines (Harvey et al., 2008; Murakoshi et al., 2011).”

    From Barriers in the brain: resolving dendritic spine morphology and compartmentalization (2014) · cites this paper as Murakoshi et al., 2011

    The passages indexed under Abstract (page unavailable) report that HRas activity spreads into surrounding spines over about 10 μm, while RhoA activity spreads about 5 μm along the dendrite and invades adjacent spines only slightly. They do not support the specific claim that Ras activity typically invades 10–20 neighboring spines. (LLM, conf=0.88)

    Experimental — accuracy not yet measured

  • Cdc42 activity remained spatially confined, because it had an intrinsic inactivation time constant of 6 s and therefore depends on continuous activation by CaMKII.

    “Nevertheless, Cdc42 activity remained spatially confined, because it had an intrinsic inactivation time constant of 6 s and therefore depends on continuous activation by CaMKII (Murakoshi et al., 2011).”

    From Barriers in the brain: resolving dendritic spine morphology and compartmentalization (2014) · cites this paper as Murakoshi et al., 2011

    The passage indexed under Abstract (page unavailable) says Cdc42 activity was confined to stimulated spines and infers an inactivation time constant of about 6 s. It concludes that Cdc42 must be continuously activated at those spines, but describes CaMKII signaling as transient; it does not say CaMKII continuously activates Cdc42. (LLM, conf=0.88)

    Experimental — accuracy not yet measured

  • There is compelling evidence that CaMKII, via phosphorylation, initiates a series of actin-based cytoskeletal rearrangements in the spine.

    “Indeed, there is compelling evidence that CaMKII, via phosphorylation, initiates a series of actin-based cytoskeletal rearrangements in the spine (32, 312–314).”

    From Synaptic memory and CaMKII (2023) · cites this paper as [312]

    The Abstract reports that RhoA and Cdc42 regulate the actin cytoskeleton and that their activation depends on CaMKII, linking CaMKII signalling to structural plasticity in dendritic spines. It does not establish that CaMKII initiates those rearrangements specifically via phosphorylation. (LLM, conf=0.85)

    Experimental — accuracy not yet measured

  • Spine growth is likely to be a multifaceted event involving regulated changes in cytoskeletal elements, membrane addition, and receptor trafficking under the control of multiple small GTPases.

    “Indeed spine growth is likely to be a multifaceted event involving regulated changes in cytoskeletal elements, membrane addition, and receptor trafficking under the control of multiple small GTPases”

    From Ral mediates activity‐dependent growth of postsynaptic membranes via recruitment of the exocyst (2013) · cites this paper as Murakoshi et al, 2011

    The indexed Abstract (page not provided) links spine enlargement to RhoA and Cdc42 signalling and describes Rho GTPases as regulators of the actin cytoskeleton. It does not describe membrane addition or receptor trafficking as components of spine growth, so it supports only part of the attributed claim. (LLM, conf=0.87)

    Experimental — accuracy not yet measured

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Authors
Murakoshi, H., Wang, H., & Yasuda, R.
Affiliations
  • Duke Medical Center (US)
  • Howard Hughes Medical Institute (US)
Corresponding author
Yasuda, Ryohei
ORCID
Venue
Nature
Publisher
Springer Science and Business Media LLC
Published
2011-03-20
Volume
472
Issue
7341
Pages
100-104
ISSN
  • 0028-0836 (ISSN-L)
  • 1476-4687
DOI
10.1038/nature09823
PMC
PMC3105377
OpenAlex
W2092348167
Semantic Scholar
68ac950b74f2a3fe5c7522a7290439c9214f5f35
Cited by
564
References
43
Citations by year
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FWCI
17.75
Type
journal article
Language
en
Open access
Licence
www.springer.com/tdm (tdm)
Locations
  • Nature (publishedVersion)
  • PubMed (publishedVersion)
  • Europe PMC (PubMed Central) (acceptedVersion)
  • PubMed Central (acceptedVersion)
  • RePEc: Research Papers in Economics (submittedVersion)
Funders
  • Howard Hughes Medical Institute
  • National Institutes of Health
  • National Institute of Mental Health (R01MH080047)
  • National Institute on Drug Abuse (R01DA027807)
  • National Institute of Neurological Disorders and Stroke (R01NS068410)
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
dendritic spines, Rho GTPases, RhoA, Cdc42, long-term potentiation, synaptic plasticity, CaMKII, spine morphogenesis, actin cytoskeleton, CA1 pyramidal neurons, hippocampus, glutamate uncaging, fluorescence lifetime imaging, learning and memory
MeSH terms
Animals, Enzyme Activation, Humans, Learning, Microscopy, Fluorescence, Neuronal Plasticity, Phosphoproteins, Time Factors, Signal Transduction, Long-Term Potentiation, Pyramidal Cells, GTPase-Activating Proteins, rho GTP-Binding Proteins, rhoA GTP-Binding Protein, Dendritic Spines, Rats, Calcium-Calmodulin-Dependent Protein Kinase Type 2

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-11-02.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-11-02.

Cited sources are checked by gpt-6-sol.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

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