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Cited by 160Neurobiology and Insect Physiology ResearchMemory and Neural MechanismsProtein Tyrosine Phosphatases

The Phosphatase SHP2 Regulates the Spacing Effect for Long-Term Memory Induction

Open access
Pagani, Mario R., Oishi, Kimihiko, Gelb, Bruce D., Zhong, Yi·2009·Cell
DOI 10.1016/j.cell.2009.08.033PMC PMC2770243
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Abstract

SUMMARY A common property of long-term memory (LTM) induction is the requirement for repeated training sessions spaced over time. The phenomena of better memory being formed with resting intervals between training sessions is called the spacing effect, for which the underlying molecular and neural bases are largely unknown. Our study reveals that the duration of resting intervals required for inducing LTM can be regulated by activity levels of the protein tyrosine phosphatase corkscrew (CSW) in Drosophila. Our studies demonstrate that wild-type CSW overexpression dramatically shortens the inter-trial interval required for LTM induction. In contrast, overexpression of gain-of-function CSWs prolong the resting interval for induction of LTM formation. Further biochemical analysis reveals that LTM-inducing training regimens generate repetitive waves of CSW-dependent mitogen-activated protein kinase activation. The length of that kinase activity wave appears to define the duration of the resting interval. Thus, we establish that the spacing effect has a molecular basis and CSW/SHP2 is key in its regulation.

AI snapshot

Written from the paper’s full text.

TL;DR

This study identifies the protein tyrosine phosphatase corkscrew (CSW)/SHP2 as a molecular regulator of the spacing effect for long-term memory (LTM) induction in Drosophila. CSW activity sets the resting interval between training trials by controlling the kinetics of training-induced MAPK activation waves.

Key findings

  • Overexpression of wild-type csw shortened the inter-trial interval required for LTM induction from the standard 15 min to 150 sec (2.5 min); 10 massed trials produced protein synthesis-dependent LTM in these flies.
  • Gain-of-function csw mutants (D61Y, A72S, T73I, E76K, I282V, N308D) reduced 24-hr memory/LTM after spaced training but not immediate memory or ARM; LTM was rescued by lengthening rest intervals to 40 min for D61Y/E76K and 30 min for I282V.
  • Spaced training generated repetitive CSW-dependent MAPK activation waves after each trial, whereas massed training produced only one peak after the 10th trial; wild-type csw overexpression produced 10 waves during massed training, while GOF CSW failed to reset MAPK after a subsequent trial.
  • Acute csw RNAi or the SHP2 inhibitor NSC-87877 reduced 24-hr memory; low-dose NSC-87877 (50 μM for 8 h before spaced training) completely rescued 24-hr memory in D61Y and E76K GOF flies, while 100 μM abolished LTM in controls.

Methods

  • Drosophila olfactory aversive conditioning: 3–4-day-old flies, groups of ~100, trained with odor (OCT/MCH) paired with electric shock; performance index measured in a T-maze. Immediate memory was tested after one trial; 24-hr memory after 10 spaced trials (15-min intervals) or massed training (no inter-trial intervals), with modified massed protocols using 150-sec or 45-sec intervals.
  • Genetics and pharmacology: UAS-csw transgenes expressed via OK107, 247, c739, heat-shock GAL4, or TARGET RNAi; cycloheximide to block protein synthesis; NSC-87877 to inhibit SHP2/CSW. MAPK activation was measured by western blot of 30 fly heads per sample using anti-phospho-p44/42 and anti-total p44/42, normalized p-MAPK/total MAPK.
  • Statistics: one-way ANOVA with planned pairwise comparisons, Bonferroni correction, p<0.05.

Limitations

  • The paper does not include an explicit limitations section. Evident limitations: all experiments are in Drosophila; human relevance is inferred from conserved SHP2/Noonan syndrome mutations but not directly tested in humans.
  • MAPK activity was measured in whole-head homogenates, not in specific mushroom body neurons or circuits, so the cellular locus of the activation waves is not resolved.
  • Behavioral memory scores are group-level performance indices from ~100 flies; the study does not report single-fly or circuit-specific recordings.

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

Integrity signals

Registry

Crossref · 10.1016/j.cell.2009.08.033

Cites

58 of 58 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 47 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    Wild-type CSW overexpression shortens the resting interval required to induce LTM from 15 min to 2.5 min.

    “Our studies demonstrate that wild-type CSW overexpression dramatically shortens the inter-trial interval required for LTM induction.”
    • Also stated in: § CSW Regulates Durations of Resting Intervals Needed to Elicit LTM · plain
      “In other words, the resting interval required to induce LTM was shortened from 15 min to 2.5 min, the first observation that the resting interval can be manipulated.”
    Quote in the paperSubstantial claim
  • Findingown data

    Overexpression of gain-of-function CSW mutants prolongs the resting interval for induction of LTM formation.

    “In contrast, overexpression of gain-of-function CSWs prolong the resting interval for induction of LTM formation.”
    • Also stated in: § INTRODUCTION · plain
      “We found that csw GOF mutations impair LTM formation by prolonging the length of the resting intervals between repetitive training required for induction of LTM.”
    Quote in the paperSubstantial claim
  • Findingown data

    LTM-inducing training regimens generate repetitive waves of CSW-dependent MAPK activation.

    “Further biochemical analysis reveals that LTM-inducing training regimens generate repetitive waves of CSW-dependent mitogen-activated protein kinase activation.”
    Quote in the paperSubstantial claim
  • Findingown data

    Cycloheximide treatment did not affect 24-hr memory scores significantly in transgenic fruit flies overexpressing GOF mutant CSW.

    “In contrast, cycloheximide treatment did not affect 24-hr memory scores significantly in transgenic fruit flies overexpressing GOF mutant CSW.”
    Quote in the paperSubstantial claim
  • Findingown data

    Feeding adult Drosophila NSC-87877 before and after training significantly reduced 24-hr memory in control and wild-type csw transgenic fruit flies.

    “After feeding adult Drosophila NSC-87877 for several hours before and after training (see Experimental Procedures), 24-hr memory in control and wild-type csw transgenic fruit flies was reduced significantly (Figure 2E).”
    Quote in the paperSubstantial claim
  • May combine two claims. 36
  • Classified as probably not a substantial claim. 17

  • May combine two claims.

    Findingown data

    Disease-associated mutations in Drosophila models of Noonan syndrome hampered memory formation and altered the spacing effect.

    “In the course of studying Drosophila models of Noonan syndrome (NS), we discovered that disease-associated mutations hampered memory formation and altered the spacing effect.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    One trial or 5-trial massed training did not induce any 24-hr memory enhancement in flies overexpressing wild-type CSW.

    “In testing this possibility, we found that one trial or 5-trial massed training did not induce any 24-hr memory enhancement in flies overexpressing wild-type CSW.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    24-hr memory scores elicited by massed training were similar among control and GOF mutant csw transgenic flies, confirming ARM remains normal in these mutants.

    “The 24-hr memory scores elicited in this way were similar among the control group (OK107;+) and the transgenic fruit flies overexpressing GOF mutant CSW (Figure 3B), confirming that ARM remains normal in these transgenic mutants.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    After a single 1-hr heat shock, 24-hr memory formation was diminished in flies expressing the mutant allele D61Y but not in those expressing E76K or wild-type csw.

    “After a single 1-hr heat shock, 24-hr memory formation was diminished in flies expressing the mutant allele D61Y but not in those expressing E76K or wild-type csw (Figures 2A and S5A-C).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    24-hr memory was significantly reduced in transgenic fruit flies overexpressing any of the GOF csw mutant alleles (D61Y, A72S, T73I, E76K, I282V and N308D) but not in those overexpressing wild-type csw.

    “In contrast, 24-hr memory was significantly reduced in transgenic fruit flies overexpressing any of the GOF csw mutant alleles (i.e. D61Y, A72S, T73I, E76K, I282V and N308D) but not in those overexpressing wild-type csw (Figure 1C and Table S1).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    csw silencing through RNAi at restrictive temperature reduced 24-hr memory whereas memory induction was unchanged in control groups.

    “In contrast, when the same fly lines were transferred to a restrictive temperature (29°C) for four days, csw silencing through expression of its RNAi reduced 24-hr memory whereas memory induction was unchanged in the control groups (Figures 2D and S8).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    An increase in MAPK activity was detected at 20 min after spaced training and the increase decayed away by 30 min.

    “An increase in MAPK activity was detected at 20 min after spaced training and that the increase decayed away by 30 min (Figure 5B).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    MAPK activation was apparent after essentially every trial with spaced training, but was never observed during massed training.

    “MAPK activation was apparent after essentially every trial with spaced training, but that was never observed during massed training.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    In wild-type flies subjected to spaced training, MAPK is activated during each 15-min rest interval and is reset to the basal level by the following training cycle.

    “For wild-type flies subjected to spaced training, MAPK is activated during each 15-min rest interval and is reset to the basal level by the following training cycle.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: MAPK activation measured in head homogenates reflects the neuronal signaling relevant to memory formation.

  • May combine two claims.

    Findingown data

    Modified massed training with 150-sec resting intervals was capable of producing memory enhancement while only ARM-like memory was elicited when 45-sec resting intervals were employed with wild-type csw transgenic flies.

    “The data presented here together with those presented earlier demonstrate that modified massed training with 150-sec resting intervals was capable of producing the memory enhancement while only ARM-like was elicited when 45-sec resting intervals were employed with fruit flies overexpressing the wild-type csw transgene.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    No training-dependent activation of MAPK was detected by unpaired or backward training, suggesting that the observed MAPK activation is specific to associative conditioning.

    “No training-dependent activation of MAPK was detected by unpaired or backward training (Figure S11), suggesting that the observed MAPK activation is specific to associative conditioning.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    In flies overexpressing E76K CSW mutant, 50 μM SHP2 inhibitor reduced slightly the overall training-induced MAPK activation compared with vehicle, but not at any specific time point after training.

    “At this lower concentration, the SHP2 inhibitor reduced slightly the overall training-induced MAPK activation compared with vehicle, but not at any specific time point after training (Figure S12).”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: MAPK activation measured in head homogenates reflects the neuronal signaling relevant to memory formation.
    • Rests on an assumption: NSC-87877 at the doses used specifically inhibits SHP2/CSW phosphatase activity without other effects.

  • May combine two claims.

    Findingown data

    For control and wild-type csw transgenic flies, 24-hr memory was unaffected or slightly increased, respectively, as the resting interval was lengthened from the standard 15 min up to 40 min.

    “For the control and wild-type csw transgenic flies, 24-hr memory was unaffected or slightly increased, respectively, as the resting interval was lengthened from the standard 15 min up to 40 min (Figure 6D).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Massed training failed to enhance 24-hr memory in transgenic fruit flies overexpressing the phosphatase-dead cswR465M mutant, documenting that the phenomenon is phosphatase dependent.

    “Massed training failed to enhance 24-hr memory in transgenic fruit flies overexpressing this LOF mutant (Figure 3G), documenting that the phenomenon is phosphatase dependent.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    When control flies were used, modest MAPK activation was observed at 45 sec and stronger activation at 930 sec after the first trial.

    “When control flies were used, we observed modest MAPK activation at 45 sec and stronger activation at 930 sec after the first trial (Figure 5H).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The massed training-elicited 24-hr memory enhancement was retained with the c739 GAL4 driver, documenting that this LTM was forming in normal anatomic sites and not ectopically.

    “We showed that the massed training-elicited 24-hr memory enhancement was retained with this GAL4 driver (Figure 3F and Table S4), documenting that this LTM was forming in the normal anatomic sites and not ectopically.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    During the decay phase, MAPK activation associated with wild-type csw overexpression appeared normal but was slower with D61Y and E76K mutants.

    “while during the decay phase, MAPK activation associated with wild-type csw overexpression appeared to be normal but was slower with the D61Y and E76K mutants.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    All three transgenic lines (wild-type csw, D61Y, E76K) showed significantly faster MAPK activation in response to training, with strong activation at 5 min after training.

    “however, all three transgenic lines showed significantly faster activation in response to training, i.e. strong MAPK activation was observed at 5 min after training (Figure 5C)”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Using modified massed training with 150-sec resting intervals, 24-hr memory was not affected; control group showed normal ARM and memory enhancement in wild-type csw transgenic flies persisted.

    “Using this modified protocol, we found that 24-hr memory was not affected; the control group showed normal ARM and the memory enhancement in the wild-type csw transgenic flies persisted (Figure 4B).”
    Quote in the paperSubstantial claim

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

    Premisecitation

    The spacing effect is a common phenomenon in the animal kingdom.

    “This augmentation in memory formation is called the spacing effect and is a common phenomenon in the animal kingdom (Ebbinghaus, 1885; Carew et al., 1972; Tully et al., 1994; Gerber et al., 1998; Beck et al., 2000; Sutton et al., 2002; Cepeda et al., 2006; Philips et al., 2007).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Ebbinghaus, 1885

      Not checked in the free run.

    • cites Carew et al., 1972

      Not checked in the free run.

    • cites Tully et al., 1994 source

      Not checked in the free run.

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

    Premisecitation

    Mutations at positions 72, 76 and 308 increase MAPK activation and engender developmental phenotypes in Drosophila.

    “and mutations at positions 72, 76 and 308 have been shown to increase MAPK activation and engender developmental phenotypes in Drosophila (Oishi et al., 2006).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Oishi et al., 2006

      Not checked in the free run.

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

    Premisecitation

    LTM, a protein synthesis-dependent memory that does not decay after seven days, can be induced with ten learning sessions if rest intervals are provided between training trials (spaced training).

    “Long-term memory (LTM), a protein synthesis-dependent memory that does not decay after seven days, can be induced with ten learning sessions if rest intervals are provided between the training trials. This constitutes spaced training (For a detailed description, see Tully et al., 1994; Isabel et al., 2004; reviewed in Margulies et al., 2005).”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites Tully et al., 1994 source

      Not checked in the free run.

    • cites Isabel et al., 2004

      Not checked in the free run.

    • cites Margulies et al., 2005

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Premisecitation

    The PTPN11 gene and its Drosophila orthologue corkscrew (csw) encode the evolutionarily conserved protein tyrosine phosphatase SHP2.

    “The PTPN11 gene, and its orthologue in fruit flies corkscrew (csw), encodes the evolutionarily conserved protein tyrosine phosphatase SHP2 (Freeman et al., 1992; Neel et al., 2003)”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites Freeman et al., 1992

      Not checked in the free run.

    • cites Neel et al., 2003 source

      Not checked in the free run.

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

    Premisecitation

    Somatic PTPN11 mutations with generally stronger GOF effects cause certain childhood leukemias.

    “and somatic mutations with generally stronger GOF effects cause certain childhood leukemias (Tartaglia et al., 2003).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Tartaglia et al., 2003

      Not checked in the free run.

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

    Premisecitation

    Mutations causing NS have been identified in five genes, PTPN11, SOS1, RAF1, BRAF and KRAS, all of which encode proteins that are components of the Ras/MAPK signaling pathway.

    “Mutations causing NS have been identified in five genes, PTPN11, SOS1, RAF1, BRAF and KRAS, all of which encode proteins that are components of the Ras/mitogen-activated protein kinase (MAPK) signaling pathway (Gelb and Tartaglia, 2006; Aoki et al., 2008).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Gelb and Tartaglia, 2006

      Not checked in the free run.

    • cites Aoki et al., 2008

      Not checked in the free run.

  • May combine two claims.

    Study design and conductown data

    The effects of heat shock protocols or restrictive temperature specifically affected memory induction as sensorimotor abilities were unchanged.

    “Of note, the effects of the heat shock protocols or restrictive temperature specifically affected memory induction as sensorimotor abilities were unchanged (Table S2 and S3).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationown data

    GOF CSW's adverse impact on 24-hr memory reflects an acute role in memory formation and does not depend on developmental abnormalities.

    “Taken together, these data showed that GOF CSW's adverse impact on 24-hr memory reflects an acute role in memory formation and does not depend on developmental abnormalities.”
    Quote in the paperSubstantial claim

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

    Premisecitation

    Gain-of-function germline PTPN11 mutations cause about 50% of NS cases.

    “Gain-of-function (GOF) germline PTPN11 mutations cause about 50% of NS cases (Tartaglia et al., 2001)”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Tartaglia et al., 2001

      Not checked in the free run.

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

    Premisecitation

    The spacing effect has been well demonstrated in Drosophila.

    “The spacing effect has been well demonstrated in Drosophila (Tully et al., 1994; Beck et al., 2000; Ho et al., 2007).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Tully et al., 1994 source

      Not checked in the free run.

    • cites Beck et al., 2000 source

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    • cites Ho et al., 2007

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    The massed-training-elicited memory enhancement in wild-type csw transgenic flies is protein-synthesis dependent, a major feature of LTM.

    “This documented that this memory was protein-synthesis dependent, which is a major feature of LTM (Tully et al., 1994).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Tully et al., 1994 source

      Not checked in the free run.

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

    Premisecitation

    SHP2 is recruited to many receptor tyrosine kinases upon activation and is generally a positive regulator of Ras/MAPK signaling.

    “which is recruited to many receptor tyrosine kinases upon activation and is generally a positive regulator of Ras/MAPK signaling (Perkins et al., 1996; Bennett et al., 1994; Tang et al., 1995; Maroun et al., 2000; Oishi et al., 2006).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Perkins et al., 1996

      Not checked in the free run.

    • cites Bennett et al., 1994 source

      Not checked in the free run.

    • cites Tang et al., 1995

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    LTM was reduced in most GOF mutants while ARM remained unaffected.

    “These results suggested that LTM was reduced in most GOF mutants while ARM remained unaffected.”
    Quote in the paperSubstantial claim

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

    Premisecitation

    CSW is a key signaling relay in pathways in C. elegans, Drosophila, Xenopus and mammals.

    “CSW is a key signaling relay in pathways in C. elegans, Drosophila, Xenopus and mammals (for review see, Neel et al., 2003).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Neel et al., 2003 source

      Not checked in the free run.

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

    Premisecitation

    MAPK activity has been implicated in memory formation in invertebrates and vertebrates.

    “In addition, MAPK activity has been implicated in memory formation in invertebrates and vertebrates (Kandel, 2001; Kelleher et al., 2004; Cammarota et al., 2007; Mayford, 2007).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Kandel, 2001 source

      Not checked in the free run.

    • cites Kelleher et al., 2004 source

      Not checked in the free run.

    • cites Cammarota et al., 2007

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    Acute reduction of phosphatase activity allows fruit flies overexpressing csw GOF mutations to form LTM normally and correlates with reduced training-dependent MAPK activation.

    “Thus, acute reduction of phosphatase activity is capable of allowing fruit flies overexpressing csw GOF mutations to form LTM normally and correlates with reduced training-dependent MAPK activation.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: MAPK activation measured in head homogenates reflects the neuronal signaling relevant to memory formation.
    • Rests on an assumption: NSC-87877 at the doses used specifically inhibits SHP2/CSW phosphatase activity without other effects.

  • May combine two claims.

    Interpretationown data

    LTM was disrupted by overexpression of GOF mutant csw transgenes, while overexpression of wild-type csw transgene promoted LTM formation in response to massed training.

    “Taken together, these observations showed that LTM was disrupted by overexpression of the GOF mutant csw transgenes, while overexpression of the wild-type csw transgene promoted LTM formation in response to massed training.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    CSW is a positive regulator of signaling from a variety of growth factor receptors flowing through the Ras/MAP kinase cascade.

    “To gain insights into how CSW activity might regulate the spacing effect, we assayed Drosophila head MAP kinase (MAPK) activation at different times after training because CSW is a positive regulator of signaling from a variety of growth factor receptors flowing through the Ras/MAP kinase cascade (Perkins et al., 1996; Gelb and Tartaglia, 2006; Aoki et al., 2008).”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites Perkins et al., 1996

      Not checked in the free run.

    • cites Gelb and Tartaglia, 2006

      Not checked in the free run.

    • cites Aoki et al., 2008

      Not checked in the free run.

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

    Study design and conductnone given

    The study minimized biologic variation by using an isogenic background for all genotypes examined, identical rearing and testing conditions, and batching the analysis for all data presented in the same figure.

    “We employed several measures to minimize biologic variation, including the use of an isogenic background for all genotypes examined, identical rearing and testing conditions, and batching the analysis for all data presented in the same figure.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationown data

    csw GOF mutations cause LTM defects in Drosophila due to prolonged phosphatase activity, leading to the rest interval used during standard spaced training being inadequate to permit activated MAPK to be reset.

    “The data presented above suggested that csw GOF mutations cause LTM defects in Drosophila due to prolonged phosphatase activity, leading to the rest interval used during standard spaced training being inadequate to permit activated MAPK to be reset.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: MAPK activation measured in head homogenates reflects the neuronal signaling relevant to memory formation.

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

    Study design and conductnone given

    Multiple mutant alleles were used to support any phenotypes observed.

    “In addition, we used multiple mutant alleles to support any phenotypes observed.”
    Quote in the paperNot a substantial claim

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

    Study design and conductnone given

    Alternative approaches such as pharmacologic inhibition or RNAi were used to bolster initial observations.

    “Finally, we used alternative approaches such as pharmacologic inhibition or RNAi when possible to bolster our initial observation.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    In Drosophila, the spacing effect is well defined phenomenologically and used as a behavioral strategy to induce protein synthesis-dependent LTM.

    “In Drosophila, the spacing effect is well defined phenomenologically (Tully et al., 1994; Beck et al., 2000) and it is used as a behavioral strategy to induce protein synthesis-dependent LTM.”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites Tully et al., 1994 source

      Not checked in the free run.

    • cites Beck et al., 2000 source

      Not checked in the free run.

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

    Study design and conductnone given

    Multi-comparisons were performed by a one-way ANOVA followed by planned pair-wise comparisons, with alpha error = 0.05 corrected for multiple comparisons using the Bonferroni method, and the threshold for declaring significant differences was p<0.05.

    “Multi-comparisons were performed by a one-way ANOVA followed by planned pair-wise comparisons. The alpha error = 0.05 was corrected for multiple comparisons using the Bonferroni method. The threshold for declaring significant differences was p<0.05.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    There is a wave of MAPK activity after each training trial, making for 10 peaks in all.

    “Thus, there is a wave of MAPK activity after each training trial, making for 10 peaks in all.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: MAPK activation measured in head homogenates reflects the neuronal signaling relevant to memory formation.

  • May combine two claims.

    Interpretationreasoning

    The standard spaced training protocol with 15 min rest intervals engenders altered MAP activity peaks in mutant CSW transgenic fruit flies, resulting in an LTM deficit.

    “Therefore, the standard spaced training protocol with 15 min rest intervals engenders altered MAP activity peaks in these mutant CSW transgenic fruit flies, resulting in an LTM deficit.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: MAPK activation measured in head homogenates reflects the neuronal signaling relevant to memory formation.

  • May combine two claims.

    Interpretationreasoning

    In transgenic fruit flies overexpressing GOF CSW mutants, MAPK activity is not reset by the subsequent training trial, apparently due to slower kinetics for its decay.

    “Although MAPK may also be activated faster in transgenic fruit flies overexpressing GOF CSW mutants, this activity is not reset by the subsequent training trial, apparently due to the slower kinetics for its decay.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: MAPK activation measured in head homogenates reflects the neuronal signaling relevant to memory formation.

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

    Study design and conductnone given

    The experiments had a balanced design; for one complete experiment, a second group of flies was trained with odor #1 (as CS−) and odor #2 (as CS+) and the two groups were used to estimate the behavioral performance index (PI).

    “The experiments had a balanced design; for one complete experiment, a second group of flies was trained with odor # 1 (as CS−) and odor # 2 (as CS+) and the two groups were used to estimate the behavioral performance index (PI).”
    Quote in the paperNot a substantial claim
47 of 47

  • The paper relies on this without support.

    The specific molecular mechanisms underlying the spacing effect are essentially unknown.

    “In animal models, it is clear that the spacing effect requires protein synthesis (Quinn and Dudai, 1976) but the specific molecular mechanisms underlying this phenomenon are essentially unknown.”

  • The paper relies on this without support.

    MAPK activation measured in head homogenates reflects the neuronal signaling relevant to memory formation.

    “MAPK activity was examined by western blot. Briefly, for each genotype and time point, 30 heads were homogenized; samples were run on 10% Tricine–glycine gels and transferred to nitrocellulose.”

  • The paper relies on this without support.

    NSC-87877 at the doses used specifically inhibits SHP2/CSW phosphatase activity without other effects.

    “Administration of the SHP2 inhibitor, NSC-87877 (Calbiochem), was performed according to the CXM protocol (Figure 2E), or only during an 8-hr period (Figure 6).”

  • The paper relies on this without support.

    LTM can be elicited with 10 repetitive training trials with an optimal spacing of 15 min.

    “It was previously established that LTM can be elicited with 10 repetitive training trials with an optimal spacing of 15 min”
4 of 4

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?

  • Spaced training leads to improved memory in invertebrates such as Aplysia californica, Drosophila melanogaster and bees, and in rodents and non-human primates.

    “Spaced training also leads to improved memory in invertebrates, such as the mollusk Aplysia californica11–14, Drosophila melanogaster15,16 and bees17, and in rodents18,19 and non-human primates20,21.”

    From The right time to learn: Mechanisms and optimization of spaced learning (2016) · cites this paper as [16]

  • In Drosophila melanogaster olfactory learning, each spaced training trial generated a distinct wave of MAPK activity, whereas massed training trials were too close together to generate distinct waves.

    “In an olfactory learning protocol, each spaced training trial generated a distinct wave of MAPK activity, whereas massed training trials were too close together to generate distinct waves.”

    From The right time to learn: Mechanisms and optimization of spaced learning (2016) · cites this paper as [16]

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Related

Authors
Pagani, M. R., Oishi, K., Gelb, B. D., & Zhong, Y.
Affiliations
  • Cold Spring Harbor Laboratory (US)
  • Mount Sinai Hospital (US)
Corresponding author
Zhong, Yi
ORCID
Venue
Cell
Publisher
Elsevier BV
Published
2009-10
Volume
139
Issue
1
Pages
186-198
ISSN
0092-8674 (ISSN-L)
DOI
10.1016/j.cell.2009.08.033
PMC
PMC2770243
OpenAlex
W2019100219
Semantic Scholar
9c6abc50177692486b7fd61b1d5d85bbc3d8734c
Cited by
157
References
59
Citations by year
2026: 3 · 2025: 4 · 2024: 14 · 2023: 9 · 2022: 11 · 2021: 4 · 2020: 14 · 2019: 8 · 2018: 8 · 2017: 10 · 2016: 9 · 2015: 15 · 2014: 6 · 2013: 11 · 2012: 10
FWCI
4.28
Type
journal article
Language
en
Open access
Licence
Locations
  • Cell (publishedVersion)
  • PubMed (publishedVersion)
  • PubMed Central (acceptedVersion)
  • Cold Spring Harbor Laboratory Institutional Repository (Cold Spring Harbor Laboratory) (acceptedVersion)
Funders
  • National Institutes of Health
  • National Heart, Lung, and Blood Institute (HL 71207, R01HL071207)
  • National Institute on Deafness and Other Communication Disorders (R01DC005784, 5R01 DC05784-05A1)
  • National Institute of Neurological Disorders and Stroke (R01NS064331)
Topics
  • Life Sciences › Neuroscience › Cellular and Molecular Neuroscience › Neurobiology and Insect Physiology Research
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Memory and Neural Mechanisms
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Protein Tyrosine Phosphatases
Keywords
spacing effect, long-term memory, corkscrew, SHP2, protein tyrosine phosphatase, Drosophila, mushroom body neurons, MAPK activation, memory consolidation, intellectual disability, intertrial interval
MeSH terms
Animals, Humans, Learning, Memory, Neurons, Signal Transduction, Transgenes, MAP Kinase Signaling System, Mushroom Bodies, Drosophila Proteins, Protein Tyrosine Phosphatases, Non-Receptor

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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.

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