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Cited by 352Neurological Disease Mechanisms and TreatmentsAcute Ischemic Stroke ManagementBarrier Structure and Function Studies

The smallest stroke: occlusion of one penetrating vessel leads to infarction and a cognitive deficit

Open access
Shih, Andy Y, Blinder, Pablo, Tsai, Philbert S, Friedman, Beth, Stanley, Geoffrey, Lyden, Patrick D, Kleinfeld, David·2013·Nature Neuroscience
DOI 10.1038/nn.3278PMC PMC3952571
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Abstract

Microinfarctions are present in the aged and injured human brain. Their clinical relevance is controversial, with postulated sequelae ranging from cognitive sparing to vascular dementia. To address the consequences of microinfarcts, we used controlled optical methods to create occlusions of individual penetrating arterioles or venules in rat cortex. Single microinfarcts, targeted to encompass all or part of a cortical column, impaired performance in a macrovibrissa-based behavioral task. Furthermore, the targeting of multiple vessels resulted in tissue damage that coalesced across cortex, even though the intervening penetrating vessels were acutely patent. Post-occlusion administration of memantine, a glutamate receptor antagonist that reduces cognitive decline in Alzheimer's disease, ameliorated tissue damage and perceptual deficits. Collectively, these data imply that microinfarcts likely contribute to cognitive decline. Strategies that have received limited success in the treatment of ischemic injury, which include therapeutics against excitotoxicity, may be successful against the progressive nature of vascular dementia.

AI snapshot

Written from the paper’s full text.

TL;DR

In rat cortex, optically occluding a single penetrating arteriole or venule produced a columnar microinfarct and impaired a macrovibrissa gap-crossing task, while multiple such occlusions coalesced into larger damage. Post-occlusion Memantine reduced infarct size and the perceptual deficit, suggesting microinfarcts can contribute to vascular cognitive decline.

Key findings

  • Single penetrating arteriole or venule occlusion caused microinfarcts with statistically identical volumes: 220 ± 140 nL vs. 210 ± 100 nL; diameters 460 ± 70 μm vs. 500 ± 120 μm; depths 1.17 ± 0.32 mm vs. 1.30 ± 0.25 mm. Deep microvessel occlusion caused minute damage, with a maximum infarct volume of 0.8 nL for direct branches and no detectable damage for capillaries.
  • Acute effects included loss of evoked neuronal Ca2+ responses within the first 2 h after single arteriole or venule occlusion, hypoxic core tissue with pO2 < 10 mm Hg at 6 h, and spreading depression waves at 30–70 μm/s.
  • ON-target single penetrating vessel occlusion (n = 10; 4 arterioles, 6 venules) reduced the 0.5-chance gap-crossing distance by about 1 cm; OFF-target occlusions (n = 3) caused no deficit, and macrovibrissa removal in ON-target animals decreased crossing by only ~0.1 cm.
  • Memantine given after occlusion reduced median infarct radius from 230 to 50 μm, and treated animals (n = 7) crossed essentially the same gap as before occlusion. Multiple occlusions spaced ≤ 1.6 mm apart coalesced; occluding 5.4 ± 1.1% of penetrating vessels caused complete infarction of intervening tissue (n = 7), while NMDAR antagonists increased the coalescence threshold to 0.7 mm, a fivefold increase in minimum areal density.

Methods

  • 220 male rats were used: 80 Sprague Dawley rats for physiological and anatomical measurements, and 140 Long Evans rats for behavioral experiments, of which 20 of 140 completed training. Anesthetized animals had cranial windows over somatosensory cortex and were imaged with in vivo two-photon microscopy.
  • Targeted occlusions were made in penetrating vessels using Rose Bengal photosensitizer plus focused green laser light (60–90 s), and in deep microvessels using amplified ultrashort laser pulses (complete within 120 s). Histology and immunostaining included α-NeuN, propidium iodide, Hypoxyprobe, α-3-nitrotyrosine, α-aquaporin-4, α-IgG, α-CD68, and α-VGLUT2.
  • Behavior used a macrovibrissa gap-crossing task with psychometric curves; ON-target vs. OFF-target occlusions were compared. MK-801 (1 mg/kg, pre-occlusion) and Memantine (20 mg/kg, 30 min post-occlusion) were given intraperitoneally. Statistics used repeated-measures ANOVA with Tukey post hoc, and Kruskal-Wallis with Dunn’s post hoc.

Limitations

  • Stated in the paper: the occurrence of microinfarct coalescence in humans remains to be addressed; the study examined subacute stages with astrogliosis and macrophage infiltration but incomplete cavitation, not chronic cysts or linear scars; optically induced infarcts start at the cortical surface, whereas human microinfarcts can be completely contained within grey matter; high-field MRI and better animal models are needed.
  • Evident from the text: all experiments used male rats; behavioral cohorts were small (ON-target n = 10, OFF-target n = 3, Memantine n = 7) with high training attrition (20 of 140 completed training); acute imaging was performed under anesthesia; and behavioral follow-up was limited to 4–7 days post-occlusion, so long-term recovery or remapping was not assessed.

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

Integrity signals

Registry

Crossref · 10.1038/nn.3278

Cites

59 of 59 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 34 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    Occlusion of a single penetrating arteriole decreased the number of neurons responsive to hindlimb stimulation precipitously within the first two hours.

    “The number of neurons responsive to hindlimb stimulation was found to decrease precipitously within the first two hours after occlusion of a single penetrating arteriole (Fig. 3c).”
    Quote in the paperSubstantial claim
  • Findingcitation

    Occlusion of either a penetrating arteriole or venule generated severe hypoxia with pO2 below 10 mm Hg in the acute period 6 hours post-occlusion.

    “occlusion of either a penetrating arteriole or venule generated severely hypoxic conditions in the acute period of 6 hours post-occlusion, i.e., pO2 < 10 mm Hg, as reported by α-Hypoxyprobe™ staining in post-hoc histology19 (Fig. 3f, left panel).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [19] Shih, A.Y. et al. Active dilation of penetrating arterioles restores red blood cell flux to penumbral neocortex after focal stroke. J. Cereb. Blood Flow Metab. 29, 738–751 (2009). source

      Not checked in the free run.

  • Findingcitation

    Hypoxic tissue overlapped precisely with a column of severe vascular pathology in the microinfarct core, marked by retention of fluorescein-dextran in deep microvasculature endothelia.

    “The hypoxic tissue overlapped precisely with a column of severe vascular pathology in the microinfarct core (Fig. 3f, right panel), as highlighted by retention of the circulating fluorescein-dextran in the endothelia of the deep microvasculature24.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [24] Chen, B. et al. Severe blood brain barrier disruption and surrounding tissue injury. Stroke 40, 666–674 (2009).

      Not checked in the free run.

  • Findingown data

    Occlusion of a single penetrating venule produced a similar decrease in responsive neurons.

    “A similar effect was observed following occlusion of a single penetrating venule (Fig. 3d).”
    Quote in the paperSubstantial claim
  • Findingown data

    Memantine-treated ON-target microinfarcts tended to be much smaller and often covered only a small fraction of the target column.

    “those with the administration of Memantine tended to be much smaller, and resultant microinfarcts often covered only a small fraction of the target column (Fig 7b & Supplementary Table 1).”
    Quote in the paperSubstantial claim
  • May combine two claims. 22
  • The quote only partly states this claim. 2
  • Classified as probably not a substantial claim. 18

  • May combine two claims.

    Findingown data

    Penetrating vessels supported volume flux predominantly from 100 pL/s to 10 nL/s, while deep microvessels supported values primarily between 1 and 100 pL/s.

    “Penetrating vessels supported values of flux19 predominantly from 100 pL/s to 10 nL/s, while deep microvessels supported values primarily between 1 and 100 pL/s (Fig. 2b).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [19] Shih, A.Y. et al. Active dilation of penetrating arterioles restores red blood cell flux to penumbral neocortex after focal stroke. J. Cereb. Blood Flow Metab. 29, 738–751 (2009). source

      Not checked in the free run.

  • May combine two claims.

    Findingown data

    Forelimb cortex remained responsive to stimulation over three hours after hindlimb occlusion, indicating that stroke-induced loss of function was not due to general metabolic run-down.

    “The forelimb area remained responsive to stimulation over a period of three hours, indicating that stroke-induced loss of function did not result from a general metabolic run-down of the animals (Fig. 3e).”
    Quote in the paperSubstantial claim

  • May combine two claims. The quote only partly states this claim.

    Findingown data

    Occlusion of a single penetrating vessel produced multiple hallmarks of ischemic injury, including oxidative protein damage, astrocyte pathology, blood-brain barrier leakage, membrane degradation, and macrophage marker reactivity.

    “the microinfarct core exhibited increased labeling with α-3-nitrotyrosine, indicative of oxidative protein damage within cells and vasculature25, as well as reduced α-aquaporin-4 staining and increased rat α-immunoglobulin G staining, indicative of pathology in astrocytes and blood brain barrier leakage26, respectively (Supplementary Fig. 2).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [25] Calabrese, V., Mancuso, C., Calvani, M., Rizzarelli, E. & Butterfield, D.A. Nitric oxide in the central nervous system: neuroprotection versus neurotoxicity. Nat. Rev. Neurosci. 8, 766–775 (2007). source

      Not checked in the free run.

    • cites [26] Friedman, B. et al. Acute vascular disruption and Aquaporin 4 loss after stroke. Stroke 40, 2182–2190 (2009). source

      Not checked in the free run.

  • May combine two claims.

    Findingown data

    Each cubic millimeter of rat cortex contains on average six penetrating arterioles and 16 penetrating venules.

    “Each cubic millimeter of rat cortex contains on average six penetrating arterioles and 16 penetrating venules (n = 9 rats).”
    Quote in the paperNot a substantial claim

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

    Findingown data

    Removal of the single C1 or C2 macrovibrissa in the ON-target cohort resulted in a small decrease of about 0.1 cm in navigable gap size for a 0.5-chance of crossing.

    “removal of the single C1 or C2 macrovibrissa in the ON-target cohort resulted in a small, i.e., ~ 0.1 cm, decrease in the navigable gap size for a 0.5-chance of crossing across the cohort (Fig. 6g; cf red & blue bars).”
    Quote in the paperNot a substantial claim

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

    Findingown data

    Calcium transients in individual neurons showed a near-instant rise and then exponential decay lasting 1 to 2 seconds.

    “The [Ca2+] transients from individual neurons, indicative of action potential firing, exhibited an effectively instantaneous increase followed by an exponential decay over a 1 to 2 s period (Fig. 3b).”
    Quote in the paperNot a substantial claim

  • May combine two claims. The quote only partly states this claim.

    Findingown data

    Occlusion of deep microvessels caused minute tissue infarction; direct branches produced at most 0.8 nL damage, and capillaries produced no detectable damage.

    “In contrast to the case for penetrating vessels, the tissue infarction detected after occlusion of deep microvessels was minute (Fig. 4c,e).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Histology showed that blocking only a single penetrating vessel was sufficient to ablate an entire cortical column within vS1 cortex in the ON-target group and a similarly sized region outside vS1 in the OFF-target group.

    “These data showed that blockade of only a single penetrating vessel was sufficient to ablate an entire cortical column within the vS1 cortex of the ON-target group (Fig. 6e & Supplementary Fig. 5) and a similarly sized region outside of vS1 cortex for the OFF-target group (Fig. 6i & Supplementary Table 1).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    ON-target animals could still perform the task when the gap was short enough to touch the target with the snout, but with larger gaps they could no longer detect the target even though videography showed macrovibrissa contact.

    “In each case, the animal could still perform the task when the gap was short enough for the animal to touch the target platform with its snout (Fig. 6f; red circle). However, with larger gaps the rat could no longer detect the target platform, even though videography showed that the target platform was contacted by the rat’s macrovibrissa (Fig. 6f; red square).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Both MK-801 given before occlusion and Memantine given after occlusion significantly reduced the total volume of infarcted tissue in the multiple-occlusion model.

    “We observed that both antagonists significantly reduced the total volume of infarcted tissue (Fig. 8d–g).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Occlusion of a penetrating venule generated a microinfarction remarkably similar to that from arteriole occlusion, with loss of α-NeuN staining and reactive astrogliosis.

    “Indeed, occlusion of a penetrating venule generated a microinfarction with remarkable similarity to that caused by occlusion of a penetrating arteriole, as seen with the loss of staining for α-NeuN (Fig. 4b & Supplementary Fig. 4b) and reactive astrogliosis (Supplementary Fig. 4b).”
    Quote in the paperSubstantial claim

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

    Findingown data

    Eventually, rats used their macrovibrissae to feel the target platform edge when it was beyond the snout, typically at gaps of 14 to 18 cm depending on rat size.

    “Finally, they learned to use their macrovibrissae to feel the edge of the target platform when it was past their snout, typically at a gap distance of 14 to 18 cm, which depended upon the size of the rat.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Over two days after occlusion of sets of penetrating vessels, clots propagated beyond the initial microinfarct core and decreased perfusion of neighboring penetrating vessels.

    “Over a period of two days, these clots propagated beyond the initial core of the microinfarct to decrease the perfusion of neighboring penetrating vessels (Fig. 8c & Supplementary Fig. 6).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Occlusion of a single penetrating arteriole was sufficient to disrupt the vibrissa column and abolish processing of cortical input.

    “We found that the occlusion of a single penetrating arteriole was sufficient to disrupt the vibrissa column and abolish the processing of cortical input.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Both MK-801 and Memantine, delivered intraperitoneally, were highly effective at reducing microinfarct volumes caused by occlusion of either a penetrating arteriole or venule.

    “Both antagonists, delivered by intraperitoneal injection, were found to be highly effective at reducing microinfarct volumes caused by occlusion of either a penetrating arteriole (Fig. 5d) or venule (Fig. 5e).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The volume of infarction correlated with pre-occlusion RBC flux through the vessel; greater flux led to larger microinfarcts.

    “The volume of infarction is correlated with the pre-occlusion flux of RBCs through the vessel (Fig. 4d); occlusion of vessels with greater flux led to larger microinfarcts.”
    Quote in the paperNot a substantial claim

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

    Findingown data

    For very small lesions from deep microvessel thrombosis, damage was often confined to one slice.

    “With extremely small lesions caused by deep microvessel thrombosis, the damage was often limited to only a single slice (Fig. 4e and Supplementary Fig. 1e,f).”
    Quote in the paperNot a substantial claim

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

    Findingown data

    Initially, rats crossed the gap only when they could reach the other platform with a front paw.

    “Initially, they were found to cross a gap only if the other platform was reachable with a front paw.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Cortical microinfarcts are present in the brains of aged and demented humans and have diameters around 0.1 to 1 mm.

    “Post-mortem studies of patients with dementia have identified, in addition to other pathologies, an abundance of cortical microinfarcts4–7 with diameters on the order of 0.1 to 1 mm (Fig. 1a).”
    Quote in the paperSubstantial claim0 of 4 sources checked
    • cites [4] Vinters, H.V. et al. Neuropathologic substrates of ischemic vascular dementia. J. Neuropathol. Exp. Neurol. 59, 931–945 (2000). source

      Not checked in the free run.

    • cites [5] Kövari, E. et al. Cortical microinfarcts and demyelination affect cognition in cases at high risk for dementia. Neurology 68, 927–931 (2007). source

      Not checked in the free run.

    • cites [6] Arvanitakis, Z., Leurgans, S.E., Barnes, L.L., Bennett, D.A. & Schneider, J.A. Microinfarct pathology, dementia and cognitive systems. Stroke 42, 722–727 (2011). source

      Not checked in the free run.

    • cites [7] Jouvent, E. et al. Intracortical infarcts in small vessel disease: a combined 7-T postmortem MRI and neuropathological case study in cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopthy. Stroke 42, 27–30 (2011). source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Loss of flow in a single cortical penetrating arteriole produces a nominally columnar microinfarction that can extend through the full depth of cortex.

    “Loss of flow to even a single cortical penetrating arteriole will generate a nominally columnar microinfarction that can extend through the full depth of cortex8, 13 (Fig. 1b).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [8] Blinder, P., Shih, A.Y., Rafie, C.A. & Kleinfeld, D. Topological basis for the robust distribution of blood to rodent neocortex. Proc. Natl. Acad. Sci. USA 107, 12670–12675 (2010). source

      Not checked in the free run.

    • cites [13] Drew, P.J. et al. Chronic optical access through a polished and reinforced thinned skull. Nat. Methods 7, 981–984 (2010). source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Study design and conductnone given

    The occluded vessel was periodically monitored to ensure the clot remained stable over the entire imaging period.

    “The occluded vessel was periodically monitored to ensure that the clot remained stable over the entire imaging period.”
    Quote in the paperSubstantial claim

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

    Premisecitation

    Propidium iodide labels necrotic tissue.

    “For labeling of necrotic tissue, propidium iodide was injected intraperitoneally 2 hours prior to perfusion fixation, at a concentration of 1 mg/kg in a volume of 1 mL saline27.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [27] Unal Cevik, I. & Dalkara, T. Intravenously administered propidium iodide labels necrotic cells in the intact mouse brain after injury. Cell Death Differ. 10, 928–929 (2003). source

      Not checked in the free run.

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

    Premisecitation

    Sulforhodamine 101 labels astrocytes selectively.

    “Astrocytes were selectively labeled with sulforhodamine 101 (SR101)58.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [58] Nimmerjahn, A., Kirchhoff, F., Kerr, J.N. & Helmchen, F. Sulforhodamine 101 as a specific marker of astroglia in the neocortex in vivo. Nat. Methods 1, 31–37 (2004). source

      Not checked in the free run.

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

    Study design and conductown data

    Non-specific α-NeuN staining in the infarct core could be distinguished from neuronal nuclei by morphology.

    “Non-specific α-NeuN staining in the microinfarct core, likely due to undigested tissue matter, was easily distinguished from neuronal nuclei based on morphology.”
    Quote in the paperNot a substantial claim

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

    Study design and conductnone given

    Arterial pressure, blood gas levels, and pH remained normal throughout the calcium imaging and acute blood flow experiments.

    “Mean arterial blood pressure, blood gases, and blood pH were maintained within normal physiological levels throughout the Ca2+ imaging and acute blood flow experiments.”
    Quote in the paperSubstantial claim

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

    Study design and conductown data

    The rats kept about 90% of their starting body mass for the whole study.

    “All rats maintained ~90% of their original body weight over the duration of the study.”
    Quote in the paperNot a substantial claim

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

    Premisecitation

    Pimonidazole immunostaining marks hypoxic tissue.

    “For pimonidazole hydrochloride (Hypoxyprobe™; Hypoxyprobe.com) immunostaining of hypoxic tissue19, pimonidazole was injected through the femoral artery catheter one hour prior to perfusion fixation at a concentration of 60 mg/kg in a volume of 100 μL saline.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [19] Shih, A.Y. et al. Active dilation of penetrating arterioles restores red blood cell flux to penumbral neocortex after focal stroke. J. Cereb. Blood Flow Metab. 29, 738–751 (2009). source

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    The brain possesses remarkable plasticity and it is likely that over time focal loss of cortical function in this task will be recovered through remapping of surrounding viable tissue.

    “Indeed, the brain possesses remarkable plasticity and it is likely that, over time, the focal loss of cortical function in this task will be recovered through remapping of surrounding viable tissue46, 47.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [46] Troncoso, E. et al. Recovery of evoked potentials, metabolic activity and behavior in a mouse model of somatosensory cortex lesion: role of the neural cell adhesion molecule (NCAM). Cereb. Cortex 14, 332–341 (2004). source

      Not checked in the free run.

    • cites [47] Carmichael, S.T. Plasticity of cortical projections after stroke. Neuroscienist 9, 64–75 (2003). source

      Not checked in the free run.

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

    Interpretationreasoning

    A fall during a blank trial was required for every trained rat and taught them to probe before crossing.

    “Falling during a blank trial was a necessary event for all trained rats, as it reinforced the need to palpate before crossing.”
    • Also stated in: § Macrovibrissa-dependent behavioral testing · plain
      “This adverse experience assured that it would not jump without actively probing for the target platform in future trials.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Interpretationreasoning

    The gap-crossing task is based on localized sensory input leading to a cognitive decision and motor plan, rather than a purely sensory measure.

    “The task is based upon localized sensory input that leads to a cognitive decision and a motor plan, i.e., to cross or not to cross, as opposed to a purely sensory measure.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    Accumulation of multiple microinfarcts leads to multiplicative tissue damage, a novel mechanism of cortical injury that may result from small vessel disease.

    “Further, we show that an accumulation of multiple microinfarcts leads to multiplicative tissue damage (Fig. 8), a novel mechanism of cortical injury that may result from small vessel disease.”
    Quote in the paperSubstantial claim

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

    Premisecitation

    In later stages, a microinfarct is expected to become a fluid-filled cyst, which eventually collapses to become a linear scar or pucker in chronic stages.

    “In later stages, the microinfarct is expected to become a fluid-filled cyst, which eventually collapses to become a linear scar or ‘pucker’ in chronic stages3.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [3] Smith, E.E., Schneider, J.A., Wardlaw, J.M. & Greenberg, S.M. Cerebral microinfarcts: the invisible lesions. Lancet Neurol. 11, 272–282 (2012). source

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    Delayed thrombosis within the microvasculature may be involved in coalescence, as recruitment of neighboring penetrating vessels into the ischemic zone occurs approximately 12 to 24 hours after initial occlusions.

    “Rather, delayed thrombosis within the microvasculature may be involved, as recruitment of neighboring penetrating vessels into the ischemic zone occurs approximately 12 to 24 hours after the initial occlusions (Fig. 8c)”
    Quote in the paperSubstantial claim

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

    Study design and conductown data

    About 30% of the rats initially entered reached this training stage.

    “In toto, approximately 30 % of the initial rats achieved this level of training.”
    Quote in the paperNot a substantial claim

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

    Study design and conductown data

    About 15% of the rats initially entered reached this training stage.

    “In toto, approximately 15 % of the initial rats achieved this level of training.”
    Quote in the paperNot a substantial claim

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

    Premisecitation

    Venular thrombosis may involve additional mechanisms above ischemia, such as increased intracranial pressure and diapedesis of RBCs.

    “In contrast to arterial occlusion, venular thrombosis may involve additional mechanisms above ischemia, such as increased intracranial pressure and diapedesis of RBCs43.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [43] Villringer, A., Mehraein, S. & Einhäupl, K.M. Pathophysiological aspects of cerebral sinus venous thrombosis (SVT). J. Neuroradiol. 21, 72–80 (1994).

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    Therapeutic administration has a profound effect on both the size of isolated microinfarcts and the coalescence of multiple microinfarcts.

    “In toto, these data show that therapeutic administration has a profound effect on not only the size of isolated microinfarcts, but also the coalescence of multiple microinfarcts (Fig. 8i).”
    Quote in the paperSubstantial claim
37 of 37

  • The paper relies on this without support.

    The etiology and cognitive consequences of human cortical microinfarcts are unknown.

    “The etiology and cognitive consequences of human cortical microinfarcts are unknown.”

  • The paper relies on this without support.

    It is not clear whether microinfarcts are largely benign or contribute to cognitive decline.

    “Thus it is not clear if microinfarcts are largely benign or a contributing factor.”

  • The paper relies on this without support.

    Neuronal calcium transients indicate action potential firing.

    “The [Ca2+] transients from individual neurons, indicative of action potential firing, exhibited an effectively instantaneous increase followed by an exponential decay over a 1 to 2 s period (Fig. 3b).”

  • The paper relies on this without support.

    MK-801 and memantine are NMDA receptor antagonists.

    “The NMDAR antagonists MK-801 (Tocris) and Memantine (Tocris) were dissolved in sterile phosphate buffered saline (PBS) and stored at room temperature.”
4 of 4

Claims other papers make about this one

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Cites

Flagged first, then by citations

Research works printed but not linked: 3

  1. Driscoll, J.D., Shih, A.Y., Drew, P.J., Cauwenberghs, G. & Kleinfeld, D. Two-photon imaging of blood flow in cortex. in Imaging in Neuroscience: A Laboratory Manual (eds. Helmchen, F., Konnerth, A. & Yuste, R.) 927–938 (Cold Spring Harbor Laboratory Press, New York, 2011).
  2. Shih, A.Y. et al. Optically induced occlusion of single blood vessels in neocortex. in Imaging in Neuroscience: A Laboratory Manual (eds. Helmchen, F., Konnerth, A. & Yuste, R.) 939–948 (Cold Spring Harbor Laboratory Press, New York, 2011).
  3. Paxinos, G. & Watson, C. The Rat Brain in Stereotaxic Coordinates (Academic Press, San Diego, 1986).

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Related

Authors
Shih, A. Y., Blinder, P., Tsai, P. S., Friedman, B., Stanley, G., Lyden, P. D., & Kleinfeld, D.
Affiliations
  • University of California San Diego (US)
  • Medical University of South Carolina (US)
  • Cedars-Sinai Medical Center (US)
Corresponding author
Kleinfeld, David
ORCID
Venue
Nature Neuroscience
Publisher
Springer Science and Business Media LLC
Published
2012-12-16
Volume
16
Issue
1
Pages
55-63
ISSN
  • 1097-6256 (ISSN-L)
  • 1546-1726
DOI
10.1038/nn.3278
PMC
PMC3952571
OpenAlex
W2013392475
Semantic Scholar
442467e8c749718b52d0ab337667395eb19db40c
Cited by
351
References
59
Citations by year
2026: 16 · 2025: 20 · 2024: 28 · 2023: 18 · 2022: 29 · 2021: 37 · 2020: 33 · 2019: 20 · 2018: 24 · 2017: 24 · 2016: 24 · 2015: 33 · 2014: 25 · 2013: 19
FWCI
12.41
Type
journal article
Language
en
Open access
Licence
www.springer.com/tdm (tdm)
Locations
  • Nature Neuroscience (publishedVersion)
  • PubMed (publishedVersion)
  • Europe PMC (PubMed Central) (acceptedVersion)
  • PubMed Central (acceptedVersion)
Funders
  • National Institutes of Health (DP1OD006831)
  • National Institute of Mental Health (R01MH085499, MH085499)
  • National Institute of Neurological Disorders and Stroke (NS047101, P30NS047101)
  • National Institute of Biomedical Imaging and Bioengineering (R01EB003832, EB/003832)
Topics
  • Life Sciences › Neuroscience › Neurology › Neurological Disease Mechanisms and Treatments
  • Health Sciences › Medicine › Epidemiology › Acute Ischemic Stroke Management
  • Life Sciences › Neuroscience › Neurology › Barrier Structure and Function Studies
Keywords
cortical microinfarcts, penetrating arterioles, excitotoxicity, memantine, glutamate receptor antagonists, cognitive decline, vascular dementia, cortical columns, ischemic brain injury
MeSH terms
Animals, Brain Mapping, Calcium, Cognition Disorders, Disease Models, Animal, Glial Fibrillary Acidic Protein, Humans, Male, Memantine, Models, Biological, Neural Pathways, Phosphopyruvate Hydratase, Psychomotor Performance, Somatosensory Cortex, Vibrissae, Dizocilpine Maleate, Rats, Sprague-Dawley, Microscopy, Confocal, Neuroprotective Agents, Infarction, Middle Cerebral Artery, Rats, Long-Evans, Brain Infarction, Imaging, Three-Dimensional, Rats, Microvessels

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 2026-10-08.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-08.

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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