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

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Read our FAQs * Contact customer support SIMILAR CONTENT BEING VIEWED BY OTHERS NEUROVASCULAR COUPLING AND OXYGENATION ARE DECREASED IN HIPPOCAMPUS COMPARED TO NEOCORTEX BECAUSE OF

MICROVASCULAR DIFFERENCES Article Open access 27 May 2021 WHITE MATTER DAMAGE AS A CONSEQUENCE OF VASCULAR DYSFUNCTION IN A SPONTANEOUS MOUSE MODEL OF CHRONIC MILD CHRONIC HYPOPERFUSION WITH

ENOS DEFICIENCY Article Open access 10 August 2022 LONGITUDINAL HIPPOCAMPAL VOLUMETRIC CHANGES IN MICE FOLLOWING BRAIN INFARCTION Article Open access 13 May 2021 REFERENCES * Gorelick, P.B.

et al. Vascular contributions to cognitive impairment and dementia: a statement for healthcare professionals from the American Heart Association/American Stroke Association. _Stroke_ 42,

2672–2713 (2011). Article  PubMed  PubMed Central  Google Scholar  * Brundel, M., de Bresser, J., van Dillen, J.J., Kappelle, L.J. & Biessels, G.J. Cerebral microinfarcts: a systematic

review of neuropathological studies. _J. Cereb. Blood Flow Metab._ 32, 425–436 (2012). Article  PubMed  PubMed Central  Google Scholar  * Smith, E.E., Schneider, J.A., Wardlaw, J.M. &

Greenberg, S.M. Cerebral microinfarcts: the invisible lesions. _Lancet Neurol._ 11, 272–282 (2012). Article  PubMed  PubMed Central  Google Scholar  * Vinters, H.V. et al. Neuropathologic

substrates of ischemic vascular dementia. _J. Neuropathol. Exp. Neurol._ 59, 931–945 (2000). Article  CAS  PubMed  Google Scholar  * Kövari, E. et al. Cortical microinfarcts and

demyelination affect cognition in cases at high risk for dementia. _Neurology_ 68, 927–931 (2007). Article  PubMed  Google Scholar  * 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). Article  PubMed  PubMed Central  Google Scholar  * 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). Article  Google Scholar  * 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). Article  CAS  PubMed  PubMed Central  Google Scholar  * Lauwers, F., Cassot, F., Lauwers-Cances, V., Puwanarajah, P.

& Duvernoy, H. Morphometry of the human cerebral cortex microcirculation: general characteristics and space-related profiles. _Neuroimage_ 39, 936–948 (2008). Article  PubMed  Google

Scholar  * Bär, T. The vascular system of the cerebral cortex. _Adv. Anat. Embryol. Cell Biol._ 59, 1–62 (1980). Article  Google Scholar  * Nishimura, N., Schaffer, C.B., Friedman, B.,

Lyden, P.D. & Kleinfeld, D. Penetrating arterioles are a bottleneck in the perfusion of neocortex. _Proc. Natl. Acad. Sci. USA_ 104, 365–370 (2007). Article  CAS  PubMed  Google Scholar

  * Nguyen, J., Nishimura, N., Fetcho, R.N., Iadecola, C. & Schaffer, C.B. Occlusion of cortical ascending venules causes blood flow decreases, reversals in flow direction, and vessel

dilation in upstream capillaries. _J. Cereb. Blood Flow Metab._ 31, 2243–2254 (2011). Article  PubMed  PubMed Central  Google Scholar  * Drew, P.J. et al. Chronic optical access through a

polished and reinforced thinned skull. _Nat. Methods_ 7, 981–984 (2010). Article  CAS  PubMed  PubMed Central  Google Scholar  * Sofroniew, M.V. & Vinters, H.V. Astrocytes: biology and

pathology. _Acta Neuropathol._ 119, 7–35 (2010). Article  PubMed  Google Scholar  * Tsai, P.S. et al. Correlations of neuronal and microvascular densities in murine cortex revealed by direct

counting and colocalization of cell nuclei and microvessels. _J. Neurosci._ 29, 14553–14570 (2009). Article  CAS  PubMed  PubMed Central  Google Scholar  * Weber, B., Keller, A.L.,

Reichold, J. & Logothetis, N.K. The microvascular system of the striate and extrastriate visual cortex of the macaque. _Cereb. Cortex_ 18, 2318–2330 (2008). Article  PubMed  Google

Scholar  * Svoboda, K., Denk, W., Kleinfeld, D. & Tank, D.W. _In vivo_ dendritic calcium dynamics in neocortical pyramidal neurons. _Nature_ 385, 161–165 (1997). Article  CAS  PubMed 

Google Scholar  * Kleinfeld, D., Mitra, P.P., Helmchen, F. & Denk, W. Fluctuations and stimulus-induced changes in blood flow observed in individual capillaries in layers 2 through 4 of

rat neocortex. _Proc. Natl. Acad. Sci. USA_ 95, 15741–15746 (1998). Article  CAS  PubMed  PubMed Central  Google Scholar  * 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). Article  PubMed  Google Scholar  * Shih, A.Y. et al. Two-photon

microscopy as a tool to study blood flow and neurovascular coupling in the rodent brain. _J. Cereb. Blood Flow Metab._ 32, 1277–1309 (2012). Article  CAS  PubMed  PubMed Central  Google

Scholar  * Schaffer, C.B. et al. Two-photon imaging of cortical surface microvessels reveals a robust redistribution in blood flow after vascular occlusion. _PLoS Biol._ 4, e22 (2006).

Article  PubMed  PubMed Central  CAS  Google Scholar  * Nishimura, N. et al. Targeted insult to individual subsurface cortical blood vessels using ultrashort laser pulses: three models of

stroke. _Nat. Methods_ 3, 99–108 (2006). Article  CAS  PubMed  Google Scholar  * Stosiek, C., Garaschuk, O., Holthoff, K. & Konnerth, A. _In vivo_ two-photon calcium imaging of neuronal

networks. _Proc. Natl. Acad. Sci. USA_ 100, 7319–7324 (2003). Article  CAS  PubMed  PubMed Central  Google Scholar  * Chen, B. et al. Severe blood brain barrier disruption and surrounding

tissue injury. _Stroke_ 40, 666–674 (2009). CAS  Google Scholar  * 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). Article  CAS  PubMed  Google Scholar  * Friedman, B. et al. Acute vascular disruption and Aquaporin 4 loss

after stroke. _Stroke_ 40, 2182–2190 (2009). Article  PubMed  PubMed Central  Google Scholar  * 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). Article  CAS  PubMed  Google Scholar  * Soontornniyomkij, V. et al. Cerebral microinfarcts associated

with severe cerebral beta-amyloid angiopathy. _Brain Pathol._ 20, 459–467 (2010). Article  PubMed  Google Scholar  * Siesjô, B.K. & Bengtsson, F. Calcium fluxes, calcium antagonists and

calcium-related pathology in brain ischemia, hypoglycemia, and spreading depression: a unifying hypothesis. _J. Cereb. Blood Flow Metab._ 9, 127–140 (1989). Article  PubMed  Google Scholar 

* Murphy, T.H., Li, P., Betts, K. & Liu, R. Two-photon imaging of stroke onset _in vivo_ reveals that NMDA receptor–independent ischemic depolarization is the major cause of rapid

reversible damage to dendrites and spines. _J. Neurosci._ 28, 1756–1772 (2008). Article  CAS  PubMed  PubMed Central  Google Scholar  * Orgogozo, J.M., Rigaud, A.S., Stoffler, A., Mobius,

H.J. & Forette, F. Efficacy and safety of Memantine in patients with mild to moderate vascular dementia. _Stroke_ 33, 1834–1839 (2002). Article  CAS  PubMed  Google Scholar  * Olivares,

D. et al. N-Methyl D-Aspartate (NMDA) receptor antagonists and memantine treatment for Alzheimer's disease, vascular dementia and Parkinson's disease. _Curr. Alzheimer Res._ 9,

746–758 (2012). Article  CAS  PubMed  PubMed Central  Google Scholar  * Woolsey, T.A. & Van Der Loos, H. The structural organization of layer IV in the somatosensory region (SI) of mouse

cerebral cortex. _Brain Res._ 17, 205–242 (1970). Article  CAS  PubMed  Google Scholar  * Kleinfeld, D. & Deschênes, M. Neuronal basis for object location in the vibrissa scanning

sensorimotor system. _Neuron_ 72, 455–468 (2011). Article  CAS  PubMed  PubMed Central  Google Scholar  * Hutson, K.A. & Masterton, R.B. The sensory contribution of a single

vibrissa's cortical barrel. _J. Neurophysiol._ 56, 1196–1223 (1986). Article  CAS  PubMed  Google Scholar  * Masino, S.A., Kwon, M.C., Dory, Y. & Frostig., R.D. Characterization of

functional organization within rat barrel cortex using intrinsic signal optical imaging through a thinned skull. _Proc. Natl. Acad. Sci. USA_ 90, 9998–10002 (1993). Article  CAS  PubMed 

PubMed Central  Google Scholar  * Armstrong-James, M., Fox, K. & Das-Gupta, A. Flow of excitability within barrel cortex on striking a single vibrissa. _J. Neurophysiol._ 68, 1345–1358

(1992). Article  CAS  PubMed  Google Scholar  * Lashley, K.S. Mass action in cerebral function. _Science_ 73, 245–254 (1931). Article  CAS  PubMed  Google Scholar  * Reisberg, B. et al.

Memantine in moderate-to-severe Alzheimer's disease. _N. Engl. J. Med._ 348, 1333–1341 (2003). Article  CAS  PubMed  Google Scholar  * Wilcock, G.K. Memantine for the treatment of

dementia. _Lancet Neurol._ 2, 503–505 (2003). Article  CAS  PubMed  Google Scholar  * Woolsey, T.A. et al. Neuronal units linked to microvascular modules in cerebral cortex: response

elements for imaging the brain. _Cereb. Cortex_ 6, 647–660 (1996). Article  CAS  PubMed  Google Scholar  * Cassot, F. et al. Branching patterns for arterioles and venules of the human

cerebral cortex. _Brain Res._ 1313, 62–78 (2010). Article  CAS  PubMed  Google Scholar  * Villringer, A., Mehraein, S. & Einhäupl, K.M. Pathophysiological aspects of cerebral sinus

venous thrombosis (SVT). _J. Neuroradiol._ 21, 72–80 (1994). CAS  PubMed  Google Scholar  * Brown, W.R. & Thore, C.R. Cerebral microvascular pathology in aging and neurodegeneration.

_Neuropathol. Appl. Neurobiol._ 37, 56–74 (2011). Article  CAS  PubMed  PubMed Central  Google Scholar  * Zhang, S. & Murphy, T.H. Imaging the impact of cortical microcirculation on

synaptic structure and sensory-evoked hemodynamic responses _in vivo_. _PLoS Biol._ 5, e119 (2007). Article  PubMed  PubMed Central  CAS  Google Scholar  * 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).

Article  CAS  PubMed  Google Scholar  * Carmichael, S.T. Plasticity of cortical projections after stroke. _Neuroscienist_ 9, 64–75 (2003). Article  Google Scholar  * Mohajerani, M.H.,

Aminoltejari, K. & Murphy, T.H. Targeted mini-strokes produce changes in interhemispheric sensory signal processing that are indicative of disinhibition within minutes. _Proc. Natl.

Acad. Sci. USA_ 108, E183–E191 (2011). Article  PubMed  PubMed Central  Google Scholar  * Rosidi, N.L. et al. Cortical microhemorrhages cause local inflammation but do not trigger widespread

dendrite degeneration. _PLoS ONE_ 6, e26612 (2011). Article  CAS  PubMed  PubMed Central  Google Scholar  * Nishimura, N., Rosidi, N.L., Iadecola, C. & Schaffer, C.B. Limitations of

collateral flow after occlusion of a single cortical penetrating arteriole. _J. Cereb. Blood Flow Metab._ 30, 1914–1927 (2010). Article  PubMed  PubMed Central  Google Scholar  * Frostig,

R.D., Lieke, E.E., Ts'o, D.Y. & Grinvald, A. Cortical functional architecture and local coupling between neuronal activity and the microcirculation revealed by _in vivo_

high-resolution optical imaging of intrinsic signals. _Proc. Natl. Acad. Sci. USA_ 87, 6082–6086 (1990). Article  CAS  PubMed  PubMed Central  Google Scholar  * Kleinfeld, D. & Delaney,

K.R. Distributed representation of vibrissa movement in the upper layers of somatosensory cortex revealed with voltage sensitive dyes. _J. Comp. Neurol._ 375, 89–108 (1996). Article  CAS 

PubMed  Google Scholar  * Tsai, P.S. & Kleinfeld, D. _In vivo_ two-photon laser scanning microscopy with concurrent plasma-mediated ablation: principles and hardware realization. in

_Methods for In Vivo Optical Imaging 2nd edn._ (ed. Frostig, R.D.) 59–115 (CRC Press, 2009). * Valmianski, I. et al. Automatic identification of fluorescently labeled brain cells for rapid

functional imaging. _J. Neurophysiol._ 104, 1803–1811 (2010). Article  PubMed  PubMed Central  Google Scholar  * 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). * 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). * Nguyen, Q.-T., Dolnick, E.M., Driscoll, J. & Kleinfeld, D. MPScope 2.0: A computer system for two-photon

laser scanning microscopy with concurrent plasma-mediated ablation and electrophysiology. in _Methods for In Vivo Optical Imaging 2nd edn._ (ed. Frostig, R.D.) 117–142 (CRC Press, 2009). *

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). Article  CAS 

PubMed  Google Scholar  * Mehta, S.B., Whitmer, D., Figueroa, R., Williams, B.A. & Kleinfeld, D. Active spatial perception in the vibrissa scanning sensorimotor system. _PLoS Biol._ 5,

309–322 (2007). Article  CAS  Google Scholar  * Paxinos, G. & Watson, C. _The Rat Brain in Stereotaxic Coordinates_ (Academic Press, San Diego, 1986). Download references

ACKNOWLEDGEMENTS We thank A. Schweitzer for constructing the behavioral apparatus, S.E. Black, M. Deschênes, M.E. Diamond, F.F. Ebner, E.E. Smith and R. Swanson for discussions, and C. Mateo

for comments on an early version of the manuscript. This work was supported by the American Heart Association (Post-doctoral fellowship to A.Y.S.) and the US National Institutes of Health

(MH085499, EB003832 and OD006831 to D.K.), which further supported the University of California, San Diego Neuroscience Shared Microscopy Core (NS047101), which was used to image

histological tissue. AUTHOR INFORMATION Author notes * Andy Y Shih & Pablo Blinder Present address: Present addresses: Department of Neurosciences, Medical University of South Carolina,

Charleston, South Carolina, USA (A.Y.S.), Department of Neuroscience, Tel Aviv University, Tel Aviv, Israel (P.B.)., AUTHORS AND AFFILIATIONS * Department of Physics, University of

California at San Diego, La Jolla, California, USA Andy Y Shih, Pablo Blinder, Philbert S Tsai, Geoffrey Stanley & David Kleinfeld * Department of Pharmacology, University of California

at San Diego, La Jolla, California, USA Beth Friedman * Department of Neurology, Cedars-Sinai Hospital, Los Angeles, California, USA Patrick D Lyden * Section of Neurobiology, University of

California at San Diego, La Jolla, California, USA David Kleinfeld Authors * Andy Y Shih View author publications You can also search for this author inPubMed Google Scholar * Pablo Blinder

View author publications You can also search for this author inPubMed Google Scholar * Philbert S Tsai View author publications You can also search for this author inPubMed Google Scholar *

Beth Friedman View author publications You can also search for this author inPubMed Google Scholar * Geoffrey Stanley View author publications You can also search for this author inPubMed 

Google Scholar * Patrick D Lyden View author publications You can also search for this author inPubMed Google Scholar * David Kleinfeld View author publications You can also search for this

author inPubMed Google Scholar CONTRIBUTIONS A.Y.S., B.F., P.D.L. and D.K. designed the study. A.Y.S. and G.S. carried out the experiments. A.Y.S., P.B. and P.S.T. analyzed the data. A.Y.S.,

B.F. and D.K. wrote the manuscript. CORRESPONDING AUTHOR Correspondence to David Kleinfeld. ETHICS DECLARATIONS COMPETING INTERESTS The authors declare no competing financial interests.

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ARTICLE Shih, A., Blinder, P., Tsai, P. _et al._ The smallest stroke: occlusion of one penetrating vessel leads to infarction and a cognitive deficit. _Nat Neurosci_ 16, 55–63 (2013).

https://doi.org/10.1038/nn.3278 Download citation * Received: 01 October 2012 * Accepted: 15 November 2012 * Published: 16 December 2012 * Issue Date: January 2013 * DOI:

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