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Multi-Photon Microscopy, High Resolution Imaging Deep in Strongly Scattering Specimens

Published online by Cambridge University Press:  02 July 2020

Winfried Denk*
Affiliation:
Biological Computation Research Department Bell Laboratories, Lucent Technologies Murray Hill, NJ, 07974
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Extract

Imaging small structures substantially below the tissue surface in living specimens poses special challenges mainly because light is scattered by ever present refractive index inhomogeneities. Confocal microscoy removes the blurring caused by scattered and out-of-focus light but does so only at the expense of photodynamic damage that is often unacceptable when observing live specimens.

Multi-photon absorption microscopy[l] solves these problems because excitation is virtually limited to the focal plane. Out-of-focus photobleaching and photodamage are therefore eliminated. In scattering samples substantial improvements accrue even for the focal plane because, different from confocal microscopy, where only ballistic fluorescenc photons can be used, in the multi-photon microscope scattered photons can be utilized in addition [2-4], provided whole-field detection is used[5].

Many questions in the study of the nervous system require the investigation of intact portions of neural tissue in order to preserve the multiply branched processes of neurons, often extending over hundreds of microns, together with the local nervous circuitry.

Type
Biological Applications of Multi-photon Excitation Fluorescence Imaging
Copyright
Copyright © Microscopy Society of America 1997

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References

1.Denk, W., Strickler, J.H., and Webb, W.W., Two-photon laser scanning fluorescence microscopy. Science, 1990. 248: p. 7376.Google Scholar
2.Denk, W., et al., Anatomical and functional imaging of neurones using 2-photon laser scanning microscopy. J. Neurosci. Meth., 1994. 54(2): p. 151162.10.1016/0165-0270(94)90189-9CrossRefGoogle Scholar
3.Denk, W., Two-Photon Excitation in Functional Biological Imaging. J. Biomed. Opt., 1996. 1(3): p. 296304.10.1117/12.242945CrossRefGoogle ScholarPubMed
4.Denk, W. and Svoboda, K., Photon upmanship: why multiphoton imaging is more than a gimmick. Neuron, 1997. : p. in press.10.1016/S0896-6273(00)81237-4CrossRefGoogle Scholar
5.Denk, W., Piston, D.W., and Webb, WW., Two-photon molecular excitation in laser scanning microscopy, in The Handbook of ConfocalMicroscopy, Pawley, J., Editor. 1995, Plenum: New York. p. 445458.Google Scholar
6.Yuste, R. and Denk, W., Dendritic spines as basic functional units of neuronal integration. Nature, 1995. 375(6533). p. 682684.Google Scholar
7.Denk, W., Sugimori, M., and Llinas, R., Two types of calcium response limited to single spines in cerebellar Purkinje cells. Proc. Natl. Acad. Sci. (USA), 1995. 92(18). p. 82798282.10.1073/pnas.92.18.8279CrossRefGoogle ScholarPubMed
8.Svoboda, K., Tank, D.W., and Denk, W., Direct measurement of coupling between dendritic spines and shaft. Science, 1996. 272(5262): p. 716719.Google Scholar
9.Svoboda, K., Denk, W., Kleinfeld, D., and Tank, D., In Vivo Dendritic Calcium Dynamics in Neocortical Pyramidal Neurons. Nature, 1997. 385(6612): p. 161165.Google Scholar
10.Denk, W., Two-photon scanning photochemical microscopy: mapping ligand-gated ion channel distributions. Proc. Natl. Acad. Sci. (USA), 1994. 91: p. 66296633.10.1073/pnas.91.14.6629CrossRefGoogle ScholarPubMed