Three-dimensional confocal microscopy of the mammalian inner ear

One of the classic limitations of light microscopy has been the fact that three dimensional biological events could only be visualized in two dimensions. Recently, this shortcoming has been overcome by combining the technologies of laser scanning confocal microscopy (LSCM) and computer processing of microscopical data by volume rendering methods. We have employed these techniques to examine morphogenetic events characterizing early development of sea urchin embryos. Specifically, the fourth cleavage division was examined because it is at this point that the first morphological signs of cell differentiation appear, manifested in the production of macromeres and micromeres by unequally dividing vegetal blastomeres.The mitotic spindle within vegetal blastomeres undergoing unequal cleavage are highly polarized and develop specialized, flattened asters toward the micromere pole. In order to reconstruct the three-dimensional features of these spindles, both isolated spindles and intact, extracted embryos were fluorescently labeled with antibodies directed against either centrosomes or tubulin.

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An Engineered Three-Dimensional Stem Cell Niche in the Inner Ear by Applying a Nanofibrillar Cellulose Hydrogel with a Sustained-Release Neurotrophic Factor Delivery System

SSRN Electronic Journal ◽

10.2139/ssrn.3490431 ◽

2019 ◽

Author(s):

Hsiang-Tsun Chang ◽

Andrew M. Oleksijew ◽

Kyle S. Coots ◽

Rachel A. Heuer ◽

Kevin T. Nella ◽

...

Keyword(s):

Stem Cell ◽

Sustained Release ◽

Inner Ear ◽

Delivery System ◽

Neurotrophic Factor ◽

Stem Cell Niche ◽

Three Dimensional ◽

Nanofibrillar Cellulose ◽

Cellulose Hydrogel ◽

Cell Niche

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Reproducibility of Volumetric Assessment of the Inner Ear Using Three Dimensional Reconstruction of the High Resolution MR Sequence

Current Medical Imaging Formerly Current Medical Imaging Reviews ◽

10.2174/1573405613666170331104444 ◽

2018 ◽

Vol 14 (4) ◽

pp. 582-586

Author(s):

Nagy N.N. Naguib ◽

Ahmed M. Emam ◽

Tatjana Gruber-Rouh ◽

Marc Harth ◽

Renate Hammersting ◽

...

Keyword(s):

High Resolution ◽

Inner Ear ◽

Three Dimensional ◽

Three Dimensional Reconstruction ◽

Volumetric Assessment ◽

Dimensional Reconstruction

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Two-Photon Excitation Imaging of Glucose Metabolism in Living Tissue

Microscopy and Microanalysis ◽

10.1017/s1431927600008412 ◽

1997 ◽

Vol 3 (S2) ◽

pp. 305-306

Author(s):

David W. Piston

Keyword(s):

Confocal Microscopy ◽

Collection Efficiency ◽

Three Dimensional ◽

Spatial Filter ◽

Input Power ◽

Photon Absorption ◽

Focal Volume ◽

Two Photon ◽

Photon Excitation ◽

Two Photon Excitation

Two-photon excitation microscopy (TPEM) provides attractive advantages over confocal microscopy for three-dimensionally resolved fluorescence imaging and photochemistry. It provides three-dimensional resolution and eliminates background equivalent to an ideal confocal microscope without requiring a confocal spatial filter, whose absence enhances fluorescence collection efficiency. This results in inherent submicron optical sectioning by excitation alone. In practice, TPEM is made possible by the very high local instantaneous intensity provided by a combination of diffraction-limited focusing of a single laser beam in the microscope and the temporal concentration of 100 femtosecond pulses generated by a mode-locked laser. Resultant peak excitation intensities are 106 times greater than the CW intensities used in confocal microscopy, but the pulse duty cycle of 10−5 limits the average input power to less than 10 mW, only slightly greater than the power normally used in confocal microscopy. Because of the intensity-squared dependence of the two-photon absorption, the excitation is limited to the focal volume.

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The morphology of the inner ear of squamate reptiles and its bearing on the origin of snakes

Royal Society Open Science ◽

10.1098/rsos.170685 ◽

2017 ◽

Vol 4 (8) ◽

pp. 170685 ◽

Cited By ~ 11

Author(s):

Alessandro Palci ◽

Mark N. Hutchinson ◽

Michael W. Caldwell ◽

Michael S. Y. Lee

Keyword(s):

Geometric Morphometrics ◽

Inner Ear ◽

Phylogenetic Signal ◽

Three Dimensional ◽

Lizard Species ◽

Squamate Reptiles ◽

Strong Affinity ◽

Ear Morphology

The inner ear morphology of 80 snake and lizard species, representative of a range of ecologies, is here analysed and compared to that of the fossil stem snake Dinilysia patagonica , using three-dimensional geometric morphometrics. Inner ear morphology is linked to phylogeny (we find here a strong phylogenetic signal in the data that can complicate ecological correlations), but also correlated with ecology, with Dinilysia resembling certain semi-fossorial forms ( Xenopeltis and Cylindrophis ), consistent with previous reports. We here also find striking resemblances between Dinilysia and some semi-aquatic snakes, such as Myron (Caenophidia, Homalopsidae). Therefore, the inner ear morphology of Dinilysia is consistent with semi-aquatic as well as semi-fossorial habits: the most similar forms are either semi-fossorial burrowers with a strong affinity to water ( Xenopeltis and Cylindrophis ) or amphibious, intertidal forms which shelter in burrows ( Myron). Notably, Dinilysia does not cluster as closely with snakes with exclusively terrestrial or obligate burrowing habits (e.g. scolecophidians and uropeltids). Moreover, despite the above similarities, Dinilysia also occupies a totally unique morphospace, raising issues with linking it with any particular ecological category.

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