scholarly journals Spectral selectivity model for light transmission by the intermediate filaments in Müller cells

2017 ◽  
Vol 173 ◽  
pp. 282-290 ◽  
Author(s):  
Igor Khmelinskii ◽  
Tatiana Golubeva ◽  
Elena Korneeva ◽  
Mikhail Inyushin ◽  
Lidia Zueva ◽  
...  
Keyword(s):  
Intermediate Filaments ◽  
Light Transmission ◽  
Müller Cells ◽  
Muller Cells ◽  
Spectral Selectivity ◽  
Selectivity Model

scholarly journals The anatomy of the foveola reinvestigated

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4482 ◽  
Author(s):  
Alexander V. Tschulakow ◽  
Theo Oltrup ◽  
Thomas Bende ◽  
Sebastian Schmelzle ◽  
Ulrich Schraermeyer
Keyword(s):  
Light Beam ◽  
Focused Ion Beam ◽  
Light Transmission ◽  
Ion Beam ◽  
Incident Light ◽  
3D Structure ◽  
Müller Cells ◽  
Bright Spot ◽  
Muller Cells ◽  
Outer Segments

Objective In the foveola of the eye, photoreceptors and Müller cells with a unique morphology have been described, but little is known about their 3D structure and orientation. Considering that there is an angle-dependent change in the foveolar photoreceptor response for the same light beam, known as the Stiles Crawford Effect of the first kind (SCE I), which is still not fully understood, a detailed analysis of the anatomy of the foveolar cells might help to clarify this phenomenon. Methods Serial semithin and ultrathin sections, and focused ion beam (FIB) tomography were prepared from 32 foveolae from monkeys (Macaca fascicularis) and humans. Foveolae were also analyzed under the electron microscope. Serial sections and FIB analysis were then used to construct 3D models of central Müller and photoreceptor cells. In addition, we measured the transmission of collimated light under the light microscope at different angles after it had passed through human foveae from flat mounted isolated retinae. Results In monkeys, outer segments of central foveolar cones are twice as long as those from parafoveal cones and do not run completely parallel to the incident light. Unique Müller cells are present in the central foveolae (area of 200 µm in diameter) of humans and monkeys. Light entering the fovea center, which is composed only of cones and Müller cells, at an angle of 0° causes a very bright spot after passing through this area. However, when the angle of the light beam is changed to 10°, less light is measured after transpasssing through the retina, the foveolar center becomes darker and the SCE-like phenomenon is directly visible. Measurements of the intensities of light transmission through the central foveola for the incident angles 0 and 10° resemble the relative luminance efficiency for narrow light bundles as a function of the location where the beam enters the pupil as reported by Stiles and Crawford. The effect persisted after carefully brushing away the outer segments. Conclusion We show that unique cones and Müller cells with light fibre-like properties are present in the center of the fovea. These unique Müller cells cause an angle dependent, SCE-like drop in the intensity of light guided through the foveola. Outer segments from the foveolar cones of monkeys are not straight.

scholarly journals Foveolar Müller Cells of the Pied Flycatcher: Morphology and Distribution of Intermediate Filaments Regarding Cell Transparency

2016 ◽  
Vol 22 (2) ◽  
pp. 379-386 ◽  
Author(s):  
Lidia Zueva ◽  
Tatiana Golubeva ◽  
Elena Korneeva ◽  
Vladimir Makarov ◽  
Igor Khmelinskii ◽  
...  
Keyword(s):  
Intermediate Filaments ◽  
Müller Cells ◽  
Müller Cell ◽  
Light Transport ◽  
Pied Flycatcher ◽  
Muller Cells ◽  
Fiber Cells ◽  
Physical Mechanisms ◽  
Muller Cell ◽  
Reported Data

AbstractSpecialized intermediate filaments (IFs) have critical importance for the clearness and uncommon transparency of vertebrate lens fiber cells, although the physical mechanisms involved are poorly understood. Recently, an unusual low-scattering light transport was also described in retinal Müller cells. Exploring the function of IFs in Müller cells, we have studied the morphology and distribution pattern of IFs and other cytoskeletal filaments inside the Müller cell main processes in the foveolar part of the avian (pied flycatcher) retina. We found that some IFs surrounded by globular nanoparticles (that we suggest are crystallines) are present in almost every part of the Müller cells that span the retina, including the microvilli. Unlike IFs implicated in the mechanical architecture of the cell, these IFs are not connected to any specific cellular membranes. Instead, they are organized into bundles, passing inside the cell from the endfeet to the photoreceptor, following the geometry of the processes, and repeatedly circumventing numerous obstacles. We believe that the presently reported data effectively confirm that the model of nanooptical channels built of the IFs may provide a viable explanation of Müller cell transparency.

scholarly journals The anatomy of the foveola reinvestigated

2018 ◽  
Author(s):  
Alexander V. Tschulakow ◽  
Theo Oltrup ◽  
Thomas Bende ◽  
Sebastian Schmelzle ◽  
Ulrich Schraermeyer
Keyword(s):  
Light Beam ◽  
Focused Ion Beam ◽  
Light Transmission ◽  
Ion Beam ◽  
Incident Light ◽  
3D Structure ◽  
Müller Cells ◽  
Bright Spot ◽  
Muller Cells ◽  
Outer Segments

Objective. In the foveola of the eye, photoreceptors and Müller cells with a unique morphology have been described, but little is known about their 3D structure and orientation. Considering that there is an angle-dependent change in the foveolar photoreceptor response for the same light beam, known as the Stiles Crawford Effect of the first kind (SCE I), which is still not fully understood, a detailed analysis of the anatomy of the foveolar cells might help to clarify this phenomenon. Methods. Serial semithin and ultrathin sections, and focused ion beam (FIB) tomography were -prepared from 32 foveolae from monkeys (Macaca fascicularis) and humans. Foveolae were also analyzed under the electron microscope. Serial sections and FIB analysis were then used to construct 3D models of central Müller and photoreceptor cells. In addition, we measured the transmission of collimated light under the light microscope at different angles after it had passed through human foveae from flat mounted isolated retinae. Results. In monkeys, outer segments of central foveolar cones are twice as long as those from parafoveal cones and do not run completely parallel to the incident light. Unique Müller cells are present in the central foveolae (area of 200 µm in diameter) of humans and monkeys. Light entering the fovea center, which is composed only of cones and Müller cells, at an angle of 0 degrees causes a very bright spot after passing through this area. However, when the angle of the light beam is changed to 10 degrees, less light is measured after transpasssing through the retina, the foveolar center becomes darker and the SCE-like phenomenon is directly visible. Measurements of the intensities of light transmission through the central foveola for the incident angles 0 and 10 degrees resemble the relative luminance efficiency for narrow light bundles as a function of the location where the beam enters the pupil as reported by Stiles and Crawford. The effect persisted after carefully brushing away the outer segments. Conclusion. We show that unique cones and Müller cells with light fibre-like properties are present in the center of the fovea. These unique Müller cells cause an angle dependent, SCE-like drop in the intensity of light guided through the foveola. Outer segments from the foveola cones of monkeys are not straight.

scholarly journals The anatomy of the foveola reinvestigated

2018 ◽  
Author(s):  
Alexander V. Tschulakow ◽  
Theo Oltrup ◽  
Thomas Bende ◽  
Sebastian Schmelzle ◽  
Ulrich Schraermeyer
Keyword(s):  
Light Beam ◽  
Focused Ion Beam ◽  
Light Transmission ◽  
Ion Beam ◽  
Incident Light ◽  
3D Structure ◽  
Müller Cells ◽  
Bright Spot ◽  
Muller Cells ◽  
Outer Segments

Objective. In the foveola of the eye, photoreceptors and Müller cells with a unique morphology have been described, but little is known about their 3D structure and orientation. Considering that there is an angle-dependent change in the foveolar photoreceptor response for the same light beam, known as the Stiles Crawford Effect of the first kind (SCE I), which is still not fully understood, a detailed analysis of the anatomy of the foveolar cells might help to clarify this phenomenon. Methods. Serial semithin and ultrathin sections, and focused ion beam (FIB) tomography were -prepared from 32 foveolae from monkeys (Macaca fascicularis) and humans. Foveolae were also analyzed under the electron microscope. Serial sections and FIB analysis were then used to construct 3D models of central Müller and photoreceptor cells. In addition, we measured the transmission of collimated light under the light microscope at different angles after it had passed through human foveae from flat mounted isolated retinae. Results. In monkeys, outer segments of central foveolar cones are twice as long as those from parafoveal cones and do not run completely parallel to the incident light. Unique Müller cells are present in the central foveolae (area of 200 µm in diameter) of humans and monkeys. Light entering the fovea center, which is composed only of cones and Müller cells, at an angle of 0 degrees causes a very bright spot after passing through this area. However, when the angle of the light beam is changed to 10 degrees, less light is measured after transpasssing through the retina, the foveolar center becomes darker and the SCE-like phenomenon is directly visible. Measurements of the intensities of light transmission through the central foveola for the incident angles 0 and 10 degrees resemble the relative luminance efficiency for narrow light bundles as a function of the location where the beam enters the pupil as reported by Stiles and Crawford. The effect persisted after carefully brushing away the outer segments. Conclusion. We show that unique cones and Müller cells with light fibre-like properties are present in the center of the fovea. These unique Müller cells cause an angle dependent, SCE-like drop in the intensity of light guided through the foveola. Outer segments from the foveola cones of monkeys are not straight.

scholarly journals Localization of αA-Crystallin in Rat Retinal Müller Glial Cells and Photoreceptors

2018 ◽  
Vol 24 (5) ◽  
pp. 545-552 ◽  
Author(s):  
Astrid Zayas-Santiago ◽  
David S. Ríos ◽  
Lidia V. Zueva ◽  
Mikhail Y. Inyushin
Keyword(s):  
Glial Cells ◽  
Light Transmission ◽  
Müller Cells ◽  
Cell Types ◽  
Confocal Imaging ◽  
Muller Cells ◽  
Müller Glial Cells ◽  
Fluorescence Confocal Imaging ◽  
Light Guides ◽  
Epithelium Cells

AbstractTransparent cells in the vertebrate optical tract, such as lens fiber cells and corneal epithelium cells, have specialized proteins that somehow permit only a low level of light scattering in their cytoplasm. It has been shown that both cell types contain (1) beaded intermediate filaments as well as (2) α-crystallin globulins. It is known that genetic and chemical alterations to these specialized proteins induce cytoplasmic opaqueness and visual complications. Crystallins were described previously in the retinal Müller cells of frogs. In the present work, using immunocytochemistry, fluorescence confocal imaging, and immuno-electron microscopy, we found that αA-crystallins are present in the cytoplasm of retinal Müller cells and in the photoreceptors of rats. Given that Müller glial cells were recently described as “living light guides” as were photoreceptors previously, we suggest that αA-crystallins, as in other highly transparent cells, allow Müller cells and photoreceptors to minimize intraretinal scattering during retinal light transmission.

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