scholarly journals Daily mitochondrial dynamics in cone photoreceptors

2020 ◽  
Vol 117 (46) ◽  
pp. 28816-28827
Author(s):  
Michelle M. Giarmarco ◽  
Daniel C. Brock ◽  
Brian M. Robbings ◽  
Whitney M. Cleghorn ◽  
Kristine A. Tsantilas ◽  
...  
Keyword(s):  
Light Exposure ◽  
Mitochondrial Dynamics ◽  
Three Dimensional ◽  
Cone Photoreceptors ◽  
Energy Demands ◽  
Mitochondrial Turnover ◽  
And Function ◽  
Extracellular Structures ◽  
Endoplasmic Reticula ◽  
Daily Changes

Cone photoreceptors in the retina are exposed to intense daylight and have higher energy demands in darkness. Cones produce energy using a large cluster of mitochondria. Mitochondria are susceptible to oxidative damage, and healthy mitochondrial populations are maintained by regular turnover. Daily cycles of light exposure and energy consumption suggest that mitochondrial turnover is important for cone health. We investigated the three-dimensional (3D) ultrastructure and metabolic function of zebrafish cone mitochondria throughout the day. At night retinas undergo a mitochondrial biogenesis event, corresponding to an increase in the number of smaller, simpler mitochondria and increased metabolic activity in cones. In the daytime, endoplasmic reticula (ER) and autophagosomes associate more with mitochondria, and mitochondrial size distribution across the cluster changes. We also report dense material shared between cone mitochondria that is extruded from the cell at night, sometimes forming extracellular structures. Our findings reveal an elaborate set of daily changes to cone mitochondrial structure and function.

Daily mitochondrial dynamics in cone photoreceptors

2020 ◽  
Author(s):  
Michelle Marie Giarmarco ◽  
Daniel C Brock ◽  
Brian M Robbings ◽  
Whitney M Cleghorn ◽  
Kristine A Tsantilas ◽  
...  
Keyword(s):  
Light Exposure ◽  
Mitochondrial Dynamics ◽  
Cone Photoreceptors ◽  
Mitochondrial Structure ◽  
Energy Demands ◽  
Daily Cycles ◽  
Mitochondrial Turnover ◽  
And Function ◽  
Extracellular Structures ◽  
Daily Changes

Cone photoreceptors in the retina are exposed to intense daylight, and have higher energy demands in darkness. Cones produce energy using a large cluster of mitochondria. Mitochondria are susceptible to oxidative damage, and healthy mitochondrial populations are maintained by regular turnover. Daily cycles of light exposure and energy consumption suggest that mitochondrial turnover is important for cone health. We investigated the 3-D ultrastructure and metabolic function of zebrafish cone mitochondria throughout the day. At night cones undergo a mitochondrial biogenesis event, corresponding to an increase in the number of smaller, simpler mitochondria and increased metabolic activity. In the daytime, ER and autophagosomes associate more with mitochondria, and mitochondrial size distribution across the cluster changes. We also report dense material shared between cone mitochondria that is extruded from the cell in darkness, sometimes forming extracellular structures. Our findings reveal an elaborate set of daily changes to cone mitochondrial structure and function.

Multidimensional fluorescence microscopy in live cell imaging – A mini review

2012 ◽  
Vol 1 (1) ◽  
Author(s):  
Herbert Schneckenburger ◽  
Petra Weber ◽  
Michael Wagner ◽  
Thomas Bruns ◽  
Verena Richter ◽  
...  
Keyword(s):  
Fluorescence Microscopy ◽  
Fluorescent Proteins ◽  
Light Exposure ◽  
Single Cells ◽  
Three Dimensional ◽  
Fluorescence Lifetime Imaging ◽  
Single Plane ◽  
Fluorescent Markers ◽  
And Function ◽  
Multidimensional Fluorescence

AbstractFluorescence microscopy methods are described with high spatial, spectral, and temporal resolution. In addition to three-dimensional (3D) microscopy, based on confocal, structured, or single-plane illumination, spectral imaging and fluorescence lifetime imaging microscopy are used to probe the conformation of fluorescent molecules as well as their interaction with the microenvironment. In addition to single cells or cell monolayers, 3D cell cultures are used increasingly, as they are more representative for tissue morphology and function. All methods are discussed in the context of controlled light exposure, which is regarded as a key parameter to maintain cell viability. The applications presented in this mini review include autofluorescence measurements of glioblastoma cells as well as various fluorescent markers or fluorescent proteins.

scholarly journals Rutin and Gallic Acid Regulates Mitochondrial Functions via the SIRT1 Pathway in C2C12 Myotubes

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 286
Author(s):  
Wei-Tang Chang ◽  
Shih-Chien Huang ◽  
Hsin-Lin Cheng ◽  
Shiuan-Chih Chen ◽  
Chin-Lin Hsu
Keyword(s):  
Gallic Acid ◽  
Molecular Mechanisms ◽  
Citrate Synthase ◽  
Mitochondrial Dynamics ◽  
C2c12 Myotubes ◽  
Gene Expressions ◽  
Mitochondrial Functions ◽  
Mitochondrial Turnover ◽  
And Function

Mitochondria are highly dynamic organelles, balancing synthesis and degradation in response to increases in mitochondrial turnover (i.e., biogenesis, fusion, fission, and mitophagy) and function. The aim of this study was to investigate the role of polyphenols in the regulation of mitochondrial functions and dynamics in C2C12 myotubes and their molecular mechanisms. Our results indicate that gallic acid and rutin are the most potential polyphenol compounds in response to 15 phenolic acids and 5 flavonoids. Gallic acid and rutin were associated with a significantly greater mitochondrial DNA (cytochrome b and COX-II), mitochondrial enzymatic activities (including citrate synthase and cytochrome c oxidase), and intracellular ATP levels in C2C12 myotubes. Moreover, gallic acid and rutin significantly increased the gene expressions of mitochondrial turnover in C2C12 myotubes. Our findings indicated that gallic acid and rutin may have a beneficial effect on mitochondrial dynamics via regulation of the SIRT1-associated pathway in C2C12 myotubes.

Conformation of Ribosomes from Escherichia Coli

1974 ◽  
Vol 32 ◽  
pp. 210-211
Author(s):  
M. Boublik ◽  
W. Hellmann ◽  
F. Jenkins
Keyword(s):  
Binding Sites ◽  
Ribosomal Proteins ◽  
Fluorescent Dyes ◽  
Protein Biosynthesis ◽  
Three Dimensional ◽  
Spatial Arrangement ◽  
Dimensional Structure ◽  
Complete Understanding ◽  
And Function

The present knowledge of the three-dimensional structure of ribosomes is far too limited to enable a complete understanding of the various roles which ribosomes play in protein biosynthesis. The spatial arrangement of proteins and ribonuclec acids in ribosomes can be analysed in many ways. Determination of binding sites for individual proteins on ribonuclec acid and locations of the mutual positions of proteins on the ribosome using labeling with fluorescent dyes, cross-linking reagents, neutron-diffraction or antibodies against ribosomal proteins seem to be most successful approaches. Structure and function of ribosomes can be correlated be depleting the complete ribosomes of some proteins to the functionally inactive core and by subsequent partial reconstitution in order to regain active ribosomal particles.

Structure and function of neural networks in the retina

1988 ◽  
Vol 46 ◽  
pp. 26-27
Author(s):  
Peter Sterling
Keyword(s):  
Ganglion Cells ◽  
Three Dimensional ◽  
Structure And Function ◽  
Synaptic Connections ◽  
Visual Axis ◽  
One Dimensional ◽  
Cat Retina ◽  
Ultrathin Sections ◽  
And Function ◽  
Insight Into

The synaptic connections in cat retina that link photoreceptors to ganglion cells have been analyzed quantitatively. Our approach has been to prepare serial, ultrathin sections and photograph en montage at low magnification (˜2000X) in the electron microscope. Six series, 100-300 sections long, have been prepared over the last decade. They derive from different cats but always from the same region of retina, about one degree from the center of the visual axis. The material has been analyzed by reconstructing adjacent neurons in each array and then identifying systematically the synaptic connections between arrays. Most reconstructions were done manually by tracing the outlines of processes in successive sections onto acetate sheets aligned on a cartoonist's jig. The tracings were then digitized, stacked by computer, and printed with the hidden lines removed. The results have provided rather than the usual one-dimensional account of pathways, a three-dimensional account of circuits. From this has emerged insight into the functional architecture.

Structural Role of rRNAs on the Ribosomal Subunits from E. Coli by Scanning Transmission Electron Microscopy

1981 ◽  
Vol 39 ◽  
pp. 424-425
Author(s):  
M. Boublik ◽  
N. Robakis ◽  
J.S. Wall
Keyword(s):  
Three Dimensional ◽  
Uranyl Acetate ◽  
Dimensional Structure ◽  
Electron Microscopic ◽  
Ribosomal Subunits ◽  
E Coli ◽  
Freeze Dried ◽  
16S Rna ◽  
Scanning Transmission ◽  
And Function

The three-dimensional structure and function of biological supramolecular complexes are, in general, determined and stabilized by conformation and interactions of their macromolecular components. In the case of ribosomes, it has been suggested that one of the functions of ribosomal RNAs is to act as a scaffold maintaining the shape of the ribosomal subunits. In order to investigate this question, we have conducted a comparative TEM and STEM study of the structure of the small 30S subunit of E. coli and its 16S RNA.The conventional electron microscopic imaging of nucleic acids is performed by spreading them in the presence of protein or detergent; the particles are contrasted by electron dense solution (uranyl acetate) or by shadowing with metal (tungsten). By using the STEM on freeze-dried specimens we have avoided the shearing forces of the spreading, and minimized both the collapse of rRNA due to air drying and the loss of resolution due to staining or shadowing. Figure 1, is a conventional (TEM) electron micrograph of 30S E. coli subunits contrasted with uranyl acetate.

Predicting spatial activity patterns in a neural map from a probabilistic atlas of 3-D reconstructed neurons

1995 ◽  
Vol 53 ◽  
pp. 812-813
Author(s):  
G. Jacobs ◽  
F. Theunissen
Keyword(s):  
Activity Patterns ◽  
Three Dimensional ◽  
Sensory System ◽  
Neural System ◽  
Probabilistic Atlas ◽  
Uniform Sample ◽  
Dimensional Reconstruction ◽  
The Time Domain ◽  
And Function ◽  
Visualization Techniques

In order to understand how the algorithms underlying neural computation are implemented within any neural system, it is necessary to understand details of the anatomy, physiology and global organization of the neurons from which the system is constructed. Information is represented in neural systems by patterns of activity that vary in both their spatial extent and in the time domain. One of the great challenges to microscopists is to devise methods for imaging these patterns of activity and to correlate them with the underlying neuroanatomy and physiology. We have addressed this problem by using a combination of three dimensional reconstruction techniques, quantitative analysis and computer visualization techniques to build a probabilistic atlas of a neural map in an insect sensory system. The principal goal of this study was to derive a quantitative representation of the map, based on a uniform sample of afferents that was of sufficient size to allow statistically meaningful analyses of the relationships between structure and function.

scholarly journals Efficient 3D printing via photooxidation of ketocoumarin based photopolymerization

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiaoyu Zhao ◽  
Ye Zhao ◽  
Ming-De Li ◽  
Zhong’an Li ◽  
Haiyan Peng ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Visible Light ◽  
Light Exposure ◽  
Three Dimensional ◽  
3D Printer ◽  
Light Penetration ◽  
Viable Solution

AbstractPhotopolymerization-based three-dimensional (3D) printing can enable customized manufacturing that is difficult to achieve through other traditional means. Nevertheless, it remains challenging to achieve efficient 3D printing due to the compromise between print speed and resolution. Herein, we report an efficient 3D printing approach based on the photooxidation of ketocoumarin that functions as the photosensitizer during photopolymerization, which can simultaneously deliver high print speed (5.1 cm h−1) and high print resolution (23 μm) on a common 3D printer. Mechanistically, the initiating radical and deethylated ketocoumarin are both generated upon visible light exposure, with the former giving rise to rapid photopolymerization and high print speed while the latter ensuring high print resolution by confining the light penetration. By comparison, the printed feature is hard to identify when the ketocoumarin encounters photoreduction due to the increased lateral photopolymerization. The proposed approach here provides a viable solution towards efficient additive manufacturing by controlling the photoreaction of photosensitizers during photopolymerization.

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