Rod Outer Segment
Rod Outer Segment - Related Videos
09:36
Outer-Boundary Assisted Segmentation and Quantification of Trabecular Bones by an Imagej Plugin
0 Views •
2018
We present a workflow for segmenting and quantifying trabecular bones for 2D and 3D images based on the bone's outer boundary using an ImageJ plugin. This approach is more efficient and accurate than the current manual hand-contouring approach, and provides layer-by-layer quantifications, which are not available in current commercial software.
10:02
Large-Scale Purification of Porcine or Bovine Photoreceptor Outer Segments for Phagocytosis Assays on Retinal Pigment Epithelial Cells
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Cited by 62 •
2014
This article describes the protocol for the purification of photoreceptor outer segment fragments (POS) via ultracentrifugation from porcine/bovine retinae using homogenization and sucrose gradient centrifugation. This protocol allows the preparation of large stocks of POS aliquots, labeled or unlabeled, that can then be stored at -80 °C.
11:09
Rodent Identification I
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2015
Source: Kay Stewart, RVT, RLATG, CMAR; Valerie A. Schroeder, RVT, RLATG. University of Notre Dame, IN A fundamental requirement of biomedical research is the proper identification of research animals. It is essential that the right animal is utilized for procedures and data collection. Laboratory mice and rats can be identified with the following permanent methods: ear tags, ear punch codes, microchip implantation, tail tattoos for adult mice, and toe tattoos for neonates. Temporary methods of...
14:12
Rodent Identification II
0 Views •
2015
Source: Kay Stewart, RVT, RLATG, CMAR; Valerie A. Schroeder, RVT, RLATG. University of Notre Dame, IN Animal records must be accurately maintained to ensure that data collection is correct. Records range from maintaining information on cage cards to having a detailed database with all of the relevant information on each animal. The primary component of recordkeeping is the individual identification of research animals. There are a variety of methods suitable for identifying mice and rats. This...
11:06
Method for the Isolation of Francisella tularensis Outer Membranes
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Cited by 11 •
2010
A protocol for separating inner and outer membranes from Francisella tularensis by spheroplasting, osmotic lysis, and sucrose density gradient ultracentrifugation.
FAQs
Light detection begins when photons activate rhodopsin in the disc membranes. This activation initiates a G protein signaling cascade that reduces cyclic GMP, a signaling molecule, and causes ion channels to close. The resulting hyperpolarization changes the rod’s electrical state, providing the mechanism by which events in the outer segment contribute to neural signaling during dim-light vision.
Stacked discs provide a concentrated membrane environment for rhodopsin and other phototransduction proteins. Their organization places the molecular components of light signaling within the rod outer segment rather than distributing them throughout the cell. For neuroscience research, this arrangement links cellular architecture with signaling and makes disc structure an important feature when interpreting retinal physiology.
Renewal depends on a spatial cycle: new discs form near the base of the rod outer segment, while older material is ultimately shed at the tip. This ongoing replacement means the compartment is maintained through coordinated addition and removal rather than remaining static. Studying that cycle can connect structural maintenance with photoreceptor health and degeneration.
Hyperpolarization is the key electrical consequence of the molecular cascade. After cyclic GMP levels fall and ion channels close, the rod’s membrane potential shifts in a direction that can alter downstream neural signaling. This step connects photon-triggered chemistry inside the outer segment to the electrical information processed during retinal responses.
Researchers can use the rod outer segment as a focused system for examining retinal physiology at several levels. Its disc organization supports studies of rhodopsin and phototransduction proteins, while its renewal pattern supports investigation of material shedding and compartment maintenance. Together, these features provide structural and functional readouts relevant to understanding how rod photoreceptors operate.
Changes affecting this compartment are relevant to inherited blindness and photoreceptor degeneration because both signaling performance and structural renewal are central to rod function. Investigations of the outer segment can relate changes in phototransduction or maintenance to retinal dysfunction. This knowledge also provides scientific context for developing and evaluating potential vision-restoring therapies.