Cortex Medulla
Cortex Medulla - Related Videos
04:27
Analyzing Dendritic Morphology Across Drosophila Medulla Layers and Columns
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2025
Source: Ting, C., et al., Analyzing Dendritic Morphology in Columns and Layers. J. Vis. Exp. (2017)This video demonstrates the procedure of preparing a Drosophila brain, capturing horizontal and frontal image stacks of GFP-labeled medulla dendrites under a confocal microscope, and creating a 3D reconstruction to analyze their morphology across layers and columns.
01:21
Brainstem: Control Centers of Medulla
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2025
The medulla oblongata is a crucial part of the brainstem responsible for controlling various autonomic and involuntary functions. It contains several nuclei, including the olivary, cuneate, gracile, and solitary nuclei. Olivary Nucleus The olivary nucleus, or inferior olivary nucleus, is located within the ventrolateral part of the medulla oblongata. It is primarily involved in motor coordination and motor learning. The olivary nucleus receives input from the spinal cord, cerebellum, and motor...
01:27
Sympathetic Pathways: Collateral Ganglia and Adrenal Medulla
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2025
The sympathetic pathways of the collateral ganglia and adrenal medulla serve unique but interconnected roles in the sympathetic response. Collateral Ganglia Sympathetic preganglionic axons reach the collateral ganglia along the route of splanchnic nerves. These nerves bypass the sympathetic trunk and communicate with sympathetic postganglionic neurons housed in the prevertebral ganglia. These ganglia supply the organs of the abdominopelvic cavity. The greater splanchnic nerve, formed by the...
08:35
Detecting Cortex Fragments During Bacterial Spore Germination
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Cited by 8 •
2016
Herein, we describe a colorimetric assay to detect the presence of reducing sugars during bacterial spore germination.
03:05
Colorimetric Detection of Cortex Degradation During Bacterial Spore Germination
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2025
Source: Francis, M. B., et al. Detecting Cortex Fragments During Bacterial Spore Germination. J. Vis. Exp. (2016).This video demonstrates a colorimetric method to detect cortex degradation during bacterial spore germination by measuring the release of reducing sugars over time. Using N-acetylglucosamine standards and time-point samples, the assay quantifies sugar concentration through a purple chromogenic reaction, indicating the extent of cortex hydrolysis.
FAQs
The cortical checkpoint retains thymocytes that can recognize self-major histocompatibility complex molecules, while cells lacking this recognition do not proceed through development. This selection step establishes the basic capacity for T cells to interact with MHC during later immune responses. It therefore contributes to repertoire quality before cells encounter the medullary mechanisms that promote self-tolerance.
Migration through the thymus places developing thymocytes in sequential cellular environments rather than exposing them to all selection signals at once. After cortical positive selection, surviving cells move toward the medulla and encounter medullary epithelial cells and dendritic cells. This ordered progression links functional MHC recognition with later testing against tissue-restricted antigens.
Tissue-restricted antigens allow medullary selection to test whether developing T cells could react against proteins associated with specific body tissues. Presentation of these antigens by medullary epithelial cells and dendritic cells helps remove potentially self-reactive cells. The resulting reduction in autoreactive T cells supports self-tolerance and helps limit the risk of autoimmune disease.
These cell populations contribute to different selection environments. Cortical epithelial cells participate in positive selection, emphasizing recognition of self-major histocompatibility complex molecules. In the medulla, epithelial cells and dendritic cells present tissue-restricted antigens for negative selection. Their complementary roles connect selection for useful immune recognition with elimination of harmful self-reactivity.
Examining the relationship between cortical and medullary regions provides a framework for asking whether thymic dysfunction affects early positive selection, later negative selection, or the progression between them. Such analysis is relevant because disruption of these coordinated compartments could alter the balance between T-cell diversity and self-tolerance. The framework is useful in studies of thymic dysfunction and immune development.
Effective responses to infection require a T-cell repertoire broad enough to support recognition while remaining sufficiently self-tolerant to avoid damaging the host. The cortex-medulla sequence contributes to both properties by combining selection for MHC recognition with screening against tissue-restricted self-antigens. Consequently, this anatomical organization links thymic development with the quality and safety of later immune responses.
This organization supports investigations spanning immunology, infection, developmental biology, and thymic dysfunction. Researchers can use it as a framework for examining how cellular location, selection stage, and antigen presentation influence T-cell development. Comparing the two regions also helps connect anatomical structure with outcomes such as repertoire diversity, self-tolerance, and susceptibility to disrupted immune regulation.