If you believe the theory of six degrees of separation, we’re all connected to each other (and possibly to Kevin Bacon) by common friends and friend-of-friends. It might feel like a small world – in fact, these patterns crops up in all sorts of places. Small world networks connect distant brain cells, and help these lymph nodes (outlined in grey) fight infections. A network of fibroblastic reticular cells (FRCs, red) spreads out inside each node, producing chemicals (green) to support immune cells while they zip around the node gathering antigens – chemical information used to target bacteria. These mouse lymph nodes are treated with different doses of a toxin that destroys FRC networks. A high dose crumples the lymph node in the bottom right. Amazingly, many of these networks repair themselves, showing just how committed immune defences are to keeping their small worlds alive.
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BPoD stands for Biomedical Picture of the Day. Managed by the MRC Laboratory of Medical Sciences until Jul 2023, it is now run independently by a dedicated team of scientists and writers. The website aims to engage everyone, young and old, in the wonders of biology, and its influence on medicine. The ever-growing archive of more than 4000 research images documents over a decade of progress. Explore the collection and see what you discover. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.
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