Protein in Nerves Determines Which Brain Connections Stay, Which Go

This knowledge should be transferable to how neurons decide to die off post-stroke. Ask your researcher about it.
http://www.biosciencetechnology.com/news/2014/04/protein-nerves-determines-which-brain-connections-stay-which-go?et_cid=3860152&et_rid=648870051&location=top
A newborn baby, for all its cooing cuddliness, is a data acquisition machine, absorbing information to finish honing the job of brain wiring that started before birth. This is true nowhere more so than the eyes, which start life peering at a blurry world and within months can make out a crisp, three-dimensional image of a mobile dangling overhead.
This process of refining the brain's wiring involves cutting off some of the excess nerve connections we have at birth while strengthening connections we use all the time. Some estimates show that as many as half of the brain's connections formed during development are clipped back as the final wiring takes shape.
Carla Shatz, the David Starr Jordan Director of Stanford Bio-X, and her team, including postdoctoral researcher Hanmi Lee, PhD, and Bio-X graduate fellow Jaimie Adelson, recently found a protein that is essential for the brain to remove those excess connections. The team specifically showed a role for the protein in the developing visual system in mice, but their findings, published March 30 in Nature, appear to apply broadly across the developing brain.
Shatz said the discovery helps clear up something that has been a mystery to those who study brain development: How does the decision get made to eliminate some connections? It also settles a decade-long debate over whether the nervous system or the immune system is making those decisions. (Spoiler alert: It's the nervous system.)

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