Dynamic Behavior of Progenitor Cells in Brain Discovered

May 9, 2013
Johns Hopkins Medicine
http://www.sciencedaily.com/releases/2013/05/130509142142.htm
 

Summary:

 

Neuroscientists at Johns Hopkins discovered that cells in the brain remain highly dynamic in the adult brain, where they transform into cells that insulate nerve fibers and help form scars that aid in tissue repair.  They think that these mulyipurpose cells, which are distributed around the brain, are important in their research.  Disapperance of one of these progenitor cells causes a neighbor to quickly divide to form a replacement, ensuring that cell loss and cell addition are kept in balance.  These progenitor cells are also called oligodendrocyte precursor cells (OPCs), which are very dynamic. Compare to adult brain cells, these are able to respond to any repairs needed while maintaining their numbers.  OPCs "support cells in the brain and spinal cord responsible for wrapping nerve fibers to create insulation known as myelin. Without myelin, the electrical signals sent by neurons travel poorly and some cells die due to the lack of metabolic support from oligodendrocytes."  However, the function of OPCs in the adult brain wasn't clear.  To find out, researches genetically modified mice so that their OPCs contained a fluorescent protein along their edges.  Using special microscopes that allow imaging deep inside the brain, they watched these cells in living mice for over a month.  When they examined the brain, OPCs were continuously moving through the brain tissue, extending their "tentacles".  Even though the progenitors are dynamic, each cell maintained its own area by repelling other OPCs when they came in contact.  The cells seemed to sense each other's presence and know how to control the number of cells in their population.  Researches also tested their response to injury by using a laser to create a small wound in the brain. Surprisingly, OPCs migrated to the injury site and contributed to scar formation by cell division of neighboring OPCs.

Connection:

In our human systems unit, we covered nervous systems, where we learned about nerve cells, how the communicate with each other and how they send signals with the help of myelin shealt.  Myelin helps send electrical signals faster.  As said previously, without myelin, some cells die due to the lack of metabolic support from oligodendrocytes.  There are many diseases caused by this, where a patient has neurons that has signals traveling poorly and having cell damage.   With this new discovery, they can easily help heal a patient who has brain cell damage.