When neurons within the brain cease to exist, they must be removed immediately so the neighboring brain tissue can go on operating normally and in a healthy manner.
A highly specialized cell named the Microglia takes charge of the process known as phagocytosis, which means “to eat cell” in Greek, getting rid of damaged neurons as they die off. These miniature cells are made up of a large number of branches that are steadily moving throughout the interior of the brain in search of particles that need to be removed. They are able to pick up on and get rid of foreign elements, such as deceased neurons. At least this is what was previously believed up until a new publication in PLoS Biology journal.
The new study conducted by the University of the Basque Country observed the neuronal death process and microglial phagocytosis in a diseased brain for the first time. Brain samples were removed from epilepsy patients from the University Hospital of Cruces as well as epileptic mice.
Researchers have known for a long time that neurons die during epileptic convulsions. What they did not realize was that the microglia is not able to “see” neurons while working inside of an epileptic brain. They literally are unable to find or discard them, a behavior that is completely unexpected. When neurons are not removed, they begin to build up and cause further damage to surrounding neurons. This causes an inflammatory response within the brain which leads to even further harm and damage to the brain.
This latest discovery brings hope to a whole new channel of therapies that may be able to relieve the effects of not just epilepsy but a wide range of brain diseases. The research group that authorized the work is continuing the exploration of developmental drugs that may promote the “clean up” of neurons.