Gardening in the Brain

[thinker_jeff]

Gardeners know that some trees require regular pruning: some of their branches have to be cut so that others can grow stronger. The same is true of the developing brain: cells called microglia prune the connections between neurons, shaping how the brain is wired, scientists at the European Molecular Biology Laboratory (EMBL) in Monterotondo, Italy, discovered. Published online in Science, the findings could one day help understand neurodevelopmental disorders like autism.

 

"We're very excited, because our data shows microglia are critical to get the connectivity right in the brain," says Cornelius Gross, who led the work: "they 'eat up' synapses to make space for the most effective contacts between neurons to grow strong."

 

Microglia are related to the white blood cells that engulf pathogens and cellular debris, and scientists knew already that microglia perform that same clean-up task when the brain is injured, 'swallowing up' dead and dying neurons. Looking at the developing mouse brain under the microscope, Gross and colleagues found proteins from synapses -- the connections between neurons -- inside microglia, indicating that microglia are able to engulf synapses too.

 

To probe further, the scientists introduced a mutation that reduced the number of microglia in the developing mouse brain.

 

"What we saw was similar to what others have seen in at least some cases of autism in humans: many more connections between neurons," Gross says. "So we should be aware that changes in how microglia work might be a major factor in neurodevelopmental disorders that have altered brain wiring."

 

The microglia-limiting mutation the EMBL scientists used has only temporary effects, so eventually the number of microglia increases and the mouse brain establishes the right connections. However, this happens later in development than it normally would, and Gross and colleagues would now like to find out if that delay has long-term consequences. Does it affect the behaviour of the mice behaviour, for example? At the same time, Gross and colleagues plan to investigate what microglia do in the healthy adult brain, where their role is essentially unknown.

 

This work was carried out in collaboration with the groups of Davide Ragozzino at the University of Rome and Maurizio Giustetto and Patrizia Panzanelli at the University of Turin.

 

http://www.sciencedaily.com/releases/2011/07/110721142410.htm

Edited August 3, 2011 by thinker_jeff

[Marqq]

Your link was broken... Good Link to same article

Thanks so much for sharing a real advance in neuroscience...I'd imagine the high hopes of possible cures for existing conditions (autism, MS, etc.) will end up getting dashed a bit, but it's still pretty likely that finding abnormalities and treating them during development will lead to a very significant change in the world's neurological disabilities.

[thinker_jeff]

Your link was broken... Good Link to same article

Thanks for the reminding.

The link has been repaired.

[Ringer]

There has been a remarkable amount of research on glial cells of late, all of which I think is amazingly important. The book The Other Brain is supposed to be a fairly well written book about some of the recent discoveries. I haven't read it myself, but it has been recommended to me from a couple of my professors.

[Ahsan Iqbal]

Thanks for sharing the valuable information.

[Realitycheck]

I read somewhere that microglia are also used similar to the immune system for destroying alien invaders on the other side of the blood/brain barrier. Their numbers are probably pretty limited though.

[Ahsan Iqbal]

I read somewhere that microglia are also used similar to the immune system for destroying alien invaders on the other side of the blood/brain barrier. Their numbers are probably pretty limited though.

Yes this is correct. Microglia are an important component of the immune system on the other side of blood-brain barrier. The have a phagocytic activity similar to phagocytes found elsewhere in the body. And it is essential because blood phagocytes cannot enter the brain tissue so there must be someone to take care of stuff there.

[lawljj]

Cool article

 

I'm assuming that the material from the dead neurons are used to create new neurons or repair neurons.

 

 

Waste not want not