The mystery of how brain imaging works may have been solved by researchers who have shown--for the first time--that star-shaped brain cells called astrocytes make non-invasive brain scans possible. Why blood flow is linked to neuronal activity has been a mystery. Now scientists have discovered that star-shaped brain cells called astrocytes--previously considered bit players by most neuroscientists--make noninvasive brain scans possible.
Of the two major cell types in the brain, glia outnumber neurons nine to one.
Astrocytes--the most common type of glia--extend their branching tendrils both around synapses--through which neurons communicate--and along blood vessels. Astrocytes receive signals directly from neurons and provide their own neuron-like responses to directly regulate blood flow, providing the missing link between neurons and blood vessels.
Mystery behind brain imaging unlocked
