Great things are happening in imaging science right now. Using a really spectacular method and doing some very painstaking and pioneering work, it became possible to watch cells at work in the living brain. The results of this effort are just beginning to flow in. Two fresh examples are top articles in the well-known scientific journals Science and Neuron, respectively.

The first one of these studies, done at MIT, shows that, contrary to prevailing belief, astrocytes influence complex neuronal computations such as the duration and selectivity of brain cell responses to stimuli from the outside world. Thereby, they are playing an important role in determining how the "outside world" is perceived.

The second one of these studies, done by Harvard University neuroscientists, points into the same direction, namely the astrocytes, so far considered "passive filling substance" in the brain; in fact have a major influence on brain activity regulation.

What really is spectacular about both of the studies is the insight they provide into very widely used medical brain imaging: functional magnetic resonance imaging (fMRI). What the studies convincingly are showing is, that the astrocytes make for the actual signal that is measured with fMRI, namely the bloof flow changes in the brain, for instance during active perception. So there is no meaningful fMRI imaging without functioning astrocytes.

Importantly, these remarkable results are laying the groundwork for further important study of how this exquisite neurovascular coupling mediated by astrocytes may go awry in neurodegenerative diseases, such as Alzheimer's disease, as well as in the normally aging brain.