Glia: all that and a bag of chips -- but what kind?

A fascinating study which further clarifies the role of those fascinating, complex, busy busy cells, the glia:

http://www.sciencedaily.com/releases/2011/12/111229131354.htm?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+sciencedaily%2Fmind_brain+%28ScienceDaily%3A+Mind+%26+Brain+News%29

ScienceDaily (2011-12-29) -- New research indicates that glia cells are "the brain's supervisors." By regulating the synapses, they control the transfer of information between neurons, affecting how the brain processes information. This new finding could be critical for technologies based on brain networks, as well as provide a new avenue for research into disorders such as Alzheimer's disease and epilepsy.

This study indicates that glia regulate the speed of synaptic transmission, slowing or speeding up synaptic events according to what is needed. This means, for instance, that epileptic seizures, which are synaptic storms, relate to glial misbehavior.

The next question is, how? Why? What causes the glia to modulate a given transmission?

I'm looking forward to further studies on this.