Glutamate Mediated Astrocytic Filtering of Neuronal Activity
Figure 9
Network parameters affect astrocytic [Ca2+]i traces.
A, Ca2+ and B, IP3 traces of isolated astrocytes in response to different stimulation frequencies. Above 2 Hz, as shown on Fig. 7, astrocytes start responding with Ca2+ oscillations. Below 2 Hz, IP3 and Ca2+ levels reach a frequency-dependent steady-state; when these steady-state concentrations are high enough to trigger CICR (i.e. for high enough stimulation frequency), astrocytes respond with large Ca2+ oscillations. C, Increasing the stimulation frequency increases the astrocyte oscillation frequencies. Whatever the coupling degree k, the oscillation frequency reaches a plateau for high stimulation frequencies. The height of this plateau however strongly depends on the astrocyte coupling degree. Isolated astrocytes oscillate much faster than connected ones. Error bars denote standard deviation (n = 130 astrocytes).