Fig. 3.

Glutamate receptor antagonists reduced the prevalence of both fast and slow astrocytic Ca²⁺ signals. (A) The AMPA receptor antagonist CNQX and the mGluR5a antagonist MPEP significantly reduced the mean of ROIs responding both with fast and slow Ca²⁺ signals, but not to the same degree. The percentage of responding ROIs during 15-s, 2-Hz whisker stimulation was studied in n = 10 ROIs from three animals for CNQX and n = 23 ROIs from six animals for MPEP. Error bars represent SEM. (B) Examples of drug effects in percentage of baseline Ca²⁺ activity (ΔF/F₀) in some astrocytes using the calcium indicator OGB and 2-Hz stimulation of the whisker pad. The size of the Ca²⁺ responses, in astrocytic structures only, is shown in color scale overlaid 2-PM images of the field of view. Images on the Left show the size of the sum of the fast Ca²⁺ signal 10 to 120 ms after stimulation with or without drugs; images on the Right are of a sum of part of the slow astrocytic Ca²⁺ signals after 4 s of stimulation. (Scale bar: 10 µm.)