Figure 1.

Astrocytes are activated during focal seizure propagation in cortical slices. (A) Image sequence of the fluorescence signal change in layer V–VI neurons (n, black arrows) and astrocytes (a, yellow arrowheads) from the entorhinal cortex of a young rat after slice loading with the Ca²⁺ dye Oregon-Green BAPTA1-AM during a propagating ictal discharge. (B) Simultaneous patch-clamp recording from one neuron [black trace; the patch-pipette is indicated in (A)] and ΔF/F₀ traces of the Ca²⁺ signal in the same neuron (superimposed red trace) and other neighboring neurons (red traces) and astrocytes (blue traces). The Ca²⁺ signal from all neurons precisely matched the electrical activity of the patched neuron during both the interictal event (single event at trace onset) and the subsequent ictal discharge. Astrocytes were strongly activated during the ictal discharge while they were poorly activated by the interictal discharge (adapted from Gomez-Gonzalo et al., 2010).