Sulforhodamine 101 (SR101) does not label astrocytes in brainstem slices as strong and specific as in the hippocampus or cortex. To minimize excitatory side effects, the concentration of Sulforhodamine 101 has to be kept as low as possible or the labeling procedure can be performed after the actual experiment.

In vivo , epileptic activity can be induced by intra-hippocampal injection of small volumes of 10 μM Sulforhodamine 101 or topical application of 100 μM.