a.) Average gamma burst-triggered CSDs of X-irradiated and sham animals show similar patterns of current sources and sinks. This implies that events in both groups arise due to, or are coordinated by, similar inputs. The mean amplitude of gamma bursts is significantly larger in X-irradiated animals (n = 9 X-ray, 9 sham animals; p = 0.001, two-tailed Student’s t-test). b.) Similar to above, transgenic GFAP:TK animals given the drug ganciclovir (25 mg/mL) via subcutaneous minipump show comparable gamma burst-triggered CSDs and increased gamma burst amplitude, compared with wild-type littermates also administered ganciclovir (n = 10 TK, 9 wt animals; p = 0.017, two-tailed Student’s t-test).