Fig. 8.

Low H₂O₂ concentrations slowly induce PDS formation. Example of a recording in which 100 μM H₂O₂ led to the delayed formation of PDS-like events. a–c Caffeine alone for 5 min (b) and in combination with H₂O₂ for further 10 min (c) did not affect discharge patterns, as compared to the control recording (a). d–f After about 15 min in caffeine + H₂O₂, enhancement of EPSPs occurred (showing up as a change in the spike after potential, see the arrowheads in c and d) which progressed (arrowheads in e) until PDS emerged, one is shown in f. Hence, augmentation of EPSPs (d, e) precedes the formation of PDS-like events (f)