Giant "dark" neurons (A, B, C and D) in the pontine reticular formation at 3 hours survival time after focal-cortical 4-AP crystal application (A and C) and systemic injection of pilocarpine (B and D). The PnO (A, B) and PnC (C, D) are symmetrically involved in both cases. The representative EEG periods demonstrate the late phase of the generalized convulsive status epilepticus (E and F). Three hours after the 4-AP application, the power spectral density (PSD) graph of the one-hour-long EEG recording shows a high peak at the slow frequencies (1-1.5 Hz; G). After the pilocarpine injection, the PSD analysis also shows a peak at the slow frequencies (1.5-2 Hz) and an additional increase in the power at around 6 Hz (H). The control PSDs (gray lines) were calculated from 30 min EEG recordings before the treatment of each rat. Abbreviations: ISS and CSS: ipsi- and contralateral somatosensory cortex, CFC: contralateral frontal cortex, 6: abducens nucleus, 7n: facial nerve or its root, CG: central grey, DRV: dorsal raphe nucleus, ventral part, IRt: intermediate reticular nucleus, mlf: medial longitudinal fasciculus, MnR: median raphe nucleus, P5: peritrigeminal zone, Pa6: paraabducens nucleus, pd: predorsal bundle, PDTg: posterodorsal tegmental nucleus, PMnR: paramedian raphe nucleus, PnC: pontine reticular nucleus, caudal part, PnO: pontine reticular nucleus, oral part, scp: sup cerebellar peduncule, SPTg: subpeduncular tegmental nucleus, ts: tectospinal tract, tz: trapezoid body, 4-AP: 4-aminopyridine, PILO: pilocarpine. Scale bars: A, B, C and D = 400 μm, E and F = 200 μV.