title: Developmental patterns of postictal refractoriness and potentiation akin to cortical stimulation.
abstract: Postictal refractoriness checked by paired stimulations of the limbic structures was demonstrated to fail in rats<2 weeks old. Cortical epileptic afterdischarges were used in our study to examine if this phenomenon is restricted to old cortical structures or if it is a general one. Rats 12, 15, 18, 25, and 90 days old with implanted electrodes formed the experimental groups. Stimulation was performed by 15-s series of 1-msec pulses with suprathreshold intensity and frequency of 8 Hz. Paired stimulation of the cerebral cortex in 12-day-old rats elicited the second afterdischarge, even if the 30-s interval was used. Refractoriness started to appear in the third postnatal week and developed progressively so that 25-day-old rats did not differ from adult animals, that is, an interval longer than 1 min was necessary for elicitation of the second seizure.
authors.affiliation: Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
authors.forename: Pavel
authors.initials: P
authors.lastname: Mareš
authors.forename: Hana
authors.initials: H
authors.lastname: Kubová
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002540:Cerebral Cortex / Q000254:growth & development* / Q000502:physiology; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D004569:Electroencephalography; D008032:Limbic System / Q000254:growth & development* / Q000502:physiology; D051381:Rats; D012032:Refractory Period, Electrophysiological / Q000502:physiology*; D012640:Seizures / Q000503:physiopathology*
keywords: Cortical afterdischarges; Postnatal development; Rat; Refractoriness