Generalization of seizures parallels the formation of "dark" neurons in the hippocampus and pontine reticular formation after focal-cortical application of 4-aminopyridine (4-AP) in the rat

Péter Baracskay, Zsuzsanna Szepesi, Gergely Orbán, Gábor Juhász, András Czurkó

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14 Citations (Scopus)


Distribution and time course of the occurrence of "dark" neurons were compared with the EEG activity and behavior of rats during 4-aminopyridine (4-AP) induced epileptic seizures. A crystal of the K+ channel blocker 4-AP (0.5 mg/kg) was placed onto the exposed parieto-occipital cortex of Halothane-anesthetized rats for 40 min. Thereafter, the anesthesia was discontinued and the behavioral signs of the epileptic seizure activity were observed. The presence of "dark" neurons was demonstrated by the sensitive silver method of Gallyas in rats sacrificed at 0, 3 and 6 h after the end of the 4-AP crystal application. The EEG activity was recorded in the rats with longer survival times. The EEG analysis revealed the generalization of the epileptic seizures. We found that the formation of "dark" neurons in the hippocampus and the pontine reticular formation paralleled the generalization of the seizures.

Original languageEnglish
Pages (from-to)217-228
Number of pages12
JournalBrain research
Publication statusPublished - Sep 4 2008



  • Animal model
  • Astrocyte
  • Cell injury
  • Dark neuron
  • Epilepsy
  • Hippocampus
  • Neurogliaform cell
  • Pontine reticular formation
  • Status epilepticus

ASJC Scopus subject areas

  • Neuroscience(all)
  • Molecular Biology
  • Clinical Neurology
  • Developmental Biology

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