Background & Objectives : Cortical spreading depression (SD), a self-propagating depolarization of neuroglial cells, is believed to play a role in different neurological disorders including epilepsy and migraine aura. A brief period of excitation heralds SD which is immediately followed by nerve cell depression and later by prolonged excitation. The aim of the present study was to investigate relationship between SD and late phase of excitability and seizure burst activity inlateral amygdale of rat.

  Methods: Male Wistar rats with 250-350 gram body weight were used. We usedamygdale slices taken from Wistar rats. SD was induced by KCl. After superfusion of these slices with sub-epileptic concentration of bicuculline for 45 min, the induction of SD in the lateral amygdale resulted in presence of interictal and ictalepileptiform field potentials.

  Results: After initiation of SD in lateral amygdale, glutamate receptors (NMDA, AMPA) antagonists as well as K⁺ and Ca⁺⁺ channels blockers were able to decrease the amplitude of excitatory postsynaptic potentials.

  Conclusion: The results imply a possible role for SD in temporal lobe epilepsy in predisposed neural tissue with increased excitation or decreased inhibition. The study of the late phase of SD excitability may help us to understand the mechanism of SD action in associated neurological disorders. This finding may improve the therapeutic strategies for treatment of epilepsy.