Frontiers in Neurology (Jun 2017)

A New Rat Model of Epileptic Spasms Based on Methylazoxymethanol-Induced Malformations of Cortical Development

  • Eun-Hee Kim,
  • Mi-Sun Yum,
  • Minyoung Lee,
  • Eun-Jin Kim,
  • Woo-Hyun Shim,
  • Tae-Sung Ko

DOI
https://doi.org/10.3389/fneur.2017.00271
Journal volume & issue
Vol. 8

Abstract

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Malformations of cortical development (MCDs) can cause medically intractable epilepsies and cognitive disabilities in children. We developed a new model of MCD-associated epileptic spasms by treating rats prenatally with methylazoxymethanol acetate (MAM) to induce cortical malformations and postnatally with N-methyl-d-aspartate (NMDA) to induce spasms. To produce cortical malformations to infant rats, two dosages of MAM (15 mg/kg, intraperitoneally) were injected to pregnant rats at gestational day 15. In prenatally MAM-exposed rats and the controls, spasms were triggered by single (6 mg/kg on postnatal day 12 (P12) or 10 mg/kg on P13 or 15 mg/kg on P15) or multiple doses (P12, P13, and P15) of NMDA. In prenatally MAM-exposed rats with single NMDA-provoked spasms at P15, we obtain the intracranial electroencephalography and examine the pretreatment response to adrenocorticotropic hormone (ACTH) or vigabatrin. Rat pups prenatally exposed to MAM exhibited a significantly greater number of spasms in response to single and multiple postnatal NMDA doses than vehicle-exposed controls. Vigabatrin treatment prior to a single NMDA dose on P15 significantly suppressed spasms in MAM group rats (p < 0.05), while ACTH did not. The MAM group also showed significantly higher fast oscillation (25–100 Hz) power during NMDA-induced spasms than controls (p = 0.047). This new model of MCD-based epileptic spasms with corresponding features of human spasms will be valuable for future research of the developmental epilepsy.

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