Prenatal methotrexate exposure delays onset of low Mg(2+)-induced epileptiform discharges in the entorhinal cortex.
We determined the effects of prenatal exposure to DNA synthesis inhibitor methotrexate (MTX) on: (a) the susceptibility to low Mg(2+)-induced epileptiform activity in deep layers (IV-V) of medial entorhinal cortex in vitro; and (b) neuronal counts in this area. Low Mg(2+)-induced discharges developed significantly later in slices from prenatally MTX-exposed rats than in control slices. Neuronal counts were increased in the layer V of medial entorhinal cortex of prenatally MTX-exposed rats. Results indicate that: (a) MTX-induced prenatal brain DNA impairment is antiepileptogenic; and (b) simple increases in neuronal numbers may not be associated with epileptogenic effects.
Kábová
R
R
Department of Normal, Pathological and Clinical Physiology, Charles University, Third Faculty of Medicine, Prague, Czech Republic.
Velísek
L
L
D000818:Animals; D002452:Cell Count; D018728:Entorhinal Cortex / Q000187:drug effects*; D004827:Epilepsy / Q000209:etiology / Q000517:prevention & control*; D005260:Female; D008275:Magnesium Deficiency / Q000503:physiopathology*; D008727:Methotrexate / Q000494:pharmacology*; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats; D017207:Rats, Sprague-Dawley
D019384:Nucleic Acid Synthesis Inhibitors; D008727:Methotrexate