Postictal events in amygdala-kindled female rats with and without estradiol replacement.
This study investigated the effect of estradiol on ictal and postictal events in ovariectomized female rats kindled by daily amygdala stimulation during the presence or absence of estradiol replacement. Although ictal components of kindled seizures were not altered by estradiol, several postictal events such as myoclonic jerks were significantly increased by estradiol. Twelve days after kindling, estradiol-replaced rats with electrodes in the basal, lateral, or cortical amygdala nuclei developed brief postictal "bursts" of behavioral and EEG activity which developed into a secondary seizure in some rats. Rats without estradiol never displayed these postictal events. Pretreatment of rats with pentylenetetrazol, 20 mg/kg, 15 days after kindling, resulted in a further increase in the incidence of bursts and secondary seizures in the presence of estradiol; these events were most prominent in rats kindled in the absence of estradiol. Pentylenetetrazol also caused a significant increase in myoclonic jerks in estradiol-replaced rats, and postictal spikes in all rats. A series of five consecutive generalized seizures at 48-h intervals caused an increase in bursts in rats with estradiol replacement, but not in rats without estradiol. The results indicate that estradiol exerts excitatory effects during the postictal period following amygdala-kindled seizures and suggest that multiple regions mediate the postictal effects of estradiol, perhaps depending on the intraamygdala site of kindling stimulations.
D000679:Amygdala / Q000187:drug effects; D000818:Animals; D004569:Electroencephalography; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D007696:Kindling, Neurologic / Q000187:drug effects*; D008564:Membrane Potentials / Q000187:drug effects; D010052:Ovariectomy; D010433:Pentylenetetrazole / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D004958:Estradiol; D010433:Pentylenetetrazole