Article

Estradiol alters afterdischarge threshold and acquisition of amygdala kindled seizures in male rats

Shahid Beheshti University of Medical Sciences, Teheran, Tehrān, Iran
Neuroscience Letters (Impact Factor: 2.06). 05/2003; 340(1):41-4. DOI: 10.1016/S0304-3940(03)00074-0
Source: PubMed

ABSTRACT We have previously shown that estradiol (E(2)) can initially increase and then decrease kindle seizure parameters in amygdala kindled male rats. This study focuses on the effects of estradiol benzoate (EB) on afterdischarge (AD) threshold and electrical kindling acquisition in intact male rats. After implantation of tripolar and monopolar electrodes in amygdala and dura surface respectively, effects of EB on AD threshold and electrical kindling acquisition were investigated by daily injection of EB (microg/kg) or sesame oil (EB solvent) in different groups of male rats. AD threshold was reduced significantly 0.25 h post EB treatment and reached to the lowest value after 24 h and remained almost constant at low values. Also, the number of trials for stage 5 (S(5)) and cumulative seconds of AD to complete kindling decreased significantly, when compared to rats without EB treatment. These results support a marked influence of E(2) on seizure process and convulsive pattern in the brain of male rats. Base on the previous reports about female rats and our findings, these E(2) effects are probably not sex dependent.

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    • "Acute administration of estradiol enhances the frequency and severity of PTZ-induced seizures (Reddy, 2004b), an effect consistent with its activity in several experimental models of partial and limbic seizures (Nicoletti et al., 1985; Hom and Buterbaugh, 1986). The proconvulsant-like activity of estradiol is most consistently demonstrated after chronic treatment in male rodents (Pericic et al., 1996; Saberi and Pourgholami, 2003). Further, studies in slices supported the idea that estrogen facilitates hippocampus excitability (Wong and Moss, 1994; Tauboll et al., 1991; Joels, 1997, see review Scharfman and MacLusky, 2006). "
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