Acute effects of 17 beta-estradiol on brain excitability studied in vitro and in vivo.
The acute effects of 17 beta-estradiol on brain excitability were studied in vitro and in vivo utilizing rat hippocampal slices and a cat cerveau isolé preparation. The hippocampal slices were perfused with 17 beta-estradiol (10(-7)-10(-10) M) for 30 min. No effects were observed on synaptic activation and inhibition and on the response to iontophoretically applied GABA in intact and ovariectomized female rats (n = 43). In males (n = 32), however, a small (12%) but significant increase in population spike amplitude was observed after 30 min exposure to 10(-9) M 17 beta-estradiol. Higher and lower concentrations were ineffective. In vivo, no acute effects of 17 beta-estradiol on focal epileptic seizure thresholds, evoked potentials, or augmenting response were observed in the visual cortex of non-estrous female cats (n = 11; median dose 1 micrograms/kg, range 0.5 microgram/kg-10 mg/kg).
Department of Neurology, Rikshospitalet, University of Oslo, Norway.
E
E
Taubøll
S
S
Lindström
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L
Gjerstad
D000818:Animals; D001921:Brain / Q000187:drug effects*; D002415:Cats; D003655:Decerebrate State / Q000503:physiopathology; D004558:Electric Stimulation; D004827:Epilepsy / Q000503:physiopathology; D004958:Estradiol / Q000494:pharmacology*; D005071:Evoked Potentials / Q000187:drug effects; D005260:Female; D066298:In Vitro Techniques; D007478:Iontophoresis; D008297:Male; D010052:Ovariectomy; D010634:Phenobarbital / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013569:Synapses / Q000187:drug effects
D004958:Estradiol; D010634:Phenobarbital