Estrogen enhances potassium-stimulated acetylcholine release in the rat hippocampus.
Short-term estrogen replacement has been shown to enhance basal forebrain cholinergic function. Whether or not long-term estrogen replacement can enhance basal forebrain cholinergic function has been questioned in light of recent studies showing that several cholinergic measures which are increased following short-term treatment are not increased following longer-term (>30 days) treatment. In the present study, in vivo microdialysis was used to assess the effects of continuous estradiol replacement on basal forebrain cholinergic function. Our data show that 6-7 weeks of continuous estradiol replacement significantly enhanced potassium-stimulated acetylcholine release in the hippocampus of ovariectomized rats, and that this effect was reversed following discontinuation of the estrogen treatment. These data are consistent with the hypothesis that estrogen-mediated effects on cholinergic neurons can contribute to the effects of long-term estrogen replacement on cognitive performance recently described.
Gabor
Rachel
R
Juniata College, Huntingdon, PA 16652, USA.
Nagle
Rajesh
R
Johnson
David A
DA
Gibbs
Robert B
RB
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D004343:Drug Implants; D004357:Drug Synergism; D004958:Estradiol / Q000008:administration & dosage / Q000494:pharmacology*; D015914:Estrogen Replacement Therapy; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D023421:Models, Animal; D011188:Potassium / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D004343:Drug Implants; D004958:Estradiol; D000109:Acetylcholine; D011188:Potassium