Estrogen and estrogen-progesterone treatments counteract the effect of scopolamine on reinforced T-maze alternation in female rats.
The purpose of the experiments was to determine if steroid hormone treatments would attenuate the effect of the muscarinic receptor blocker scopolamine on a memory task. Ovariectomized rats were trained first to alternate for food reward between the arms of a T maze. Following training, females treated with scopolamine hydrobromide (0.2 mg/kg ip) did not alternate correctly between the arms of the T maze and responded at chance levels. However, when estradiol benzoate (25 micrograms) was administered 72, 48, and 24 hr before testing alone or in combination with progesterone (500 micrograms) administered 4-6 hr before testing, females alternated successfully between the arms of the T maze following scopolamine administration. Results indicate that gonadal steroids can completely counteract the impairment of T maze performance induced by scopolamine in female rats.
Dohanich
G P
GP
Department of Psychology and Neuroscience Program, Tulane University, New Orleans, Louisiana 70118.
Fader
A J
AJ
Javorsky
D J
DJ
D000818:Animals; D001070:Appetitive Behavior / Q000187:drug effects*; D004958:Estradiol / Q000031:analogs & derivatives* / Q000494:pharmacology; D005260:Female; D018782:Maze Learning / Q000187:drug effects*; D008570:Memory, Short-Term / Q000187:drug effects; D011939:Mental Recall / Q000187:drug effects*; D009949:Orientation / Q000187:drug effects*; D011374:Progesterone / Q000494:pharmacology*; D051381:Rats; D011930:Reaction Time / Q000187:drug effects; D011976:Receptors, Muscarinic / Q000187:drug effects*; D012601:Scopolamine / Q000037:antagonists & inhibitors* / Q000494:pharmacology
D011976:Receptors, Muscarinic; D011374:Progesterone; D004958:Estradiol; C010452:estradiol-17 beta-benzoate; D012601:Scopolamine