title: In mice tonic estrogen replacement therapy improves non-spatial and spatial memory in a water maze task.
abstract: We investigated the effects of estrogen replacement therapy on water maze non-spatial and spatial navigation in mice. Three groups of mice were ovariectomized and two of these groups being implanted with s.c. pellets that produce blood levels of estrogen close to those found in estrous (estrogen low, 75-100 pg/ml blood) or proestrous (estrogen high, 300-400 pg/ml). The behavioral assessment was initiated 7 days after pellet implantation. Non-spatial navigation to a clearly visible platform was stimulated by low and high levels of estrogen. However, spatial navigation to a hidden platform was improved by low estrogen levels. We found that estrogen improves two different types of memory processes that depend on striatal (non-spatial navigation) and hippocampal (spatial) memory systems.
authors.affiliation: Department of Neuroscience and Neurology, University of Kuopio, Finland.
authors.forename: A
authors.initials: A
authors.lastname: Rissanen
authors.forename: J
authors.initials: J
authors.lastname: Puoliväli
authors.forename: T
authors.initials: T
authors.lastname: van Groen
authors.forename: P
authors.initials: P
authors.lastname: Riekkinen
mesh_terms: D000818:Animals; D004343:Drug Implants; D015914:Estrogen Replacement Therapy; D004967:Estrogens / Q000097:blood / Q000494:pharmacology*; D004971:Estrus; D005260:Female; D018782:Maze Learning / Q000187:drug effects / Q000502:physiology*; D008568:Memory / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D010052:Ovariectomy; D011359:Proestrus; D013028:Space Perception
chemical_list: D004343:Drug Implants; D004967:Estrogens