Plastic changes in dendritic spines of hippocampal CA1 pyramidal neurons from ovariectomized rats after estradiol treatment

• Published in: Brain research Vol. 1470; pp. 1 - 10
• Main Authors: Velázquez-Zamora, Dulce A, González-Tapia, David, González-Ramírez, Myrna M, Flores-Soto, Mario E, Vázquez-Valls, Eduardo, Cervantes, Miguel, González-Burgos, Ignacio
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 27.08.2012; Elsevier
• Subjects: adults; Analysis of Variance; Animals; Biological and medical sciences; brain; CA1; CA1 Region, Hippocampal - cytology; CA1 Region, Hippocampal - drug effects; central nervous system diseases; cognition; Dendritic spine; Dendritic Spines - drug effects; Dose-Response Relationship, Drug; estradiol; Estradiol - pharmacology; Estrogen; estrogen replacement therapy; Estrogens - pharmacology; Female; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation - drug effects; General aspects. Hormone interactions. Hormone actions on several organ systems. Adaptive reactions; Hippocampus; laboratory animals; mushrooms; Neurology; neurons; Ovariectomy; Plasticity; Pyramidal Cells - drug effects; Pyramidal Cells - ultrastructure; Rats; Rats, Sprague-Dawley; Silver Staining; sprouting; synaptic transmission; Synaptophysin; Synaptophysin - metabolism; Vertebrates: endocrinology; women; Dendritic spine; Synaptophysin; CA1; Hippocampus; Plasticity; Estrogen; Replacement therapy; Cognitive disorder; Ovariectomy; Rat; Rodentia; Central nervous system; Estradiol; Ovarian hormone; Encephalon; Vertebrata; Mammalia; Treatment; Animal; Synaptic plasticity; Sex steroid hormone; Pyramidal neuron
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/j.brainres.2012.06.012

Abstract Cognitive impairment or its recovery has been associated with the absence or reestablishment of estrogenic actions in the central nervous system of female experimental animals or women. It has been proposed that these cognitive phenomena are related to estrogen-mediated modulatory activity of synaptic transmission in brain structures involved in cognitive functions. In the present work a morphological study was conducted in adult female ovariectomized rats to evaluate estradiol-dependent dendritic spine sprouting in hippocampal pyramidal neurons, and changes in the presynaptic marker synaptophysin. Three or ten days after estradiol treatment (10 μg/day, twice) in the ovariectomized rats, a significant increase of synaptophysin was observed, which was coincident with a significant higher numerical density of thin (22%), stubby (36%), mushroom (47%) and double spines (125%), at day 3, without significant changes of spine density at day 10, after treatment. These results may be interpreted as evidence of pre- and postsynaptic plastic events that may be involved in the modulation of cognitive-related behavioral performance after estrogen replacement therapy.