title: Vesicular acetylcholine transporter knock-down mice show sexual dimorphism on memory.
abstract: The key neural substrates involved in memory and cognitive tasks have been reported to receive important modulation from ovarian hormones. In fact, neurochemical systems associated with cognitive functions, such as the cholinergic system, are, at least in part, under modulation of estrogens. Here we show that vesicular acetylcholine transporter (VAChT) mutant mice, which express lower levels of the VAChT (VAChT KD) and reduced acetylcholine release, present sexual dimorphism on memory. We evaluate short- and long-term object recognition memories (STM and LTM) in both sexes. We have showed previously, and confirm here, that VAChT KDHET male mice present deficits in both STM and LTM object recognition memories in comparison with WT. In contrast, VAChT KDHET female mice present deficit in LTM, but not in STM. To test if the female hormones levels could be a determinant factor on sexual dimorphism observed, we submitted female mice to ovariectomy (OVX) or sham-surgery. After 1 week (1 w), we evaluate STM. Female hormone deprivation promotes STM impairment in VAChT KDHET, but not in WT female mice. Our results strongly suggest that the sexual dimorphism observed in VAChT KDHET mice on STM is due to modulation of cholinergic system by ovarian hormones.
authors.affiliation: Núcleo de Neurociências, Departamento de Fisiologia e Biofísica, ICB, Universidade Federal de Minas Gerais, Rua Antônio Carlos 6627, CEP 31270-901 Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Suellem B
authors.initials: SB
authors.lastname: Capettini
authors.forename: Márcio F D
authors.initials: MF
authors.lastname: Moraes
authors.forename: Vânia F
authors.initials: VF
authors.lastname: Prado
authors.forename: Marco A M
authors.initials: MA
authors.lastname: Prado
authors.forename: Grace S
authors.initials: GS
authors.lastname: Pereira
mesh_terms: D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D005260:Female; D012739:Gonadal Steroid Hormones / Q000378:metabolism; D008297:Male; D008568:Memory / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010052:Ovariectomy; D012727:Sex Characteristics; D050494:Vesicular Acetylcholine Transport Proteins / Q000235:genetics*
chemical_list: D012739:Gonadal Steroid Hormones; D050494:Vesicular Acetylcholine Transport Proteins; D000109:Acetylcholine