title: Sex differences in the septo-hippocampal cholinergic system in rats: behavioral consequences.
abstract: The hippocampus is processing temporal and spatial information in particular contexts or episodes. Using freely moving rats, we monitored extracellular levels of acetylcholine (ACh), a critical neurotransmitter activating hippocampal circuits. We found that the ACh release in the dorsal hippocampus increases during the period of learning or exploration, exhibiting a sex-specific 24-h release profile. Moreover, neonatal increase in circulating androgen not only androgenizes behavioral and hormonal features, but also produces male-type ACh release profile after the development. The results suggest neonatal sexual differentiation of septo-hippocampal cholinergic system. Environmental conditions (such as stress, housing or food) of animals further affected the ACh release.Although recent advances of neuroscience successfully revealed molecular/cellular mechanism of learning and memory, most research were performed using male animals at specific time period. Sex-specific or time-dependent hippocampal functions are still largely unknown.
authors.affiliation: Department of Physiology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura Kanazawaku, Yokohama, 236-0004, Japan. dm650314@med.yokohama-cu.ac.jp
authors.forename: Dai
authors.initials: D
authors.lastname: Mitsushima
mesh_terms: D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D002369:Castration / Q000379:methods; D018678:Cholinergic Agents / Q000378:metabolism*; D005260:Female; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D051381:Rats; D020665:Septum of Brain / Q000187:drug effects / Q000378:metabolism*; D012727:Sex Characteristics; D013256:Steroids / Q000494:pharmacology; D013997:Time Factors
chemical_list: D018678:Cholinergic Agents; D013256:Steroids; D000109:Acetylcholine