title: Repeated treatment with oxytocin promotes hippocampal cell proliferation, dendritic maturation and affects socio-emotional behavior.
abstract: Rewarding social behaviors including positive social interactions and sexual behaviors are shown to regulate adult neurogenesis, but the underlying biological mechanisms remain elusive. Oxytocin, a neurohypophysial hormone secreted after exposure to social interaction or sexual behaviors, has a profound role in the formation of social bonding and regulation of emotional distress. While the acute effect of oxytocin was usually studied, relatively scarce evidence showed the behavioral consequence of repeated oxytocin treatment. The purpose of the current study was to investigate the effect of repeated oxytocin treatment on hippocampal cell proliferation, dendritic maturation of new born neurons and social/emotional behaviors. Adult male Sprague-Dawley rats received treatment with either vehicle or oxytocin (1mg/kg) daily for two weeks. Behavioral tests revealed that oxytocin increased social behaviors and reduced the anxiety- and depression-like behaviors. Cell proliferation, differentiation and the dendritic complexity of new born neurons in the hippocampus were promoted by oxytocin treatment. Depression- and anxiety-like behaviors were induced by repeated treatment of corticosterone (40mg/kg) for two weeks while oxytocin treatment reversed the behavioral disturbances. Suppression of cell proliferation caused by corticosterone was reverted by oxytocin treatment in which cell proliferation, cell differentiation, and dendritic complexity increased. The present findings reveal that oxytocin not only enhances cell proliferation, but also promotes the development of the new neurons which is associated with the induction of positive emotional and social behaviors. The results also suggest that oxytocin may be a potential therapeutic agent for treatment of emotional and social dysfunction.
authors.affiliation: Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, China.
authors.forename: Dalinda Isabel
authors.initials: DI
authors.lastname: Sánchez-Vidaña
authors.affiliation: Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, China.
authors.forename: Ngai-Man Jackie
authors.initials: NM
authors.lastname: Chan
authors.affiliation: Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, China.
authors.forename: Alan H L
authors.initials: AH
authors.lastname: Chan
authors.affiliation: Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, China.
authors.forename: Katy K Y
authors.initials: KK
authors.lastname: Hui
authors.affiliation: Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, China.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Lee
authors.affiliation: Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, China.
authors.forename: Hoi-Yi
authors.initials: HY
authors.lastname: Chan
authors.affiliation: Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, China.
authors.forename: Yuen Shan
authors.initials: YS
authors.lastname: Law
authors.affiliation: Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, China.
authors.forename: Mei Yi
authors.initials: MY
authors.lastname: Sze
authors.affiliation: Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, China.
authors.forename: Wai-Ching Sarah
authors.initials: WC
authors.lastname: Tsui
authors.affiliation: Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, China.
authors.forename: Timothy K H
authors.initials: TK
authors.lastname: Fung
authors.affiliation: Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, China. Electronic address: benson.lau@polyu.edu.hk.
authors.forename: Benson Wui-Man
authors.initials: BW
authors.lastname: Lau
authors.affiliation: Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, China.
authors.forename: Cynthia Y Y
authors.initials: CY
authors.lastname: Lai
mesh_terms: D000818:Animals; D001007:Anxiety / Q000188:drug therapy / Q000473:pathology / Q000503:physiopathology; D049109:Cell Proliferation / Q000187:drug effects* / Q000502:physiology; D003345:Corticosterone; D003712:Dendrites / Q000187:drug effects* / Q000502:physiology; D018891:Dentate Gyrus / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D003863:Depression / Q000188:drug therapy / Q000473:pathology / Q000503:physiopathology; D004195:Disease Models, Animal; D008297:Male; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D055495:Neurogenesis / Q000187:drug effects / Q000502:physiology; D010121:Oxytocin / Q000494:pharmacology*; D011619:Psychotropic Drugs / Q000494:pharmacology*; D017207:Rats, Sprague-Dawley; D012919:Social Behavior
chemical_list: D011619:Psychotropic Drugs; D010121:Oxytocin; D003345:Corticosterone
keywords: anxiety-like behaviors; dendritic complexity; depression-like behaviors; hippocampal cell proliferation; neurogenesis; oxytocin