title: The influence of social environment in early life on the behavior, stress response, and reproductive system of adult male Norway rats selected for different attitudes to humans.
abstract: The influence of social disturbance in early life on behavior, response of blood corticosterone level to restraint stress, and endocrine and morphometric indices of the testes was studied in 2-month Norway rat males from three populations: not selected for behavior (unselected), selected for against aggression to humans (tame), and selected for increased aggression to humans (aggressive). The experimental social disturbance included early weaning, daily replacement of cagemates from days 19 to 25, and subsequent housing in twos till the age of 2months. The social disturbance increased the latent period of aggressive behavior in the social interaction test in unselected males and reduced relative testis weights in comparison to the corresponding control groups. In addition, experimental unselected rats had smaller diameters of seminiferous tubules and lower blood testosterone levels. In the experimental group, tame rats had lower basal corticosterone levels, and aggressive animals had lower hormone levels after restraint stress in comparison to the control. The results suggest that the selection in two directions for attitude to humans modifies the response of male rats to social disturbance in early life. In this regard, the selected rat populations may be viewed as a model for investigation of (1) neuroendocrinal mechanisms responsible for the manifestation of aggression and (2) interaction of the hypothalamic-pituitary-adrenal and hypothalamic-pituitary-gonadal systems in stress.
authors.affiliation: Institute of Cytology and Genetics, Novosibirsk, Russia. Electronic address: gulevich@bionet.nsc.ru.
authors.forename: R G
authors.initials: RG
authors.lastname: Gulevich
authors.affiliation: Institute of Cytology and Genetics, Novosibirsk, Russia. Electronic address: shikhsvt@bionet.nsc.ru.
authors.forename: S G
authors.initials: SG
authors.lastname: Shikhevich
authors.affiliation: Institute of Cytology and Genetics, Novosibirsk, Russia. Electronic address: msol@bionet.nsc.ru.
authors.forename: M Yu
authors.initials: MY
authors.lastname: Konoshenko
authors.affiliation: Institute of Cytology and Genetics, Novosibirsk, Russia. Electronic address: korimma@bionet.nsc.ru.
authors.forename: R V
authors.initials: RV
authors.lastname: Kozhemyakina
authors.affiliation: Institute of Cytology and Genetics, Novosibirsk, Russia. Electronic address: herbek@bionet.nsc.ru.
authors.forename: Yu E
authors.initials: YE
authors.lastname: Herbeck
authors.affiliation: Institute of Cytology and Genetics, Novosibirsk, Russia.
authors.forename: L A
authors.initials: LA
authors.lastname: Prasolova
authors.affiliation: Institute of Cytology and Genetics, Novosibirsk, Russia.
authors.forename: I N
authors.initials: IN
authors.lastname: Oskina
authors.affiliation: Institute of Cytology and Genetics, Novosibirsk, Russia.
authors.forename: I Z
authors.initials: IZ
authors.lastname: Plyusnina
mesh_terms: D000328:Adult; D000367:Age Factors; D000374:Aggression; D000818:Animals; D000831:Animals, Newborn; D001290:Attitude; D003345:Corticosterone / Q000097:blood; D005106:Exploratory Behavior / Q000502:physiology*; D005786:Gene Expression Regulation / Q000502:physiology; D006801:Humans; D007031:Hypothalamus / Q000378:metabolism; D007398:Interpersonal Relations; D059648:Kisspeptins / Q000235:genetics; D008297:Male; D051381:Rats; D012098:Reproduction / Q000502:physiology*; D012931:Social Environment; D013315:Stress, Psychological / Q000097:blood / Q000503:physiopathology*; D013737:Testis / Q000473:pathology; D013739:Testosterone / Q000097:blood
chemical_list: C491406:Kiss1 protein, rat; D059648:Kisspeptins; D013739:Testosterone; D003345:Corticosterone
keywords: Aggressive; Behavior; Early-life environment; Rats; Tame