Biomedical subjects

N K Sandnabba

Publications and source records attributed to N K Sandnabba.

5 recordsLinked to original sources

PubMed2001

Sadomasochistically oriented behavior: diversity in practice and meaning.

One hundred and eighty-four subjects (22 women and 162 men) who were members of two sadomasochistically oriented clubs answered a semistructured questionnaire containing items relating to a variety of sexual behaviors. Using a multivariate statistical analysis that geometrically represents the co-occurrence of individual actions as a visual array (Guttman (1954). In Lazarfeld, P. E. (ed.), Mathematical Thinking in the Social Sciences, Free Press, Glencoe, IL.) four qualitatively different sexual scripts emerged: hypermasculinity; administration and receiving of pain; physical restriction; and psychological humiliation. Although similar themes have been suggested before, this study demonstrated their empirical base. Humiliation was significantly associated more with females and with heterosexual orientation in men, while hypermasculinity was associated with males and with homosexual orientation in men.

Female↗

PubMed1997

Sex-related coping responses in mice selectively bred for aggression.

Sex differences in strategies of coping with novel situations were studied in three strains of mice with regard to metabolism and open-field and maze activity as well as learning-induced adjustment. The 140 mice were selectively bred for high (Turku Aggressive [TA]) and low (Turku Nonaggressive [TNA]) levels of aggressiveness and originated from a Swiss albino stock normally distributed [N] for aggressiveness. The results indicated that TNA sex differences are more similar to those of the control N mice as compared to those of TA mice. In maze learning, however, the sex differences of TA mice are more in agreement with those of the N strain. Recordings of metabolism and open-field as well as maze activity were correlates of both gender and strain. Sex differences in learning-induced open-field coping behavior were unrelated to strain.

Adaptation, Psychological↗

PubMed1996

Selective breeding for isolation-induced intermale aggression in mice: associated responses and environmental influences.

Aggressive (TA) and nonaggressive (TNA) lines of mice were established by selective breeding for isolation-induced intermale aggression. This paper summarizes and updates studies performed on the TA and TNA lines. The genetic analysis revealed that in these lines the genes for aggression are located on the autosomes and demonstrate a Mendelian segregation. The genes are expressed only in the presence of androgens which are normally present only in males. Behavioral and biological responses associated with high and low levels of aggression in TA and TNA mice are reviewed. Line differences have been found in olfactory communication and marking behavior, in maternal and predatory aggression in females, in locomotor activity, and in learning abilities. Also, correlated neurochemical and endocrinological responses to the selection have been detected. Maternal factors during the preweaning period do not significantly affect the development of aggression in TA and TNA males, while early postweaning exposure to aggression or sex enhanced later aggressive and sexual activity. Early experience and genetic disposition for aggression are correlated, with TA males showing the greatest increase in the behaviors studied.

Aggression↗

PubMed1995

Predatory aggression in male mice selectively bred for isolation-induced intermale aggression.

Male mice differing in their genetically determined disposition for isolation-induced intermale aggression were compared on behaviors related to predatory aggression. An ongoing sequence of selective breeding established high-aggressive (Turku Aggressive: TA) and low-aggressive (Turku Non-Aggressive: TNA) lines from an outbred Swiss albino foundation stock. The parental strain, designated the Normal (N) strain, has been kept as a control line and is bred without regard to aggressiveness. Testing consisted of dropping a live cricket into the home cage of the individually housed experimental mice. Results showed that the TA males displayed shorter latencies to attack and spent more time in chasing, attacking, and consuming crickets than did TNA and N males. The TNA males displayed significantly less predatory aggression than both the TA and N males. When brothers of the males tested for predatory aggression were tested for intermale aggression, a similarly significant effect of breeding line was obtained for the latency to attack. Testing consisted of placing an intact male mouse into the cage of the male to be tested. The results suggest that there may be parallels in genetic variation between intermale and predatory attacking.

Aggression↗

PubMed1994

Effects of testosterone exposure and fighting experience on the aggressive behavior of female and male mice selectively bred for intermale aggression.

Exposure of female mice to testosterone resulted in aggressive behavior as a function of breeding line in two lines of mice selectively bred for high (Turku Aggressive, TA) and low (Turku Nonaggressive, TNA) levels of aggressiveness. Female TA mice that received a single injection of testosterone propionate (TP) (1 mg in 0.05 ml peanut oil) on the second day of life, and starting at 120 days of age received daily injections for seven consecutive days, displayed aggressive behavior on a level comparable to that of socially isolated males of the same line, whereas control TA females (injected with 0.05 ml peanut oil) and TP-exposed TNA females were totally nonaggressive. The level of aggressiveness was assessed by means of dyadic tests against intact male opponents. Early and adult exposure to TP did not lead to increased aggressiveness in male TNA mice. Fighting experience in combination with prolonged TP treatment changed the aggressiveness of the TP-exposed TA females, leading to decreased aggressiveness in defeated animals. The genetically correlated low level of aggressiveness of TNA male and female mice was unaffected by any combination of TP exposure, learning and social isolation. It is concluded that differences in testosterone reactivity of target organs, other than those which are Y chromosome determined, i.e., the testes, are responsible for the aggressiveness in the strains studied.

Aggression↗