Juvenilized play fighting in subordinate male rats

As pairs of male juvenile sibling rats that are housed together become sexually mature, they develop a dominance-subordinance relationship. These dominance relationships appear to be reflected in the play fighting of the pairmates both as juveniles and as young adults, in that the seemingly subordinate partner initiates more playful attacks at both ages. However, as adults, even though it is the subordinate that initiates more playful attacks, it is the subordinate that is pinned on his back by the partner most often. Dominant pairmates were found to switch to defensive patterns typically found in adult males. In contrast, the subordinates, when contacted on the nape, were more likely to retain the juvenile pattern of turning over to supine. Therefore, the subordinate pairmate of an adult pair of male siblings both initiates more playful attacks and defends itself in a more juvenile manner than its dominant partner, and this leads to it being pinned more frequently. This pattern of behavior by subordinate rats is suggested to function as a friendship maintenance mechanism permitting co-existence in multimale colonies.     

Factors influencing maternal attack on conspecific intruders by lactating female “TO” strain mice

Factors regulating maternal attack in “TO” strain mice were investigated to determine 1) optimal conditions for inducing this behaviour and 2) the likely utility of this activity. Lactating females were more likely to attack male intruders than female intruders. The mate's presence reduced maternal attack in this strain, or (putting it conversely) aggression was generated in the male's absence. Removal of the mothers from their litters for four to five hours also suppressed maternal attack. Investigation of the bite targets in the maternal attack suggested that it is a defensive, rather than an offensive, response.     

To Use or Not to Use: Male Partners' Perspectives on Decision Making About Prenatal Diagnosis

We conducted an exploratory, qualitative pilot study investigating the use of genetic counseling and prenatal genetic technologies between women and their male partners for two referral groups: pregnant women 35 years of age and over (AMA) at the time of delivery and pregnant women with an abnormal maternal serum triple screen (MSAFP3). The convenience sample consisted of 25 semistructured interviews and 50 observations of genetic counseling sessions. Male partners' styles of decision making and the way they viewed prenatal diagnosis decision making were examined. We defined three decision-making styles based on our interpretation of the data: (1) domain, (2) joint-delegated, and (3) saliency. The male partners also seemed to view prenatal diagnosis as either an information decision or an action decision and appeared to take a more active role in decision making when the decision was viewed as an action decision.     

Partial purification of male mus musculus urinary aggression-promoting chemosignal

An attempt was made to purify an aggression-promoting chemosignal of male SJL/J mice. It was shown in Experiment 1 that the chemosignal is present in intact-male urine (IU) but not in urine (CU) from castrated males. In Experiments 3 and 4, a head-space distillation technique was used to isolate the volatile components of IU. It was shown that aggression-promoting cues were present in the volatile portion of IU and not in the nonvolatile portion. Also CU was tested for behavioral activity under the procedures of Experiments 3 and 4 and was found not to contain the chemosensory cue.     

Ethopharmacological studies of the effects of β-carbolines and benzodiazepines on murine aggression

The behavioral profiles generated by a benzodiazepine (BDZ) agonist (diazepam), an “inverse” agonist (β-carboline-3-carboxylate ethyl ester, βC-3-CEE), and dihydro-(DHβCs) and tetrahydro-β-carbolines (THβCs) were investigated on aggressive isolated mice using a computerized ethopharmacological technique. Augmentation of intraspecific sociability with a concurrent reduction of aggression are characteristic features of diazepam's effects, whereas βC-3-CEE exerts the opposite effects. βC-3-CEE countered the prosocial activity of diazepam and had intrinsic activities on intraspecific behaviour. Some DHβCs (harmalol and 6-methoxy-harmalan) and THβCs (1-methyl-6-hydroxy-THβC and tetrahydronorharmane) may exacerbate aggression at low (BDZ-negative) doses (1 mg/kg), and inhibit such behavior at higher (serotonin-positive) doses (10-15 mg/kg). The ethological profiles of DHβCs were different from the profiles of THβCs. Differences in ethological profiles of βC-3-CEE, DHβCs, and THβCs seem to reflect the neurochemical (mainly BDZ-and serotonergic) properties of these substances.     

Psychological characteristics of infertile couples: can they predict pregnancy and treatment persistence?

The paper describes an exploratory study of the relative importance of different psychological variables for the prediction of (a) pregnancies and (b) treatment continuation in a sample of 140 couples seeking specialized infertility treatment one year after their first contact with an infertility clinic. The couples filled out questionnaires dealing with psychological and interpersonal functioning, marital and life satisfaction, child-related attitudes, causal attribution of infertility and general expectations towards the treatment. It could be shown that the psychological variables explain a relatively small amount of the variance of the pregnancy criterion. Nevertheless, there were some indications supporting the hypothesis that psychological complaints can be seen as a ‘risk factor’ associated with a lower pregnancy rate. Couples who had terminated treatment after one year indicated a higher amount of psychological and interpersonal complaints (females) as well as partner problems (males and females), and a dominance of internal attributions of the fertility problem. This result—which might help to develop strategies for counselling couples making use of the new reproductive technologies—highlights the importance of attribution and cognitive appraisal in coping with infertility. © 1998 John Wiley & Sons, Ltd.     

Counselling needs of patients receiving treatment with gamete donation

Couples experiencing infertility may be offered treatment with gamete donation where other methods of treatment have failed or are inappropriate. This paper examines a range of concerns related to gamete donation. The paper does not attempt to present a comprehensive and critical review of the literature but concentrates on selecting from the literature, in addition to clinical material, issues which have been identified as contributing to an understanding of patients' experience of treatment with donated gametes. The concerns include feelings and attitudes towards the donor, the role the donor plays in the couple's relationship, feelings about not being the genetic parent and whether to disclose the donation to the potential child and others. These concerns form a basis for counselling couples about the implications of gamete donation for themselves and any children born as a result. The difficulties faced by some people are illustrated by consideration of a single case where the experience of donation linked up with unique aspects of that individual. Therapeutic counselling offers couples faced with such difficulties the opportunity to explore in a more extensive way the underlying dynamics of their concerns, enabling them to think about and make sense of their experience. © 1998 John Wiley & Sons, Ltd.     

Role of female aggression in prevention of infanticidal behavior in male common voles,Microtus arvalis (Pallas, 1779)

Infanticidal behavior of male common voles (Microtus arvalis) was investigated in relation to the age of unfamiliar pups. Sires from 18 pairs were removed after parturition of their offspring and replaced by unfamiliar males at different ages of the neonates. In group 1, containing six females with their offspring, the new male was introduced into the females' cages on day 1 after the parturition. In group 2 the new male was introduced on day 5 after parturition and in group 3 on day 9 after parturition. The male was removed after 3 days and the neonates recounted. Male common voles killed up to 100% of the neonates in litters containing neonates younger than 9 days by rapid bites to the head of the neonates (groups 1 and 2, mortality rates of 0.86 and 0.38). However, with older pups, a mortality rate of 0.06 was observed while 33% of the intruder males showed signs of injuries (group 3). These findings show that infanticidal behavior of male common voles represents one factor of pup mortality. The results are discussed in relation to changes in the degree of maternal aggression and in the context of the social system of the common vole for solving the conflict between postpartum estrous mating and infanticidal behavior of male common voles. Aggr. Behav. 23:293–298, 1997. © 1997 Wiley-Liss, Inc.     

Pre-breeding aggression in male and female three-spined sticklebacks (gasterosteus aculeatus)

The reactions of 34 female and 32 male three-spined sticklebacks to a conspecific were observed in the month before the breeding season. Factor analysis indicated that the organization of the response in the two sexes was very similar; in both cases, axes labelled “aggression,” “threat,” “curiosity,” and “sex” emerged, with male fish having significantly higher scores on the first factor and females on the second. Any theory of the causes of aggression in sticklebacks should accommodate these facts.     

Effects of neonatal treatment with cyproterone acetate on aggressive behavior induced by footshock in adult male rats

High levels of androgens are required to organize aggressive behavior in adult male rats. Footshock-induced aggression was tested in Wistar rats allocated to one of three experimental groups: control (oil-injected) males (M), males neonatally injected with the antiandrogen cyproterone acetate (CA), and males treated as in the CA group but gonadectomized just before puberty (CAG). An antiaggressive effect of CA in those adult male rats neonatally treated with this compound was found. Neonatal exposure to cyproterone acetate exerts an antiandrogenic effect over the expression of shock-induced aggressive behavior. The behavioral effects of CA were not countered by adult treatment with testosterone propionate.