Aggressive behavior in the psychiatric clinic

Self and other directed violence of male psychiatric patients have been registered. The diagnostic analysis revealed an unequivocal correlation to delusional diseases and cerebroorganic hamper. Few patients caused a high percentage of all registered aggressions. Due to limited possibilities of drug treatment, changes of organization of communication and of the socio-organisational framework are aspired for the future.     

Learning strategy selection in the water maze and hippocampal CREB phosphorylation differ in two inbred strains of mice

Learning strategy selection was assessed in two different inbred strains of mice, C57BL/6 and DBA/2, which are used for developing genetically modified mouse models. Male mice received a training protocol in a water maze using alternating blocks of visible and hidden platform trials, during which mice escaped to a single location. After training, mice were required to choose between the spatial location where the platform had been during training (a place strategy) and a visible platform presented in a new location (a cued/response strategy). Both strains of mice had similar escape performance on the visible and hidden platform trials during training. However, in the strategy preference test, C57BL/6 mice selected a place strategy significantly more often than DBA/2 mice. Because much evidence implicates the hippocampus and striatum as important neural substrates for spatial/place and cued/response learning, respectively, the engagement of the hippocampus was then assessed after either place or cue training by determining levels of cAMP response element-binding protein (CREB) and phosphorylated CREB (pCREB) in these two mouse strains. Results revealed that hippocampal CREB levels in both strains of mice were significantly increased after place in comparison to cued training. However, the relation of hippocampal pCREB levels to training was strain dependent; pCREB was significantly higher in C57BL/6 mice than in DBA/2 mice after place training, while hippocampal pCREB levels did not differ between strains after cued training. These findings indicate that pCREB, specifically associated with place/spatial training, is closely tied to differences in spatial/place strategy preference between C57BL/6 and DBA/2 mice.     

Aggressive behavior in children's dolls' house play

The present study addressed the question of whether there are gender and age differences in aggressive behavior when it is studied as the spontaneous expression of mental contents and not as the result of immediate social interaction. This study also investigated whether aggression, in terms of mental content, is related to temperamental aspects. Aggressive behaviors were examined in make‐believe play, in relation to age, gender, and temperament in a near‐ecological context, i.e., the Dolls' House Play. The participants, 55 boys and 47 girls, subdivided into three age levels (4 years–4 years and 6 months; 5–6 years; and 7 years and 6 months–8 years and 6 months) were requested to represent what happens in their family 1) during Mealtimes; 2) at Bedtime; 3) on the Saddest day; and 4) the Happiest day; their Dolls' House Play was then recorded. Children's temperaments were measured with the TABC‐Teachers' form [Martin, The Temperament Assessment Battery for Children, Brandon, VT: Clinical Psychology Publishing, 1998]. Data analysis was conducted considering aggressive behaviors in their distinct expressions—physical, verbal, direct, and indirect. Results revealed no statistical differences between boys and girls when all aggressive behaviors were compounded. However, when the distinct types of aggressiveness were considered, boys presented statistically higher levels of physical aggression than girls did. Moreover, boys and girls reacted with different types of aggression in the different emotional contexts created by the four episodes. Few age differences were observed. Surprisingly, there was a significantly greater presence of indirect verbal aggressiveness in younger children. With respect to temperament, a higher level of negative emotivity was significantly linked to a greater degree of aggressive behaviors in some of the episodes. In conclusion, this paper confirms gender differences in the type of aggressive behavior children display even in the absence of any immediate social interaction, which might itself trigger aggression. Aggr. Behav. 30:504–519, 2004. © 2004 Wiley‐Liss, Inc.     

Hysterectomy-induced maternal behavior during pregnancy in the rat.

Hysterectomies were performed between the 10th and 19th day of pregnancy, and females were tested with pups for the onset of maternal behavior starting 0,24, 48, or 72 hr after surgery. Pups remained with the females overnight, and testing was repeated daily with fresh pups until females exhibited maternal behavior. Latencies for the onset of maternal behavior were shorter after hysterectomy on the 10th and 16th days of pregnancy than in intact pregnant females at the same stages of pregnancy; latencies became shorter, the later the termination of pregnancy. When the ovaries were removed along with hysterectomy during pregnancy, short-latency maternal behavior no longer was exhibited. Pregnant females were tested during the last 40 hr of pregnancy: nest building began at 34 hr prepartum and retrieving at 28 hr prepartum. The effect of hysterectomy during pregnancy on ovarian secretion of estrogen and progesterone is reviewed, and it is concluded that the rise in estrogen secretion, which follows hysterectomy during pregnancy, is most likely the cause of the rapid onset of maternal behavior after hysterectomy. A similar proposal is made for the prepartum onset of maternal behavior in intact pregnant females.     

Aggressive and nonaggressive antisocial behavior in adolescence

This study examined whether a distinction between aggressive and nonaggressive antisocial behavior can be empirically verified in a large (254 girls and 254 boys) nonclinical (community) sample of Dutch adolescents between 12 and 18 years old. The results of confirmatory factor analysis for both boys and girls shows that aggressive and nonaggressive antisocial behaviors do not represent a single underlying dimension, but two separate constructs with moderate independence among them. These findings suggest that the conceptualization of adolescent antisocial behavior as a one-dimensional phenomenon is of questionable utility and supports growing evidence that aggressive antisocial behavior is distinct from other forms of antisocial behavior.     

Behavior genetic analysis of Water-T-Maze learning in inbred strains of mice,their hybrids,and selected second generation crosses

Summary The Water-T-Maze was used to investigate the genetically determined apparatus-dependent behavior of mice. Special importance was attached to the mode of inheritance involved. For this purpose we used NMRI, C3H/HeJ, Balb/c, Balb/cN, DBA/2, C57Bl/6 inbred mouse strains, together with their offspring and the F₂-hybrids of C3H/HeJ and DBA/2. Furthermore investigations were carried out to examine the effect of the environment on the expression of behavior. After these experiments had proved that there is a predominantly genetic derivation for behavioral expression, a possible relationship between the conditioning effect and the age of the animals was investigated. The animal's age has quantitative effects on the expression of behavior, but it does not lead to any qualitative behavioral changes. Nevertheless early conditioning of the animals apparently manifests itself in long-term memory. On the whole the mode of inheritance in Water-T-Maze learning appears to imply a polygene-dependent model in which clear dominant effects are present, as shown in the results of the F₂-generation. No sex-related differences were observed. In general, the results demonstrate a definite involvement of genetic factors in the areas of conditioning and behavior.