Effect of Human Infant Gut Microbiota on Mouse Behavior, Dendritic Complexity, and Myelination.

The mammalian gut microbiome influences numerous developmental processes. In human infants it has been linked with cognition, social skills, hormonal responses to stress, and brain connectivity. Yet, these associations are not necessarily causal. The present study tested whether two microbial stool communities, common in human infants, affected behavior, myelination, dendritic morphology, and spine density when used to colonize mouse models. Humanized animals were more like specific-pathogen free mice than germ-free mice for most phenotypes, although in males, both humanized groups were less social. Both humanized groups had thinner myelin sheaths in the hippocampus, than did germ-free animals. Humanized animals were similar to each other except for dendritic morphology and spine density where one group had greater dendritic length in the prefrontal cortex, greater dendritic volume in the nucleus accumbens, and greater spine density in both regions, compared to the other. Results add to a body of literature suggesting the gut microbiome impacts brain development. Teaser: Fecal transplants from human infants with highly abundant Bifidobacterium , an important inhabitant of the intestinal tract of breastfed newborns, may promote brain connectivity in mice.

Young female offenders and the New Zealand Youth Justice System: the need for a gender-specific response.

Young female offenders comprise approximately one fifth of the New Zealand youth offender population; however, they remain an understudied population of offenders. This paper aims to provide a current overview of the key characteristics of this population and recommendations for how the youth justice system could better cater to this population. These recommendations include more training of professionals (specifically judges, youth advocates and justice coordinators) and practitioners (specifically social workers, psychologists and youth workers) in the youth-justice system in matters specific to young female offenders. A gender-responsive and trauma-informed approach to addressing offending behaviour is also necessary. There is a need for new empirical research in the New Zealand context on young female offenders and the best way to address offending by this group. Finally, a focus on the diversity of young female offenders is a priority, given the over-representation of indigenous and ethnic-minority communities in justice jurisdictions worldwide.

Does childhood neglect contribute to violent behavior in adulthood? A review of possible links.

Child neglect, whether intentional or unintentional on the part of caregivers, has serious and far-reaching negative consequences for children. Neglect is the most prevalent form of child maltreatment and has been associated with impaired cognitive development, changes in brain structure and nervous systems, behavioral and personality disorders and poor academic performance. However, the role of child neglect, and subtypes of neglect, in the development of adult violent behavior is not well understood. The "cycle of violence" hypothesis, which predicts that individuals exposed to child physical abuse are more likely to be physically violent in adulthood, is well supported by the literature. However, a growing number of studies suggests that child neglect may be equally predictive, or more predictive, of adult violent behavior than child physical abuse. The present review considers a range of studies that investigate aspects of this relationship, and identifies key patterns and trends that have emerged from these investigations. Methodological issues and limitations of the existing literature are also identified and new research directions suggested. This review also considers studies that support the possibility of protective factors against the development of adult violent behavior in victims of child neglect.