Developmental psychobiology最新文献

In male hamsters, puberty is associated with increased serotonin innervation and unusual responses to fluoxetine, such as enhanced play-fighting activity against intruders but also an acceleration of its maturation from attacks focused on the face (frontal attacks) to the lower belly and rump, suggesting a role for serotonin (5-HT). We tested the role of 5-HT_1A and 5-HT₃ receptor subtypes on play-fighting behavior observed during resident intruder tests through peripheral treatment with receptor agonists and antagonists. Contrary to observations in adult hamsters, we did not observe any overarching effects of treatment on measures of play-fighting activity, nor its maturation from frontal attacks. However, secondary analyses highlighted variability within the datasets. A subgroup of animals presented inhibited play-fighting activity in response to treatment with DPAT, a 5-HT_1A receptor agonist, but these animals also showed enhanced locomotor activity and reduced interest in engaging their opponents. In addition, early juvenile agonistic behavior was predictive of responsiveness to other treatments. The 5-HT_1A receptor antagonist, WAY, caused a reduction in play-fighting activity in high attackers and an increase in low attackers. Though high attackers under pretest conditions were equally inhibited by CBG, a 5-HT₃ receptor agonist, they performed a higher proportion of frontal attacks. Finally, the density of 5-HT_1A and 5-HT₃ receptor immunoreactivity was compared among subjects sampled at postnatal Day 35 (early puberty) or postnatal Day 70 (adulthood) within areas mediating the control of social behavior in adults. Adult males showed a higher density of immunolabeling for 5-HT_1A receptors in the anterior hypothalamus and medial amygdala, as well as 5-HT₃ receptors in the lateral septum. The data suggest that the development of 5-HT receptor expression participates in the control of play-fighting activity and its maturation during puberty in male hamsters.

The experience of maltreatment in childhood is associated with poorer developmental and health outcomes. This may be explained by the capacity for maltreatment to dysregulate stress-responsive neurophysiological systems, including the hypothalamic–pituitary–adrenal (HPA) axis. This study presents the results of the first meta-analysis that examines the association between maltreatment and resting HPA-axis activity in children and the role of “third variables” in accounting for observed heterogeneity in this association. Analyses of 18 studies, including N = 2216 children, indicated that although there was no difference in resting HPA-axis activity between children who had been maltreated and those who had not (standardized mean difference [SMD] = 0.04), there was substantial heterogeneity in the association between maltreatment and HPA-axis activity across studies (I² = 58.60%, p = 0.001). Further analyses revealed that the association between maltreatment and resting HPA-axis activity was contingent upon the source of information regarding maltreatment (B = 0.33, p = 0.002) and the degree to which maltreated and comparison groups differed in their socioeconomic status (B = 0.39, p = 0.037).

This study evaluated information shared with parents about infant development through formal sources in five countries and international organizations (i.e., regions). Consistent findings among regions were: (1) Tendency to format information as developmental milestones; (2) Sharing primarily information about motor development, but most often repeating recommendations for advancing language development; (3) Variability in specific information shared among regions and among sources within each region about the same general topics; and (4) Consensus mentioning seven behaviors representing early exploratory, mobility, and communication abilities that support learning and expression. Differences in the content shared among the regions are also described. The findings provide insight into commonalities and differences in educational practices that likely reflect more universal versus regional cultural beliefs and values.

Aggression is commonly associated with increased experiences of peer rejection and maladaptive social information processing biases throughout development. Little is known about the neural correlates of peer rejection that might underlie social information processing biases, and whether these neural correlates are common or different across early- and mid-adolescents on a continuum of aggression. Using the Cyberball task, we examined mediofrontal theta (4–7 Hz) event-related EEG spectral power during conditions of explicit and ambiguous social exclusion in 117 participants (57 early adolescents, ages 10–12 years, and 60 mid-adolescents, ages 14–16 years). Participants with at least 10 artifact-free trials per condition were included in further EEG analysis. In total, 95 participants (42 early adolescents, 53 mid-adolescents) were included for further analyses of EEG spectral theta power. Results examining moderation effects between aggression level and age groups showed that mid-adolescents, but not early adolescents, with higher levels of aggression displayed enhanced theta power during the early processing (200–400 ms) of ambiguous (“not my turn”) exclusion events. The pattern of heightened neural sensitivity to ambiguous exclusion events reflects early detection and inclusion monitoring which might facilitate processing biases that are more prominent among mid-adolescents with higher levels of aggression.

Long-term effects of social play on neural and behavioral development remain unclear. We investigated whether just 1 h of juvenile social play could rescue the effects of play deprivation on stress-related behavior and markers of neural plasticity. Syrian hamsters were reared from postnatal days 21–43 in three conditions: peer isolation, peer isolation with daily social play sessions (dyadic play), or group-housed with littermates. In adulthood, subjects were exposed to acute social defeat stress, and we examined changes in perineuronal net (PNN) expression surrounding parvalbumin (PV) neurons in the prelimbic (PL), infralimbic (IL), and basolateral amygdala (BLA). Peer deprivation led to exaggerated submissive and defensive behavior in a conditioned defeat test, but 1 h of dyadic play rescued the heightened conditioned defeat response in both males and females. In females, play deprivation reduced PNN/PV coexpression in the PL and IL compared to control groups with opportunities for social play. Males exposed to peer isolation showed elevated agonistic behavior when returned to their littermates compared to males exposed to 1-h play encounters. These findings indicate juvenile social play has long-lasting effects on PNN expression surrounding PV cells in the medial prefrontal cortex, which allows for the development of species’ typical agonistic behavior and greater stress resistance in adulthood. The ability of just 1 h of social play to rescue the effects of peer isolation highlights the powerful role of social interactions in neural and behavioral development.