Social scaffolding of human amygdala-mPFCcircuit development

Differential functional organization of amygdala-medial prefrontal cortex networks in macaque and human

Over the course of evolution, the amygdala (AMG) and medial frontal cortex (mPFC) network, involved in behavioral adaptation, underwent structural changes in the old-world monkey and human lineages. Yet, whether and how the functional organization of this network differs remains poorly understood. Using resting-state functional magnetic resonance imagery, we show that the functional connectivity (FC) between AMG nuclei and mPFC regions differs between humans and awake macaques. In humans, the AMG-mPFC FC displays U-shaped pattern along the corpus callosum: a positive FC with the ventromedial prefrontal (vmPFC) and anterior cingulate cortex (ACC), a negative FC with the anterior mid-cingulate cortex (MCC), and a positive FC with the posterior MCC. Conversely, in macaques, the negative FC shifted more ventrally at the junction between the vmPFC and the ACC. The functional organization divergence of AMG-mPFC network between humans and macaques might help understanding behavioral adaptation abilities differences in their respective socio-ecological niches.

Childhood abuse and neglect and profiles of adult emotion dynamics

Childhood maltreatment (CM) is experienced by ∼40% of all children at major personal and societal costs. The divergent associations between emotional, physical, and sexual abuse or neglect in childhood and differences in adult emotional functioning and regulation were examined in terms of daily emotion intensity, variability, instability, inertia, and diversity, reported over 30 days by 290 Dutch aged 19-73. Participants described their abuse/neglect experiences retrospectively using the Childhood Trauma Questionnaire (CTQ). Dissecting CM effects on adult emotion dynamics may inform theories on the ontogenesis and functioning of emotions, on effects of abuse and neglect, to better understand (dys)functional emotional development, and to prevent their adverse sequelae. Structural equation models (SEM) showed that most types of CM were associated with specific patterns of emotion dynamics, and only emotional abuse had no unique effects on the emotional dynamic indices. Emotional neglect was associated with most measures of emotion dynamics (i.e., less intense, variable, unstable, and diverse emotions). Sexual abuse associated with increases and physical neglect decreases in negative affect variability and instability. Physical abuse was associated with inertia but with a small effect size. Social contact frequency did not mediate much of the relationship between CM types and emotion dynamics.

Leveraging the developmental neuroscience of caregiving to promote resilience among youth exposed to adversity

Early adversity is a major risk factor for the emergence of psychopathology across development. Identifying mechanisms that support resilience, or favorable mental health outcomes despite exposure to adversity, is critical for informing clinical intervention and guiding policy to promote youth mental health. Here we propose that caregivers play a central role in fostering resilience among children exposed to adversity via caregiving influences on children's corticolimbic circuitry and emotional functioning. We first delineate the numerous ways that caregivers support youth emotional learning and regulation and describe how early attachment lays the foundation for optimal caregiver support of youth emotional functioning in a developmental stage-specific manner. Second, we outline neural mechanisms by which caregivers foster resilience-namely, by modulating offspring corticolimbic circuitry to support emotion regulation and buffer stress reactivity. Next, we highlight the importance of developmental timing and sensitive periods in understanding caregiving-related mechanisms of resilience. Finally, we discuss clinical implications of this line of research and how findings can be translated to guide policy that promotes the well-being of youth and families.

Shaping the development of complex social behavior

Early life experiences can have an enduring impact on the brain and behavior, with implications for stress reactivity, cognition, and social behavior. In particular, the neural systems that contribute to the expression of social behavior are altered by early life social environments. However, paradigms that have been used to alter the social environment during development have typically focused on exposure to stress, adversity, and deprivation of species-typical social stimulation. Here, we explore whether complex social environments can shape the development of complex social behavior. We describe lab-based paradigms for studying early life social complexity in rodents that are generally focused on enriching the social and sensory experiences of the neonatal and juvenile periods of development. The impact of these experiences on social behavior and neuroplasticity is highlighted. Finally, we discuss the degree to which our current approaches for studying social behavior outcomes give insight into "complex" social behavior and how social complexity can be better integrated into lab-based methodologies.

Infant pain vs. pain with parental suppression: Immediate and enduring impact on brain, pain and affect

BACKGROUND

In the short term, parental presence while a human infant is in pain buffers the immediate pain responses, although emerging evidence suggests repeated social buffering of pain may have untoward long-term effects.

METHODS/FINDING

To explore the short- and long-term impacts of social buffering of pain, we first measured the infant rat pup's [postnatal day (PN) 8, or 12] response to mild tail shock with the mother present compared to shock alone or no shock. Shock with the mother reduced pain-related behavioral activation and USVs of pups at both ages and reduced Fos expression in the periaqueductal gray, hypothalamic paraventricular nucleus, and the amygdala at PN12 only. At PN12, shock with the mother compared to shock alone differentially regulated expression of several hundred genes related to G-protein-coupled receptors (GPCRs) and neural development, whereas PN8 pups showed a less robust and less coherent expression pattern. In a second set of experiments, pups were exposed to daily repeated Shock-mother pairings (or controls) at PN5-9 or PN10-14 (during and after pain sensitive period, respectively) and long-term outcome assessed in adults. Shock+mother pairing at PN5-9 reduced adult carrageenan-induced thermal hyperalgesia and reduced Fos expression, but PN10-14 pairings had minimal impact. The effect of infant treatment on adult affective behavior showed a complex treatment by age dependent effect. Adult social behavior was decreased following Shock+mother pairings at both PN5-9 and PN10-14, whereas shock alone had no effect. Adult fear responses to a predator odor were decreased only by PN10-14 treatment and the infant Shock alone and Shock+mother did not differ.

CONCLUSIONS/SIGNIFICANCE

Overall, integrating these results into our understanding of long-term programming by repeated infant pain experiences, the data suggest that pain experienced within a social context impacts infant neurobehavioral responses and initiates an altered developmental trajectory of pain and affect processing that diverges from experiencing pain alone.

Perceptions of neighborhood threat and caregiver support in early adolescence: Sex differences in neural and behavioral correlates in the ABCD study

BACKGROUND

Adolescents, particularly racial and ethnic minorities, are at increased risk for neighborhood threat and violence exposure, which impacts behavioral and neural outcomes. Caregiver support is associated with healthy socioemotional adjustment and self-regulatory and coping behaviors; however, it remains unclear whether caregiver support, specifically, consolation, can moderate the behavioral and neural impacts of neighborhood threat.

OBJECTIVE

The aim of this study was to examine the role of youth-perceived neighborhood threat on neural and behavioral correlates and to test the moderating potential of caregiver support. Sex differences in associations were examined.

PARTICIPANTS AND SETTING

11,559 nine- and ten-year old youth enrolled in the multi-site Adolescent Brain Cognitive Development (ABCD) Study at baseline.

METHODS

Associations were examined via linear regression models employing youth-perceived neighborhood threat and caregiver support. Regression and interaction models controlled for youth age, sex, race and ethnicity, primary caregiver's education, family income, family structure, youth-perceived school threat, and intracranial volume when examining neural outcomes. An ANOVA employing a Chi-square test and simple slopes analysis were used to identify significant interactions in moderation models.

RESULTS

Neighborhood threat is associated with structural alterations in the left amygdala (p = .004). Meanwhile, caregiver support interacts in a dose-response fashion with neighborhood threat to attenuate its relationship with left amygdala volume (p = .008). Among youth reporting neighborhood threat, problematic behaviors were more common (p < .0001). While not significant, males reported higher rates of neighborhood threat than females (p = .267). Females reported greater levels of caregiver support (p = .017). Lastly, racial and ethnic differences in neighborhood threat and caregiver support were evident (p < .001).

CONCLUSIONS

While youth may not have been exposed to direct or immediate sources of threat and violence, these findings shed light on the impact of neighborhood threat perception on problematic behaviors and amygdala volume among nine- and ten-year olds. Future research should identify other culturally inclusive sources and measures of support and resiliency.

Multiple routes of communication within the amygdala-mPFC network: A comparative approach in humans and macaques

The network formed by the amygdala (AMG) and the medial Prefrontal Cortex (mPFC), at the interface between our internal and external environment, has been shown to support some important aspects of behavioral adaptation. Whether and how the anatomo-functional organization of this network evolved across primates remains unclear. Here, we compared AMG nuclei morphological characteristics and their functional connectivity with the mPFC in humans and macaques to identify potential homologies and differences between these species. Based on selected studies, we highlight two subsystems within the AMG-mPFC circuits, likely involved in distinct temporal dynamics of integration during behavioral adaptation. We also show that whereas the mPFC displays a large expansion but a preserved intrinsic anatomo-functional organization, the AMG displays a volume reduction and morphological changes related to specific nuclei. We discuss potential commonalities and differences in the dialogue between AMG nuclei and mPFC in humans and macaques based on available data.

Serotonin transporter (5-HTT) gene network moderates the impact of prenatal maternal adversity on orbitofrontal cortical thickness in middle childhood

In utero, the developing brain is highly susceptible to the environment. For example, adverse maternal experiences during the prenatal period are associated with outcomes such as altered neurodevelopment and emotion dysregulation. Yet, the underlying biological mechanisms remain unclear. Here, we investigate whether the function of a network of genes co-expressed with the serotonin transporter in the amygdala moderates the impact of prenatal maternal adversity on the structure of the orbitofrontal cortex (OFC) in middle childhood and/or the degree of temperamental inhibition exhibited in toddlerhood. T1-weighted structural MRI scans were acquired from children aged 6-12 years. A cumulative maternal adversity score was used to conceptualize prenatal adversity and a co-expression based polygenic risk score (ePRS) was generated. Behavioural inhibition at 18 months was assessed using the Early Childhood Behaviour Questionnaire (ECBQ). Our results indicate that in the presence of a low functioning serotonin transporter gene network in the amygdala, higher levels of prenatal adversity are associated with greater right OFC thickness at 6-12 years old. The interaction also predicts temperamental inhibition at 18 months. Ultimately, we identified important biological processes and structural modifications that may underlie the link between early adversity and future deviations in cognitive, behavioural, and emotional development.

Examining resting-state network connectivity in children exposed to perinatal maternal adversity using anatomically weighted functional connectivity (awFC) analyses; A preliminary report

Introduction

Environmental perturbations during critical periods can have pervasive, organizational effects on neurodevelopment. To date, the literature examining the long-term impact of early life adversity has largely investigated structural and functional imaging data outcomes independently. However, emerging research points to a relationship between functional connectivity and the brain’s underlying structural architecture. For instance, functional connectivity can be mediated by the presence of direct or indirect anatomical pathways. Such evidence warrants the use of structural and functional imaging in tandem to study network maturation. Accordingly, this study examines the impact of poor maternal mental health and socioeconomic context during the perinatal period on network connectivity in middle childhood using an anatomically weighted functional connectivity (awFC) approach. awFC is a statistical model that identifies neural networks by incorporating information from both structural and functional imaging data.

Methods

Resting-state fMRI and DTI scans were acquired from children aged 7–9 years old.

Results

Our results indicate that maternal adversity during the perinatal period can affect offspring’s resting-state network connectivity during middle childhood. Specifically, in comparison to controls, children of mothers who had poor perinatal maternal mental health and/or low socioeconomic status exhibited greater awFC in the ventral attention network.

Discussion

These group differences were discussed in terms of the role this network plays in attention processing and maturational changes that may accompany the consolidation of a more adult-like functional cortical organization. Furthermore, our results suggest that there is value in using an awFC approach as it may be more sensitive in highlighting connectivity differences in developmental networks associated with higher-order cognitive and emotional processing, as compared to stand-alone FC or SC analyses.

The effects of social isolation stress and discrimination on mental health

Social isolation and discrimination are growing public health concerns associated with poor physical and mental health. They are risk factors for increased morbidity and mortality and reduced quality of life. Despite their detrimental effects on health, there is a lack of knowledge regarding translation across the domains of experimental research, clinical studies, and real-life applications. Here, we review and synthesize evidence from basic research in animals and humans to clinical translation and interventions. Animal models indicate that social separation stress, particularly in early life, activates the hypothalamic-pituitary-adrenal axis and interacts with monoaminergic, glutamatergic, and GABAergic neurotransmitter systems, inducing long-lasting reductions in serotonin turnover and alterations in dopamine receptor sensitivity. These findings are of particular importance for human social isolation stress, as effects of social isolation stress on the same neurotransmitter systems have been implicated in addictive, psychotic, and affective disorders. Children may be particularly vulnerable due to lasting effects of social isolation and discrimination stress on the developing brain. The effects of social isolation and loneliness are pronounced in the context of social exclusion due to discrimination and racism, during widespread infectious disease related containment strategies such as quarantine, and in older persons due to sociodemographic changes. This highlights the importance of new strategies for social inclusion and outreach, including gender, culture, and socially sensitive telemedicine and digital interventions for mental health care.

Prospective longitudinal associations between harsh parenting and corticolimbic function during adolescence

Childhood adversity is thought to undermine youth socioemotional development via altered neural function within regions that support emotion processing. These effects are hypothesized to be developmentally specific, with adversity in early childhood sculpting subcortical structures (e.g., amygdala) and adversity during adolescence impacting later-developing structures (e.g., prefrontal cortex; PFC). However, little work has tested these theories directly in humans. Using prospectively collected longitudinal data from the Fragile Families and Child Wellbeing Study (FFCWS) (N = 4,144) and neuroimaging data from a subsample of families recruited in adolescence (N = 162), the current study investigated the trajectory of harsh parenting across childhood (i.e., ages 3 to 9) and how initial levels versus changes in harsh parenting across childhood were associated with corticolimbic activation and connectivity during socioemotional processing. Harsh parenting in early childhood (indexed by the intercept term from a linear growth curve model) was associated with less amygdala, but not PFC, reactivity to angry facial expressions. In contrast, change in harsh parenting across childhood (indexed by the slope term) was associated with less PFC, but not amygdala, activation to angry faces. Increases in, but not initial levels of, harsh parenting were also associated with stronger positive amygdala-PFC connectivity during angry face processing.

Does pubertal stage mediate the association between family environment and structure and function of the amygdala-mPFC circuit? A replication study of the longitudinal ABCD cohort

Psychosocial acceleration theory suggests that early stress accelerates pubertal development. Using half of the baseline Adolescent Brain and Cognitive Development (ABCD) cohort, Thijssen et al. (2020) provide support that accelerated puberty following stressful family environments may promote neurodevelopment. Here, we replicate and extend those analyses using 1) data from the second half of the ABCD sample (n = 3300 +, ages 9-10), and 2) longitudinal imaging data from the original sample (n = 1800 +, ages 11-12). A family environment latent variable was created and related to anterior cingulate cortex (ACC) thickness, area, white matter fractional anisotropy, amygdala volume, and cingulo-opercular network (CON)-amygdala resting-state functional connectivity. Results from the independent sample replicate the mediating effects of family environment through pubertal stage on amygdala-CON functional connectivity. Sex-stratified analyses show indirect effects via pubertal stage in girls; boys show evidence for direct associations. Analyses using wave 2 imaging data or wave 2-wave 1 difference scores from the originally-analyzed sample replicate the resting-state indirect effects. The current paper replicates the mediating role for puberty in the association between family environment and neurodevelopment. As both direct and indirect associations were found, puberty may be one of multiple mechanisms driving accelerated neurodevelopment following environmental stress.

Observed parental spontaneous scaffolding predicts neurocognitive signatures of child emotion regulation

Emotion regulation (ER), a key predictor of positive adjustment throughout the lifespan, is forged in development with profound contributions from parents. In particular, parent scaffolding of child cognition and emotion serves to bolster child regulatory abilities beyond what they could achieve alone. Through habitual parent-child interactions, scaffolded ER likely becomes internalized and drives foundations of neurocognitive regulatory circuitry. Yet, biobehavioral research is needed to establish predictive links between parent scaffolding behaviors and neurocognitive signatures of adaptive child ER. The present study examined observed parental spontaneous scaffolding of child performance during emotionally and cognitively challenging behavioral tasks to predict a neurocognitive signature of adaptive ER: the late positive potential (LPP). The LPP is an event-related potential (ERP) that is modulated by reappraisal, a widely-studied ER strategy defined as interpreting a stimulus in a more positive light. Reduced magnitude of the LPP via reappraisal is a signature of adaptive ER because it predicts both reduced emotional arousal and increased use of adaptive ER strategies. Ninety-seven (49 females; M_age = 6.96, SD = 1.15) 5 to 9 year olds were recruited along with one parent each. Parents and children then completed a cognitively challenging blocks task and a frustrating waiting task, which were subsequently coded to quantify scaffolding quality. Participants completed a Directed Reappraisal Task (DRT) in which unpleasant pictures were paired with either reappraisal or negative interpretations while EEG was recorded. Results showed that greater parental use of high-quality scaffolding predicted greater reduction of the LPP via reappraisal. These findings suggest that habitual parent scaffolding supports adaptive ER measured at the neurocognitive level in childhood. Further, results highlight the importance of examining parent-child interactions when evaluating biological processes underlying ER in childhood.

Brain functional connectivities that mediate the association between childhood traumatic events, and adult mental health and cognition

BACKGROUND

Childhood traumatic events are risk factors for psychopathology, but large-scale studies of how childhood traumatic events relate to mental health and cognition in adulthood, and how the brain is involved, are needed.

METHODS

The associations between childhood traumatic events (such as abuse and neglect, and defined by the 'Childhood Trauma' questions in the UK Biobank database) and brain functional connectivity, mental health problems, and cognitive performance were investigated by a univariate correlation analysis with 19,535 participants aged 45-79 from the UK Biobank dataset. The results were replicated with 17,747 independent participants in the second release from the same dataset.

FINDINGS

Childhood traumatic events were significantly associated with mental health problems in adulthood including anxiety (r=0.19, p<1.0 × 10^-323), depression (r=0.21, p<1.0 × 10^-323), and self-harm (r=0.24, p<1.0 × 10^-323), and with adult cognitive performance including fluid intelligence (r=-0.05, p=2.8 × 10^-10) and prospective memory (r=-0.04, p=6.8 × 10^-8). Functional connectivities of the medial and lateral temporal cortex, the precuneus, the medial orbitofrontal cortex; and the superior, middle and inferior prefrontal cortex extending back to precentral regions were negatively correlated with the childhood traumatic events (FDR corrected, p<0.01). These lower functional connectivities significantly mediated the associations between childhood traumatic events and addiction, anxiety, depression and well-being (all p<1.0 × 10^-3), and cognitive performance. The association between childhood traumatic events and behavioural measures and functional connectivity were confirmed in a replication with different participants in the second release of the UK Biobank dataset.

INTERPRETATION

Childhood traumatic events are strongly associated with adult mental health problems mediated by brain functional connectivities in brain areas involved in executive function, emotion, face processing, and memory. This understanding may help with prevention and treatment.

FUNDING

Funding was provided by the National Key R&D Program of China (No. 2018YFC1312900 and No. 2019YFA0709502).

Mothers’ Attachment Representations and Children’s Brain Structure

Ample research demonstrates that parents’ experience-based mental representations of attachment—cognitive models of close relationships—relate to their children’s social-emotional development. However, no research to date has examined how parents’ attachment representations relate to another crucial domain of children’s development: brain development. The present study is the first to integrate the separate literatures on attachment and developmental social cognitive neuroscience to examine the link between mothers’ attachment representations and 3- to 8-year-old children’s brain structure. We hypothesized that mothers’ attachment representations would relate to individual differences in children’s brain structures involved in stress regulation—specifically, amygdala and hippocampal volumes—in part via mothers’ responses to children’s distress. We assessed 52 mothers’ attachment representations (secure base script knowledge on the Attachment Script Assessment and self-reported attachment avoidance and anxiety on the Experiences in Close Relationships scale) and children’s brain structure. Mothers’ secure base script knowledge was significantly related to children’s smaller left amygdala volume but was unrelated to hippocampal volume; we found no indirect links via maternal responses to children’s distress. Exploratory analyses showed associations between mothers’ attachment representations and white matter and thalamus volumes. Together, these preliminary results suggest that mothers’ attachment representations may be linked to the development of children’s neural circuitry related to stress regulation.

Stress and adolescence: vulnerability and opportunity during a sensitive window of development

Adolescence is a period of dynamic change across multiple systems. Concurrent maturation of neural, biological, and psychosocial functioning renders adolescence a time of heightened sensitivity to both negative and positive experiences. Here, we review recent literature across these domains, discuss risk and opportunity in the context of ongoing neural development, and highlight promising directions for future research. Finally, we propose that conceptualizing adolescence as a sensitive window during which plasticity across multiple systems is enhanced may support the identification of links between experience, neurodevelopment, and psychopathology.

Social relationships and children’s perceptions of adversity

Having sensitive, contingent, and supportive social relationships has been linked to more positive outcomes after experiences of early childhood adversity. Traditionally, social relationships are construed as moderators that buffer children from the effects of exposure to adverse events. However, recent data support an alternative view: that supportive social relationships influence children’s later outcomes by shaping their perceptions of safety and stress, regardless of the particular events to which children are exposed. This perspective has implications for understanding vulnerability and resilience in children.

Infant Attachment and Social Modification of Stress Neurobiology

Decades of research have informed our understanding of how stress impacts the brain to perturb behavior. However, stress during development has received specific attention as this occurs during a sensitive period for scaffolding lifelong socio-emotional behavior. In this review, we focus the developmental neurobiology of stress-related pathology during infancy and focus on one of the many important variables that can switch outcomes from adaptive to maladaptive outcome: caregiver presence during infants' exposure to chronic stress. While this review relies heavily on rodent neuroscience research, we frequently connect this work with the human behavioral and brain literature to facilitate translation. Bowlby's Attachment Theory is used as a guiding framework in order to understand how early care quality impacts caregiver regulation of the infant to produce lasting outcomes on mental health.

Early life stress and neural development: Implications for understanding the developmental effects of COVID-19

Chronic and/or extreme stress in childhood, often referred to as early life stress, is associated with a wide range of long-term effects on development. Given this, the COVID-19 pandemic has led to concern about how stress due to the pandemic will affect children's development and mental health. Although early life stress has been linked to altered functioning of a number of neural and biological systems, there is a wide range of variability in children's outcomes. The mechanisms that influence these individual differences are still not well understood. In the past, studies of stress in childhood focused on the type of events that children encountered in their lives. We conducted a review of the literature to formulate a new perspective on the effects of early life stress on development. This new, topological model, may increase understanding of the potential effects of the COVID-19 pandemic on children's development. This model is oriented on children's perceptions of their environment and their social relationships, rather than specific events. These factors influence central and peripheral nervous system development, changing how children interpret, adapt, and respond to potentially stressful events, with implications for children's mental and physical health outcomes.

Biological signatures of emotion regulation flexibility in children: Parenting context and links with child adjustment

Emotion regulation (ER) is a key facet of positive adjustment throughout the lifespan. Recent theoretical and empirical innovations suggest that current methods for assessing ER are limited, because they measure discrete strategy use instead of ER flexibility and are insensitive to ecologically valid social contexts that influence ER. This is particularly important for studying the impact of parenting on ER development during childhood. The current study (N = 93; 47 females; M_age = 6.98, SD = 1.12) examined child ER flexibility during a directed reappraisal task (DRT) with two parenting contexts: passive parent presence or active scaffolding. Two biological signatures of ER flexibility were measured: respiratory sinus arrhythmia (RSA), an index of physiological flexibility; and the late positive potential (LPP), an index of neurocognitive flexibility. Emotion regulation behavior was observed during a frustrating wait, and parents reported on child ER and adjustment. Greater ER flexibility indexed via the LPP and RSA both predicted observed ER during the frustrating wait, but only RSA predicted parent-reported trait ER and fewer adjustment problems. Emotion regulation flexibility indexed by the LPP was bolstered by parent presence and scaffolding of child ER during the DRT, but RSA measures were not sensitive to parenting context. Taken together, the results provide converging evidence for the conceptualization of ER in terms of physiological and neurocognitive flexibility in childhood. Furthermore, among school-aged children, while physiological flexibility broadly predicted parent-reported child adjustment, neurocognitive flexibility may be context-sensitive and predictive of concurrent observed ER.

Developmental outcomes of early adverse care on amygdala functional connectivity in nonhuman primates

Despite the strong link between childhood maltreatment and psychopathology, the underlying neurodevelopmental mechanisms are poorly understood and difficult to disentangle from heritable and prenatal factors. This study used a translational macaque model of infant maltreatment in which the adverse experience occurs in the first months of life, during intense maturation of amygdala circuits important for stress and emotional regulation. Thus, we examined the developmental impact of maltreatment on amygdala functional connectivity (FC) longitudinally, from infancy through the juvenile period. Using resting state functional magnetic resonance imaging (MRI) we performed amygdala-prefrontal cortex (PFC) region-of-interest and exploratory whole-brain amygdala FC analyses. The latter showed (a) developmental increases in amygdala FC with many regions, likely supporting increased processing of socioemotional-relevant stimuli with age; and (b) maltreatment effects on amygdala coupling with arousal and stress brain regions (locus coeruleus, laterodorsal tegmental area) that emerged with age. Maltreated juveniles showed weaker FC than controls, which was negatively associated with infant hair cortisol concentrations. Findings from the region-of-interest analysis also showed weaker amygdala FC with PFC regions in maltreated animals than controls since infancy, whereas bilateral amygdala FC was stronger in maltreated animals. These effects on amygdala FC development may underlie the poor behavioral outcomes associated with this adverse experience.

Neural meaning making, prediction, and prefrontal-subcortical development following early adverse caregiving

Early adversities that are caregiving-related (crEAs) are associated with a significantly increased risk for mental health problems. Recent neuroscientific advances have revealed alterations in medial prefrontal cortex (mPFC)-subcortical circuitry following crEAs. While this work has identified alterations in affective operations (e.g., perceiving, reacting, controlling, learning) associated with mPFC-subcortical circuitry, this circuitry has a much broader function extending beyond operations. It plays a primary role in affective meaning making, involving conceptual-level, schematized knowledge to generate predictions about the current environment. This function of mPFC-subcortical circuitry motivates asking whether mPFC-subcortical phenotypes following crEAs support semanticized knowledge content (or the concept-level knowledge) and generate predictive models. I present a hypothesis motivated by research findings across four different lines of work that converge on mPFC-subcortical neuroanatomy, including (a) the neurobiology supporting emotion regulation processes in adulthood, (b) the neurobiology that is activated by caregiving cues during development, (c) the neurobiology that is altered by crEAs, and (d) the neurobiology of semantic-based meaning making. I hypothesize that the affective behaviors following crEAs result in part from affective semantic memory processes supported by mPFC-subcortical circuitry that over the course of development, construct affective schemas that generate meaning making and guide predictions. I use this opportunity to review some of the literature on mPFC-subcortical circuit development following crEAs to illustrate the motivation behind this hypothesis. Long recognized by clinical science and cognitive neuroscience, studying schema-based processes may be particularly helpful for understanding how affective meaning making arises from developmental trajectories of mPFC-subcortical circuitry.

Development and Validation of the Parental Assistance with Child Emotion Regulation (PACER) Questionnaire

Caregivers play a central role in promoting emotion regulation throughout infancy, childhood, and adolescence. However, there are no existing psychometric measures to assess how parents assist children in employing emotion regulation strategies for negative emotions. We therefore developed the Parental Assistance with Child Emotion Regulation (PACER) Questionnaire to assess the degree to which parents assist their children in their use of ten different regulation strategies. In this paper, we describe the development of the PACER and examine its psychometric properties (N = 407 parents of children ages birth to 17 years). In so doing, we also use the PACER to comprehensively explore the links between parent-assisted emotion regulation and indices of parent and child stress, symptomatology, and attachment. Confirmatory factor analyses of the PACER items supported its intended ten-factor structure (corresponding to ten specific regulation strategies), which was invariant across different child age and sex categories. PACER scale scores had excellent internal consistency and generally acceptable test-retest reliability over a one-week period. Convergent validity was established via correlations between PACER scales and indices of parental emotion sensitivity, expressivity, and regulation, as well as parents' perception of the efficacy of their assistance with children's execution of emotion regulatory strategies. Lower parental facilitation of stereotypically adaptive emotion regulatory strategies was associated with higher child internalizing and externalizing problems and with poorer parent-child relationship quality. Overall, these findings suggest that the PACER may be a useful tool for the assessment of parental assistance with child emotion regulation across development.

Emotion regulation strategy usage explains links between institutional caregiving and elevated internalizing symptoms

Early adversity, including institutional orphanage care, is associated with the development of internalizing disorders. Previous research suggests that institutionalization can disrupt emotion regulation processes, which contribute to internalizing symptoms. However, no prior work has investigated how early orphanage care shapes emotion regulation strategy usage (e.g., cognitive reappraisal, expressive suppression) and whether the said strategy usage contributes to internalizing symptoms. This study probed emotion regulation strategy usage and internalizing symptoms in a sample of 36 previously institutionalized and 58 comparison youth. As hypothesized, previously institutionalized youth exhibited higher rates of internalizing symptoms than comparison youth, and more frequent use of suppression partially accounted for the relationship between early institutional care and elevated internalizing symptoms. Contrary to our initial hypotheses, reappraisal use did not buffer previously institutionalized or comparison youth against internalizing symptoms. Our findings highlight the potential utility of targeting emotion regulation strategy usage in adversity-exposed youth in future intervention work.

Early life stress and development: potential mechanisms for adverse outcomes

BACKGROUND

Chronic and/or extreme stress in early life, often referred to as early adversity, childhood trauma, or early life stress, has been associated with a wide range of adverse effects on development. However, while early life stress has been linked to negative effects on a number of neural systems, the specific mechanisms through which early life stress influences development and individual differences in children's outcomes are still not well understood.

MAIN TEXT

The current paper reviews the existing literature on the neurobiological effects of early life stress and their ties to children's psychological and behavioral development.

CONCLUSIONS

Early life stress has persistent and pervasive effects on prefrontal-hypothalamic-amygdala and dopaminergic circuits that are at least partially mediated by alterations in hypothalamic-pituitary-adrenal axis function. However, to date, this research has primarily utilized methods of assessment that focus solely on children's event exposures. Incorporating assessment of factors that influence children's interpretation of stressors, along with stressful events, has the potential to provide further insight into the mechanisms contributing to individual differences in neurodevelopmental effects of early life stress. This can aid in further elucidating specific mechanisms through which these neurobiological changes influence development and contribute to risk for psychopathology and health disorders.

Defining Immediate Effects of Sensitive Periods on Infant Neurobehavioral Function

During a sensitive period associated with attachment, the infant brain has unique circuitry that enables the specialized adaptive behaviors required for survival in infancy. This infant brain is not an immature version of the adult brain. Within the attachment relationship, the infant remains close (proximity seeking) to the caregiver for nurturing and survival needs, but the caregiver also provides the immature infant with the physiological regulation interaction needed before self-regulation matures. Here we provide examples from the human and animal literature that illustrate some of these regulatory functions during sensitive periods, recent advances demonstrating the supporting transient neural mechanisms, and how these systems go awry in the absence of species-expected caregiving.

An ecological approach to understanding the developing brain: Examples linking poverty, parenting, neighborhoods, and the brain

We describe an ecological approach to understanding the developing brain, with a focus on the effects of poverty-related adversity on brain function. We articulate how combining multilevel ecological models from developmental science and developmental psychopathology with human neuroscience can inform our approach to understanding the developmental neuroscience of risk and resilience. To illustrate this approach, we focus on associations between poverty and brain function, the roles parents and neighborhoods play in this context, and the potential impact of developmental timing. We also describe the major challenges and needed advances in these areas of research to better understand how and why poverty-related adversity may impact the developing brain, including the need for: a population neuroscience approach with greater attention to sampling and representation, genetically informed and causal designs, advances in assessing context and brain function, caution in interpretation of effects, and a focus on resilience. Work in this area has major implications for policy and prevention, which are discussed. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Pubertal development mediates the association between family environment and brain structure and function in childhood

Psychosocial acceleration theory suggests that pubertal maturation is accelerated in response to adversity. In addition, suboptimal caregiving accelerates development of the amygdala–medial prefrontal cortex circuit. These findings may be related. Here, we assess whether associations between family environment and measures of the amygdala–medial prefrontal cortex circuit are mediated by pubertal development in more than 2000 9- and 10-year-old children from the Adolescent Brain Cognitive Development Study (http://dx.doi.org/10.15154/1412097). Using structural equation modeling, demographic, child-reported, and parent-reported data on family dynamics were compiled into a higher level family environment latent variable. Magnetic resonance imaging preprocessing and compilations were performed by the Adolescent Brain Cognitive Development Study's data analysis core. Anterior cingulate cortex (ACC) thickness, area, white matter fractional anisotropy, amygdala volume, and cingulo-opercular network–amygdala resting-state functional connectivity were assessed. For ACC cortical thickness and ACC fractional anisotropy, significant indirect effects indicated that a stressful family environment relates to more advanced pubertal stage and more mature brain structure. For cingulo-opercular network–amygdala functional connectivity, results indicated a trend in the expected direction. For ACC area, evidence for quadratic mediation by pubertal stage was found. Sex-stratified analyses suggest stronger results for girls. Despite small effect sizes, structural measures of circuits important for emotional behavior are associated with family environment and show initial evidence of accelerated pubertal development.

An exploration of amygdala-prefrontal mechanisms in the intergenerational transmission of learned fear

Humans learn about their environments by observing others, including what to fear and what to trust. Observational fear learning may be especially important early in life when children turn to their parents to gather information about their world. Yet, the vast majority of empirical research on fear learning in youth has thus far focused on firsthand classical conditioning, which may fail to capture one of the primary means by which fears are acquired during development. To address this gap in the literature, the present study examined observational fear learning in youth (n = 33; age range: 6-17 years) as they watched videos of their parent and an "unfamiliar parent" (i.e., another participant's parent) undergo fear conditioning. Youth demonstrated stronger fear learning when observing their parent compared to an unfamiliar parent, as indicated by changes in their self-reported liking of the stimuli to which their parents were conditioned (CS+, a geometric shape paired with an aversive noise; CS-, a geometric shape never paired with an aversive noise) and amygdala responses. Parent trait anxiety was associated with youth learning better (i.e., reporting a stronger preference for the CS- relative to CS+), and exhibiting stronger medial prefrontal-amygdala connectivity. Neuroimaging data were additionally acquired from a subset of parents during firsthand conditioning, and parental amygdala and mPFC activation were associated with youth's neural recruitment. Together, these results suggest that youth preferentially learn fears via observation of their parents, and this learning is associated with emotional traits and neural recruitment in parents.

Maternal Antecedents to Adolescent Girls' Neural Regulation of Emotion

The purpose of this study was to investigate contributions of maternal emotional resources to individual differences in adolescents' functional connectivity during emotion regulation. Participants included 35 adolescent girls who completed an implicit emotion regulation task during fMRI. Mothers reported on the quality of their adult attachment and emotional awareness when youth were in elementary school. Higher anxious attachment and lower emotional awareness were significantly correlated with more positive amygdala-right ventrolateral prefrontal cortex connectivity, a pattern linked in prior research with ineffective emotion regulation and emotional difficulties. Further, there was an indirect effect of anxious attachment on adolescent connectivity through emotional awareness. These results suggest that compromised maternal emotional resources in childhood may be linked to atypical neural processing of emotions.

A lifespan developmental science perspective on trauma experiences in refugee situations

Developmental science theory and empirical research on refugee situations requires an updated approach to the study of trauma as a multi-systemic and multilevel phenomenon. We present a theoretical framework that integrates developmental science approaches to highlight critical threats to development in situations of violent displacement. Given the complexities of displacement (causes, trajectories, and living circumstances once displaced), this theoretical model highlights the utility of an approach that recognizes the person-age-context fit in which displaced individuals live their lives and how both trauma and ongoing major disruption to daily life affects outcomes. In so doing, we aim to broaden understanding for future trauma and intervention research as well as practice with those who experience potentially traumatic events and severe disruption to their social ecology at different points in the lifespan.

The association between parenting and the error-related negativity across childhood and adolescence

Anxiety is the most common form of psychopathology, and it is often characterized by chronic impairment across the lifespan. Researchers have identified core neural markers that confer risk for anxious outcomes. An increased error-related negativity (ERN) in anxious individuals has been shown to prospectively predict onset of anxiety disorders across development. Hence, it is critical to examine environmental factors that may shape the ERN. In the current study, we use a large sample of 170 female adolescents aged 10-17 to investigate whether the ERN mediates the relationship between parenting style and anxiety diagnostic status. This study replicates previous findings, and it extends previous work by suggesting that this relationship is more robust in young children as compared to adolescents. Interventions targeting the ERN via parenting may be most effective during childhood.

Preliminary Evidence of the Role of Medial Prefrontal Cortex in Self-Enhancement: A Transcranial Magnetic Stimulation Study

Humans employ a number of strategies to improve their position in their given social hierarchy. Overclaiming involves presenting oneself as having more knowledge than one actually possesses, and it is typically invoked to increase one’s social standing. If increased expectations to possess knowledge is a perceived social pressure, such expectations should increase bouts of overclaiming. As the medial prefrontal cortex (MPFC) is sensitive to social pressure and disruption of the MPFC leads to decreases in overclaiming, we predicted that transcranial magnetic stimulation (TMS) applied to the MPFC would reduce overclaiming and the effects would be enhanced in the presence of social pressure. Twelve participants were given a test in which half of the words were real and half were fake, and they were asked how well they knew each word. They were not told that any of the words were fake. Half of the participants were exposed to social pressure while the other half were not. Following TMS delivered to the MPFC, overclaiming rates decreased, specifically under conditions of high social pressure. Medial PFC TMS did not influence real word responses and real words did not interact with the MPFC and social pressure. These preliminary findings support the significant role the MPFC plays in social cognition and the importance of the MPFC in mediating socially meaningful situations. We suggest the role of the MPFC as being highly influenced by the premium placed on social manipulation in human evolution.

Rethinking Concepts and Categories for Understanding the Neurodevelopmental Effects of Childhood Adversity

Discovering the processes through which early adverse experiences affect children’s nervous-system development, health, and behavior is critically important for developing effective interventions. However, advances in our understanding of these processes have been constrained by conceptualizations that rely on categories of adversity that are overlapping, have vague boundaries, and lack consistent biological evidence. Here, we discuss central problems in understanding the link between early-life adversity and children’s brain development. We conclude by suggesting alternative formulations that hold promise for advancing knowledge about the neurobiological mechanisms through which adversity affects human development.

Optogenetic reactivation of prefrontal social neural ensembles mimics social buffering of fear

Social buffering occurs when the presence of a companion attenuates the physiological and/or behavioral effects of a stressful or fear-provoking event. It represents a way in which social interactions can immediately and potently modulate behavior. As such, social buffering is one mechanism by which strong social support increases resilience to mental illness. Although the behavioral and neuroendocrine impacts of social buffering are well studied in multiple species, including humans, the neuronal underpinnings of this behavioral phenomenon remain largely unexplored. Previous work has shown that the infralimbic prefrontal cortex (IL-PFC) is important for processing social information and, in separate studies, for modulating fear and anxiety. Thus, we hypothesized that socially active cells within the IL-PFC may integrate social information to modulate fear responsivity. To test this hypothesis, we employed social buffering paradigms in male and female mice. Similar to prior studies in rats, we found that the presence of a cagemate reduced freezing in fear- and anxiety-provoking contexts. In accordance with previous work, we demonstrated that interaction with a novel or familiar conspecific induces activity in the IL-PFC as evidenced by increased immediate early gene (IEG) expression. We then utilized an activity-dependent tagging murine line, the ArcCreER^T2 mice, to express channelrhodopsin (ChR2) in neurons active during the social encoding of a new cagemate. We found that optogenetic reactivation of these socially active neuronal ensembles phenocopied the effects of cagemate presence in male and female mice in learned and innate fear contexts without being inherently rewarding or altering locomotion. These data suggest that a social neural ensemble within the IL-PFC may contribute to social buffering of fear. These neurons may represent a novel therapeutic target for fear and anxiety disorders.

Neural signatures of child cognitive emotion regulation are bolstered by parental social regulation in two cultures

Caregiver impact on the efficacy of cognitive emotion regulation (ER; i.e. reappraisal) during childhood is poorly understood, particularly across cultures. We tested the hypothesis that in children from Japan and the USA, a neurocognitive signature of effective reappraisal, the late positive potential (LPP), will be bolstered by cognitive scaffolding by parents, and explored whether the two cultures differed in whether mere physical proximity of parents provides similar benefit. Five-to-seven-year-olds (N = 116; n_Japan = 58; n_USA = 58) completed a directed reappraisal task (EEG-recorded) in one of three contexts: (i) parent-scaffolding, (ii) parent-present and (iii) parent-absent. Across cultures, those in the parent-scaffolding group and parent-present group showed effective reappraisal via the LPP relative to those in the parent-absent group. Results suggest that scaffolding is an effective method through which parents in these two cultures buttress child ER, and even parental passive proximity appears to have a meaningful effect on child ER across cultures.

Influences of early-life stress on frontolimbic circuitry: Harnessing a dimensional approach to elucidate the effects of heterogeneity in stress exposure

Early-life stress confers profound and lasting risk for developing cognitive, social, emotional, and physical health problems. The effects of stress on the developing brain contribute to this risk, with frontolimbic circuitry particularly susceptible to early experiences, possibly due to its innervation with glucocorticoid receptors and the timing of frontolimbic circuit maturation. To date, the majority of studies on stress and frontolimbic circuitry have employed a categorical approach, comparing stress-exposed versus non-stress-exposed youth. However, there is vast heterogeneity in the nature of stress exposure and in outcomes. Recent forays into understanding the psychobiological effects of stress have employed a dimensional approach focused on experiential, environmental, and temporal factors that influence the association between stress and subsequent vulnerability. This review highlights empirical findings that inform a dimensional approach to understanding the effects of stress on frontolimbic circuitry. We identify the timing, type, severity, controllability, and predictability of stress, and the degree to which a caregiver is involved, as specific features of stress that may play a substantial role in differential outcomes. We propose a framework for the effects of these features of stress on frontolimbic development that may partially determine how heterogeneity in stress exposure influences this circuitry and, ultimately, mental health.

More than meets the eye: The neural development of emotion face processing during infancy

This study explored the impact of infant temperament and maternal stress on the development of the infant medial prefrontal cortex (mPFC) among sixteen 6-8-month-old infants. Functional Near Infrared Spectroscopy (fNIRS) was used to measure activation of the infant mPFC in response to angry, happy, and sad faces. Infant temperament and dimensions of maternal stress were measured with the Infant Behavior Questionnaire and the Parenting Stress Index Respectively. Infants with high negative emotionality demonstrated increased mPFC activation in association with all emotion face conditions. Negative emotionality moderated the effect of total maternal stress on mPFC activation to angry and sad faces. Mother-infant dysfunctional interaction was related to increased mPFC activation associated with happy faces, supporting the "novelty hypothesis", in which the mPFC responds more strongly to unique experiences. Therefore, this study provides additional evidence that infant temperament and the quality of the mother-infant relationship influence the development of the mPFC and how infants process emotions.

Maternal Buffering of Adolescent Dysregulation in Socially Appetitive Contexts: From Behavior to the Brain

Adolescents are more susceptible to dysregulation in positive social contexts, compared to children. We investigated whether maternal presence would buffer these effects in adolescence. Fifty-four adolescents and children (age range = 8-17 years, Mage  = 13.38 years) completed a social go-nogo task during an fMRI scan alone and in the presence of their mother. We found age-related patterns, such that older relative to younger youth displayed more disinhibition toward socially appetitive than socially aversive stimuli, which was buffered by maternal presence. Furthermore, with age, maternal buffering in socially appetitive contexts elicited heightened activation in the ventromedial prefrontal cortex and amygdala-medial prefrontal cortex connectivity. Findings underscore the importance of caregivers in promoting the neural regulation of their offspring during adolescence.

Childhood Adversity and Neural Development: A Systematic Review

An extensive literature on childhood adversity and neurodevelopment has emerged over the past decade. We evaluate two conceptual models of adversity and neurodevelopment-the dimensional model of adversity and stress acceleration model-in a systematic review of 109 studies using MRI-based measures of neural structure and function in children and adolescents. Consistent with the dimensional model, children exposed to threat had reduced amygdala, medial prefrontal cortex (mPFC), and hippocampal volume and heightened amygdala activation to threat in a majority of studies; these patterns were not observed consistently in children exposed to deprivation. In contrast, reduced volume and altered function in frontoparietal regions were observed consistently in children exposed to deprivation but not children exposed to threat. Evidence for accelerated development in amygdala-mPFC circuits was limited but emerged in other metrics of neurodevelopment. Progress in charting neurodevelopmental consequences of adversity requires larger samples, longitudinal designs, and more precise assessments of adversity.

The nature and nurture of social development: The role of 5-HTTLPR and gene-parenting interactions

Social skills are traditionally viewed as acquired through social environments including parenting. However, biopsychosocial models highlight the importance of genetic influences and gene-environment interactions (G×Es) in child development. Extant G×E investigations often fail to account for developmental changes in the phenotype or rigorously assess the social environment using observational measures. The present study prospectively assessed 110 children (44.5% female) and their parents to explore biologically plausible independent and interactive associations of the serotonin transporter-linked polymorphic region (5-HTTLPR) and observed positive and negative parenting in prediction of (a) initial levels of social skills at school entry (age 6 years) and (b) developmental changes in social skills across the early school years (ages 6-9 years). Overall, the SS (vs. SL/LL) 5-HTTLPR genotype inversely predicted social skills across all domains, although parenting behavior moderated these associations wherein putative G×E effects differed by developmental timing and social skills domain. Positive parenting positively predicted concurrent (age 6) overall social skills for children with SL/LL genotypes, but not the SS genotype. However, for the SS group only, age 6 positive parenting positively predicted prospective growth in social responsibility, although negative parenting positively predicted growth in social cooperation. Findings suggest that 5-HTTLPR may signal differential sensitivities to parenting styles and patterns of social development, which may help to inform targeted intervention approaches to enhance person-environment fit. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Friendship and social functioning following early institutional rearing: The role of ADHD symptoms

Early institutional rearing is associated with increased risk for subsequent peer relationship difficulties, but the underlying mechanisms have not been identified. Friendship characteristics, social behaviors with peers, normed assessments of social problems, and social cue use were assessed in 142 children (mean age = 10.06, SD = 2.02; range 7-13 years), of whom 67 were previously institutionalized (PI), and 75 were raised by their biological families. Anxiety and attention-deficit/hyperactivity disorder (ADHD) symptoms, often elevated among PI children, were examined as potential mediators of PI status and baseline social functioning and longitudinal follow-ups (2 and 4 years later). Twenty-seven percent of PI children fell above the Child Behavior Checklist Social Problems cutoff. An examination of specific social behaviors with peers indicated that PI and comparison children did not differ in empathic concern or peer social approach, though parents were more likely to endorse aggression/overarousal as a reason that PI children might struggle with friendships. Comparison children outperformed PI children in computerized testing of social cue use learning. Finally, across these measures, social difficulties exhibited in the PI group were mediated by ADHD symptoms with predicted social problems assessed 4 years later. These findings show that, when PI children struggle with friendships, mechanisms involving attention and behavior regulation are likely contributors.

Glucocorticoid receptor expression in the stress-limbic circuitry is differentially affected by prenatal alcohol exposure and adolescent stress

The dense expression of glucocorticoid receptors (GR) within the amygdala, medial prefrontal cortex (mPFC) and paraventricular nucleus of hypothalamus (PVN) mediates many aspects of emotional and stress regulation. Importantly, both prenatal alcohol exposure (PAE) and adolescent stress are known to induce emotional and stress dysregulation. Little is known, however, about how PAE and/or adolescent stress may alter the expression of GR in the amygdala, mPFC, and PVN. To fill this gap, we exposed PAE and control adolescent male and female rats to chronic mild stress (CMS) and assessed GR mRNA expression in the amygdala, mPFC, and PVN immediately following stress or in adulthood. We found that the effects of PAE on GR expression were more prevalent in the amygdala, while effects of adolescent stress on GR expression were more prevalent in the mPFC. Moreover, PAE effects in the amygdala were more pronounced during adolescence and adolescent stress effects in the mPFC were more pronounced in adulthood. GR expression in the PVN was affected by both PAE and adolescent stress. Finally, PAE and/or adolescent stress effects were distinct between males and females. Together, these results suggest that PAE and adolescent CMS induce dynamic alterations in GR expression in the amygdala, mPFC, and PVN, which manifest differently depending on the brain area, age, and sex of the animal. Additionally, these data indicate that PAE-induced hyperresponsiveness to stress and increased vulnerability to mental health problems may be mediated by different neural mechanisms depending on the sex and age of the animal.

Pubertal development mediates the association between family environment and brain structure and function in childhood

Psychosocial acceleration theory suggests that pubertal maturation is accelerated in response to adversity. In addition, suboptimal caregiving accelerates development of the amygdala-medial prefrontal cortex circuit. These findings may be related. Here, we assess whether associations between family environment and measures of the amygdala-medial prefrontal cortex circuit are mediated by pubertal development in more than 2000 9- and 10-year-old children from the Adolescent Brain Cognitive Development Study (http://dx.doi.org/10.15154/1412097). Using structural equation modeling, demographic, child-reported, and parent-reported data on family dynamics were compiled into a higher level family environment latent variable. Magnetic resonance imaging preprocessing and compilations were performed by the Adolescent Brain Cognitive Development Study's data analysis core. Anterior cingulate cortex (ACC) thickness, area, white matter fractional anisotropy, amygdala volume, and cingulo-opercular network-amygdala resting-state functional connectivity were assessed. For ACC cortical thickness and ACC fractional anisotropy, significant indirect effects indicated that a stressful family environment relates to more advanced pubertal stage and more mature brain structure. For cingulo-opercular network-amygdala functional connectivity, results indicated a trend in the expected direction. For ACC area, evidence for quadratic mediation by pubertal stage was found. Sex-stratified analyses suggest stronger results for girls. Despite small effect sizes, structural measures of circuits important for emotional behavior are associated with family environment and show initial evidence of accelerated pubertal development.

Neurobiology of maternal regulation of infant fear: the role of mesolimbic dopamine and its disruption by maltreatment

Child development research highlights caregiver regulation of infant physiology and behavior as a key feature of early life attachment, although mechanisms for maternal control of infant neural circuits remain elusive. Here we explored the neurobiology of maternal regulation of infant fear using neural network and molecular levels of analysis in a rodent model. Previous research has shown maternal suppression of amygdala-dependent fear learning during a sensitive period. Here we characterize changes in neural networks engaged during maternal regulation and the transition to infant self-regulation. Metabolic mapping of 2-deoxyglucose uptake during odor-shock conditioning in postnatal day (PN)14 rat pups showed that maternal presence blocked fear learning, disengaged mesolimbic circuitry, basolateral amygdala (BLA), and plasticity-related AMPA receptor subunit trafficking. At PN18, when maternal presence only socially buffers threat learning (similar to social modulation in adults), maternal presence failed to disengage the mesolimbic dopaminergic system, and failed to disengage both the BLA and plasticity-related AMPA receptor subunit trafficking. Further, maternal presence failed to block threat learning at PN14 pups following abuse, and mesolimbic dopamine engagement and AMPA were not significantly altered by maternal presence-analogous to compromised maternal regulation of children in abusive relationships. Our results highlight three key features of maternal regulation: (1) maternal presence blocks fear learning and amygdala plasticity through age-dependent suppression of amygdala AMPA receptor subunit trafficking, (2) maternal presence suppresses engagement of brain regions within the mesolimbic dopamine circuit, and (3) early-life abuse compromises network and molecular biomarkers of maternal regulation, suggesting reduced social scaffolding of the brain.

Effects of early maternal care on adolescent attention bias to threat in nonhuman primates

Attention bias towards threat using dot-probe tasks has mainly been reported in adults with stress-related disorders such as PTSD and other anxiety disorders, in some cases associated with early life stress or traumatic experiences. Studies during adolescence are scarce and inconsistent, which highlights the need to increase our understanding of the developmental processes that predict attentional biases, given that this is a time of emergence of psychopathology. Here, we use a translational nonhuman primate model of early life stress in the form of infant maltreatment to examine its long-term impact on attentional biases during adolescence using the dot-probe task and identify interactions with early life risk factors, such as prenatal exposure to stress hormones and emotional/stress reactivity during infancy. Maltreated animals showed higher reaction times to social threat than animals that experienced competent maternal care, suggesting interference of negative valence stimuli on attentional control and cognitive processes. Higher emotional reactivity during infancy in Maltreated animals predicted attention bias towards threat, whereas higher levels of prenatal cortisol exposure was associated with bias away (avoidance of) threat in maltreated and control groups. Our findings suggest that different postnatal experiences and early biobehavioral mechanisms regulate the development of emotional attention biases during adolescence.

Is adolescence the missing developmental link in Microbiome-Gut-Brain axis communication?

Gut microbial research has recently opened new frontiers in neuroscience and potentiated novel therapies for mental health problems (Mayer, et al., 2014). Much of our understanding of the gut microbiome's role in brain function and behavior, however, has been largely derived from research on nonhuman animals. Even less is known about how the development of the gut microbiome influences critical periods of neural and behavioral development, particularly adolescence. In this review, we first discuss why the gut microbiome has become increasingly relevant to developmental cognitive neuroscience and provide a synopsis of the known connections of the gut microbiome with social-affective brain function and behavior, specifically highlighting human developmental work when possible. We then focus on adolescence, a key period of neurobiological and social-affective development. Specifically, we review the links between the gut microbiome and six overarching domains of change during adolescence: (a) social processes, (b) motivation and behavior, (c) neural development, (d) cognition, (e) neuroendocrine function, and (f) physical health and wellness. Using a developmental science perspective, we summarize key changes across these six domains to underscore the promise for the gut microbiome to bidirectionally influence and transform adolescent development.

Developing a neurobehavioral animal model of poverty: Drawing cross-species connections between environments of scarcity-adversity, parenting quality, and infant outcome

Children reared in impoverished environments are at risk for enduring psychological and physical health problems. Mechanisms by which poverty affects development, however, remain unclear. To explore one potential mechanism of poverty's impact on social-emotional and cognitive development, an experimental examination of a rodent model of scarcity-adversity was conducted and compared to results from a longitudinal study of human infants and families followed from birth (N = 1,292) who faced high levels of poverty-related scarcity-adversity. Cross-species results supported the hypothesis that altered caregiving is one pathway by which poverty adversely impacts development. Rodent mothers assigned to the scarcity-adversity condition exhibited decreased sensitive parenting and increased negative parenting relative to mothers assigned to the control condition. Furthermore, scarcity-adversity reared pups exhibited decreased developmental competence as indicated by disrupted nipple attachment, distress vocalization when in physical contact with an anesthetized mother, and reduced preference for maternal odor with corresponding changes in brain activation. Human results indicated that scarcity-adversity was inversely correlated with sensitive parenting and positively correlated with negative parenting, and that parenting fully mediated the association of poverty-related risk with infant indicators of developmental competence. Findings are discussed from the perspective of the usefulness of bidirectional-translational research to inform interventions for at-risk families.