Epigenetic and Neurodevelopmental Perspectives on Variation in Parenting Behavior

Mental health and well-being in children and adolescents

The guideline discusses the various milestones in typical neurodevelopment and the various checkpoints where atypical development can be picked up. There is also a remarkable influence of epigenetics and parenting on child development and well - being. It is also essential to establish effective communication to facilitate healthy child development. Well being in children is largely impacted by schooling, curricular design, inclusivity, teacher training and awareness of newer developments, parent teacher interaction. A clinician must also be well acquainted with the National Education Program and its impact. A healthy environment, exercise, adequate nutrition, microplastics on children and adolescents, global warming are key factors in the development of children. It is indispensable for clinicians to approach well- being in a scientific way and get a clear understanding of the laws and policies for child welfare and protection.

Epigenome-Wide Associations of Placental DNA Methylation and Behavioral and Emotional Difficulties in Children at 3 Years of Age

The placenta is a key organ for fetal and brain development. Its epigenome can be regarded as a biochemical record of the prenatal environment and a potential mechanism of its association with the future health of the fetus. We investigated associations between placental DNA methylation levels and child behavioral and emotional difficulties, assessed at 3 years of age using the Strengths and Difficulties Questionnaire (SDQ) in 441 mother-child dyads from the EDEN cohort. Hypothesis-driven and exploratory analyses (on differentially methylated probes (EWAS) and regions (DMR)) were adjusted for confounders, technical factors, and cell composition estimates, corrected for multiple comparisons, and stratified by child sex. Hypothesis-driven analyses showed an association of cg26703534 (AHRR) with emotional symptoms, and exploratory analyses identified two probes, cg09126090 (intergenic region) and cg10305789 (PPP1R16B), as negatively associated with peer relationship problems, as well as 33 DMRs, mostly positively associated with at least one of the SDQ subscales. Among girls, most associations were seen with emotional difficulties, whereas in boys, DMRs were as much associated with emotional than behavioral difficulties. This study provides the first evidence of associations between placental DNA methylation and child behavioral and emotional difficulties. Our results suggest sex-specific associations and might provide new insights into the mechanisms of neurodevelopment.

Family Context, Parenting and Child Development: An Epigenetic Approach

This paper presents an essay that uses an epigenetic approach to attain an inclusive and in-depth understanding of the influence of family context and quality of parenting on children’s psychological development. Based on the identification of a key developmental process in which interactions are continuously internalised, the approach draws attention to the bidirectional and systemic nature of intrafamily and parenting interactions and highlights the multiple factors that influence them, which are linked to the developmental history of the species, the individual characteristics of both the child and their parents, and contextual variables. In response to these internalised interactions, the body activates epigenetic mechanisms, such as DNA methylation, which may affect the phenotypic expression of the genome. Theoretical and methodological implications are discussed in light of the current process of identifying the biological profiles underlying negative and positive parenting practices. Some insights are offered regarding the challenges and opportunities that parents and policymakers should address in the 21st century in connection with the promotion of positive parenting, taking into account the epigenetic processes triggered by adverse environments for children and their families.

Early Life Adversity and Males: Biology, Behavior, and Implications for Fathers' Parenting

Fathers have an important and unique influence on child development, but influences on fathers' parenting have been vastly understudied in the scientific literature. In particular, very little empirical research exists on the effects of early life adversity (ELA; e.g. childhood maltreatment, parental separation) on later parenting among fathers. In this review, we draw from both the human and non-human animal literature to examine the effects of ELA, specifically among males, in the following areas: 1) neurobiology and neurocognitive functioning, 2) hormones and hormone receptors, 3) gene-environment interactions and epigenetics, and 4) behavior and development. Based on these findings, we present a conceptual model to describe the biological and behavioral pathways through which exposure to ELA may influence parenting among males, with a goal of guiding future research and intervention development in this area. Empirical studies are needed to improve understanding of the relationship between ELA and father's parenting, inform the development of paternal and biparental interventions, and prevent intergenerational transmission of ELA.

Epigenetic Alterations of Maternal Tobacco Smoking during Pregnancy: A Narrative Review

In utero exposure to maternal tobacco smoking is the leading cause of birth complications in addition to being associated with later impairment in child's development. Epigenetic alterations, such as DNA methylation (DNAm), miRNAs expression, and histone modifications, belong to possible underlying mechanisms linking maternal tobacco smoking during pregnancy and adverse birth outcomes and later child's development. The aims of this review were to provide an update on (1) the main results of epidemiological studies on the impact of in utero exposure to maternal tobacco smoking on epigenetic mechanisms, and (2) the technical issues and methods used in such studies. In contrast with miRNA and histone modifications, DNAm has been the most extensively studied epigenetic mechanism with regard to in utero exposure to maternal tobacco smoking. Most studies relied on cord blood and children's blood, but placenta is increasingly recognized as a powerful tool, especially for markers of pregnancy exposures. Some recent studies suggest reversibility in DNAm in certain genomic regions as well as memory of smoking exposure in DNAm in other regions, upon smoking cessation before or during pregnancy. Furthermore, reversibility could be more pronounced in miRNA expression compared to DNAm. Increasing evidence based on longitudinal data shows that maternal smoking-associated DNAm changes persist during childhood. In this review, we also discuss some issues related to cell heterogeneity as well as downstream statistical analyses used to relate maternal tobacco smoking during pregnancy and epigenetics. The epigenetic effects of maternal smoking during pregnancy have been among the most widely investigated in the epigenetic epidemiology field. However, there are still huge gaps to fill in, including on the impact on miRNA expression and histone modifications to get a better view of the whole epigenetic machinery. The consistency of maternal tobacco smoking effects across epigenetic marks and across tissues will also provide crucial information for future studies. Advancement in bioinformatic and biostatistics approaches is key to develop a comprehensive analysis of these biological systems.

Maternal and paternal effects on offspring internalizing problems: Results from genetic and family-based analyses

It is unclear to what extent parental influences on the development of internalizing problems in offspring are explained by indirect genetic effects, reflected in the environment provided by the parent, in addition to the genes transmitted from parent to child. In this study, these effects were investigated using two innovative methods in a large birth cohort. Using maternal-effects genome complex trait analysis (M-GCTA), the effects of offspring genotype, maternal or paternal genotypes, and their covariance on offspring internalizing problems were estimated in 3,801 mother-father-child genotyped trios. Next, estimated genetic correlations within pedigree data, including 10,688 children, were used to estimate additive genetic effects, maternal and paternal genetic effects, and a shared family effect using linear mixed effects modeling. There were no significant maternal or paternal genetic effects on offspring anxiety or depressive symptoms at age 8, beyond the effects transmitted via the genetic pathway between parents and children. However, indirect maternal genetic effects explained a small, but nonsignificant, proportion of variance in childhood depressive symptoms in both the M-GCTA (~4%) and pedigree (~8%) analyses. Our results suggest that parental effects on offspring internalizing problems are predominantly due to transmitted genetic variants, rather than the indirect effect of parental genes via the environment.

Influence of Maternal Care on Behavioural Development of Domestic Dogs (Canis Familiaris) Living in a Home Environment

Simple Summary

Maternal care in dogs and its impact on the behavioural development of puppies has become the subject of growing research interest. In order to determine the effects of maternal care on the behaviour of family dog puppies, maternal care during the first three weeks after birth was observed in 12 litters of puppies reared in a home environment (72 puppies). The behavioural responses of the puppies were assessed at two months of age, in an arena and an isolation test. In both tests, the amount of maternal care was found to be positively associated with some stress behaviours and, in the arena test, also with the puppies’ interest in an unfamiliar person who was present during the test. These behaviours are similar to those observed during the separation of other young mammals from an attachment figure with which they have a high quality of bond. Amount of maternal care was also found to be negatively associated with exploration and play. The difference in results between the present study and our previous study involving laboratory dogs reared in relative social isolation suggests that the developmental trajectory of puppies is influenced by a combination of maternal behaviour and social and physical environmental enrichment.

Abstract

Maternal care has been shown to affect the development of the brain, behaviour, social skills and emotional systems of the young of many mammalian species including dogs. The aim of the present study was to determine the effects of maternal care on the behavioural responses of family dog puppies towards environmental and social stimuli. In order to do this, maternal care (licking puppy’s ano-genital area, licking the puppy, nursing and mother-puppy contact) during the first three weeks after birth was assessed in 12 litters of domestic dog puppies reared in home environments (total = 72 puppies). The behavioural responses of puppies were assessed in an arena and an isolation test, which were performed when the puppies were two-month old. Data were analysed using principal components analysis and projection to latent structures regression. A systematic relationship was found between maternal care and behaviour in both tests. In the arena test, maternal care was found to be positively associated with approach to the stranger, attention oriented to the stranger, time spent near the enclosure, yawning, whining and yelping (R²Y = 0.613, p = 8.2 × 10⁻⁹). Amount of maternal care was negatively associated with the number of squares crossed and the time spent individually playing with the rope. In the isolation test, the amount of maternal care was positively associated with standing posture, paw lifting, and howling, and it was negatively associated with yawning, lying down and nose licking (R²Y = 0.507, p = 0.000626). These results suggest that the amount of maternal care received during early life influences the pattern of behavioural responses and coping strategies of puppies at two-months of age. On the basis of these findings it could be speculated that early maternal care contributes to adaption to the environment in which family puppies are developing, with particular regard to social relationships with people.

Plasticity of the Maternal Brain Across the Lifespan

Maternal behavior is dynamic and highly sensitive to experiential and contextual factors. In this review, this plasticity will be explored, with a focus on how experiences of females occurring from the time of fetal development through to adulthood impact maternal behavior and the maternal brain. Variation in postpartum maternal behavior is dependent on estrogen sensitivity within the medial preoptic area of the hypothalamus and activation within mesolimbic dopamine neurons. This review will discuss how experiences across the lifespan alter the function of these systems and the multigenerational consequences of these neuroendocrine and behavioral changes. These studies, based primarily on the examination of maternal behavior in laboratory rodents and nonhuman primates, provide mechanistic insights relevant to our understanding of human maternal behavior and to the mechanisms of lifelong plasticity.

DNA methylation, early life environment, and health outcomes

Epigenetics, and especially DNA methylation, have recently become provocative biological explanations for early-life environmental effects on later health. Despite the large increase in papers on the topic over the last few years, many questions remain with regards to the biological feasibility of this mechanism and the strength of the evidence to date. In this review, we examine the literature on early-life effects on epigenetic patterns, with special emphasis on social environmental influences. First, we review the basic biology of epigenetic modification of DNA and debate the role of early-life stressful, protective, and positive environments on gene-specific, system-specific, and whole-genome epigenetic patterns later in life. Second, we compare the epigenetic literatures of both humans and other animals and review the research linking epigenetic patterns to health in order to complete the mechanistic pathway. Third, we discuss physical environmental and social environmental effects, which have to date, generally not been jointly considered. Finally, we close with a discussion of the current state of the area's research, its future direction, and its potential use in pediatric health.

Psychopathic personality traits and their influence on parenting quality: results from a nationally representative sample of Americans

Psychopathic personality traits have consistently been found to predict a range of negative and dysfunctional outcomes. As a result, it is somewhat surprising that the research to date has failed to empirically examine the potential association between psychopathic personality traits and parenting quality. The current study addressed this omission in the literature by analyzing a community sample of adults. The results revealed that respondents scoring higher on psychopathic personality traits tended to report more negative parenting quality. These results were detected for both males and females and remained significant even after controlling for the effects of parental transmission and child-effects. To our knowledge, this is the first study to show a statistically significant association between psychopathic personality traits and parenting quality. We conclude with a discussion of what these findings mean for psychopathy research and the parenting the literature.

Bdnf DNA methylation modifications in the hippocampus and amygdala of male and female rats exposed to different caregiving environments outside the homecage

We have previously shown in infant rats that brief and repeated experiences with a stressed dam outside the homecage (maltreatment) alters methylation of DNA associated with the brain-derived neurotrophic factor (bdnf) gene within the developing and adult prefrontal cortex. BDNF is a key mediator of activity-dependent processes that have a profound influence on neural development and plasticity. Here we examined whether maltreatment also alters bdnf DNA methylation in two additional regions known to be prominently affected by diverse forms of early life adversity in humans- the hippocampus and amygdala. We found significant bdnf DNA methylation modifications present within the adult hippocampus (dorsal and ventral) and amygdala (central/basolateral complex). We observed that the nature of change differed between sexes, gene locus (bdnf I vs. IV), and brain region. Furthermore, a manipulation that did not produce any obvious behavior difference in infants (brief and repeated experiences with a nurturing foster dam) also had long-term effects on methylation. These data provide further empirical support of DNA methylation modifications as biological consequences of caregiving environments.

What's mom got to do with it? Contributions of maternal executive function and caregiving to the development of executive function across early childhood

Executive functions (EFs; e.g. working memory, inhibitory control) are mediated by the prefrontal cortex and associated with optimal cognitive and socio-emotional development. This study provides the first concurrent analysis of the relative contributions of maternal EF and caregiving to child EF. A group of children and their mothers (n = 62) completed age-appropriate interaction (10, 24, 36 months) and EF tasks (child: 24, 36, and 48 months). Regression analyses revealed that by 36 months of age, maternal EF and negative caregiving behaviors accounted for unique variance in child EF, above and beyond maternal education and child verbal ability. These findings were confirmed when using an early child EF composite-our most reliable measure of EF - and a similar pattern was found when controlling for stability in child EF. Furthermore, there was evidence that maternal EF had significant indirect effects on changes in child EF through maternal caregiving. At 24 months, EF was associated with maternal EF, but not negative caregiving behaviors. Taken together, these findings suggest that links between negative caregiving and child EF are increasingly manifested during early childhood. Although maternal EF and negative caregiving are related, they provide unique information about the development of child EF. A video abstract of this article can be viewed at http://www.youtube.com/watch?v=NPKXFbbrkps.

Electroencephalographic activity of preterm infants is increased by Family Nurture Intervention: a randomized controlled trial in the NICU

OBJECTIVE

To assess the impact of Family Nurture Intervention (FNI) on electroencephalogram (EEG) activity in preterm infants (26-34 weeks gestation).

METHODS

Two groups were tested in a single, level IV neonatal intensive care unit (NICU; standard care or standard care plus FNI) using a randomized controlled trial design. The intervention consists of sessions designed to achieve mutual calm and promote communication of affect between infants and their mothers throughout the NICU stay. EEG recordings were obtained from 134 infants during sleep at ∼35 and ∼40 weeks postmenstrual age (PMA). Regional brain activity (power) was computed for 10 frequency bands between 1 and 48 Hz in each of 125 electrodes.

RESULTS

Near to term age, compared to standard care infants, FNI infants showed robust increases in EEG power in the frontal polar region at frequencies 10 to 48 Hz (20% to 36% with p-values <0.0004). Effects were significant in both quiet and active sleep, regardless of gender, singleton-twin status, gestational age (26-30 or 30-35 weeks) or birth weight (<1500 or >1500 g).

CONCLUSION

FNI leads to increased frontal brain activity during sleep, which other investigators find predictive of better neurobehavioral outcomes.

SIGNIFICANCE

FNI may be a practicable means of improving outcomes in preterm infants.

Effects of glucocorticoid treatment given in early or late gestation on growth and development in sheep

Antenatal corticosteroids are used to augment fetal lung maturity in human pregnancy. Dexamethasone (DEX) is also used to treat congenital adrenal hyperplasia of the fetus in early pregnancy. We previously reported effects of synthetic corticosteroids given to sheep in early or late gestation on pregnancy length and fetal cortisol levels and glucocorticoids alter plasma insulin-like growth factor (IGF) and insulin-like growth factor binding protein (IGFBP) concentrations in late pregnancy and reduce fetal weight. The effects of administering DEX in early pregnancy on fetal organ weights and betamethasone (BET) given in late gestation on weights of fetal brain regions or organ development have not been reported. We hypothesized that BET or DEX administration at either stage of pregnancy would have deleterious effects on fetal development and associated hormones. In early pregnancy, DEX was administered as four injections at 12-hourly intervals over 48 h commencing at 40–42 days of gestation (dG). There was no consistent effect on fetal weight, or individual fetal organ weights, except in females at 7 months postnatal age. When BET was administered at 104, 111 and 118 dG, the previously reported reduction in total fetal weight was associated with significant reductions in weights of fetal brain, cerebellum, heart, kidney and liver. Fetal plasma insulin, leptin and triiodothyronine were also reduced at different times in fetal and postnatal life. We conclude that at the amounts given, the sheep fetus is sensitive to maternal administration of synthetic glucocorticoid in late gestation, with effects on growth and metabolic hormones that may persist into postnatal life.

Parenting as Phenotype: A Behavioral Genetic Approach to Understanding Parenting

This article discusses the behavioral genetic (BG) approach to parenting. Parenting is considered a phenotype that can be influenced by nature and nurture. Genetic contributions to parenting are conceptualized as evidence of genotype-environment correlation (rGE). Early BG studies focused on demonstrating that some parenting dimensions were heritable due to passive and evocative rGE processes. Current studies are investigating moderators and mediators of genetic and environmental contributions to parenting. The paper uses parent and child report data on parental warmth from the Twins, Adoptees, Peers, and Siblings (TAPS) study to illustrate the BG approach. Results show that heritability is significant for parent and child reports, but environmental influences differ by information source. Three questions are addressed concerning the BG approach to parenting: What is the nature of parenting? How does the approach inform parenting practice and interventions? What are the future directions?

Parenting and Beyond: Common Neurocircuits Underlying Parental and Altruistic Caregiving

Interpersonal relationships constitute the foundation on which human society is based. The infant-caregiver bond is the earliest and most influential of these relationships. Driven by evolutionary pressure for survival, parents feel compelled to provide care to their biological offspring. However, compassion for non-kin is also ubiquitous in human societies, motivating individuals to suppress their own self-interests to promote the well-being of non-kin members of the society. We argue that the process of early kinship-selective parental care provides the foundation for non-exclusive altruism via the activation of a general Caregiving System that regulates compassion in any of its forms. We propose a tripartite structure of this system that includes (1) the perception of need in another, (2) a caring motivational or feeling state, and (3) the delivery of a helping response to the individual in need. Findings from human and animal research point to specific neurobiological mechanisms including activation of the insula and the secretion of oxytocin that support the adaptive functioning of this Caregiving System.

Differentiating Maternal Sensitivity to Infant Distress and Non-Distress

Drawing from a domain specificity perspective, we assert that maternal sensitivity to infant distress cues is distinct from maternal sensitivity to non-distress cues. We review evidence from prior research demonstrating that the two constructs have more unshared than shared variance and that sensitivity to infant distress is a unique predictor of infants' early emotional well-being when both types of sensitivity are examined as simultaneous predictors. In addition, we present new evidence to test the hypothesis that maternal sensitivity to infant distress and non-distress have different origins. We draw on data from a subset of mothers and infants who participated in Phase I of the NICHD Study of Early Child Care (Study 1) and from 101 mother-infant dyads who participated in a longitudinal study of the origins of maternal sensitivity (Study 2). In both studies, maternal sensitivity to distress and non-distress were rated when infants were 6 months old. In both studies, socio-demographic risk (i.e., young, unmarried, low income mothers) was a stronger predictor of sensitivity to non-distress than of sensitivity to distress. In Study 2, mothers' emotional and cognitive responses to videotapes of crying infants during the prenatal period predicted maternal sensitivity during tasks designed to elicit infant fear and frustration but were unrelated to maternal sensitivity in a non-arousing free play context. Maternal sensitivity during infancy can be further divided into specific sub-types that have unique origins and unique effects on subsequent child well-being. Methodological, theoretical, and applied implications of such an approach are discussed.

Intergenerational Continuity and Discontinuity in Harsh Parenting

The Family Transitions Project began in 1989 to see how rural families in Iowa were coping with the severe economic downturn in agriculture at that time. In this report we show that cohort members who were treated harshly by their parents tended to emulate these behaviors with their children. However, if they co-parented with a partner who demonstrated a warm and supportive parenting style, intergenerational continuity was disrupted.