Natural variation in maternal sensitivity is reflected in maternal brain responses to infant stimuli

The extended neural architecture of human attachment: An fMRI coordinate-based meta-analysis of affiliative studies

Functional imaging studies and clinical evidence indicate that cortical areas relevant to social cognition are closely integrated with evolutionarily conserved basal forebrain structures and neighboring regions, enabling human attachment and affiliative emotions. The neural circuitry of human affiliation is continually being unraveled as functional magnetic resonance imaging (fMRI) becomes increasingly prevalent, with studies examining human brain responses to various attachment figures. However, previous fMRI meta-analyses on affiliative stimuli have encountered challenges, such as low statistical power and the absence of robustness measures. To address these issues, we conducted an exhaustive coordinate-based meta-analysis of 79 fMRI studies, focusing on personalized affiliative stimuli, including one's infants, family, romantic partners, and friends. We employed complementary coordinate-based analyses (Activation Likelihood Estimation and Signed Differential Mapping) and conducted a robustness analysis of the results. Findings revealed cluster convergence in cortical and subcortical structures related to reward and motivation, salience detection, social bonding, and cognition. Our study thoroughly explores the neural correlates underpinning affiliative responses, effectively overcoming the limitations noted in previous meta-analyses. It provides an extensive view of the neural substrates associated with affiliative stimuli, illuminating the intricate interaction between cortical and subcortical regions. Our findings significantly contribute to understanding the neurobiology of human affiliation, expanding the known human attachment circuitry beyond the traditional basal forebrain regions observed in other mammals to include uniquely human isocortical structures.

An in-depth analysis of the polyvagal theory in light of current findings in neuroscience and clinical research

The polyvagal theory has led to the understanding of the functions of the autonomic nervous system in biological development in humans, since the vagal system, a key structure within the polyvagal theory, plays a significant role in addressing challenges of the mother-child dyad. This article aims to summarize the neurobiological aspects of the polyvagal theory, highlighting some of its strengths and limitations through the lens of new evidence emerging in several research fields-including comparative anatomy, embryology, epigenetics, psychology, and neuroscience-in the 25 years since the theory's inception. Rereading and incorporating the polyvagal idea in light of modern scientific findings helps to interpret the role of the vagus nerve through the temporal dimension (beginning with intrauterine life) and spatial dimension (due to the numerous connections of the vagus with various structures and systems) in the achievement and maintenance of biopsychosocial well-being, from the uterus to adulthood.

Inaccuracies in plasma oxytocin extraction and enzyme immunoassay techniques

Numerous studies have reported extensive associations between plasma oxytocin (OXT) concentrations and various human physiological and neurobehavioral processes. Measurement of OXT is fraught with difficulty due to its low molecular weight and plasma concentrations, with no consensus as to the optimal conditions for pre-analytical sample extraction, standards for immunoassay validation or the ideal protease inhibitors to prevent OXT degradation. Previous attempts at determining the efficacy of various purification techniques such as solid phase extraction (SPE) or ultrafiltration have only utilized human plasma samples, making it difficult to dissect out whether the effect of interference comes from the extraction process itself or cross-reactivity with other proteins. By testing these on pure OXT solutions, we demonstrate poor recovery efficacy and reliability of reversed phase SPE (maximum 58.1%) and ultrafiltration (<1%) techniques, and the potential for the former to introduce interference into enzyme immunoassay (EIA) measurements. The clonality of antibodies used in EIA kits also potentially contributes to the differences in the readings obtained, and we validate an EIA kit which did not require pre-analytical sample extraction with low cross-reactivity and high reliability (intraclass correlation coefficient 0.980 (95% CI 0.896-0.999). Biochemical techniques used for measuring plasma OXT concentrations must therefore be internally validated prior to translation into clinical studies.

Brain circuits for maternal sensitivity and pain involving anterior cingulate cortex among mothers receiving buprenorphine treatment for opioid use disorder

Opioid-induced deficits in maternal behaviors are well-characterized in rodent models. Amid the current epidemic of opioid use disorder (OUD), prevalence among pregnant women has risen sharply. Yet, the roles of buprenorphine replacement treatment for OUD (BT/OUD) in the brain functions of postpartum mothers are unclear. Using functional magnetic resonance imaging (fMRI), we have developed an evolutionarily conserved maternal behavior neurocircuit (MBN) model to study human maternal care versus defensive/aggressive behaviors critical to mother-child bonding. The anterior cingulate gyrus (ACC) is not only involved in the MBN for mother-child bonding and attachment, but also part of an opioid sensitive "pain-matrix". The literature suggests that prescription opioids produce physical and emotional "analgesic" effects by disrupting specific resting-state functional connectivity (rs-FC) of ACC to regions related to MBN. Thus, in this longitudinal study, we report findings of overlapping MBN and pain matrix circuits, for mothers with chronic exposure of BT/OUD. A total of 32 mothers were studied with 6 min rs-FC at 1 month (T1) and 4 months postpartum (T2), including seven on BT/OUD and 25 non-BT/OUD mothers as a comparison group. We analyzed rs-FC between the insula, putamen, and the dorsal anterior cingulate cortex (DACC) and rostral ACC (RACC), as the regions of interest that mediate opioid analgesia. BT/OUD mothers, as compared to non-BT/OUD mothers, showed less left insula-RACC rs-FC but greater right putamen-DACC rs-FC at T1, with these between-group differences diminished at T2. Some of these rs-FC results were correlated with the scores of postpartum parental bonding questionnaire. We found time-by-treatment interaction effects on DACC and RACC-dependent rs-FC, potentially identifying brain mechanisms for beneficial effects of BT, normalizing dysfunction of maternal brain and behavior over the first four months postpartum. This study complements recent studies to ascertain how BT/OUD affects maternal behaviors, mother-child bonding, and intersubjectivity and reveals potential MBN/pain-matrix targets for novel interventions.

Empathy for others versus for one's child: Associations with mothers' brain activation during a social cognitive task and with their toddlers' functioning

Caregivers who are higher in dispositional empathy tend to have children with better developmental outcomes; however, few studies have considered the role of child-directed (i.e., "parental") empathy, which may be relevant for the caregiver-child relationship. We hypothesized that mothers' parental empathy during their child's infancy will be a stronger predictor of their child's social-emotional functioning as a toddler than will mothers' dispositional empathy. We further explored whether parental and dispositional empathy have shared or distinct patterns of neural activation during a social-cognitive movie-watching task. In 118 mother-infant dyads, greater parental empathy assessed when infants were 6 months old was associated with more social-emotional competencies and fewer problems in the children 1 year later, even after adjusting for dispositional empathy. In contrast, dispositional empathy was not associated with child functioning when controlling for parental empathy. In a subset of 20 mothers, insula activation was positively associated with specific facets of both dispositional and parental empathy, whereas right temporoparietal junction activation was associated only with parental empathy. Thus, dispositional and parental empathy appear to be dissociable by both brain and behavioral metrics. Parental empathy may be a viable target for interventions, especially for toddlers at risk for developing social-emotional difficulties.

Trait coping styles and the maternal neural and behavioral sensitivity to an infant

During the postpartum period, new mothers experience drastic changes in their body, brain, and life circumstances. Stress from the emotional and physical demands of caring for an infant is associated with negative mood and parenting outcomes. The use of active coping strategies can increase mothers’ resilience during the postpartum period. However, little is known about the association between coping styles and maternal brain responses to infant cues. In the current study, we examined the associations among trait coping style, maternal brain responses, and behavioral sensitivity in a socioeconomically diverse sample of first-time mothers (N = 59). The use of more active trait coping strategies compared to passive coping strategies was associated with increased brain responses to infant cry sounds in brain regions that are critically involved in motivation and emotion regulation—substantia nigra, anterior cingulate gyrus, and inferior frontal gyrus. Increased brain activations in the midbrain and anterior cingulate gyrus were further associated with higher levels of maternal sensitivity observed during interactions with the infant. Thus, the findings provide support for mothers’ use of more active coping styles to promote neural and behavioral resilience for a positive transition to parenthood.

Neural and Affective Responses to Prolonged Eye Contact with One's Own Adolescent Child and Unfamiliar Others

Eye contact is crucial for the formation and maintenance of social relationships, and plays a key role in facilitating a strong parent-child bond. However, the precise neural and affective mechanisms through which eye contact impacts on parent-child relationships remain elusive. We introduce a task to assess parents' neural and affective responses to prolonged direct and averted gaze coming from their own child, and an unfamiliar child and adult. While in the scanner, 79 parents (n = 44 mothers and n = 35 fathers) were presented with prolonged (16-38 s) videos of their own child, an unfamiliar child, an unfamiliar adult, and themselves (i.e., targets), facing the camera with a direct or an averted gaze. We measured BOLD-responses, tracked parents' eye movements during the videos, and asked them to report on their mood and feelings of connectedness with the targets after each video. Parents reported improved mood and increased feelings of connectedness after prolonged exposure to direct versus averted gaze and these effects were amplified for unfamiliar targets compared to their own child, due to high affect and connectedness ratings after videos of their own child. Neuroimaging results showed that the sight of one's own child was associated with increased activity in middle occipital gyrus, fusiform gyrus and inferior frontal gyrus relative to seeing an unfamiliar child or adult. While we found no robust evidence of specific neural correlates of eye contact (i.e., contrast direct > averted gaze), an exploratory parametric analysis showed that dorsomedial prefrontal cortex (dmPFC) activity increased linearly with duration of eye contact (collapsed across all "other" targets). Eye contact-related dmPFC activity correlated positively with increases in feelings of connectedness, suggesting that this region may drive feelings of connectedness during prolonged eye contact with others. These results underline the importance of prolonged eye contact for affiliative processes and provide first insights into its neural correlates. This may pave the way for new research in individuals or pairs in whom affiliative processes are disrupted.

Compassion within conflict: Toward a computational theory of social groups informed by maternal brain physiology

Benevolent intersubjectivity developed in parent-infant interactions and compassion toward friend and foe alike are non-violent interventions to group behavior in conflict. Based on a dyadic active inference framework rooted in specific parental brain mechanisms, we suggest that interventions promoting compassion and intersubjectivity can reduce stress, and that compassionate mediation may resolve conflicts.

Do empathy and oxytocin predict responsiveness to a crying infant simulator in expecting and non-expecting couples? A multilevel study

Infant crying is a strong emotional stimulus that elicits caregiving responses in adults. Here we examine the role of empathy (measured with the Polish version of Interpersonal Reactivity Index) and salivary oxytocin in modulating sensitive responsiveness to a crying infant simulator in two groups of heterosexual couples: 111 expecting or 110 not expecting a baby. Sensitive responsiveness was observed during a standardized procedure using the Ainsworth Sensitivity Scale while participants took care of the infant simulator, both individually and as a couple. Other-oriented empathy predicted elevated levels of individual but not couple sensitive responsiveness. More OT reactivity to crying predicted less responsiveness in non-expecting couples, which might be explained by their stronger focus on task performance. This study uniquely combined hormonal, observational and self-report measures in couples, and showed that personality and hormonal correlates of sensitive responsiveness might be studied before the child's birth with the use of infant simulators.

Empathy at birth: Mother's cortex synchronizes with that of her newborn in pain

Early neonatal relation with the caregiver is vital for newborn survival and for the promotion of an appropriate neural development. The aim of this study was to assess if the empathic cortical response of a mother to her baby's pain is synchronized with the neonatal cortical response to the painful stimulation. We used hyperscanning, a functional neuroimaging approach that allows studying functional synchronization between two brains. Sixteen mother-newborn dyads were recruited. Maternal and neonatal cortical activities were simultaneously monitored, by near-infrared spectroscopy, during a heel prick performed on the baby and observed by the mother. Multiple paired t test was used to identify cortical activation, and wavelet transform coherence method was used to explore possible synchronization between the maternal and neonatal cortical areas. Activations were observed in mother's parietal cortex, bilaterally, and in newborn's superior motor/somatosensory cortex. The main functional synchronization analysis showed that mother's left parietal cortex activity cross-correlated with that of her newborn's superior motor/somatosensory cortex. Such synchronization dynamically changed throughout assessment, becoming positively cross-correlated only after the leading role in synchronizing cortical activities was taken up by the newborn. Thus, maternal empathic cortical response to baby pain was guided by and synchronized to the newborn's cortical response to pain. We conclude that, in case of potential danger for the infant, brain areas involved in mother-newborn relationship appear to be already co-regulated at birth.

Recent Neuroscience Advances in Human Parenting

The transition to parenthood entails brain adaptations to the demands of caring for a newborn. This chapter reviews recent neuroscience findings on human parenting, focusing on neuroimaging studies. First, we describe the brain circuits underlying human maternal behavior, which comprise ancient subcortical circuits and more sophisticated cortical regions. Then, we present the short-term and long-term functional and structural brain adaptations that characterize the transition to motherhood, discuss the long-term effects of parenthood on the brain, and propose several underlying neural mechanisms. We also review neuroimaging findings in biological fathers and alloparents (such as other relatives or adoptive parents), who engage in parenting without directly experiencing pregnancy or childbirth. Finally, we describe perinatal mental illnesses and discuss the neural responses associated with such disorders. To date, studies indicate that parenthood is a period of enhanced brain plasticity within brain areas critical for cognitive and social processing and that both parenting experience and gestational-related factors can prime such plasticity.

Neural Representation of the Parent-Child Attachment from Infancy to Adulthood

Attachment theory is built on the assumption of consistency; the mother–infant bond is thought to underpin the life-long representations individuals construct of attachment relationships. Still, consistency in the individual’s neural response to attachment-related stimuli representing his or her entire relational history has not been investigated. Mothers and children were followed across two decades and videotaped in infancy (3–6 months), childhood (9–12 years) and young adulthood (18–24 years). In adulthood, participants underwent functional magnetic resonance imaging while exposed to videos of own mother–child interactions (Self) vs unfamiliar interactions (Other). Self-stimuli elicited greater activations across preregistered nodes of the human attachment network, including thalamus-to-brainstem, amygdala, hippocampus, anterior cingulate cortex (ACC), insula and temporal cortex. Critically, self-stimuli were age-invariant in most regions of interest despite large variability in social behavior, and Bayesian analysis showed strong evidence for lack of age-related differences. Psycho–physiological interaction analysis indicated that self-stimuli elicited tighter connectivity between ACC and anterior insula, consolidating an interface associating information from exteroceptive and interceptive sources to sustain attachment representations. Child social engagement behavior was individually stable from infancy to adulthood and linked with greater ACC and insula response to self-stimuli. Findings demonstrate overlap in circuits sustaining parental and child attachment and accord with perspectives on the continuity of attachment across human development.

The neuroscience of social feelings: mechanisms of adaptive social functioning

Social feelings have conceptual and empirical connections with affect and emotion. In this review, we discuss how they relate to cognition, emotion, behavior and well-being. We examine the functional neuroanatomy and neurobiology of social feelings and their role in adaptive social functioning. Existing neuroscience literature is reviewed to identify concepts, methods and challenges that might be addressed by social feelings research. Specific topic areas highlight the influence and modulation of social feelings on interpersonal affiliation, parent-child attachments, moral sentiments, interpersonal stressors, and emotional communication. Brain regions involved in social feelings were confirmed by meta-analysis using the Neurosynth platform for large-scale, automated synthesis of functional magnetic resonance imaging data. Words that relate specifically to social feelings were identfied as potential research variables. Topical inquiries into social media behaviors, loneliness, trauma, and social sensitivity, especially with recent physical distancing for guarding public and personal health, underscored the increasing importance of social feelings for affective and second person neuroscience research with implications for brain development, physical and mental health, and lifelong adaptive functioning.

Mother brain is wired for social moments

Reorganization of the maternal brain upon childbirth triggers the species-typical maternal social behavior. These brief social moments carry profound effects on the infant's brain and likely have a distinct signature in the maternal brain. Utilizing a double-blind, within-subject oxytocin/placebo administration crossover design, mothers' brain was imaged twice using fMRI while observing three naturalistic maternal-infant contexts in the home ecology; 'unavailable', 'unresponsive', and 'social', when mothers engaged in synchronous peek-a-boo play. The social condition elicited greater neural response across the human caregiving network, including amygdala, VTA, hippocampus, insula, ACC, and temporal cortex. Oxytocin impacted neural response primarily to the social condition and attenuated differences between social and non-social stimuli. Greater temporal consistency emerged in the 'social' condition across the two imaging sessions, particularly in insula, amygdala, and TP. Findings describe how mother's brain varies by caregiving experiences and gives salience to moments of social synchrony that support infant development and brain maturation.

Neural signatures of parental empathic responses to imagined suffering of their adolescent child

Empathy is deemed indispensable for sensitive caregiving. Neuroimaging studies have identified canonical empathy networks consisting of regions supporting cognitive and affective aspects of empathy. However, not much is known about how these regions support empathy towards one's own offspring and how this neural activity relates to parental caregiving. We introduce a novel task to assess affective and neural responses to the suffering of one's own adolescent child. While in the scanner, 60 parents (n = 35 mothers, n = 25 fathers) were confronted with unpleasant situations involving their own child, an unfamiliar child, and themselves. Parents were asked to vividly imagine these situations and indicate their levels of distress. Parents reported higher levels of distress when imagining suffering for their own child relative to an unfamiliar child or themselves. Neuroimaging results showed increased activation within the cognitive empathy network (i.e., temporoparietal junction, dorsomedial- and ventromedial prefrontal cortex) when contrasting suffering of one's own child versus an unfamiliar child or the self. The task also engaged regions of the affective empathy network (i.e., anterior insula and anterior mid-cingulate cortex), which was however not modulated by whether suffering was for the self, one's own child, or an unfamiliar child. Parental care did not co-vary with activity in the empathy networks, but parents who were perceived as less caring exhibited increased activity in anterior prefrontal regions when imagining their own child suffering. These results provide new insights into neural processes supporting parental empathy, highlighting the importance of regions in the cognitive empathy network when confronted with the suffering of their own adolescent child, and suggest that additional (i.e., emotion regulation) networks may be relevant for parental caring behavior in daily life.

Affective Neural Mechanisms of a Parenting-Focused Mindfulness Intervention

OBJECTIVES

Behavioral evidence suggests that parenting-focused mindfulness interventions can improve parenting practices and enhance family wellbeing, potentially operating through altered emotional processing in parents. However, the mechanisms through which parent mindfulness interventions achieve their positive benefits have not yet been empirically tested, knowledge which is key to refine and maximize intervention effects. Thus, as part of a randomized controlled trial, the present study examined the affective mechanisms of an 8-week parenting-focused mindfulness intervention, the Parenting Mindfully (PM) intervention, versus a minimal-intervention parent education control.

METHODS

Twenty highly stressed mothers of adolescents completed pre- and post-intervention behavioral and fMRI sessions, in which mothers completed a parent-adolescent conflict interaction, fMRI emotion task, and fMRI resting state scan. Mothers reported on their mindful parenting, and maternal emotional reactivity to the parent-adolescent conflict task was assessed via observed emotion expression, self-reported negative emotion, and salivary cortisol reactivity.

RESULTS

Results indicated that the PM intervention increased brain responsivity in left posterior insula in response to negative affective stimuli, and altered resting state functional connectivity in regions involved in self-reference, behavioral regulation, and social-emotional processing. Changes in mothers' brain function and connectivity were associated with increased mindful parenting and decreased emotional reactivity to the parent-adolescent conflict task.

CONCLUSIONS

Findings suggest that mindfulness-based changes in maternal emotional awareness at the neurobiological level are associated with decreased emotional reactivity in parenting interactions, illuminating potential neurobiological targets for future parent-focused intervention.

How stress can influence brain adaptations to motherhood

Research shows that a woman's brain and body undergo drastic changes to support her transition to parenthood during the perinatal period. The presence of this plasticity suggests that mothers' brains may be changed by their experiences. Exposure to severe stress may disrupt adaptive changes in the maternal brain and further impact the neural circuits of stress regulation and maternal motivation. Emerging literature of human mothers provides evidence that stressful experience, whether from the past or present environment, is associated with altered responses to infant cues in brain circuits that support maternal motivation, emotion regulation, and empathy. Interventions that reduce stress levels in mothers may reverse the negative impact of stress exposure on the maternal brain. Finally, outstanding questions regarding the timing, chronicity, types, and severity of stress exposure, as well as study design to identify the causal impact of stress, and the role of race/ethnicity are discussed.

Neurobiology of peripartum mental illness

At least one in seven pregnant or recently postpartum women will experience a mental illness such as an anxiety disorder, depressive disorder, or substance use disorder. These mental illnesses have detrimental effects on the health of the mother, child, and family, but little is known about the hypothalamic and other neural correlates of maternal mental health concerns. The transition to parenthood alone is a time of remarkable neural plasticity, so it is perhaps not surprising that current research is showing that maternal mental illness has unique neural profiles. Furthermore, the neural systems affected by peripartum mental illness overlap and interact with the systems involved in maternal caregiving behaviors, and mother-infant interactions are, therefore, highly susceptible to disruption. This review discusses what we know about the unique neural changes occurring during peripartum mental illness and the role of the hypothalamus in these illnesses. With an improved understanding of the neural correlates of maternal mental health and disease, we will be better equipped to predict risk, develop effective treatments, and ultimately prevent suffering for millions of parents during this critical time in life.

Effects of applying amoxicillin in juvenile mice on enamel mineralization and the expression of kallikrein‑related peptidase 4 and tight junction proteins in ameloblasts

Amoxicillin is a common pediatric drug. However, to the best of our knowledge, the role of amoxicillin in enamel hypomineralization has not yet been fully elucidated. The aim of the present study was to assess the effects of amoxicillin on enamel mineralization, the morphology of ameloblasts, as well as the expression of kallikrein-related peptidase 4 (KLK4), and the tight junction proteins, claudin 1 (CLDN1), claudin 4 (CLDN4) and occludin (OCLN), in ameloblasts of juvenile mice. A total of 36 3-day-old Kunming mice were randomly divided into three groups. The mice were administered 0, 50 or 100 mg/kg amoxicillin by intragastric administration for 19 days. The surface morphology and calcium (Ca), phosphorous (P) and carbon contents of mandibular incisors and first molars were examined by scanning electron microscopy and energy dispersive X-ray spectroscopy. Histological changes in the ameloblasts of mandibular incisors were analyzed by hematoxylin and eosin staining. The KLK4, CLDN1, CLDN4 and OCLN expression levels of ameloblasts were observed by immunohistochemical staining. The incidence of white patches in the incisor was 100% in the 100 mg/kg amoxicillin-treated groups. A greater number of enamel defects were observed in the incisal/occlusal half of mandibular incisors/molars compared with in the cervical half in the amoxicillin-treated groups. Following phosphoric-acid treatment, the enamel rod and interrod were aligned in a disorderly manner in the amoxicillin-treated groups. Amoxicillin decreased the Ca/P ratio in the enamel of mandibular incisors and molars. More intercellular spaces among maturation ameloblasts were observed in the amoxicillin-treated groups. Amoxicillin decreased KLK4 and CLDN1, CLDN4 and OCLN expression in mature ameloblasts. The administration of amoxicillin in juvenile mice induced enamel hypomineralization, and the effects of amoxicillin on enamel hypomineralization may be mediated via multiple pathways.

Brain Responses to Emotional Infant Faces in New Mothers and Nulliparous Women

The experience of motherhood is one of the most salient events in a woman’s life. Motherhood is associated with a series of neurophysiological, psychological, and behavioral changes that allow women to better adapt to their new role as mothers. Infants communicate their needs and physiological states mainly through salient emotional expressions, and maternal responses to infant signals are critical for infant survival and development. In this study, we investigated the whole brain functional response to emotional infant faces in 20 new mothers and 22 nulliparous women during functional magnetic resonance imaging scans. New mothers showed higher brain activation in regions involved in infant facial expression processing and empathic and mentalizing networks than nulliparous women. Furthermore, magnitudes of the activation of the left parahippocampal gyrus and the left fusiform gyrus, recruited during facial expression processing, were positively correlated with empathic concern (EC) scores in new mothers when viewing emotional (happy-sad) faces contrasted to neutral faces. Taken together, these results indicate that the experience of being a mother affects human brain responses in visual and social cognitive brain areas and in brain areas associated with theory-of-mind related and empathic processing.

Maternal Neurobiological Processing of Negative Adolescent Stimuli: Relations With Positive Parenting and Relationship Quality

We examined associations between maternal affective neurobiology and positive parenting in a study of 20 mothers of adolescents. Mothers underwent functional magnetic resonance imaging during an emotion image task, rated parent-adolescent relationship quality, and completed an adolescent interaction task in which positive parenting behaviors were observed. Maternal structure was associated with lower responsivity in emotional processing regions in the general negative image contrast and was related to greater dorsolateral prefrontal cortex activation to negative adolescent images. Parent-adolescent relationship quality was associated with lower precuneus activation to negative adolescent images. Findings are among the first to connect functional brain processing with observed parenting behaviors for parents of adolescent children, and underscore the relative importance of affective processing in parenting older children.

Potential Neural Mediators of Mom Power Parenting Intervention Effects on Maternal Intersubjectivity and Stress Resilience

Stress resilience in parenting depends on the parent's capacity to understand subjective experiences in self and child, namely intersubjectivity, which is intimately related to mimicking other's affective expressions (i. e., mirroring). Stress can worsen parenting by potentiating problems that can impair intersubjectivity, e.g., problems of "over-mentalizing" (misattribution of the child's behaviors) and "under-coupling" (inadequate child-oriented mirroring). Previously we have developed Mom Power (MP) parenting intervention to promote maternal intersubjectivity and reduce parenting stress. This study aimed to elucidate neural mechanisms underlying the effects of MP with a novel Child Face Mirroring Task (CFMT) in functional magnetic-resonance-imaging settings. In CFMT, the participants responded to own and other's child's facial pictures in three task conditions: (1) empathic mirroring (Join), (2) non-mirroring observing (Observe), and (3) voluntary responding (React). In each condition, each child's neutral, ambiguous, distressed, and joyful expressions were repeatedly displayed. We examined the CFMT-related neural responses in a sample of healthy mothers (n = 45) in Study 1, and MP effects on CFMT with a pre-intervention (T1) and post-intervention (T2) design in two groups, MP (n = 19) and Control (n = 17), in Study 2. We found that, from T1 to T2, MP (vs. Control) decreased parenting stress, decreased dorsomedial prefrontal cortex (dmPFC) during own-child-specific voluntary responding (React to Own vs. Other's Child), and increased activity in the frontoparietal cortices, midbrain, nucleus accumbens, and amygdala during own-child-specific empathic mirroring (Join vs. Observe of Own vs. Other's Child). We identified that MP effects on parenting stress were potentially mediated by T1-to-T2 changes in: (1) the left superior-temporal-gyrus differential responses in the contrast of Join vs. Observe of own (vs. other's) child, (2) the dmPFC-PAG (periaqueductal gray) differential functional connectivity in the same contrast, and (3) the left amygdala differential responses in the contrast of Join vs. Observe of own (vs. other's) child's joyful vs. distressed expressions. We discussed these results in support of the notion that MP reduces parenting stress via changing neural activities related to the problems of "over-mentalizing" and "under-coupling." Additionally, we discussed theoretical relationships between parenting stress and intersubjectivity in a novel dyadic active inference framework in a two-agent system to guide future research.

Early postpartum resting-state functional connectivity for mothers receiving buprenorphine treatment for opioid use disorder: A pilot study

Between 1999 and 2014, the prevalence of opioid use disorder (OUD) among pregnant women quadrupled in the USA. The standard treatment for peripartum women with OUD is buprenorphine. However, the maternal behavior neurocircuit that regulates maternal behavior and mother-infant bonding has not been previously studied for human mothers receiving buprenorphine treatment for OUD (BT). Rodent research shows opioid effects on reciprocal inhibition between maternal care and defence maternal brain subsystems: the hypothalamus and periaqueductal gray, respectively. We conducted a longitudinal functional magnetic resonance imaging (fMRI) pilot study in humans to specifically examine resting-state functional connectivity (rs-FC) between the periaqueductal gray and hypothalamus, as well as to explore associations with maternal bonding for BT. We studied 32 mothers who completed fMRI scans at 1 month (T1) and 4 months postpartum (T2), including seven mothers receiving buprenorphine for OUD and 25 non-OUD mothers as a comparison group (CG). The participants underwent a 6-minute resting-state fMRI scan at each time point. We measured potential bonding impairments using the Postpartum Bonding Questionnaire to explore how rs-FC with periaqueductal gray is associated with bonding impairments. Compared to CG, BT mothers differed in periaqueductal gray-dependent rs-FC with the hypothalamus, amygdala, insular cortex and other brain regions at T1, with many of these differences disappearing at T2, suggesting potential therapeutic effects of continuing buprenorphine treatment. In contrast, the "rejection and pathological anger" subscale of the Postpartum Bonding Questionnaire at T1 and T2 was associated with the T1-to-T2 increases in periaqueductal gray-dependent rs-FC with the hypothalamus and amygdala. Preliminary evidence links maternal bonding problems for mothers with OUD early in the postpartum to connectivity between specific care and defence maternal brain circuits, which may be mitigated by buprenorphine treatment. This exploratory study supports a potential mechanism for investigating both the therapeutic benefits and risks of opioids for maternal care and bonding with infants.

Effects of opioids on the parental brain in health and disease

The epidemic of opioid use disorder (OUD) directly affects millions of women of child-bearing age. Unfortunately, parenting behaviors - among the most important processes for human survival - are vulnerable to the effects of OUD. The standard of care for pregnant women with OUD is opioid maintenance therapy (OMT), of which the primary objective is to mitigate addiction-related stress. The aim of this review is to synthesize current information specific to pregnancy and parenting that may be affected by OUD. We first summarize a model of the parental brain supported by animal research and human neuroimaging. We then review animal models of exogenous opioid effects on parental brain and behavior. We also present preliminary data for a unifying hypothesis that may link different effects of exogenous opioids on parenting across species and in the context of OMT. Finally, we discuss future directions that may inform research and clinical decision making for peripartum women with OUD.

Maternal childhood adversity, OXTR genotype and cognitive load impact on perceptual and behavioral responses to infant crying

The crying of infants elicits aversive feelings and poses a risk for child abuse. Maternal childhood maltreatment can have negative parenting ability consequences and interact with the oxytocin receptor (OXTR) single nucleotide polymorphism (rs53576) to predict maternal response to infant distress stimuli. Recent studies have highlighted the importance of individual vulnerability differences to situational cognitive load in parenting situations. The current study, in which 124 mothers participated in a standardized infant vocalization paradigm, examined three-way interaction on subjective empathy, behavior intention, and handgrip force response to a crying infant. Participants were asked to squeeze a handgrip dynamometer at maximal and half strength while memorizing a meaningless alphabet syllable as the cognitive load manipulation. Significant interactions were also observed between OXTR rs53576, childhood adversity, and cognitive load when predicting excessive force and harsh response intention on hearing a crying infant. These findings suggested that, as the G allele carriers of OXTR rs53576 appear to be susceptible to the effects of severe childhood adversity, inter- and intra-individual approaches are needed when assessing maternal responses to infant stimuli.

Severity of anxiety moderates the association between neural circuits and maternal behaviors in the postpartum period

Neuroimaging research has suggested that activity in the amygdala, center of the socioemotional network, and functional connectivity between the amygdala and cortical regions are associated with caregiving behaviors in postpartum mothers. Anxiety is common in the early postpartum period, with severity ranging from healthy maternal preoccupation to clinical disorder. However, little is known about the influence of anxiety on the neural correlates of early caregiving. We examined these relationships in a community cohort of 75 postpartum women (ages 18-22; predominantly low-SES, minority race) who listened to infant cry sounds while undergoing an fMRI assessment. Maternal self-reported symptoms of anxiety were mostly within the subclinical range. Positive and negative caregiving behaviors during filmed face-to-face mother-infant interactions were coded by independent observers. The results from whole-brain analyses showed that anxiety severity moderated the brain-maternal behavior relationships. Specifically, our results showed that the higher a mother's anxiety, the stronger the association between positive caregiving (i.e., maternal warmth and involvement) and amygdala-right posterior superior temporal sulcus (amygdala-RpSTS) functional connectivity. These results remained significant when we controlled for symptoms of depression and contextual variables. These findings suggest that functional connectivity between the amygdala and a social perception region (RpSTS) plays a particularly important role for anxious mothers in facilitating their positive parenting. These findings extend our understanding of the specific neural circuits that support positive maternal caregiving in the context of maternal anxiety, and they may help inform the future design of personalized and effective interventions.

Neural pathways of maternal responding: systematic review and meta-analysis

Functional magnetic resonance imaging (fMRI) has increasingly been employed to establish whether there is a specific brain neural network dedicated to maternal responsiveness. We undertook systematic review and meta-analysis of all studies in which healthy new mothers were exposed to visual stimuli of own versus other infants to determine the quality of evidence for a dedicated maternal neural network. Systematic literature review revealed a pattern of specific neural responses commonly induced by visual infant paradigms. Brain areas consistently reported as activated in mothers in response to own versus unknown infant included the left thalamus, bilateral pre-central gyrus, left limbic lobe, uncus, amygdala and left caudate. These regions are implicated in reward, attention, emotion processing and other core social cognitive skills. Meta-analysis, however, revealed a more limited subset of brain areas activated in mothers specifically in response to their own versus unknown infant and suggested considerable inter-study variability. Further work is needed if functional imaging is to become an objective tool for the assessment of neural pathways associated with distinct patterns of maternal care behaviour. Such a tool would be invaluable in developing biomarkers of neural activity associated with healthy maternal care and for monitoring treatment/intervention effects of costly parenting interventions.

Epigenetic Transmission of Maternal Behavior: Impact on the Neurobiological System of Healthy Mothers

Quality of maternal caregiving not only impacts children's development but can also result in heritable changes in gene expression (i.e., in an epigenetic manner). Consequently, when women become mothers, they adopt parenting behavior similar to that they received at family of origin. This transgenerational transmission of maternal behavior may also be associated with changes in the neurobiological system of future mothers. This review aims to highlight the effect quality of perceived parenting has on maternal behavior and the neurobiological system of mothers, specifically the oxytocin system, brain morphology and brain function. This would likely help in finding biomarkers that profile the impact of perceived parenting on mothers, and thus allow identification of mothers who experience poor-quality parenting for intervention.

Maternal sensitivity is associated with configural processing of infant's cues in preterm and full-term mothers

BACKGROUND

Prematurity may affect mother-infant bonding and alter maternal sensitivity to infant's cues. Efficient perception of infants' facial and bodily cues is a crucial aspect of maternal sensitivity and may be challenged by prematurity, as infants' signals may not be easily intelligible. However, it is still unexplored how premature birth impacts the maternal ability to perceive infants' signals.

AIMS

To investigate whether prematurity influences the perceptual sensitivity of mothers to infants' cues and, in particular, the configural processing of the faces and bodies of familiar and unfamiliar infants.

STUDY DESIGN

The inversion effect paradigm was used to evaluate the configural vs. detail-based processing of the face and body of own or others' infants. Preterm mothers were compared to full-term mothers with either low or high maternal sensitivity.

PARTICIPANTS

Forty-three healthy full-term and twenty-one preterm mothers of infants aged about six months.

OUTCOME MEASURES

Maternal sensitivity during dyadic interaction, gestational age, accuracy and reaction time in a delayed matching-to-sample task of upright vs. inverted body and face stimuli (i.e., inversion effect).

RESULTS

Preterm mothers were found to be less sensitive than the full-term ones. Higher maternal sensitivity during dyadic interaction was associated with lower inversion effect for unfamiliar as compared to own infants' bodies. However, preterm mothers and full-term mothers with low sensitivity showed comparable inversion effect in perceiving unfamiliar infants' faces or bodies.

CONCLUSIONS

Preterm birth per se does not directly affect body configural processing, but it may be associated to reduced maternal sensitivity, ultimately leading to a less refined perception of own infant's cues.

Preliminary evidence for neural responsiveness to infants in mothers with schizophrenia and the implications for healthy parenting

Schizophrenia is a severe mental illness that may significantly affect maternal sensitive behaviour. Neural correlates of maternal behaviour represent a potentially valuable means of differentiating objectively between healthy mothers expressing variations in maternal sensitivity. As mothers with schizophrenia (MWS) show deficits in behavioural responses to infants compared to healthy mothers, we explored whether maternal brain responses to infant stimuli would be significantly reduced in MWS. We also examined whether differences in maternal behaviour between healthy and ill mothers (during play interactions with own infant) were associated with differences in brain activation to infant stimuli. We found no evidence of differential 'maternal brain' responses or 'maternal behavioural' responses in 11 new MWS compared to 20 healthy new mums; neither were neural responses to infants linked to behavioural or cognitive aspects of the mother's relationship with her infant in MWS. These preliminary findings suggest maternal sensitivity differences between MWS and healthy mothers, suggested in previous studies, may be reversible in stable treated MWS.

Neuroendocrine mechanisms for parental sensitivity: overview, recent advances and future directions

Early parent-infant relationships play important roles in infants' development. New parents adapt to the developing relationship with their infants to coordinate parenting behaviors in the milieu of infant needs, hormones, moods, and stress. This review highlights research from the past two years, using non-invasive brain-imaging techniques and naturalistic tasks in mothers and fathers in relation to psychological, and endocrine measures. Recent work also connects parental brain physiology with parental sensitive behavior, parent/child outcomes and parent psychotherapy. Understanding neurobiological mechanisms underlying parenting thoughts, behaviors and moods (see Figure 1) will help identify mental health risks and contribute to parental mental health interventions and resilience.

Dentin sialoprotein facilitates dental mesenchymal cell differentiation and dentin formation

Dentin sialoprotein (DSP) is a dentin extracellular matrix protein. It is involved in dental mesenchymal cell lineages and dentin formation through regulation of its target gene expression. DSP mutations cause dentin genetic diseases. However, mechanisms of DSP in controlling dental mesenchymal cell differentiation are unknown. Using DSP as bait, we screened a protein library from mouse odontoblastic cells and found that DSP is a ligand and binds to cell surface receptor, occludin. Further study identified that the C-terminal DSP domain^{aa 363–458} interacts with the occludin extracellular loop 2^{aa 194–241}. The C-terminal DSP domain induced phosphorylation of occludin Ser⁴⁹⁰ and focal adhesion kinase (FAK) Ser⁷²² and Tyr⁵⁷⁶. Coexpression of DSP, occludin and FAK was detected in dental mesenchymal cells during tooth development. Occludin physically interacts with FAK, and occludin and FAK phosphorylation can be blocked by DSP and occludin antibodies. This DSP domain facilitates dental mesenchymal cell differentiation and mineralization. Furthermore, transplantation and pulp-capping procedures revealed that this DSP domain induces endogenous dental pulp mesenchymal cell proliferation, differentiation and migration, while stimulating blood vessel proliferation. This study elucidates the mechanism of DSP in dental mesenchymal lineages and implies that DSP may serve as a therapeutic agent for dentin-pulp complex regeneration in dental caries.

Deep mechanisms of social affect – Plastic parental brain mechanisms for sensitivity versus contempt

Insensitive parental thoughts and affect, similar to contempt, may be mapped onto a network of basic emotions moderated by attitudinal representations of social-relational value. Brain mechanisms that reflect emotional valence of baby signals among parents vary according to individual differences and show plasticity over time. Furthermore, mental health problems and treatments for parents may affect these brain systems toward or away from contempt, respectively.