Natural variations in maternal and paternal care are associated with systematic changes in oxytocin following parent-infant contact

Computationally derived parent-child interaction patterns and oxytocin in children with and without OCD

BACKGROUND

Parent-child interactive processes are important factors in pediatric OCD. Understanding biological mechanisms of parent-child interactive behaviors could help improve treatment of pediatric OCD. Oxytocin has been suggested as a biological mechanism in parent-child interactions. However, no studies in pediatric OCD exist. We used machine learning to discover latent patterns in parent-child interactive behaviors and explored associations with oxytocin in children with and without OCD.

METHODS

We used parent and child salivary oxytocin levels measured with enzyme-linked immunosorbent assay (ELISA) and investigator-rated parent-child behaviors during a frustration task. Children with or without OCD and their parents - 107 mother-child and 62 father-child pairs were included. We used two machine learning techniques, principal component analysis and archetypal analysis, to generate data-driven, theory-agnostic behavioral variables, and regression to estimate their associations with oxytocin.

RESULTS

Principal component and archetype analyses identified behavioral patterns describing the mother-child and father-child interactions. We found a positive association between child and mother oxytocin and the interaction patterns "overinvolved interaction" and "emotional interaction" and a negative association with "distant interaction". Additionally, mother oxytocin was positively associated with "supportive interaction" and "varied-coping interaction", and negatively associated with "conflictual interaction" and "negative-low support interaction". Father oxytocin was associated with "supportive interactions" only in the presence of child OCD.

CONCLUSION

Child and mother oxytocin appear related with mother-child interactive patterns. Fathers' oxytocin was related with interaction patterns only in children with OCD. Our exploratory findings can be used to generate hypothesis for future research regarding the relationship between oxytocin and maladaptive family engagement in OCD and differences between mothers and fathers' behaviors when the child has OCD.

The role of affective touch in mental illness: a systematic review of CT fiber dysregulation in psychological disorders and the therapeutic potential of CT fiber stimulation

Introduction

Over the past few decades, research on affective touch has clarified its impact on key psychological functions essential for environmental adaptation, such as self-awareness, self-other differentiation, attachment, and stress response. These effects are primarily driven by the stimulation of C-tactile (CT) fibers. Despite significant advancements in understanding the fundamental mechanisms of affective touch, its clinical applications in mental health remain underdeveloped. This systematic review aims to rigorously assess the scientific literature on the relationship between CT fiber stimulation and psychological disorders, evaluating its potential as a therapeutic intervention.

Methods

This systematic review was conducted in accordance with PRISMA guidelines. A search was performed in the EMBASE, PubMed, and Web of Science databases for articles published in the last 10 years. The review focused on two main aspects: (1) potential dysregulation of CT fibers in individuals with psychological disorders, and (2) psychological treatments based on CT fiber stimulation and their psychological and functional outcomes.

Results

Most studies investigating CT fiber dysregulation in psychological disorders reported sensory alterations, with patients rating affective touch as less pleasant than healthy controls. These differences were often associated with dysregulation in the reward network and interoceptive processing, with several studies suggesting reduced insular cortex activation as a contributing factor. Regarding psychological treatments, only a limited number of studies analyzed therapies based on CT fiber stimulation. Despite methodological variations and differences in psychological diagnoses, the available evidence suggests that affective touch therapies can effectively reduce symptom severity and improve interoception across different psychological conditions.

Discussion

The findings underscore the potential of affective touch as a therapeutic avenue for psychological disorders. However, given the dearth of studies on this topic, further analyses are necessary to fully understand its mechanisms and clinical efficacy. Expanding research in this area could provide valuable insights into functional impairments related to CT fiber dysregulation and support the development of targeted interventions for mental health treatment.

Infant carrying to enhance parental reflective functioning in early childhood: a model of direct and indirect pathways in a sample of adolescent mothers

Research on infant carrying/babywearing is limited but suggests that frequent close physical contact increases maternal sensitivity and responsiveness. It is unknown whether infant carrying promotes parental reflective functioning (PRF). In this prospective investigation, adolescent mothers (N=75; Mage=19.45; 57.4% non-white) in a multi-wave infant carrying intervention trial were followed from early postpartum to preschool to assess long-term impacts of infant carrying on the development of PRF. Participation in the infant carrying intervention (β=0.33, p=0.03) and maternal representation of infant carrying as supporting infant wellbeing (β=0.36, p<0.01) predicted higher PRF when children were 3.5 years old. There was a significant indirect effect from maternal representation of infant carrying as a bonding tool to enhanced PRF during the preschool period via maternal attunement at seven months (β=0.26, p=0.04). Participating in an infant carrying intervention and child-focused representations of infant carrying may support mentalizing among adolescent mothers via distinct direct and indirect pathways.

[Proprioceptive developmental care and parental mental health]

While the benefits of developmental care using tactile and/or kinaesthetic stimulation on the development of premature babies have been demonstrated in numerous research studies, this systematic review highlights their protective action against the onset of anxious and depressive symptoms in their parents. This work outlines two explanatory hypotheses -physiological and psychological- for the beneficial effect of this interactive care.

Oxytocin as a Biomarker of Differential Effects to SPACE vs. CBT Treatment of Child Anxiety Disorders

OBJECTIVE

Two lines of research, on outcome moderators and on novel treatment targets, seek to improve the overall efficacy of child anxiety treatment, with mixed results. We propose that an integration of both lines of research can lead to improved treatment efficacy. In a first proof of concept of this approach, we studied whether the interaction between baseline levels and targeted changes in peripheral oxytocin (OT) can predict differential responses to two childhood anxiety treatments.

METHOD

A total of 124 mother-child dyads participated in the study. Children's salivary OT levels were measured at baseline and again, immediately after an experimental dyadic interaction in the lab. Dyads were subsequently randomized to receive one of two treatments, differing in their targets: SPACE (Supportive Parenting for Anxious Childhood Emotions) and CBT (cognitive-behavioral therapy). Treatment outcomes were assessed using the Childhood Anxiety Related Emotional Disorders scale, reported by both mother and child.

RESULTS

The findings suggest that in SPACE, where the mother is the main agent of change, higher baseline levels of child OT, coupled with increases in OT following a positive mother-child interaction, predicted greater treatment efficacy. By contrast, in CBT, where the child is the main agent of change, higher baseline levels of child OT, coupled with a decrease in OT following the interaction, predicted greater treatment efficacy.

CONCLUSIONS

The findings highlight the importance of the integration between moderators and targets of treatments for progress toward improving treatment efficacy through precision medicine.

Needing to shout to be heard? Caregiver under-responsivity and disconnection between vocal signaling and autonomic arousal in infants from chaotic households

Children raised in chaotic households show affect dysregulation during later childhood. To understand why, we took day-long home recordings using microphones and autonomic monitors from 74 12-month-old infant-caregiver dyads (40% male, 60% white, data collected between 2018 and 2021). Caregivers in low-Confusion Hubbub And Order Scale (chaos) households responded to negative affect infant vocalizations by changing their own arousal and vocalizing in response; but high-chaos caregivers did not, whereas infants in low-chaos households consistently produced clusters of negative vocalizations around peaks in their own arousal, high-chaos infants did not. Their negative vocalizations were less tied to their own underlying arousal. Our data indicate that, in chaotic households, both communicating and responding are atypical: infants are not expressing their levels of arousal, and caregivers are under-responsive to their infants' behavioral signals.

Genetic Variants in Oxytocinergic System Genes and Their Association with Postpartum Depression Susceptibility

One of the most frequent forms of maternal morbidity following childbirth is postpartum depression. Postpartum depression (PPD), a disabling condition as a major public health concern, has a significant negative impact on the child's emotional, mental as well as intellectual development if left undiagnosed and untreated, which can later have long-term complications. The oxytocin system is an excellent candidate gene system in the maternal context. Differences in vulnerability of mothers for the onset of postpartum psychiatric disorders could be influenced by individual differences in the genetic profile of each one. In this original research, we aimed to explore if there are any possible contributions of genetic variation on both the oxytocin receptor gene (OXTR) and the oxytocin gene (OXT) to the occurrence of postpartum depression, aiming to provide the latest evidence and determine which genetic polymorphisms significantly create a susceptibility for this condition. A total of 100 mothers were preliminarily genotyped before they completed the Edinburgh Postnatal Depression Scale Questionnaire (EPDS) at 6 weeks postpartum. DNA was extracted from peripheral blood samples of the participants (N = 100) and evaluated for the oxytocin gene (OXT_rs2740210; OXT_rs4813627) and oxytocin receptor gene (OXTR_ rs237885) single nucleotide polymorphisms. The results highlighted a significant interaction between the oxytocin OXT_rs2740210 genotype and maternal postpartum depression in mothers with the CC genotype but not in those with AA/AC genotypes. This reveals that an interaction of vulnerable genotypes (CC genotype of OXT_rs2740210, C allele in genotype of OXT_rs2740210, G allele in genotype of OXT_rs4813627) with an environmental burden or other risk factors would predispose the mothers to develop postpartum depression. We found no significant association between the interaction effect of the oxytocin receptor gene OXTR_rs237885 genotype depending on the occurrence of maternal postpartum depression. These findings prove the implication of the oxytocinergic system gene variants in vulnerability for postpartum depression and indicate the need for future studies adopting a multilevel approach in order to increase understanding.

Birthing parents' neural response to infant cry: moderating effects of oxytocin and perceived childhood care

Individuals who perceive the caregiving they received from their parents as more caring tend to bond better with their infants and show more sensitive parenting behaviors. Early caregiving experiences are also related to differences in the functions of hormonal systems, including the oxytocinergic system. The current study examined how perceptions of childhood maternal care relate to parenting behaviors, oxytocin levels, and neural responses to infant stimuli. Perceived childhood maternal care was measured using the Parental Bonding Instrument (PBI) for 54 first-time birthing parents. Salivary oxytocin and observations of parenting behaviors were assessed during parent-infant play at 3.5 months postpartum. Neural activation while listening to infant cry was measured with fMRI. More positive perceptions of childhood maternal care and higher oxytocin were interactively related to greater anterior cingulate activation to own infant's cry. Higher oxytocin levels were associated with reduced left cuneus activation in response to own infant's cry when compared with control cry and matched noise. Findings suggested that positive memories of childhood caregiving may have protective functions for birthing parents with high oxytocin levels during the early postpartum period, a time when parents need to manage increased stress and form an exclusive bond with their baby.

Exploratory study to examine the neuroendocrinological changes in typically developing adults during a music-related participatory practice using computer software

There has been a growing recognition of the benefits of participating in art practices for promoting well-being and social connection. Despite this, only a limited number of studies have assessed the neuroendocrinological changes that might contribute to these benefits. In this exploratory study, we focused on a creative activity related to music composition using digital tools. The emergence of computer software to create music (CSCM) has lowered the barriers to musical technical skills and theory, making music composition more accessible. We examined whether incorporating CSCM into a music-making workshop would affect the levels of two hormones, oxytocin and cortisol, among healthy adults. These two hormones were chosen, because oxytocin is involved in prosocial behavior and bonding, while cortisol plays a role in the stress response. Considering the time it takes to learn and adapt to a typical customized CSCM, we simplified its use to allow participants to experience music-making within a short timeframe and set up two distinct workshops. One was individual music creation with the support of a facilitator (Dyad) and the other was music creation in a group (Group). Participants in the Dyad workshops showed increased oxytocin levels, whereas those in the Group workshops did not. Cortisol levels remained unchanged during the Dyad workshops, but decreased in the Group ones. These results suggest that neuroendocrinological changes may occur during music-making activities using computer software. This work highlights the potential value of CSCM-incorporated music-making activities, although further controlled studies are required to confirm these findings.

Preschool Behavioral Problems: Links with Maternal Oxytocin and Caregiving Sensitivity in the Postnatal Period, and Concurrent Maternal Psychopathology and Attachment State-of-Mind

This study investigated maternal oxytocin, caregiving sensitivity and mother-to-infant bonding at 3-months postpartum as predictors of child behavior and psychological outcomes in the preschool years, when controlling for concurrent maternal negative emotional symptoms and adult attachment state-of-mind. Forty-five mother-child dyads were assessed at 3-months and 3.5 years postpartum using mix of questionnaires, observational, interview and biological methods. Results showed that lower levels of maternal baseline oxytocin at 3-months postpartum significantly predicted emotional reactivity in the child at 3.5 years. When maternal adult attachment state-of-mind and negative emotional symptoms were included, lower levels of maternal baseline oxytocin at 3-months postpartum significantly predicted withdrawn child behavior. In addition, unresolved adult attachment and maternal negative emotional symptoms were significantly associated child behavioral disturbance in a range of areas. Findings highlight maternal postnatal oxytocin as a potential indicator of children who may be more likely to show emotional reactivity and withdrawn behavior in the preschool years.

Affective Touch in Preterm Infant Development: Neurobiological Mechanisms and Implications for Child-Caregiver Attachment and Neonatal Care

BACKGROUND/OBJECTIVES

Affective touch is crucial in infant development, particularly in regulating emotional, cognitive, and physiological processes. Preterm infants are often deprived of essential tactile stimulation owing to their early exposure to the external environment, which may affect long-term developmental outcomes. This review aimed to examine the neurobiological mechanisms of affective touch and highlight effective interventions, such as skin-to-skin contact (SSC) and kangaroo care (KC), to promote development in preterm infants.

METHODS

This review summarizes recent studies in the literature on affective touch, the role of C-tactile fibers, and the effects of tactile interventions in neonatal care. Studies were selected based on their relevance to the care and development of preterm infants, with a focus on physiological and neurodevelopmental outcomes. Key interventions, including SSC and massage therapy, are discussed in relation to their effectiveness in the neonatal intensive care unit (NICU).

RESULTS

The results suggest that affective touch, mainly through activation of tactile C-fibers, improves caregiver-infant bonding, reduces stress responses, and supports neurodevelopment in preterm infants. Interventions such as SSC and KC have also been shown to improve physiological regulation in these infants, including heart rate, breathing, and temperature control while promoting emotional regulation and cognitive development.

CONCLUSIONS

Affective touch is a key component of early development, particularly in preterm infants admitted to the NICU. Integrating tactile interventions such as SSC and KC into neonatal care practices may significantly improve long-term developmental outcomes. Future research should explore the epigenetic mechanisms underlying affective touch and further refine tactile interventions to optimize neonatal care.

Oxytocin influences parental care in male threespine stickleback across multiple time scales

Oxytocin (OXT) and its homologs are known to regulate parental care in vertebrates, but it is unknown what role these neuropeptides may play in the evolutionary loss of care. Here, we compared two recently diverged ecotypes of threespine stickleback (Gasterosteus aculeatus) that differ in parental care. Males of the common ecotype provide obligate, uniparental care to their offspring, whereas males of the white ecotype abandon their offspring after fertilization. To test if OXT plays a role in the loss of care, we manipulated OXT in males of both ecotypes via intraperitoneal injection of a vehicle control, OXT single- or double-dose, or an OXT antagonist. We observed the behavioral response to injection at two time points for commons (0 and 4 days post-fertilization (dpf)) and one for whites (0 dpf). Our results suggest that, in commons, OXT promotes the onset of care but not its maintenance. Notably, commons that ultimately terminated their clutches did not respond to OXT at 0 dpf, which may have contributed to their failure to transition to a state of care. Whites responded to OXT manipulation in a different manner than commons, suggesting that the loss of care in whites is not due to a loss of sensitivity to OXT, or insufficient levels of OXT ligand, but rather an evolutionary change to the underlying parental circuit that OXT is acting on. These results provide evidence that ancient hormonal systems like OXT can contribute to losses of care over multiple timescales.

Grandmotherhood is associated with reduced OXTR DNA methylation

In mammals, both parental and alloparental care are associated with increased brain oxytocin signaling. Grandmothers are important alloparents in many human families. Based on animal model research showing that peripheral Oxtr methylation is associated with Oxtr expression in the nucleus accumbens, we investigated whether grandmaternal caregiving is associated with lower peripheral OXTR methylation. Results reveal several regions within OXTR where grandmothers have lower DNA methylation compared with non-grandmother controls, and no regions where grandmothers have higher OXTR DNA methylation. Among grandmothers, OXTR methylation was most strongly correlated with the grandmother's assessment of the degree of positive feelings between her and the grandchild, which in turn predicted caregiving engagement. Although there was little evidence that grandmaternal OXTR methylation modulated grandmaternal neural responses to viewing photos of the grandchild within brain regions involved in caregiving motivation, it was negatively correlated with the neural response to an unknown grandchild. Thus, while OT signaling may not be essential for activating grandmaternal brain reward systems in our low-stress experimental context, it may support caregiving motivation towards unrelated children. Future longitudinal research should determine whether the transition to grandmotherhood is associated with a reduction in OXTR methylation.

Perceived vulnerability to disease in pregnancy and parenthood and its impact on newborn health

Susceptibility to diseases and fear of infections might vary intra-individually, depending on life circumstances. The main aims of the current research were to examine whether perceived vulnerability to disease (PVD) is higher in expectant women and their partners as compared to their non-pregnant peers (Study 1), and to test whether a mother's disease aversion during pregnancy relates to health of her newborn (Study 2). In Study 1 we collected cross-sectional data from 412 men and women varying in parenthood status. Pregnant female participants were more likely to exhibit higher levels of PVD as compared with childless peers, although mothers also reported relatively high PVD scores. PVD in men, generally lower than that of women, seemed to be rather independent of their parenthood status. In Study 2, a sample of 200 pregnant women completed the PVD scale during the second pregnancy trimester and a follow-up survey after their child was born. We found that PVD in pregnant women was not related to further health outcomes in their newborns. Birth weight, average Apgar score, and general health of a newborn were not associated with the pregnancy-period mother's PVD score. However, the probability of giving birth to a child with 10 Apgar points was higher in younger mothers and tended to decrease with the increasing number of health issues before pregnancy. Overall, this research contributes to understanding of the health-oriented beliefs of expectant parents and parents of infants, but it also shows that the possible, PVD-related disease avoidance has a relatively little effect on basic markers of a newborn's health.

Language environment and early language production in Slovenian infants: An exploratory study using daylong recordings

Daylong recordings provide an ecologically valid option for analyzing language input, and have become a central method for studying child language development. However, the vast majority of this work has been conducted in North America. We harnessed a unique collection of daylong recordings from Slovenian infants (age: 16-30 months, N = 40, 18 girls), and focus our attention on manually annotated measures of parentese (infant-directed speech with a higher pitch, slower tempo, and exaggerated intonation), conversational turns, infant words, and word combinations. Measures from daylong recordings showed large variation, but were comparable to previous studies with North American samples. Infants heard almost twice as much speech and parentese from mothers compared to fathers, but there were no differences in language input to boys and girls. Positive associations were found between the social-interactional features of language input (parentese, turn-taking) and infants' concurrent language production. Measures of child speech from daylong recordings were positively correlated with measures obtained through the Slovenian MacArthur-Bates Communicative Development Inventory. These results support the notion that the social-interactional features of parental language input are the foundation of infants' language skills, even in an environment where infants spend much of their waking hours in childcare settings, as they do in Slovenia.

Do Parental Hormone Levels Synchronize During the Prenatal and Postpartum Periods? A Systematic Review

Physiological synchrony is the phenomenon of linked physiological processes among two or more individuals. Evidence of linkage between dyads has been found among a broad range of physiological indices, including the endocrine systems. During the transition to parenthood, both men and women undergo hormonal changes that facilitate parenting behavior. The present review sought to address the question as to whether hormonal synchronization occurs among expecting or new parents. A systematic literature search yielded 13 eligible records. The evidence of cortisol synchrony during the prenatal period, with additional testosterone, prolactin, and progesterone covariations in the time leading up to childbirth, was found to be most significant. During the postpartum period, parental synchrony was reported for oxytocin, testosterone, and cortisol levels. The implications of these covariations were found to translate into adaptive parenting behaviors and the facilitation of romantic bond. Associations with infant development were also reported, suggesting far-reaching effects of hormonal synchrony outside the parental dyad. The results highlight the importance of physiological interrelatedness during this sensitive period, underscoring the need for further research in this field. In view of the limited data available in this research domain, we have put forward a framework for future studies, recommending the adoption of standardized research protocols and repeated collections of specimens.

Peptides and primate personality: Central and peripheral oxytocin and vasopressin levels and social behavior in two baboon species (Papio hamadryas and Papio anubis)

The neurohormones oxytocin (OT) and arginine vasopressin (AVP) are involved in social behaviors and psychiatric conditions. However, more research on nonhuman primates with complex social behaviors is needed. We studied two closely-related primate species with divergent social and mating systems; hamadryas baboons (Papio hamadryas, n=38 individuals) and anubis baboons (Papio anubis, n=46). We measured OT in cerebrospinal fluid (CSF, n=75), plasma (n=81) and urine (n=77), and AVP in CSF (n=45), and we collected over 250 hours of focal behavioral observations. Using Bayesian multivariate models, we found no clear species difference in hormone levels; the strongest support was for hamadryas having higher CSF OT levels than anubis (posterior probability [PP] for females = 0.75, males = 0.84). Looking at nine specific behaviors, OT was associated with affiliative behaviors (approach, proximity, grooming, PP ∼ 0.85 - 1.00), albeit inconsistently across sources of measurement (CSF, plasma, and urine, which were uncorrelated with each other). Most behaviors had low repeatability (R ∼ 0 - 0.2), i.e. they did not exhibit stable between-individual differences (or "personality"), and different behaviors did not neatly coalesce into higher-order factors (or "behavioral syndromes"), which cautions against the use of aggregate behavioral measures and highlights the need to establish stable behavioral profiles when testing associations with baseline hormone levels. In sum, we found some associations between peptides and social behavior, but also many null results, OT levels from different sources were uncorrelated, and our behavioral measures did not indicate clear individual differences in sociability.

[Oxytocin as a neuroprotective strategy in neonates: concept and preclinical evidence]

OBJECTIVE

Prematurity and intra-uterine growth retardation are responsible for brain damage associated with various neurocognitive and behavioral disorders in more than 9 million children each year. Most pharmacological strategies aimed at preventing perinatal brain injury have not demonstrated substantial clinical benefits so far. In contrast, enrichment of the newborn's environment appears to have positive effects on brain structure and function, influences newborn hormonal responses, and has lasting neurobehavioral consequences during infancy and adulthood. Oxytocin (OT), a neuropeptide released by the hypothalamus, may represent the hormonal basis for these long-term effects.

METHOD

This review of the literature summarizes the knowledge concerning the effect of OT in the newborn and the preclinical data supporting its neuroprotective effect.

RESULTS

OT plays a role during the perinatal period, in parent-child attachment and in social behavior. Furthermore, preclinical studies strongly suggest that endogenous and synthetic OT is capable of regulating the inflammatory response of the central nervous system in response to situations of prematurity or more generally insults to the developing brain. The long-term effect of synthetic OT administration during labor is also discussed.

CONCLUSION

All the conceptual and experimental data converge to indicate that OT would be a promising candidate for neonatal neuroprotection, in particular through the regulation of neuroinflammation.

Infant carrying: Associations with parental reflective functioning, parental bonding and parental responses to infant crying

Infant carrying may have beneficial effects on the parent-infant relationship but only limited research has been conducted in this area. Therefore, the main aim of the current study was to investigate whether infant carrying is associated with parental reflective functioning, parental bonding, and parental (emotional) and behavioral responses to infant crying, key elements within the parent-infant relationship, promoting infant development. Parents reporting high levels (N = 389) of infant carrying (six times a week or daily) and parents reporting low levels (N = 128) of infant carrying (less than once a week or not at all) who participated in an online survey about the developing parent-infant relationship in Germany were included in the present study. Standardized questionnaires were used to assess parental reflective functioning, parental bonding impairments, and emotional responses to infant crying. Further insensitive (non-responsive and hostile) behaviors in response to infant crying were assessed. Parents with high levels of infant carrying showed better parental reflective functioning, lower parental bonding problems, less negative emotions, and less insensitive behaviors in response to infant crying.

Anethole as a promising antidepressant for maternal separation stress in mice by modulating oxidative stress and nitrite imbalance

The occurrence of major depressive disorder is widespread and can be observed in individuals belonging to all societies. It has been suggested that changes in the NO pathway and heightened oxidative stress may play a role in developing this condition. Anethole is a diterpene aromatic compound found in the Umbelliferae, Apiaceae, and Schisandraceae families. It has potential pharmacological effects like antioxidant, anxiolytic, analgesic, anti-inflammatory, antidiabetic, gastroprotective, anticancer, estrogenic, and antimicrobial activities. This study aimed to investigate the potential antidepressant properties of Anethole in a mouse model experiencing maternal separation stress while also examining its impact on oxidative stress and nitrite levels. The research involved the participation of 40 male NMRI mice, separated into five distinct groups to conduct the study. The control group was administered 1 ml/kg of normal saline, while the MS groups were given normal saline and Anethole at 10, 50, and 100 mg/kg doses. The study comprised various behavioural tests, including the open field test (OFT), forced swimming test (FST), and splash test, to assess the effects of Anethole on the mice. In addition to the behavioural tests, measurements were taken to evaluate the total antioxidant capacity (TAC), malondialdehyde (MDA), and nitrite levels in the hippocampus of the mice. According to the findings, maternal separation stress (MS) led to depressive-like conduct in mice, including a rise in immobility duration during the FST and a reduction in the duration of grooming behaviour in the splash test. Additionally, the results indicated that MS correlated with an increase in the levels of MDA and nitrite and a reduction in the TAC in the hippocampus. However, the administration of Anethole resulted in an increase in grooming activity time during the splash test and a decrease in immobility time during the FST. Anethole also exhibited antioxidant characteristics, as demonstrated by its ability to lower MDA and nitrite levels while increasing the TAC in the hippocampus. The results suggest that Anethole may have an antidepressant-like impact on mice separated from their mothers, likely partly due to its antioxidant properties in the hippocampus.

Stroking in early mother-infant exchanges: The role of maternal tactile biography and interoceptive sensibility

Caress-like is a crucial component of caregiving and a key factor in mother-infant interactions. Mother's experience of touch during her own childhood (i.e., tactile biography) has been found to be related to maternal actual use of caress-like touch (i.e., stroking) during mother-infant exchanges. Evidence also suggests that maternal interoceptive sensibility (i.e., self-perceived sensitivity to inner-body sensations) might be related to sensitive caregiving abilities. However, further empirical investigation is needed to understand to what extent tactile biography and interoceptive sensibility have an impact on mothers' stroking when interacting with their infants. Using an online survey, this cross-sectional study explored the potential association between maternal tactile biography, interoceptive sensibility and use of touch for interaction with their own infants in a group of 377 Italian mothers (mean age = 33.29; SD = 4.79). We tested and compared a series of multivariate linear mediation models using maternal tactile biography as predictor, maternal use of affective touch as outcome variable and Multidimensional Assessment of Interoceptive Awareness (MAIA) subscale scores as mediators. We found that, if a mother had positive touch experiences in her own childhood, she may be more likely to use touch in a positive and nurturing way with her own infant (i.e., stroking). Furthermore, mothers' interoceptive sensibility in the form of attention regulation, self-regulation and body listening mediates the association between their past experiences of positive touch and their use of caress-like touch in mother-infant exchanges. This study highlights that maternal tactile biography is directly associated with mothers' use of caress-like touch and indirectly linked to it through the mediating role of interoceptive sensibility.

Skin-to-Skin Care and Spontaneous Touch by Fathers in Full-Term Infants: A Systematic Review

A series of studies have shown that mothers' early tactile behaviors have positive effects, both on full-term and preterm infants, and on mothers alike. Regarding fathers, research has focused mostly on paternal skin-to-skin care with preterm infants and has overlooked the tactile behavior effects with full-term newborns on infants' outcomes and on fathers themselves. The current systematic review considered the evidence regarding paternal tactile behaviors with full-term infants, including skin-to-skin care (SSC) and spontaneous touch (ST), during parent-infant interactions, and differentiated biophysiological, behavioral and psychological variables both in fathers and in infants. We also compared fathers' and mothers' tactile behaviors for potential differences. The few available studies suggest that paternal touch-SSC and ST-can have positive effects on fathers and infants alike. They also show that, despite some intrinsic differences, paternal touch is as pleasant as maternal touch. However, given the paucity of studies on the topic, we discuss why this field of research should be further explored.

Effect of tactile and/or kinesthetic stimulation therapy of preterm infants on their parents' anxiety and depressive symptoms: A systematic review

BACKGROUND

In the case of preterm birth, the idealized postnatal period is replaced by an anxious and even traumatic experience for parents. Higher prevalence of parental anxiety, postnatal depression, and posttraumatic stress disorder has been observed in mothers of preterm infants up to 18 months after childbirth. There is increasing evidence that proprioceptive stimulation has a beneficial effect on preterms' short-term outcomes. Could this care also have an impact on parental anxiety and depressive symptoms? We reviewed recent publications on the impact on parents' anxiety and depressive symptoms of delivering tactile and/or kinesthetic stimulation to their premature newborn.

METHODS

We conducted a systematic review by searching the PubMed, PsycInfo, Scopus, ScienceDirect and Google Scholar databases for English-language publications from the past 10 years. We focused on the mothers or fathers of infants born preterm (before 37 weeks of gestation) who provided tactile and/or kinesthetic stimulation to their premature newborn in the neonatal intensive care unit. Relevant outcomes were the parents' anxiety, stress, depressive symptoms, and symptoms of posttraumatic stress disorder, assessed with reliable standardized inventories.

RESULTS

Eleven articles were included in the systematic review. Results suggested a beneficial effect of parents' early tactile and kinesthetic stimulation of their preterm infants.

CONCLUSIONS

These interventions may act as protective factors against the occurrence of anxiety and depressive symptoms in parents and deserve to be studied further in this population.

Searching for the Metaverse: Neuroscience of Physical and Digital Communities

What distinguishes real-world communities from their online counterparts? Social and cognitive neuroscience research on social networks and collective intentionality will be used in the article to answer this question. Physical communities are born in places. And places engage "we-mode" neurobiological and cognitive processes as behavioral synchrony, shared attention, deliberate attunement, interbrain synchronization, and so on, which create coherent social networks of very different individuals who are supported by a "wisdom of crowd." Digital technologies remove physical boundaries, giving people more freedom to choose their activities and groups. At the same time, however, the lack of physical co-presence of community members significantly reduces their possibility of activating "we-mode" cognitive processes and social motivation. Because of this, unlike physical communities that allow interaction between people from varied origins and stories, digital communities are always made up of people who have the same interests and knowledge (communities of practice). This new situation disrupts the "wisdom of crowd," making the community more radical and less accurate (polarization effect), allowing influential users to wield disproportionate influence over the group's beliefs, and producing inequalities in the distribution of social capital. However, a new emergent technology-the Metaverse-has the potential to reverse this trend. Several studies have revealed that virtual and augmented reality-the major technologies underlying the Metaverse-can engage the same neurobiological and cognitive "we-mode" processes as real-world environments. If the many flaws in this technology are fixed, it might encourage people to engage in more meaningful and constructive interactions in online communities.

Father contribution to human resilience

Fathers have been an important source of child endurance and prosperity since the dawn of civilization, promoting adaptation to social rules, defining cultural meaning systems, teaching daily living skills, and providing the material background against which children developed; still, the recent reformulation in the role of the father requires theory-building. Paternal caregiving is rare in mammals, occurring in 3-5% of species, expresses in multiple formats, and involves flexible neurobiological accommodations to ecological conditions and active caregiving. Here, we discuss father contribution to resilience across development. Our model proposes three tenets of resilience - plasticity, sociality, and meaning - and discussion focuses on father-specific contributions to each tenet at different developmental stages; newborn, infant, preschooler, child, and adolescent. Father's style of high arousal, energetic physicality, guided participation in daily skills, joint adventure, and conflict resolution promotes children's flexible approach and social competence within intimate bonds and social groups. By expanding children's interests, sharpening cognitions, tuning affect regulation, encouraging exploration, and accompanying the search for identity, fathers support the sense of meaning, enhancing the human-specific dimension of resilience. We end by highlighting pitfalls to paternal contribution, including absence, abuse, rigidity, expectations, and gender typing, and the need to formulate novel theories to accommodate the "involved dad."

Randomized controlled trial to prevent postpartum depressive symptomatology: An infant carrier intervention

BACKGROUND

There is a need for effective interventions to reduce symptomatology of postpartum depression. The objective of this study was to test whether providing an ergonomic infant carrier would reduce postpartum depression symptomatology.

METHODS

A randomized two-arm, parallel-group trial with 100 participants was conducted between February 2018 and June 2019 in a low-income community. At 30-weeks' gestation, 50 participants were randomly assigned to receive an ergonomic infant carrier and instructions on proper use (intervention group), and 50 participants were assigned to a waitlist (control group). Participants tracked the extent of their infant carrier use and completed the Edinburgh Postpartum Depression Scale (EPDS) to assess postpartum depression symptomatology at 6-weeks postpartum.

RESULTS

Participants in the intervention group reported using an infant carrier significantly more often than the control group (β = 2.69, SE = 0.347, p < .001, 95 % CI = 2.08-3.41). The intervention group reported fewer depressive symptoms at 6-weeks postpartum than the control group (β = -0.541, p = .042).

LIMITATIONS

The sample size was relatively small and thus our results may not be generalizable to the general population.

CONCLUSION

Infant carrying may be a cost-effective intervention to reduce postpartum depression symptomatology. Large-scale studies are warranted to further examine the efficacy and cost-effectiveness of providing carriers as an intervention to reduce postpartum depression symptomatology.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov id: NCT04376021. Data Sharing Statement: Deidentified individual participant data will not be made available because we did not obtain permission to share individual data.

CLINICAL TRIAL REGISTRATION NUMBER

NCT0437602; https://beta.

CLINICALTRIALS

gov/study/NCT04376021.

Romantic love evolved by co-opting mother-infant bonding

For 25 years, the predominant evolutionary theory of romantic love has been Fisher's theory of independent emotion systems. That theory suggests that sex drive, romantic attraction (romantic love), and attachment are associated with distinct neurobiological and endocrinological systems which evolved independently of each other. Psychological and neurobiological evidence, however, suggest that a competing theory requires attention. A theory of co-opting mother-infant bonding sometime in the recent evolutionary history of humans may partially account for the evolution of romantic love. I present a case for this theory and a new approach to the science of romantic love drawing on human psychological, neurobiological, and (neuro)endocrinological studies as well as animal studies. The hope is that this theoretical review, along with other publications, will generate debate in the literature about the merits of the theory of co-opting mother-infant bonding and a new evolutionary approach to the science of romantic love.

Microsocial analysis of dyadic interactions with toddlers and mothers with borderline personality disorder

Borderline personality disorder (BPD) is known for disruptions in mother-child interaction, but possible underlying patterns of micro-behavior are barely understood. This is the first study examining behavioral dyadic synchrony-the coordinated and reciprocal adaptation of behavior-and regulation on a micro-level and relating it to macro-behavior in mothers with BPD and their toddlers. Twenty-five mothers with BPD and 29 healthy mothers participated with their 18- to 36-month-old toddlers in a frustration-inducing paradigm. Mother and toddler behavior was continuously micro-coded for gaze, affect, and vocalization. Synchrony, operationalized as the simultaneous engagement in social gaze and positive affect, and (co-)regulative behaviors and their contingencies were analyzed and associated with borderline symptom severity, the overall quality of interaction, and child internalizing and externalizing behavioral problems. Dyads with mothers with BPD showed significantly less synchrony compared to dyads with healthy mothers. Low synchrony was associated with high BPD symptom severity and low overall interaction quality. Dyads with BPD used the same amount of regulative behaviors as dyads with healthy mothers. Though both groups equally responded to children's negative emotionality, mothers with BPD were less effective in drawing the dyad back into synchrony. For dyads with BPD, regulative behaviors were negatively associated with child externalizing behaviors. BPD symptomology may reduce the effectiveness of mothers' attempts to attune to their child's needs. An emphasis on synchrony and regulative behaviors may be an important therapeutic target for parenting programs in mothers with BPD.

Epigenetic modification of the oxytocin receptor gene is associated with child-parent neural synchrony during competition

Interpersonal neural synchrony (INS) occurs when neural electrical activity temporally aligns between individuals during social interactions. It has been used as a metric for interpersonal closeness, often during naturalistic child-parent interactions. This study evaluated whether other biological correlates of social processing predicted the prevalence of INS during child-parent interactions, and whether their observed cooperativity modulated this association. Child-parent dyads (n = 27) performed a visuospatial tower-building task in cooperative and competitive conditions. Neural activity was recorded using mobile electroencephalogram (EEG) headsets, and experimenters coded video-recordings post-hoc for behavioral attunement. DNA methylation of the oxytocin receptor gene (OXTRm) was measured, an epigenetic modification associated with reduced oxytocin activity and socioemotional functioning. Greater INS during competition was associated with lower child OXTRm, while greater behavioral attunement during competition and cooperation was associated with higher parent OXTRm. These differential relationships suggest that interpersonal dynamics as measured by INS may be similarly reflected by other biological markers of social functioning, irrespective of observed behavior. Children's self-perceived communication skill also showed opposite associations with parent and child OXTRm, suggesting complex relationships between children's and their parents' social functioning. Our findings have implications for ongoing developmental research, supporting the utility of biological metrics in characterizing interpersonal relationships.

Maternal Voice and Tactile Stimulation Modulate Oxytocin in Mothers of Hospitalized Preterm Infants: A Randomized Crossover Trial

Prematurity is a major risk factor for perinatal stress and neonatal complications leading to systemic inflammation and abnormal mother-infant interactions. Oxytocin (OT) is a neuropeptide regulating the inflammatory response and promoting mother-infant bonding. The release of this hormone might be influenced by either vocal or tactile stimulation. The main objective of the current randomized, crossover, clinical trial was to assess the salivary OT/cortisol balance in mothers following the exposure of their baby born preterm to two types of sensorial interventions: maternal voice without or with contingent tactile stimulation provided by the mother to her infant. Among the 26 mothers enrolled, maternal voice intervention alone had no effect on OT and cortisol levels in the mothers, but when associated with tactile stimulation, it induced a significant increase in maternal saliva oxytocin (38.26 ± 30.26 pg/mL before vs 53.91 ± 48.84 pg/mL after, p = 0.02), particularly in the mothers who delivered a female neonate. Maternal voice intervention induced a significant reduction in cortisol and an increase in OT levels in mothers when the maternal voice with a tactile stimulation intervention was performed first. In conclusion, exposure to the maternal voice with a contingent tactile stimulation was associated with subtle changes in the maternal hormonal balance between OT and cortisol. These findings need to be confirmed in a larger sample size and may ultimately guide caregivers in providing the best intervention to reduce parental stress following preterm delivery.

Theory of mind during pregnancy and postpartum: A systematic review

Pregnancy is associated with prominent structural changes in brain areas involved in Theory of Mind (ToM), pointing to the possibility of modifications in ToM-related behavior and brain responses in parents. We performed a systematic review screening for studies that examined ToM in pregnant and/or early postpartum parents. The evaluation of the included 12 studies allowed us to construct an overview of ToM changes during pregnancy and postpartum as well as other associated factors, such as oxytocin, mental health, and parental behavior. Four studies examined ToM changes by comparing pregnant/early postpartum parents with nulliparous parents or prepregnancy measures. They reported no differences between groups measured with a self-report questionnaire but found group differences using an experimental approach. The results from the summarized studies further suggest a mediatory role of oxytocin between ToM and certain parental behavior. In addition, while no link between postpartum depression and ToM was observed, findings do point to an association between depressive and remote maternal behavior and anxious attachment style and ToM abilities in pregnant participants. Research findings regarding the interaction of ToM with both parity and maternal attachment to the fetus are ambivalent. Overall, research on this topic is scarce, limiting our ability to draw firm conclusions and stressing the need for further research on this topic. This review presents an overview of research findings on ToM and associated factors in pregnancy and the postpartum period and discusses directions for future research.

The evolved nest, oxytocin functioning, and prosocial development

Prosociality, orientation to attuned, empathic relationships, is built from the ground up, through supportive care in early life that fosters healthy neurobiological structures that shape behavior. Numerous social and environmental factors within early life have been identified as critical variables influencing child physiological and psychological outcomes indicating a growing need to synthesize which factors are the most influential. To address this gap, we examined the influence of early life experiences according to the evolved developmental niche or evolved nest and its influence on child neurobiological and sociomoral outcomes, specifically, the oxytocinergic system and prosociality, respectively. To-date, this is the first review to utilize the evolved nest framework as an investigatory lens to probe connections between early life experience and child neurobiological and sociomoral outcomes. The evolved nest is comprised of characteristics over 30 million years old and is organized to meet a child's basic needs as they mature. Converging evidence indicates that humanity's evolved nest meets the needs of a rapidly developing brain, optimizing normal development. The evolved nest for young children includes soothing perinatal experiences, breastfeeding, positive touch, responsive care, multiple allomothers, self-directed play, social embeddedness, and nature immersion. We examined what is known about the effects of each evolved nest component on oxytocinergic functioning, a critical neurobiological building block for pro-sociomorality. We also examined the effects of the evolved nest on prosociality generally. We reviewed empirical studies from human and animal research, meta-analyses and theoretical articles. The review suggests that evolved nest components influence oxytocinergic functioning in parents and children and help form the foundations for prosociality. Future research and policy should consider the importance of the first years of life in programming the neuroendocrine system that undergirds wellbeing and prosociality. Complex, interaction effects among evolved nest components as well as among physiological and sociomoral processes need to be studied. The most sensible framework for examining what builds and enhances prosociality may be the millions-year-old evolved nest.

Providing or receiving alloparental care promote partner preference and alter central oxytocin and dopamine systems in adult mandarin voles

Juveniles of cooperative breeding species usually remain in the natal area and provide care to younger siblings, a behavior considered one form of alloparenting in the natural condition. Previous studies have demonstrated the effects of providing or receiving alloparental care on adult behaviors, including anxiety-like behavior, social interaction, and parental behavior, but little is known about the influences on species-typical bonding behaviors, such as pair-bond formation. In this study, we explored this concept using socially monogamous mandarin voles (Lasiopodomys mandarinus). As the oxytocin (OT) and dopamine systems are involved in alloparental and pair-bonding behaviors, we also examined the levels of central OT and tyrosine hydroxylase (TH), as well as OT receptor (OTR) and dopamine D1-type and D2-type receptors (D1R and D2R) mRNA expression in the nucleus accumbens (NAcc) and amygdala to investigate the underlying mechanisms. Our results show that mandarin voles providing alloparental care to younger siblings displayed facilitation of partner preference formation, lower levels of OT expression in the paraventricular nucleus of the hypothalamus (PVN) and lateral hypothalamus (LH), and increased OTR and D2R mRNA expression in the NAcc compared to controls. Individuals receiving alloparental care also demonstrated facilitation of partner preference formation in adult voles. Additionally, alloparental care enhanced OT expression in the PVN, anterior medial preoptic nucleus (MPOAa), medial amygdala (MeA), and TH expression in the ventral tegmental area (VTA) and zona incerta (ZI). Furthermore, males displayed decreased D1R mRNA expression in the NAcc, whereas females showed slightly increased D2R expression in the amygdala. These results demonstrate that providing or received alloparental care can promote partner preference formation in monogamous species and that these changes are associated with altered OT and dopamine levels and their receptors in specific brain regions.

The neurobiology of hatred: Tools of Dialogue© intervention for youth reared amidst intractable conflict impacts brain, behaviour, and peacebuilding attitudes

Myths, drama, and sacred texts have warned against the fragile nature of human love; the closer the affiliative bond, the quicker it can turn into hatred, suggesting similarities in the neurobiological underpinnings of love and hatred. Here, I offer a theoretical account on the neurobiology of hatred based on our model on the biology of human attachments and its three foundations; the oxytocin system, the "affiliative brain", comprising the neural network sustaining attachment, and biobehavioural synchrony, the process by which humans create a coupled biology through coordinated action. These systems mature in mammals in the context of the mother-infant bond and then transfer to support life within social groups. During this transition, they partition to support affiliation and solidarity to one's group and fear and hatred towards out-group based on minor variations in social behaviour. I present the Tools of Dialogue© intervention for outgroup members based on social synchrony. Applied to Israeli and Palestinian youth and implementing RCT, we measured social behaviour, attitudes, hormones, and social brain response before and after the 8-session intervention. Youth receiving the intervention increased reciprocity and reduced hostile behaviour towards outgroup, attenuated the neural marker of prejudice and increased neural empathic response, reduced cortisol and elevated oxytocin, and adapted attitudes of compromise. These neural changes predicted peacebuilding support 7 years later, when young adults can engage in civil responsibilities. Our intervention, the first to show long-term effects of inter-group intervention on brain and behaviour, demonstrates how social synchrony can tilt the neurobiology of hatred towards the pole of affiliation.

Functional relationships between estradiol and paternal care in male red-bellied lemurs, Eulemur rubriventer

Fathers contribute substantially to infant care, yet the mechanisms facilitating paternal bonding and interactions with infants are not as well understood as they are in mothers. Several hormonal changes occur as males transition into parenthood, first in response to a partner's pregnancy, and next in response to interacting with the newborn. These changes may prepare fathers for parenting and help facilitate and maintain paternal care. Experimental studies with monkeys and rodents suggest that paternal care requires elevated estradiol levels, which increase when a male's partner is pregnant and are higher in fathers than non-fathers, but its role in the expression of paternal behaviors throughout infant development is unknown. To assess estradiol's role in paternal care, we analyzed the relationship between paternal estradiol metabolites and 1) offspring age, and 2) paternal care behavior (holding, carrying, huddling, playing, grooming), in wild, red-bellied lemurs (Eulemur rubriventer). We collected 146 fecal samples and 1597 h of behavioral data on 10 adult males who had newborn infants during the study. Estradiol metabolites increased four-fold in expectant males, and in new fathers they fluctuated and gradually decreased with time. Infant age, not paternal behavior, best predicted hormone levels in new fathers. These results suggest that hormonal changes occur in expectant males with facultative paternal care, but they do not support the hypothesis that estradiol is directly associated with the day-to-day expression of paternal care. Future research should explore estradiol's role in facilitating behaviors, including infant-directed attention and responsiveness, or preparing fathers for infant care generally.

Development of the Paternal Brain in Humans throughout Pregnancy

Previous studies have demonstrated that paternal caregiving behaviors are reliant on neural pathways similar to those supporting maternal care. Interestingly, a greater variability exists in parental phenotypes in men than in women among individuals and mammalian species. However, less is known about when or how such variability emerges in men. We investigated the longitudinal changes in the neural, hormonal, and psychological bases of expression of paternal caregiving in humans throughout pregnancy and the first 4 months of the postnatal period. We measured oxytocin and testosterone, paternity-related psychological traits, and neural response to infant-interaction videos using fMRI in first-time fathers and childless men at three time points (early to mid-pregnancy, late pregnancy, and postnatal). We found that paternal-specific brain activity in prefrontal areas distinctly develops during middle-to-late pregnancy and is enhanced in the postnatal period. In addition, among fathers, the timing of the development of prefrontal brain activity was associated with specific parenting phenotypes.

Proximate and Ultimate Mechanisms of Human Father-child Rough-and-tumble Play

The aim of this contribution is to attempt to understand the adaptive functions of father-child rough-and-tumble play (RTP) in humans. We first present a synthesis of the known proximate and ultimate mechanisms of peer-peer RTP in mammals and compare human parent-child RTP with peer-peer RTP. Next, we examine the possible biological adaptive functions of father-child RTP in humans, by comparing paternal behavior in humans versus biparental animal species, in light of the activation relationship theory and the neurobiological basis of fathering. Analysis of analogies reveals that the endocrine profile of fathers is highly variable across species, compared to that of mothers. This can be interpreted as fathers' evolutionary adjustment to specific environmental conditions affecting the care of the young. Given the high unpredictability and risk-taking features of RTP, we conclude that human adult-child RTP appears to have a biological adaptive function, one of 'opening to the world'.

Influence of oxytocin on parenting behaviors and parent-child bonding: A systematic review

Oxytocin (OT) plays a pivotal role in early parent-child relationship formation and bonding that is critical for the social, cognitive, and emotional development of the child. Therefore, this systematic review aims to consolidate all available evidence regarding the associations of parental OT concentration levels with parenting behavior and bonding within the past 20 years. A systematic search was conducted in five databases from 2002 to May 2022, and 33 studies were finalized and included. Due to the heterogeneity of the data, findings were presented narratively based on the type of OT and parenting outcomes. Current evidence strongly suggests that parental OT levels are positively related to parental touch and parental gaze and affect synchrony and observer-coded parent-infant bonding. No gender difference in OT levels was observed between fathers and mothers, but OT strengthens affectionate parenting in mothers and stimulatory parenting in fathers. Child OT levels were also positively associated with parental OT levels. Family and healthcare providers could encourage more positive touch and interactive play between parent and child to strengthen parent-child relationships.

Therapeutic touch and therapeutic alliance in pediatric care and neonatology: An active inference framework

Therapeutic affective touch has been recognized as essential for survival, nurturing supportive interpersonal interactions, accelerating recovery-including reducing hospitalisations, and promoting overall health and building robust therapeutic alliances. Through the lens of active inference, we present an integrative model, combining therapeutic touch and communication, to achieve biobehavioural synchrony. This model speaks to how the brain develops a generative model required for recovery, developing successful therapeutic alliances, and regulating allostasis within paediatric manual therapy. We apply active inference to explain the neurophysiological and behavioural mechanisms that underwrite the development and maintenance of synchronous relationships through touch. This paper foregrounds the crucial role of therapeutic touch in developing a solid therapeutic alliance, the clinical effectiveness of paediatric care, and triadic synchrony between health care practitioner, caregiver, and infant in a variety of clinical situations. We start by providing a brief overview of the significance and clinical role of touch in the development of social interactions in infants; facilitating a positive therapeutic alliance and restoring homeostasis through touch to allow a more efficient process of allostatic regulation. Moreover, we explain the role of CT tactile afferents in achieving positive clinical outcomes and updating prior beliefs. We then discuss how touch is implemented in treatment sessions to promote cooperative interactions in the clinic and facilitate theory of mind. This underwrites biobehavioural synchrony, epistemic trust, empathy, and the resolution of uncertainty. The ensuing framework is underpinned by a critical application of the active inference framework to the fields of pediatrics and neonatology.

Oxytocin Levels Increase and Anxiety Decreases in Mothers Who Sing and Talk to Their Premature Infants during a Painful Procedure

(1) Background: Preterm infants spend their first weeks of life in the hospital partially separated from their parents and subjected to frequent potentially painful clinical procedures. Previous research has found that early vocal contact reduces infant pain perception while simultaneously increasing oxytocin (OXT) levels. The current study aims to assess the effect of maternal singing and speaking on mothers. (2) Methods: During a painful procedure over two days, twenty preterm infants were randomly exposed to their mother's live voice (speaking or singing). Maternal OXT levels were measured twice: before and after singing, as well as before and after speaking. The anxiety and resilience responses of mothers were studied before and after the two-day interventions, regardless of the speaking/singing condition. OXT levels in mothers increased in response to both singing and speech. Concurrently, anxiety levels decreased, but no significant effects on maternal resilience were found. (3) Conclusions: OXT could be identified as a key mechanism for anxiety regulation in parents, even in sensitive care situations, such as when their infant is in pain. Active involvement of parents in the care of their preterm infants can have a positive effect on their anxiety as well as potential benefits to their sensitivity and care abilities through OXT.

[How oxytocin became overtime the attachment-mediating hormone]

Oxytocin is a pleiotropic molecule which, in addition to its facilitating action during parturition and milk ejection, is involved in social and prosocial behaviors such as attachment. This article presents, after a brief historical review, the action of oxytocin during the milk ejection reflex. Oxytocin is indeed essential for this vital function in mammals. It is both a neurohormone released into the bloodstream by the axon terminals of the posterior pituitary and a neuromodulator released in the hypothalamus by the soma and dendrites of oxytocinergic magnocellular neurons. In addition, oxytocin is also released by the axon terminals of parvocellular neurons and axon collaterals of magnocellular neurons in the brain. Both maternal attachment in rats and ewes and attachment between sexual partners in the prairie vole, one of the few monogamous rodent species, are mediated by central oxytocin. However, neither administering oxytocin into the brain nor increasing expression of the oxytocin receptor in the nucleus accumbens using a gene transfer technique converts polygamous voles to monogamous ones. Unfortunately, translation of animal data to human remains problematic due to still unsolved difficulties in modifying the level of oxytocin in the brain.

[Oxytocin: a new target for neuroprotection?]

Every year, 30 million infants worldwide are delivered after intra-uterine growth restriction (IUGR) and 15 million are born preterm. These two conditions are the leading causes of ante-/perinatal stress and brain injury responsible for neurocognitive and behavioral disorders affecting more than 9 million children each year. Most pharmacological candidates to prevent perinatal brain damage have failed to demonstrate substantial benefits. In contrast, environment enrichment based on developmental care, skin-to-skin contact and vocal/music exposure appear to exert positive effects on brain structure and function. However, mechanisms underlying these effects remain unknown. There is strong evidence that an adverse environment during pregnancy and the neonatal period can influence hormonal responses of the newborn with long-lasting neurobehavioral consequences in infancy and adulthood. In particular, excessive cortisol release in response to perinatal stress associated with prematurity or IUGR is recognized to induce brain-programming effects and neuroinflammation, a key predictor of subsequent neurological impairments. These deleterious effects are known to be balanced by oxytocin (OT), a neuropeptide released by the hypothalamus, which plays a role during the perinatal period and in social behavior. In addition, preclinical studies suggest that OT is able to regulate the central inflammatory response to injury in the adult brain. Using a rodent model of IUGR associated with developing white matter damage, we recently reported that carbetocin, a brain permeable OT receptor (OTR) agonist, induced a significant reduction of activated microglia, the primary immune cells of the brain. Moreover, this reduced microglia reactivity was associated with long-term neuroprotection. These findings make OT a promising candidate for neonatal neuroprotection through neuroinflammation regulation. However, the mechanisms linking endogenous OT and central inflammation response to injury have not yet been established. Further studies are needed to assess the protective role of OT in the developing brain through modulation of microglial activation, a key feature of brain injury observed in infants born preterm or growth-restricted. They are expected to have several impacts in the near future not only for improving knowledge of microglial cell physiology and reactivity during brain development, but also to design clinical trials testing interventions associated with endogenous OT release as a relevant strategy to alleviate neuroinflammation in neonates.

The positive effect of mother-performed infant massage on infantile eczema and maternal mental state: A randomized controlled trial

Objective

To observe the influence of MPIM on infantile eczema, quality of life, growth and maternal mental state.

Methods

This trial was a randomized controlled study. Sixty-six full-term infants with eczema were randomly divided into eczema control group (EC group, n = 33) and eczema with MPIM group (EM group, n = 33), along with healthy full-term infants in the healthy control group (HC group, n = 31). The mothers in the EC group received the instruction of routine care, while the mothers in the EM group applied massage on the infants plus receiving the same instruction of the routine care. HC group received none of any specific intervention. Data were collected in the three groups at the baseline and at the end of 2- and 5-month intervention. Before and at the end of 2-month intervention, the following indexes were investigated in infants including the growth indexes, eczema area severity index (EASI), infantile dermatitis quality of life index (IDQOL). And the scores of self-rating anxiety scale (SAS) and self-rating depression scale (SDS) were investigated in mothers at the same timepoints. At the end of 5-month intervention, the infants' growth and relapse condition of eczema were observed.

Results

Overall, 31 cases in HC group, 31 in EC group and 32 in EM group were included for data analysis. There were no significant differences in the indexes of infantile growth among the three groups (all P >0.05). The scores of EASI and IDQOL significantly lowered (both P < 0.001) in EC group following the instruction of routine care, along with reduced maternal scores of SAS and SDS (both P < 0.05). Compared with the EC group, the EM group showed significantly lower scores of EASI and IDQOL (both P < 0.001) and lower relapse rate (P < 0.01) in infants with eczema, along with significantly lower scores of SAS and SDS in mothers (both P < 0.01). Moreover, none of obvious adverse reaction was reported following MPIM, to which most of the mothers could adhere.

Conclusion

MPIM could effectively promote the remission of infantile eczema and reduce its relapse, along with relieving maternal anxiety and depression mood.

Clinical trial registration

Identifier: ChiCTR2200066246.

Advances in human oxytocin measurement: challenges and proposed solutions

Oxytocin, a neuropeptide known for its role in reproduction and socioemotional processes, may hold promise as a therapeutic agent in treating social impairments in patient populations. However, research has yet to uncover precisely how to manipulate this system for clinical benefit. Moreover, inconsistent use of standardized and validated oxytocin measurement methodologies-including the design and study of hormone secretion and biochemical assays-present unresolved challenges. Human studies measuring peripheral (i.e., in plasma, saliva, or urine) or central (i.e., in cerebrospinal fluid) oxytocin concentrations have involved very diverse methods, including the use of different assay techniques, further compounding this problem. In the present review, we describe the scientific value in measuring human endogenous oxytocin concentrations, common issues in biochemical analysis and study design that researchers face when doing so, and our recommendations for improving studies using valid and reliable methodologies.

Hormonal and behavioral responses to an infant simulator in women with and without children

We investigated the impact of maternal status on hormonal reactivity and behavioral responses to an infant simulator in 117 women (54 primiparous, 63 nulliparous). The amount of affectionate touch and motherese were analyzed as behavioral measures of caregiving. Saliva was collected before and 10 min after interaction with the infant simulator to analyze oxytocin, testosterone, cortisol, and estradiol levels. Nulliparous women also provided information about their fertility motivation. Linear mixed models indicated that greater use of affectionate touch was associated with lower overall testosterone levels. Cortisol decreased in response to the interaction in both groups. In the primiparous group, the amount of affectionate touch associated inversely with cortisol levels, whereas in the nulliparous group such association was not found. Oxytocin or estradiol reactivity to the simulator did not differ between the groups, nor were these hormones associated with behavior. Higher fertility motivation in nulliparous women was related to more motherese, and lower testosterone levels. Our results indicate that the simulator elicits hormonal reactivity both in mothers and nonmothers, but the patterns of associations between caregiving behavior and hormonal levels may be partially different. These results encourage using the infant simulator to explore hormonal processes related to the transition to parenthood.

Activation of oxytocin receptors in mouse GABAergic amacrine cells modulates retinal dopaminergic signaling

Background

Oxytocin, secreted by oxytocin neurons in the hypothalamus, is an endogenous neuropeptide involved in modulating multiple sensory information processing pathways, and its roles in the brain have been associated with prosocial, maternal, and feeding-related behaviors. Visual information is necessary for initiating these behaviors, with the retina consisting of the first stage in the visual system mediating external stimulus perception. Oxytocin has been detected in the mammalian retina; however, the expression and possible function of oxytocin receptors (OxtR) in the retina remain unknown. Here, we explore the role of oxytocin in regulating visual information processing in the retina.

Results

We observed that OxtR mRNA and protein are expressed in the mouse retina. With Oxtr-Cre transgenic mice, immunostaining, and fluorescence in situ hybridization, we found that OxtRs are mainly expressed in GABAergic amacrine cells (ACs) in both the inner nuclear layer (INL) and ganglion cell layer (GCL). Further immunoreactivity studies showed that GABAergic OxtR⁺ neurons are mainly cholinergic and dopaminergic neurons in the INL and are cholinergic and corticotrophin-releasing hormone neurons in the GCL. Surprisingly, a high level of Oxtr mRNAs was detected in retinal dopaminergic neurons, and exogenous oxytocin application activated dopaminergic neurons to elevate the retinal dopamine level. Relying on in vivo electroretinographic recording, we found that activating retinal OxtRs reduced the activity of bipolar cells via OxtRs and dopamine receptors.

Conclusions

These data indicate the functional expression of OxtRs in retinal GABAergic ACs, especially dopaminergic ACs, and expand the interactions between oxytocinergic and dopaminergic systems. This study suggests that visual perception, from the first stage of information processing in the retina, is modulated by hypothalamic oxytocin signaling.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12915-022-01405-0.

Parent-Performed Infant Massage for Improving Parental Mental State Within 18 Months Postpartum: A Systematic Review

The aim of the current review was to assess whether parent-performed infant massage (PPIM) could effectively improve the mental state of parents during the postpartum period. Several international electronic databases were thoroughly searched for relevant articles. Included studies observed the influence of PPIM on the mental state of parents of healthy full-term infants within 18 months postpartum or medically stable preterm infants during hospitalization after birth. Nine studies were included, which observed one or more aspects of parental mental state, including depression, anxiety, parental stress, or general mood state. Characteristics of participants, massage protocols, and outcome measures were heterogenous; hence, results regarding the influence of PPIM on parental mental state were inconsistent. Upon further investigation, 10-minute, home-based PPIM for at least 4 weeks is advisable for maternal depression within 5 months postpartum. Moreover, PPIM in a neonatal intensive care unit is advisable for improving the general mood of mothers of preterm infants. Additional methodologically rigorous studies are needed to provide stronger evidence. [Journal of Psychosocial Nursing and Mental Health Services, 61(4), 52-59.].

Altered hormonal patterns in borderline personality disorder mother-child interactions

BACKGROUND

Oxytocin, cortisol, and testosterone are involved in the processing of reward and stress and greatly influence mother-child interactions. Altered hormonal systems have been associated with borderline personality disorder (BPD), a disorder characterized by interpersonal deficits. Mothers with BPD tend to perceive interactions with the child as less rewarding and more stressful and interactions are often less reciprocal and have more negative states (i.e. constricted, tense, uncoordinated behaviors). Their children are at elevated risk for psychopathologies. Here, we studied underlying hormonal mechanisms of disrupted mother-child interaction in BPD.

METHODS

Twenty-five mothers with BPD and 29 healthy mothers with their 18- to 36-month-old toddlers participated in a free-play mother-child interaction, which was evaluated with the Coding Interactive Behavior (CIB) Manual. Maternal blood samples were analyzed at baseline for oxytocin, cortisol, and testosterone, and after interaction for oxytocin and cortisol.

RESULTS

Oxytocin decreased and cortisol remained unchanged in mothers with BPD while healthy mothers showed stable oxytocin and decreased cortisol after interaction. Testosterone basal levels were significantly higher in mothers with BPD. Cortisol reactivity and testosterone levels mediated the association between maternal BPD and dyadic negative states during interaction.

CONCLUSIONS

These findings suggest that alterations in oxytocin, cortisol, and testosterone contribute to disruptions in mother-child interaction in BPD. Interacting with their child might not result in reward and relief of stress in mothers with BPD in the same way as in healthy mothers. Further research is needed to understand more about dyadic bio-behavioral processes in order to provide targeted parenting support. This could break the cycle of transgenerational transmission and improve maternal and child well-being.