Effects Of Early Life Experiences Research Articles

Transgenerational disruption of functional 5-HT1AR-induced connectivity in the adult mouse brain by traumatic stress in early life.

Traumatic stress in early life is a strong risk factor for psychiatric disorders that can affect individuals across several generations. Although the underlying mechanisms have been proposed to implicate serotonergic transmission in the brain, the neural circuits involved remain poorly delineated. Using pharmacological functional magnetic resonance imaging in mice, we demonstrate that traumatic stress in postnatal life alters 5-HT1A receptor-evoked local and global functions in both, the exposed animals and their progeny when adult. Disrupted functional connectivity is consistent across generations and match limbic circuits implicated in mood disorders, but also networks not previously linked to traumatic stress. These findings underscore the neurobiology and functional mapping of transgenerational effects of early life experiences.

Development of Odor Hedonics: Experience-Dependent Ontogeny of Circuits Supporting Maternal and Predator Odor Responses in Rats.

A major component of perception is hedonic valence: perceiving stimuli as pleasant or unpleasant. Here, we used early olfactory experiences that shape odor preferences and aversions to explore developmental plasticity in circuits mediating odor hedonics. We used 2-deoxyglucose autoradiographic mapping of neural activity to identify circuits differentially activated by biologically relevant preferred and avoided odors across rat development. We then further probed this system by increasing or decreasing hedonic value. Using both region of interest and functional connectivity analyses, we identified regions within primary olfactory, amygdala/hippocampal, and prefrontal cortical networks that were activated differentially by maternal and male odors. Although some activated regions remained stable across development (postnatal days 7-23), there was a developmental emergence of others that resulted in an age-dependent elaboration of hedonic-response-specific circuitry despite stable behavioral responses (approach/avoidance) to the odors across age. Hedonic responses to these biologically important odors were modified through diet suppression of the maternal odor and co-rearing with a male. This allowed assessment of hedonic circuits in isolation of the specific odor quality and/or intensity. Early experience significantly modified odor-evoked circuitry in an age-dependent manner. For example, co-rearing with a male, which induced pup attraction to male odor, reduced activity in amygdala regions normally activated by the unfamiliar avoided male odor, making this region more consistent with maternal odor. Understanding the development of odor hedonics, particularly within the context of altered early life experience, provides insight into the development of sensory processes, food preferences, and the formation of social affiliations, among other behaviors. Odor hedonic valence controls approach-avoidance behaviors, but also modulates ongoing behaviors ranging from food preferences and social affiliation with the caregiver to avoidance of predator odors. Experiences can shape hedonic valence. This study explored brain circuitry involved in odor hedonic encoding throughout development using maternal and predator odors and assessed the effects of early life experience on odor hedonic encoding by increasing/decreasing the hedonic value of these odors. Understanding the role of changing brain circuitry during development and its impact on behavioral function is critical for understanding sensory processing across development. These data converge with exciting literature on the brain's hedonic network and highlight the significant role of early life experience in shaping the neural networks of highly biologically relevant stimuli.

Adaptive Use of Information during Growth Can Explain Long-Term Effects of Early Life Experiences.

Development is a continuous process during which individuals gain information about their environment and adjust their phenotype accordingly. In many natural systems, individuals are particularly sensitive to early life experiences, even in the absence of later constraints on plasticity. Recent models have highlighted how the adaptive use of information can explain age-dependent plasticity. These models assume that information gain and phenotypic adjustments either cannot occur simultaneously or are completely independent. This assumption is not valid in the context of growth, where finding food results both in a size increase and learning about food availability. Here, we describe a simple model of growth to provide proof of principle that long-term effects of early life experiences can arise through the coupled dynamics of information acquisition and phenotypic change in the absence of direct constraints on plasticity. The increase in reproductive value from gaining information and sensitivity of behavior to experiences declines across development. Early life experiences have long-term impacts on age of maturity, yet-due to compensatory changes in behavior-our model predicts no substantial effects on reproductive success. We discuss how the evolution of sensitive windows can be explained by experiences having short-term effects on informational and phenotypic states, which generate long-term effects on life-history decisions.

Code and simulation data from: Adaptive use of information during growth can explain long-term effects of early-life experiences. American Naturalist, Github Repository.

Code and simulation data from: Adaptive use of information during growth can explain long-term effects of early-life experiences. American Naturalist, Github Repository.

Perinatal and juvenile social environments interact to shape cognitive behaviour and neural phenotype in prairie voles.

Social environments experienced at different developmental stages profoundly shape adult behavioural and neural phenotypes, and may have important interactive effects. We asked if social experience before and after weaning influenced adult social cognition in male prairie voles. Animals were raised either with or without fathers and then either housed singly or in sibling pairs. Males that were socially deprived before (fatherless) and after (singly housed) weaning did not demonstrate social recognition or dissociate spatial from social information. We also examined oxytocin and vasopressin receptors (OTR and V1aR) in areas of the forebrain associated with social behaviour and memory. Pre- and post-wean experience differentially altered receptor expression in several structures. Of note, OTR in the lateral septum-an area in which oxytocin inhibits social recognition-was greatest in animals that did not clearly demonstrate social recognition. The combination of absentee fathers on V1aR in the retrosplenial cortex and single housing on OTR in the septohippocampal nucleus produced a unique phenotype previously found to be associated with poor reproductive success in nature. We demonstrate that interactive effects of early life experiences throughout development have tremendous influence over brain-behaviour phenotype and can buffer potentially negative outcomes due to social deprivation.

Coping Expectancies, Not Enhancement Expectancies, Mediate Trauma Experience Effects on Problem Alcohol Use: A Prospective Study From Early Childhood to Adolescence.

The relationship between experiencing trauma and increased alcohol consumption has been well established. Exposure to childhood trauma has been linked to both early onset of drinking and problematic substance use. However, the mechanisms underlying this relationship remain unclear. The results of early work suggested that drinking to relieve negative affect (i.e., drinking to cope) was driving this connection. However, the findings of more recent work suggest that drinking might be used to enhance positive affect as a way of addressing the aftereffects of early trauma. The current study looked at these two drinking expectancies as indirect pathways between the experience in early childhood of living in a home with parental violence and peak alcohol use in emerging adulthood. Participants were 1,064 children and their parents involved in a longitudinal community study of children at high risk for the development of alcoholism and a community contrast group of those at lower risk. Baseline assessment was at age 3-5 years, self-reports of internalizing behavior and drinking expectancies were obtained at age 12-14, and drinking measures were assessed at age 18-20. Results indicated that coping expectancy was a mediator of the relationship between early childhood trauma and later peak alcohol use, whereas enhancement expectancy was not. Children living in homes with parental violence were more likely to develop ineffective coping strategies, such as using alcohol to decrease negative affect. These results support the self-medication theory. They also demonstrate the long-term effects of early life experience on drinking behavior in early adulthood.

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Propagation of maternal behavior across generations is associated with changes in non-maternal cognitive and behavioral processes

Over a number of years we have studied the phenomenology of maternal behavior from endocrine, neural, experiential, and ontogenetic perspectives. Here, we focus on the effects of early life experiences with and without the mother on subsequent maternal and non-maternal behaviors of the offspring. We have used an artificial rearing procedure, which entails removing rat pups from their mother and raising them in isolation, while controlling and manipulating several aspects of their upbringing. As adults, mother-reared (MR) and artificially-reared (AR) rats are assessed on their own maternal behavior, as well several other behaviors. While both AR and MR rats nurse and successfully wean their young, the AR rats spend less time licking, grooming, and crouching over their young. Hence, being raised in social isolation does not seem to affect primary maternal motivational dynamics. Instead, isolation rearing produces alterations in the ongoing execution of the behavior and its effective organization. Here, we present evidence that changes in maternal behavior, as a result of social isolation from mother and siblings, are due to changes in top-down (e.g., sustained attention, flexibility) and bottom-up process (e.g., increased stimulus-driven behavior). These changes are likely due to alterations in brain dopamine systems, which are sensitive to early life manipulations and are modulators of bottom-up and top-down processes. Finally, we draw parallels between the rat and human maternal behavior.This article is part of a Special Issue entitled: In Honor of Jerry Hogan.

Examining negative effects of early life experiences on reproductive and sexual health among female sex workers in Tijuana, Mexico

Examining negative effects of early life experiences on reproductive and sexual health among female sex workers in Tijuana, Mexico

Sexually dimorphic effects of early life experience and adolescent Δ-9-tetrahydrocannabinol exposure in the rat

Sexually dimorphic effects of early life experience and adolescent Δ-9-tetrahydrocannabinol exposure in the rat

Examining negative effects of early life experiences on reproductive and sexual health among female sex workers in Tijuana, Mexico

ObjectiveTo explore experiences during childhood and adolescence that influenced reproductive and sexual health among women who had entered the sex industry in adolescence. MethodsA qualitative study was conducted using information provided by 25 female sex workers (FSWs) from Tijuana, Mexico, who reported entering the sex industry when younger than 18years. In-depth, semi-structured interviews were conducted with all participants between January 31, 2011, and July 8, 2011. ResultsFour interrelated themes that shaped health experiences—early sexual abuse, early illicit drug use, ongoing violence, and limited access to reproductive and sexual health care—were identified. Participants reporting these experiences were at risk of unintended teenaged pregnancy, spontaneous abortion or stillbirth, and untreated sexually transmitted infections. ConclusionPrograms and policies that address social, structural, and individual vulnerabilities during adolescence and adulthood are required to promote reproductive and sexual health among FSWs in Tijuana, Mexico.

S.12.03 Effect of early life experiences on brain structure and function: neurogenesis and decision making

S.12.03 Effect of early life experiences on brain structure and function: neurogenesis and decision making

Enriched Early Life Experiences Reduce Adult Anxiety-Like Behavior in Rats: A Role for Insulin-Like Growth Factor 1

Early life experiences can affect brain development, contributing to shape interindividual differences in stress vulnerability and anxiety-like behavior. In rodents, high levels of maternal care have long-lasting positive effects on the behavior of the offspring and stress response; post-weaning rearing in an enriched environment (EE) or massage counteract the negative effects of maternal separation or prenatal stressors. We recently found that insulin-like growth factor 1 (IGF-1) is a key mediator of early EE or massage on brain development. Whether early enrichment of experience can induce long-lasting effects on anxiety-like behavior and whether IGF-1 is involved in these effects is not known. We assessed anxiety-like behavior by means of the elevated plus maze in control adult rats and in adult rats subjected to early EE or to massage. We found that both EE and massage reduced adult anxiety-like behavior. Early IGF-1 systemic injections in rat pups reared in standard condition mimic the effects of EE and massage, reducing anxiety-like behavior in the adult; blocking early IGF-1 action in massaged and EE animals prevents massage and EE effects. In EE and IGF-1-treated animals, we assessed the hippocampal expression of glucocorticoid receptors (GRs) at postnatal day 12 (P12) and P60, finding a significantly higher GR expression at P60 for both treatments. These results suggest that IGF-1 could be involved in mediating the long-lasting effects of early life experiences on vulnerability/resilience to stress in adults.

Adverse Childhood Experiences and Adult Criminality: How Long Must We Live before We Possess Our Own Lives?

Empirical research associated with the Kaiser Permanente and Centers for Disease Control and Prevention Adverse Childhood Experiences (ACE) Study has demonstrated that ACE are associated with a range of negative outcomes in adulthood, including physical and mental health disorders and aggressive behavior. Subjects from 4 different offender groups (N = 151) who were referred for treatment at an outpatient clinic in San Diego, CA, subsequent to conviction in criminal court, completed the ACE Questionnaire. Groups (nonsexual child abusers, domestic violence offenders, sexual offenders, and stalkers) were compared on the incidence of ACE, and comparisons were made between the group offenders and a normative sample. Results indicated that the offender group reported nearly four times as many adverse events in childhood than an adult male normative sample. Eight of ten events were found at significantly higher levels among the criminal population. In addition, convicted sexual offenders and child abusers were more likely to report experiencing sexual abuse in childhood than other offender types. On the basis of a review of the literature and current findings, criminal behavior can be added to the host of negative outcomes associated with scores on the ACE Questionnaire. Childhood adversity is associated with adult criminality. We suggest that to decrease criminal recidivism, treatment interventions must focus on the effects of early life experiences.

Effects of Early Life Experiences on Brain Development of Premature Babies Admitted in Neonatal Intensive Care Unit

Infancy is the most crucial time period in children’s life during which babies require sensitive and responsive care-giving from their primary caregivers for their overall growth and development. Sick preterm babies, who require admission at Neonatal Intensive Care Unit (NICU) and experience physical separation from their parents during early days of their lives, are at high risk to encounter toxic stress that can be detrimental for their developing brains, overall development and stress regulatory mechanism in later life. This paper presents case study of a preterm baby who encountered toxic stress due to the effects of disease process, physical separation from primary caregivers, painful procedures at NICU, as well as bright and noisy environment of NICU. In the light of the presented case study and reviewed literature, modifications in the NICU environment are suggested to reduce the sources of toxic stress on the developing brains of premature babies. Role of lactation support for mothers of preterm babies, kangaroo mother care, and neurodevelopmental care in the NICU environment is highlighted to assure growth promotion, brain development, infant-mother bonding, and better cognitive functions among premature babies.

P.2.009 Effect of early life experiences on brain structure and function: neurogenesis and decision making

Several studies have been carried out to investigate the effect of child maltreatment on juvenile justice involvement and future criminal life. However, little is known about the impact of other forms of adversity, beyond abuse and neglect, on juvenile delinquency and criminal persistence. The effect of early adversity on psychosocial problems is underexplored, particularly in juvenile delinquents. This study, using the Childhood Adverse Experiences (ACE) questionnaire, a tool accessing the exposure to different types of abuse, neglect and serious household dysfunction, explored the role of each adverse experience on juvenile justice involvement, persistence in crime and psychosocial problems during young adulthood. A Portuguese sample of 75 young adults with official records of juvenile delinquency in 2010/2011, and 240 young adults from a community sample completed ACE questionnaire and measures of psychosocial adjustment. Seven out of ten adverse experiences were significantly more prevalent in young adults with juvenile justice involvement than in the community sample, after matching the main demographic variables. The strongest predictor of juvenile justice involvement and criminal persistence during early adulthood was sexual abuse. Dimensions of child/adolescent emotional maltreatment and a mental illness in the household predicted a set of psychosocial problems in young adulthood. This study indicates that early adversity is significantly related to juvenile justice involvement, criminal persistence and psychosocial problems. This study also suggests that each experience has a different role in this process. There is an urgent need to screen, prevent and stop serious adversity. Future scientific directions and recommendations for policies are provided.

Early environments, glucocorticoid receptors, and behavioral epigenetics.

In 1985, a brief report published in Behavioral Neuroscience established the link between neonatal handling and concentrations of hippocampal glucocorticoid receptors (GR) in the adult rat, suggesting a neurobiological basis for the attenuated stress reactivity observed in handled versus nonhandled offspring. To celebrate the 30th anniversary of Behavioral Neuroscience, this article explores the research that preceded and followed from this brief but significant publication. Changes in hippocampal GR induced by handling were determined to be the outcome of a cascade of cellular and molecular events involving thyroid hormones, serotonin turnover, and transcription factor binding to the Nr3c1 gene, leading to increased GR mRNA and protein. Though many hypotheses were proposed for the "handling effect," the role of handling-induced changes in maternal care, particularly pup licking/grooming (LG), generated a productive scientific framework for understanding the handling phenomenon. Indeed, LG has since been demonstrated to alter GR levels through the signaling pathways described for handling. Moreover, epigenetic mechanisms have been discovered to play a critical role in the effects of early life experience and particularly in the regulation of Nr3c1. Overall, the research avenues that have evolved from the initial finding of handling-induced changes in GR have broad applications to our understanding of plasticity, resilience, and the transmission of traits across generations.

An Exploratory Analysis of Situational Affect, Early Life Stress, and Nonsuicidal Self-Injury in College Students

Research and theory related to nonsuicidal self-injury (NSSI) have highlighted the potential role for early traumatic experiences in subsequent enactment of NSSI behaviors. The present investigation explores the impact of trauma type and timing on both (a) reported NSSI as traditionally measured and (b) in vivo NSSI assessments. Findings supported an interaction between negative affect (NA) and cumulative trauma, such that individuals with high levels of cumulative life trauma evidenced greater in vivo NSSI severity following both high and low levels of in vivo NA. Nonlinear cusp models further supported the presence of an interaction of trauma, particularly trauma prior to 6 years of age, and pre-NSSI NA in the prediction of in vivo NSSI episode severity. The present findings extend a developing literature related to the effects of early life experiences on health behavior.

Temperamental sensitivity moderates the effects of maternal love-withdrawal on perception of infant crying

Parenting has an impact on the offspring's social and behavioral outcomes. However, not all individuals are affected equally; according to the differential susceptibility hypothesis, temperamental traits may moderate the effects of early life experiences. We examined the association between young adults’ experiences of maternal love-withdrawal and their perception of infant crying, and the potentially moderating role of temperamental orienting sensitivity. In an ecologically valid but standardized setting, 132 female participants spent two consecutive evenings taking care of an infant simulator. Orienting sensitivity moderated the relation between experienced love-withdrawal and the perception of infant crying: Participants with high orienting sensitivity who experienced low levels of love-withdrawal perceived the crying bouts as less negative than others. We conclude that the long-term impact of early life experiences may be moderated by temperamental characteristics, with implications for individual dif...

Childhood adversity increases risk for nicotine dependence and interacts with α5 nicotinic acetylcholine receptor genotype specifically in males.

The relative importance of specific genetic and environmental factors in regulating nicotine dependence (ND) risk, including the effects on specific forms of childhood adversity on smoking risk, have been understudied. Genome-wide association studies and rodent models have demonstrated that the α5 nicotinic acetylcholine receptor gene (CHRNA5) is important in regulating nicotine intake. Childhood adversity increases the methylation level of the CHRNA5 promoter region in European Americans (EAs), an effect that was observed only in males (Zhang et al, submitted for publication). In view of this potential sex difference in the effects of early life experience on smoking, we investigated the presence of a sex-specific gene-by-environment effect of this marker on ND risk. A nonsynonymous SNP in CHRNA5 previously associated to ND and several related traits, rs16969968, was genotyped in 2206 EAs (1301 men and 905 women). The main and interactive effects of childhood adversity and rs16969968 genotype on diagnosis of ND and ND defined by dichotomized Fagerstrom test for ND (FTND) scores were explored. Men and women were analyzed separately to test for sex differences. Childhood adversity significantly increased ND risk in both sexes, and the effect in women was twice than that in men. Significant interactive effects of childhood adversity and rs16969968 genotype were observed in men (ND: OR=1.80, 95% CI=1.18-2.73, P=0.0044; FTND: OR=1.79, 95% CI=1.11-2.88, P=0.012). No interaction was found in women. This study provides evidence of a sex-specific gene × environment effect of CHRNA5 and childhood adversity on the risk for ND.