Effects of early adverse experiences on brain structure and function: clinical implications

The biological effects of childhood trauma

Trauma in childhood is a psychosocial, medical, and public policy problem with serious consequences for its victims and for society. Chronic interpersonal violence in children is common worldwide. Developmental traumatology, the systemic investigation of the psychiatric and psychobiological effects of chronic overwhelming stress on the developing child, provides a framework and principles when empirically examining the neurobiological effects of pediatric trauma. This article focuses on peer-reviewed literature on the neurobiological sequelae of childhood trauma in children and in adults with histories of childhood trauma.

Long-term effects of maternal separation on the responsiveness of the circadian system to melatonin in the diurnal nonhuman primate (Macaca mulatta)

Depression is often linked to early-life adversity and circadian disturbances. Here, we assessed the long-term impact of early-life adversity, particularly preweaning mother-infant separation, on the circadian system's responsiveness to a time giver or synchronizer (Zeitgeber). Mother-reared (MR) and peer-reared (PR) rhesus monkeys were subjected to chronic jet-lag, a forced desynchrony protocol of 22 hr T-cycles [11:11 hr light:dark (LD) cycles] to destabilize the central circadian organization. MR and PR monkeys subjected to the T-cycles showed split locomotor activity rhythms with periods of ~22 hr (entrained) and ~24 hr (free-running), simultaneously. Continuous melatonin treatment in the drinking water (20 μg/mL) gradually increased the amplitude of the entrained rhythm at the expense of the free-running rhythm, reaching complete entrainment by 1 wk. Upon release into constant dim light, a rearing effect on anticipation for both the predicted light onset and food presentation was observed. In MR monkeys, melatonin did not affect the amplitude of anticipatory behavior. Interestingly, however, PR macaques showed light onset and food anticipatory activities in response to melatonin treatment. These results demonstrate for the first time a rearing-dependent effect of maternal separation in macaques, imprinting long-term plastic changes on the circadian system well into late adulthood. These effects could be counteracted by the synchronizer molecule melatonin. We conclude that the melatonergic system is targeted by early-life adversity of maternal separation and that melatonin supplementation ameliorates the negative impact of stress on the circadian system.

Microstructural abnormalities in language and limbic pathways in orphanage-reared children: a diffusion tensor imaging study

This study utilized diffusion tensor imaging fiber tractography to examine the miscrostructural integrity of limbic and paralimbic white matter tracts in 36 children (age M = 124 months) with histories of early deprivation, raised from birth in orphanages and subsequently adopted into the United States, compared to 16 age-matched typically developing children. We found increased mean diffusivity bilaterally in the arcuate fasciculus and increased mean diffusivity and reduced fractional anisotropy bilaterally in the uncinate fasciculus and cingulum in children with early deprivation. Microstructural integrity of the left arcuate fasciculus and right cingulum was related to language and behavioral functioning, respectively. White matter abnormalities were also associated with length of deprivation and time in the adoptive home. Our findings suggest that white matter pathways, connecting limbic and paralimbic brain regions is abnormal in children with histories of early deprivation, with some pathways appearing more susceptible to early deprivation than others.

Self-injurious behaviour in autistic children: a neuro-developmental theory of social and environmental isolation

RATIONALE

Self-injurious behaviour is not one of the three core symptoms that define autism. However, children on the autism spectrum appear to be particularly vulnerable. Afflicted children typically slap their faces, punch or bang their heads, and bite or pinch themselves. These behaviours can be extremely destructive, and they interfere with normal social and educational activities. However, the neurobiological mechanisms that confer vulnerability in children with autism have not been adequately described.

OBJECTIVES

This review explores behavioural and neurobiological characteristics of children with autism that may be relevant for an increased understanding of their vulnerability for self-injurious behaviour.

METHODS

Behavioural characteristics that are co-morbid for self-injurious behaviour in children with autism are examined. In addition, the contributions of social and environmental deprivation in self-injurious institutionalized orphans, isolated rhesus macaques, and additional animal models are reviewed.

RESULTS

There is extensive evidence that social and environmental deprivation promotes self-injurious behaviour in both humans (including children with autism) and animal models. Moreover, there are multiple lines of convergent neuroanatomical, neurophysiological, and neurochemical data that draw parallels between self-injurious children with autism and environmentally deprived humans and animals.

CONCLUSIONS

A hypothesis is presented that describes how the core symptoms of autism make these children particularly vulnerable for self-injurious behaviour. Relevant neurodevelopmental pathology is described in cortical, limbic, and basal ganglia brain regions, and additional research is suggested.

Maternal separation impairs long term-potentiation in CA1-CA3 synapses and hippocampal-dependent memory in old rats

Exposure to chronic stress during the neonatal period is known to induce permanent long-term changes in the central nervous system and hipothalamic-pituitary-adrenal axis reactivity that are associated with increased levels of depression, anxiety, and cognitive impairments. In rodents, a validated model of early life stress is the maternal separation (MS) paradigm, which has been shown to have long-term consequences for the pups that span to adulthood. We hypothesized that the early life stress-associated effects could be exacerbated with aging, because it is often accompanied by cognitive decline. Using a MS model in which rat pups were separated from their mothers for 3 hours daily, during postnatal days 2-14, we evaluated the long-term functional consequences to aged animals (70-week-old), by measuring synaptic plasticity and cognitive performance. The baseline behavioral deficits of aged control rats were further exacerbated in MS animals, indicating that early-life stress induces sustained changes in anxiety-like behavior and hippocampal-dependent memory that are maintained much later in life. We then investigated whether these differences are linked to impaired function of hippocampal neurons by recording hippocampal long-term potentiation from Schaffer collaterals/CA1 synapses. The magnitude of the hippocampal long-term potentiation induced by high-frequency stimulation was significantly lower in aged MS animals than in age-matched controls. These results substantiate the hypothesis that the neuronal and endocrine alterations induced by early-life stress are long lasting, and are able to exacerbate the mild age-associated deficits.

The impact of self-reported childhood trauma on emotion regulation in borderline personality disorder and major depression

Early life stress is said to play a critical role in the development of borderline personality disorder (BPD) and major depressive disorder (MDD), but the underlying mediating factors remain uncertain. This study aimed to investigate self-reported childhood trauma, emotion regulation difficulties, and their associations in a sample of BPD (n = 49) and MDD (n = 48) patients and healthy control participants (n = 63). Multiple regressions were used to evaluate the impact of the quality and severity of self-reported childhood trauma on self-reported emotion regulation. The results supported an association between self-reported maltreatment experiences, especially emotional abuse and neglect, and emotion regulation difficulties. Additional analyses showed that emotion regulation difficulties influence the association between self-reported emotional abuse and acute symptomatology in the BPD subgroup. Emotion regulation difficulties may be 1 pathway through which early life stress, particularly emotional abuse, increases the risk for developing BPD symptomatology.

Early life trauma and attachment: immediate and enduring effects on neurobehavioral and stress axis development

Over half a century of converging clinical and animal research indicates that early life experiences induce enduring neuroplasticity of the HPA-axis and the developing brain. This experience-induced neuroplasticity is due to alterations in the frequency and intensity of stimulation of pups' sensory systems (i.e., olfactory, somatosensory, gustatory) embedded in mother-infant interactions. This stimulation provides "hidden regulators" of pups' behavioral, physiological, and neural responses that have both immediate and enduring consequences, including those involving the stress response. While variation in stimulation can produce individual differences and adaptive behaviors, pathological early life experiences can induce maladaptive behaviors, initiate a pathway to pathology, and increase risk for later-life psychopathologies, such as mood and affective disorders, suggesting that infant-attachment relationships program later-life neurobehavioral function. Recent evidence suggests that the effects of maternal presence or absence during this sensory stimulation provide a major modulatory role in neural and endocrine system responses, which have minimal impact on pups' immediate neurobehavior but a robust impact on neurobehavioral development. This concept is reviewed here using two complementary rodent models of infant trauma within attachment: infant paired-odor-shock conditioning (mimicking maternal odor attachment learning) and rearing with an abusive mother that converge in producing a similar behavioral phenotype in later-life including depressive-like behavior as well as disrupted HPA-axis and amygdala function. The importance of maternal social presence on pups' immediate and enduring brain and behavior suggests unique processing of sensory stimuli in early life that could provide insight into the development of novel strategies for prevention and therapeutic interventions for trauma experienced with the abusive caregiver.

Neuroimaging in children, adolescents and young adults with psychological trauma

Childhood psychological trauma is a strong predictor of psychopathology. Preclinical research points to the influence of this type of trauma on brain development. However, the effects of psychological trauma on the developing human brain are less known and a challenging question is whether the effects can be reversed or even prevented. The aim of this review is to give an overview of neuroimaging studies in traumatized juveniles and young adults up till 2012. Neuroimaging studies in children and adolescents with traumatic experiences were found to be scarce. Most studies were performed by a small number of research groups in the United States and examined structural abnormalities. The reduction in hippocampal volume reported in adults with PTSD could not be confirmed in juveniles. The most consistent finding in children and adolescents, who experienced psychological trauma are structural abnormalities of the corpus callosum. We could not identify any studies investigating treatment effects. Neuroimaging studies in traumatized children and adolescents clearly lag behind studies in traumatized adults as well as studies on ADHD and autism.

BDNF Val66Met modifies the risk of childhood trauma on obsessive-compulsive disorder

Childhood trauma has been linked to the development of later psychopathology, including obsessive-compulsive disorder (OCD). Although evidence exists to suggest that genetic and environmental factors are involved in the aetiology of OCD, little attention has been paid to the interactions that exist between genes and environment. The aim of this study was to investigate gene-by-environment interactions between childhood trauma and the BDNF Val66Met variant in patients with OCD. Childhood trauma was assessed in 134 OCD patients and 188 controls using the Childhood Trauma Questionnaire (CTQ). Linear regression models were used for statistical analyses. Gene-environment interactions were estimated by including a combined genotype and CTQ score in the models as interaction terms. All analyses were adjusted for age, gender, CTQ minimisation-denial score and home language by including them in the logistic regression models as covariates. Childhood trauma, specifically emotional abuse and neglect, increased the odds of having OCD significantly (p < 0.001). Although no significant association was observed between BDNF Val66Met and the development of OCD, interaction analysis indicated that the BDNF Met-allele interacted with childhood emotional abuse to increase the risk of OCD significantly in a dose-dependent manner (p = 0.024). To our knowledge, this is one of the first studies to investigate gene-environment interactions in OCD, and the findings indicate the importance of collating genetic and environmental variables in future studies.

The neural basis of theory of mind and its relationship to social functioning and social anhedonia in individuals with schizophrenia

Theory of mind (ToM), the ability to attribute and reason about the mental states of others, is a strong determinant of social functioning among individuals with schizophrenia. Identifying the neural bases of ToM and their relationship to social functioning may elucidate functionally relevant neurobiological targets for intervention. ToM ability may additionally account for other social phenomena that affect social functioning, such as social anhedonia (SocAnh). Given recent research in schizophrenia demonstrating improved neural functioning in response to increased use of cognitive skills, it is possible that SocAnh, which decreases one's opportunity to engage in ToM, could compromise social functioning through its deleterious effect on ToM-related neural circuitry. Here, twenty individuals with schizophrenia and 18 healthy controls underwent fMRI while performing the False-Belief Task. Aspects of social functioning were assessed using multiple methods including self-report (Interpersonal Reactivity Index, Social Adjustment Scale), clinician-ratings (Global Functioning Social Scale), and performance-based tasks (MSCEIT—Managing Emotions). SocAnh was measured with the Revised Social Anhedonia Scale. Region-of-interest and whole-brain analyses revealed reduced recruitment of medial prefrontal cortex (MPFC) for ToM in individuals with schizophrenia. Across all participants, activity in this region correlated with most social variables. Mediation analysis revealed that neural activity for ToM in MPFC accounted for the relationship between SocAnh and social functioning. These findings demonstrate that reduced recruitment of MPFC for ToM is an important neurobiological determinant of social functioning. Furthermore, SocAhn may affect social functioning through its impact on ToM-related neural circuitry. Together, these findings suggest ToM ability as an important locus for intervention.

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Individuals with schizophrenia exhibited reduced recruitment of MPFC for ToM.

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MPFC and RTPJ activities correlate with measures of social functioning and ability.

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MPFC activity mediates the relationship between social anhedonia and functioning.

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Neural circuitry supporting ToM may represent an important area for remediation.

Multifactorial determinants of target and novelty-evoked P300 amplitudes in children of addicted parents

Background

Although P300 amplitude reductions constitute a persistent finding in children of addicted parents, relatively little is known about the specificity of this finding. The major aim of this study was to investigate the association between parental rearing, adverse life events, stress-reactivity, substance use and psychopathology on the one hand, and P300 amplitude in response to both target and novel distracter stimuli on the other hand. Moreover, we assessed whether risk group status (i.e., having a parental history of Substance Use Disorders [SUD]) uniquely contributed to P300 amplitude variation above and beyond these other variables.

Methods

Event-related potentials were recorded in high-risk adolescents with a parental history of SUD (HR;n=80) and normal-risk controls (NR;n=100) while performing a visual Novelty Oddball paradigm. Stress-evoked cortisol levels were assessed and parenting, life adversities, substance use and psychopathology were examined by using self-reports.

Results

HR adolescents displayed smaller P300 amplitudes in response to novel- and to target stimuli than NR controls, while the latter only approached significance. Interestingly, the effect of having a parental history of SUD on target-P300 disappeared when all other variables were taken into account. Externalizing problem behavior was a powerful predictor of target-P300. In contrast, risk group status uniquely predicted novelty-P300 amplitude reductions above and beyond all other factors.

Conclusion

Overall, the present findings suggest that the P300 amplitude reduction to novel stimuli might be a more specific endophenotype for SUD than the target-P300 amplitude. This pattern of results underscores the importance of conducting multifactorial assessments when examining important cognitive processes in at-risk adolescents.

Impact of childhood stress on psychopathology

OBJECTIVE

Advances in our knowledge of mental disorder (MD) genetics have contributed to a better understanding of their pathophysiology. Nonetheless, several questions and doubts persist. Recent studies have focused on environmental influences in the development of MDs, and the advent of neuroscientific methodologies has provided new perspectives. Early life events, such as childhood stress, may affect neurodevelopment through mechanisms such as gene-environment interactions and epigenetic regulation, thus leading to diseases in adulthood. The aim of this paper is to review the evidence regarding the role of the environment, particularly childhood stress, in the pathophysiology of MD.

METHODOLOGY

We reviewed articles that evaluated environmental influences, with a particular focus on childhood trauma, brain morphology, cognitive functions, and the development of psychopathology and MD.

RESULTS AND CONCLUSION

MRI studies have shown that exposure to trauma at an early age can result in several neurostructural changes, such as the reduction of the hippocampus and corpus callosum. Cognitive performance and functioning are also altered in this population. Finally, childhood stress is related to an increased risk of developing MD such as depression, bipolar disorder, schizophrenia and substance abuse. We conclude that there is robust evidence of the role of the environment, specifically adverse childhood experiences, in various aspects of MD.

Hand rearing affects emotional responses but not basic cognitive performance in European starlings

Hand rearing is a common procedure in behavioural research on birds. While likely to produce tamer experimental animals, there is a risk that it could induce pathological changes in brain and behaviour similar to those seen in mammals that have experienced maternal separation. We explored the effects of hand rearing on the cognitive and behavioural development of European starlings, Sturnus vulgaris, to assess the generality of results obtained from hand-reared animals. Two groups of age-matched birds were created from the same wild population: one hand-reared from 10 days posthatch and one brought into the laboratory as independent juveniles. These groups were compared on a battery of neuropsychological tasks designed to probe different aspects of cognitive function including learning, perseverative cognition, interval timing, neophobia and impulsivity. There was no evidence for cognitive impairment in the hand-reared birds. They did not have reduced learning speed, impairments in accuracy or precision of interval timing or pathological perseverative cognition compared to the wild-caught birds. Additionally, there was no evidence that birds that developed stereotypies in laboratory cages (predominantly the wild-caught birds) had any cognitive impairments, although this may be because no birds had severe, crystallized stereotypies. There was some evidence that hand-reared birds were less neophobic and less impulsive than wild-caught birds, suggesting that hand rearing might alter emotionally mediated decision making in a direction usually associated with reduced developmental stress in mammals. This study therefore supports the use of hand rearing as an experimental procedure in behavioural research on passerine birds.

How emotional abilities modulate the influence of early life stress on hippocampal functioning

Early life stress (ELS) is known to have considerable influence on brain development, mental health and affective functioning. Previous investigations have shown that alexithymia, a prevalent personality trait associated with difficulties experiencing and verbalizing emotions, is particularly related to ELS. The aim of the present study was to investigate how neural correlates of emotional experiences in alexithymia are altered in the presence and absence of ELS. Therefore, 50 healthy individuals with different levels of alexithymia were matched regarding ELS and investigated with respect to neural correlates of audio-visually induced emotional experiences via functional magnetic resonance imaging. The main finding was that ELS modulated hippocampal responses to pleasant (>neutral) stimuli in high-alexithymic individuals, whereas there was no such modulation in low-alexithymic individuals matched for ELS. Behavioral and psychophysiological results followed a similar pattern. When considered independent of ELS, alexithymia was associated with decreased responses in insula (pleasant > neutral) and temporal pole (unpleasant > neutral). Our results show that the influence of ELS on emotional brain responses seems to be modulated by an individual's degree of alexithymia. Potentially, protective and adverse effects of emotional abilities on brain responses to emotional experiences are discussed.

Treadmill exercise exerts ameliorating effect on isolation-induced depression via neuronal activation

Maternal isolation has been used as a valid animal model of early life stress, and it induces depression to offspring. Exercise ameliorates the incidence and severity of stress-related mood disorders, such as depression and anxiety. Here in this study, we investigated the effects of treadmill exercise on brain neuronal excitation in the rat pups with maternal isolation-induced depression. Forced swimming test and immunohistochemistry for glucocorticoid receptor and c-Fos in the hippocampal dentate gyrus and hypothalamic paraventricular nucleus were conducted. Maternal isolation lasted for 6 hours per day and was continued from postnatal day 1 to postnatal day 30. The rat pups in the exercise group were forced to run on a treadmill for 30 min once a day for 10 consecutive days, starting from the postnatal day 21 until the postnatal day 30. In the present results, treadmill exercise alleviated depressive state in the maternal separated rat pups, as potently as fluoxetine treatment. Treadmill exercise also restored the expressions of glucocorticoid receptor and c-Fos in the hippocampal dentate gyrus and hypothalamic paraventricular nucleus of the maternal separated rat pups near to the control level, as fluoxetine treatment. The present study suggests the possibility that treadmill exercise can be used as the therapeutic strategy for the childhood depression induced by disturbed mother-child relationship.

Current status on behavioral and biological markers of PTSD: a search for clarity in a conflicting literature

Extensive research has identified stereotypic behavioral and biological abnormalities in post-traumatic stress disorder (PTSD), such as heightened autonomic activity, an exaggerated startle response, reduced basal cortisol levels and cognitive impairments. We have reviewed primary research in this area, noting that factors involved in the susceptibility and expression of PTSD symptoms are more complex and heterogeneous than is commonly stated, with extensive findings which are inconsistent with the stereotypic behavioral and biological profile of the PTSD patient. A thorough assessment of the literature indicates that interactions among myriad susceptibility factors, including social support, early life stress, sex, age, peri- and post-traumatic dissociation, cognitive appraisal of trauma, neuroendocrine abnormalities and gene polymorphisms, in conjunction with the inconsistent expression of the disorder across studies, confounds attempts to characterize PTSD as a monolithic disorder. Overall, our assessment of the literature addresses the great challenge in developing a behavioral and biomarker-based diagnosis of PTSD.

Repeated restraint stress enhances cue-elicited conditioned freezing and impairs acquisition of extinction in an age-dependent manner

Affective disorders are believed to involve dysfunction within the amygdala, a key structure for processing emotional information. Chronic stress may contribute to affective disorders such as depression and anxiety via its effects on the amygdala. Previous research has shown that chronic stress increases amygdala neuronal activity in an age-dependent manner. However, whether these distinct changes in amgydala neuronal activity are accompanied by age-dependent changes in amygdala-dependent affective behavior is unclear. In this study, we investigated how chronic stress impacts amgydala-dependent auditory fear conditioning in adolescent and adult rats in a repeated restraint model. We found that repeated restraint enhanced conditioned freezing in both adolescent and adult rats. But repeated restraint led to impaired acquisition of fear extinction only in adolescent rats. Along with previous findings, these results suggest that chronic stress may precipitate affective disorders via differential mechanisms, with different outcomes at different ages.

Neonatal stress modulates sickness behavior: role for proinflammatory cytokines

Neonatal stress increased the duration and augmented symptoms of sickness behavior induced by influenza virus infection or endotoxin challenge in mice. Since proinflammatory cytokines were implicated in sickness behavior, the present study sought to determine the effect of neonatal stress on cytokines-induced sickness behavior and on proinflammatory cytokine secretion. Data indicate that separation of mouse pups from the dams at an early age (maternal separation, MSP) increased the duration and augmented some of the symptoms of sickness behavior induced by proinflammatory cytokines. In addition, MSP partially suppressed cytokine and corticosterone secretion in response to endotoxin administration. These data may suggest that MSP increased sensitivity to the effects of proinflammatory cytokines on sickness behavior following an immune challenge.

Adenosine A(2A) receptor blockade reverts hippocampal stress-induced deficits and restores corticosterone circadian oscillation

Maternal separation (MS) is an early life stress model that induces permanent changes in the central nervous system, impairing hippocampal long-term potentiation (LTP) and spatial working memory. There are compelling evidences for a role of hippocampal adenosine A(2A) receptors in stress-induced modifications related to cognition, thus opening a potential window for therapeutic intervention. Here, we submitted rats to MS and evaluated the long-lasting molecular, electrophysiological and behavioral impairments in adulthood. We then assessed the therapeutic potential of KW6002, a blocker of A(2A) receptors, in stress-impaired animals. We report that the blockade of A(2A) receptors was efficient in reverting the behavior, electrophysiological and morphological impairments induced by MS. In addition, this effect is associated with restoration of the hypothalamic-pituitary-adrenal axis (HPA-axis) activity, as both the plasma corticosterone levels and hippocampal glucocorticoid receptor expression pattern returned to physiological-like status after the treatment. These results reveal the involvement of A(2A) receptors in the stress-associated impairments and directly in the stress response system by showing that the dysfunction of the HPA-axis as well as the long-lasting synaptic and behavioral effects of MS can be reverted by targeting adenosine A(2A) receptors. These findings provide a novel evidence for the use of adenosine A(2A) receptor antagonists as potential therapy against psychopathologies.

The signature of maternal rearing in the methylome in rhesus macaque prefrontal cortex and T cells

Early-life adversity is associated with a broad scope of life-long health and behavioral disorders. Particularly critical is the role of the mother. A possible mechanism is that these effects are mediated by "epigenetic" mechanisms. Studies in rodents suggest a causal relationship between early-life adversity and changes in DNA methylation in several "candidate genes" in the brain. This study examines whether randomized differential rearing (maternal vs surrogate-peer rearing) of rhesus macaques is associated with differential methylation in early adulthood. The data presented here show that differential rearing leads to differential DNA methylation in both prefrontal cortex and T cells. These differentially methylated promoters tend to cluster by both chromosomal region and gene function. The broad impact of maternal rearing on DNA methylation in both the brain and T cells supports the hypothesis that the response to early-life adversity is system-wide and genome-wide and persists to adulthood. Our data also point to the feasibility of studying the impact of the social environment in peripheral T-cell DNA methylation.

Negative reactivity in toddlers born prematurely: indirect and moderated pathways considering self-regulation, neonatal distress and parenting stress

High negative reactivity in early childhood interferes with later academic and behavioral adjustment. Thus, investigating the origins of high negative affectivity in early childhood is of high relevance for understanding emotional morbidity after preterm birth. The present work explored (1) direct prematurity-related consequences for negative reactivity, (2) self-regulatory deficits as a mechanism indirectly relating prematurity to negative affectivity and (3) the implications of the interplay between procedural distress in the neonatal period and parenting stress for preterm children's negative reactivity. The sample was comprised of 146 preterm children (very vs. moderately to late preterm) and 86 healthy full-term children, both free of major neurological impairment. Assessment involved negative affect and parenting stress (parent-report; 12, 24 months corrected age, CA), effortful control (behavioral battery, parent report; 24 months CA) and the number of potentially distressing neonatal intensive care procedures as well as severity of illness during the neonatal period (retrospective chart review). There was no direct link from prematurity to a disposition for high negative reactivity in early childhood nor was prematurity indirectly associated with higher negative reactivity through lower levels of effortful control. The relation between neonatal pain and distress and negative affectivity depended on the level of parenting stress with low parenting stress at the end of the first year of children's life buffering the negative influence of neonatal distress. The present findings underscore the importance of complex interactions among environmental factors in processes of emotional plasticity after preterm birth thereby providing critical suggestions for follow-up care.

Different pattern of changes in calcium binding proteins immunoreactivity in the medial prefrontal cortex of rats exposed to stress models of depression

Reductions in the number and size of neurons in the medial prefrontal cortex (mPFC) have been documented in many post-mortem studies of depressed patients and animals exposed to stress. Here, we examined the effect of chronic unpredictable stress (CUS) and chronic mild stress (CMS) on specific populations of neurons in the rat mPFC. Antibodies directed against parvalbumin (PV), calbindin D-28K (CB) and active caspase-3 have been used to quantify the numerical density of PV-immunoreactive (PV-ir), CB-ir and active caspase-3-ir cells, and to measure the relative optical density of neuropil. CUS decreased the density of CB-ir neurons and the optical density of CB-ir neuropil. In turn, CMS increased the densities of both CB-ir neurons and neuropil, while PV-ir neurons and PV-ir neuropil were not changed. The frequency distribution of neuronal surface areas was significantly different only for PV-ir neurons, and only between the control and CUS group. CMS reduced the density of active caspase-3-ir cells while CUS did not. We concluded that the mPFC reveals a different pattern of changes in neurons containing calcium binding proteins and active caspase-3 immunoreactivity in response to CUS and CMS.

Women's psychological profile and psychiatric diagnoses and the outcome of in vitro fertilization: is there an association?

The influence of psychological processes and psychiatric syndromes on the outcome of fertility treatments is not well understood. In this prospective study, we investigated the effect of baseline psychiatric diagnosis and situational psychiatric symptoms on several biological outcome factors of in vitro fertilization treatments (IVF). Women undergoing their first IVF treatment (n = 108) were interviewed before treatment for the presence of a lifetime DSM-IV-TR disorder. Questionnaires measuring state depression (Center for Epidemiologic Studies Depression scale), anxiety (State Trait Anxiety Inventory), and psychiatric symptomatology (Brief Symptom Inventory) were administered at ovulation induction. Outcome variables were number of retrieved and fertilized oocytes, chemical pregnancy, and a take home baby. Situational anxiety, depression, or other psychiatric symptoms had no effect on any of the outcome measures. Women diagnosed with mood or anxiety disorder prior to the onset of the IVF treatment showed a higher, though not statistically significant, pregnancy success rate compared to women without a diagnosis (57 % compared to 38 %). We speculate that in women with such psychopathology, chronic stress results in biological effects that impede successful implantation, thus impairing fertility. Fertility treatment using the IVF paradigm may bypass this negative effect, resulting in high success rates. This hypothesis should be further explored.

Children under stress - COMT genotype and stressful life events predict cortisol increase in an acute social stress paradigm

Dopamine and norepinephrine are key regulators of cognitive and affective processes. The enzyme catechol-O-methyltransferase (COMT) catabolizes catecholamines and the COMT Val158Met polymorphism has been linked to several neuropsychiatric variables. Additionally, stressful life events (SLEs) contribute substantially to affective processes. We used the stress-induced activation of the hypothalamic-pituitary-adrenal axis to investigate the effects of COMT and SLEs on the cortisol response in 119 healthy children (8-12 yr). Saliva cortisol was measured during and after the Trier Social Stress Test for Children. SLEs were assessed with a standardized interview with one of the children's parents. Linear regression analysis revealed a significant effect for COMT, with Met allele carriers showing a higher cortisol response (β=0.300, p=0.001). In turn, more SLEs lead to a less pronounced cortisol increase (β=-0.192, p=0.029) probably indicating increased resilience. Our results further underscore the essential and differential role of genetic variation and environmental factors on stress responsivity.

The neuroanatomy of psychotic diathesis: a meta-analytic review

BACKGROUND

Several studies have found widespread structural changes affecting the grey matter at various stages of schizophrenia (the prodrome, first-episode, and the chronic stage). It is unclear which of these neuroanatomical changes are associated with a predisposition or vulnerability to develop schizophrenia rather than the appearance of the clinical features of the illness.

METHODS

16 voxel-based morphometry (VBM) analyses involving 733 genetically high-risk relatives (HRR) of patients with schizophrenia, 563 healthy controls and 474 patients were meta-analysed using the Signed Differential Mapping (SDM) technique. Two meta-analyses were conducted, with one comparing HRR group with healthy controls and the other comparing HRR group with the patients.

RESULTS

A significant grey matter reduction in the lentiform nucleus, amygdala/parahippocampal gyrus and medial prefrontal cortex was seen in association with the genetic diathesis. Grey matter reduction in bilateral insula, inferior frontal gyrus, superior temporal gyrus and the anterior cingulate was seen in association with the disease expression.

CONCLUSIONS

The neuroanatomical changes associated with the genetic diathesis to develop schizophrenia appear to be different from those that contribute to the clinical expression of the illness. Grey matter abnormalities in multimodal brain regions that have a supervisory function are likely to be central to the expression of the clinical symptoms of schizophrenia.

Epigenetics and family-centered developmental care for the preterm infant

Adverse experiences early in life have the potential to disrupt normal brain development and create stress response channels in preterm infants that are different from those observed in term infants. Animal models show that epigenetic modifications mediate the effects of maternal separation and environmental stress on susceptibility to disease and psychobehavioral problems later in life. Epigenetic research has the potential to lead to the identification of biological markers, gene expression profiles, and profile changes that occur overtime in response to early-life experiences. Combined with knowledge gained through the use of advanced technologies, epigenetic studies have the promise to refine our understanding about how the brain matures and functions from multiple perspectives including the effect of the environment on brain growth and maturation. Such an understanding will pave the way for care practices that will allow the premature brain to develop to its full capacity and will lead to the best possible outcomes. Neonatal epigenetic research is emerging and rapidly advancing. As scientists overcome biological, technical, and cost-related challenges, such research has a great potential in determining key environmental factors that affect the preterm genome, allowing for targeted interventions. The purpose of this article is to explore existing literature related to epigenetic mechanisms that potentially mediate the effects of the environment on preterm infant brain development.

Associations of childhood trauma with hypothalamic-pituitary-adrenal function in borderline personality disorder and major depression

BACKGROUND

Alterations of the hypothalamus-pituitary-adrenal (HPA) axis are hallmarks in major depressive disorder (MDD) and there is some evidence about similar patterns in borderline personality disorder (BPD). This study examines HPA axis abnormalities with respect to clinical characteristics in both BPD (n=24) and MDD patients (n=33) as well as in healthy control participants (n=41).

METHOD

A 0.5mg dexamethasone suppression test was administered to evaluate basal cortisol release and HPA feedback sensitivity via salivary cortisol. Traumatic experiences in childhood as well as severity of borderline and depressive symptom severity and dissociation were obtained by self-report questionnaires.

RESULTS

Compared to the healthy control group, BPD and MDD patients exhibited both enhanced cortisol concentrations before and after the administration of 0.5mg dexamethasone. Higher cortisol levels were positively correlated to a history of childhood trauma, current dissociative symptoms and severity of borderline and depressive symptoms. Regression analyses revealed that some aspects of early trauma were associated with cortisol release before and after dexamethasone, whereas psychopathology did not contribute to the regression model.

CONCLUSIONS

HPA dysfunctions appear to be related rather to childhood trauma than to psychopathology in adulthood. Exposure to childhood trauma may contribute to long-lasting alterations in HPA activity and might enhance the risk for the development of later mental disorder.

Early life manipulations alter learning and memory in rats

Much research shows that early life manipulations have enduring behavioral, neural, and hormonal effects. However, findings of learning and memory performance vary widely across studies. We reviewed studies in which pre-weaning rat pups were exposed to stressors and tested on learning and memory tasks in adulthood. Tasks were classified as aversive conditioning, inhibitory learning, or spatial/relational memory. Variables of duration, type, and timing of neonatal manipulation and sex and strain of animals were examined to determine if any predict enhanced or impaired performance. Brief separations enhanced and prolonged separations impaired performance on spatial/relational tasks. Performance was impaired in aversive conditioning and enhanced in inhibitory learning tasks regardless of manipulation duration. Opposing effects on performance for spatial/relational memory also depended upon timing of manipulation. Enhanced performance was likely if the manipulation occurred during postnatal week 3 but performance was impaired if it was confined to the first two postnatal weeks. Thus, the relationship between early life experiences and adulthood learning and memory performance is multifaceted and decidedly task-dependent.

Cardiovascular morbidity and mortality in Finnish men and women separated temporarily from their parents in childhood--a life course study

OBJECTIVE

Early-life stress may influence health later in life. We examined morbidity and mortality from cardiovascular disease over 60 years in individuals separated temporarily from their parents in childhood due to World War II.

METHODS

We studied 12,915 members of the Helsinki Birth Cohort Study born from 1934 to 1944, of whom 1726 (13.4%) had been evacuated aboard without their parents to temporary foster families for an average of 1.8 (standard deviation = 1.1) years at an average age of 4.6 (standard deviation = 2.4) years. Data on parental separations were extracted from the Finnish National Archives. Information on use of medication for coronary heart disease and hypertension was derived from the National Register of Medication Reimbursement, and information on coronary events, stroke, and cardiovascular deaths was derived from Finnish Hospital Discharge Register and Causes of Death Register between Years 1971 and 2003.

RESULTS

Participants who were separated in childhood used medications for coronary heart disease more frequently than those who were not separated (7.2% versus 4.5%, respectively; hazard ratio [HR] = 1.29, 95% confidence interval [CI] = 1.04-1.59; p = .02). No associations between separation and all-cause mortality (HR = 1.04, 95% CI = 0.90-1.20) or cardiovascular mortality (HR = 0.94, 95% CI = 0.72-1.21) or hospitalizations for cardiovascular disease or stroke were observed.

CONCLUSIONS

Early-life stress may possibly be a factor predisposing to coronary heart disease decades later, but no evidence was found for increased risk of hospitalizations or mortality.

The development and neurobiology of infant attachment and fear

Survival of altricial infants depends on attachment to the caregiver - a process that requires infants to identify, learn, remember, and approach their attachment figure. Here we review the neurobiology of attachment in infant rats where learning about the caregiver is supported by a specialized attachment neural circuitry to promote the infant-caregiver relationship. Specifically, the attachment circuit relies on infants acquiring learned preferences to the maternal odor, and this behavior is supported by the hyperfunctioning locus coeruleus and generous amounts of norepinephrine to produce experience-induced changes in the olfactory bulb and anterior piriform cortex. Infants also possess a reduced ability to acquire learned aversions or fear, and this behavior is facilitated through attenuated amygdala plasticity to block fear learning. Presumably, this attachment circuitry constrains the infant animal to express only learned preferences regardless of the quality of care received. As pups mature, and begin to travel in and out of the nest, the specialized attachment learning becomes contextually confined to when pups are with the mother. Thus, when outside the nest, these older pups show learning more typical of adult learning, presumably to prepare for independent life outside the nest. The quality of attachment can alter this circuitry, with early life stress prematurely terminating the pups' access to the attachment system through premature functional activation of the amygdala. Overall, the attachment circuit appears to have a dual function: to keep pups close to the caregiver but also to shape pups' behavior to match the environment and define long-term emotion and cognition.

Neurobıology of repressıon: a hypothetıcal interpretatıon

Freud lived in a time when technology was incapable of explaining the biological correlates of the mental processes he described in psychoanalytic theory. During the last two decades, advances in neuroimaging methods and neuroscience have provided new insights for understanding mind-brain collaboration. Neurobiological underpinnings of psychoanalytical concepts have been an area of interest in recent years. This paper will suggest a new hypothesis for neurobiology of repression. This hypothesis will be discussed with the help of our knowledge about neurobiological mechanisms underlying perception of the emotional significance of an event, memory formation of an emotionally arousing stimulus, role of prefrontal cortex in modulation of subcortical information, neural mechanisms of suppression and molecular mechanisms of memory erasure. We suggest that dorsolateral prefrontal cortex, and especially its caudal part plays a major role for repression of childhood traumatic events. Possible molecular mechanism of memory erasure in repression is long term depression of glutamatergic neurotransmission between prefrontal cortex- thalamus- limbic system.

Interaction between FKBP5 and childhood trauma and risk of aggressive behavior

CONTEXT

Childhood trauma may predispose individuals to aggressive behavior, and both childhood trauma and aggressive behavior are associated with hypothalamic-pituitary-adrenal axis dysregulation.

OBJECTIVE

To determine whether there would be an interaction between genetic variation in FKBP5 and childhood trauma in predicting aggressive behavior.

DESIGN

Cross-sectional study. Four FKBP5 single-nucleotide polymorphisms used in previous studies (rs3800373, rs9296158, rs1360780, and rs9470080) were genotyped. Three diplotypes were derived from 2 major putatively functional haplotypes regulating protein expression that were previously associated with glucocorticoid receptor sensitivity.

SETTING

Penitentiary District of Abruzzo-Molise in central Italy.

PARTICIPANTS

A population of 583 male Italian prisoners recruited between 2005 and 2008.

MAIN OUTCOME MEASURES

A comprehensive analysis of aggression and impulsivity was undertaken using the Brown-Goodwin Lifetime History of Aggression (BGHA) questionnaire, the Buss-Durkee Hostility Inventory (BDHI), and the Barratt Impulsiveness Scale (BIS). A history of childhood trauma was investigated with the Childhood Trauma Questionnaire. The interaction between the FKBP5 diplotypes and childhood trauma on measures of aggression was analyzed. Analyses were replicated with a second behavioral measure of aggression: violent behavior in jail. Individual single-nucleotide polymorphism analysis was performed.

RESULTS

Childhood trauma had a significant effect on BGHA and BDHI scores but not on BIS scores. We observed a significant influence of the FKBP5 high-expression diplotype on both a lifetime history of aggressive behavior (BGHA) (P = .012) and violent behavior in jail (P = .025) but only in individuals exposed to childhood trauma, in particular to physical abuse. No main effect of the FKBP5 diplotypes was observed.

CONCLUSION

These data suggest that childhood trauma and variants in the FKBP5 gene may interact to increase the risk of overt aggressive behavior.

The influence of chronic stress imposed on pregnant rats on the induced bone loss in their adult offspring

BACKGROUND AND OBJECTIVE

Stress during pregnancy may alter offspring susceptibility to diseases during adulthood. In the present study, female Lewis rats were subjected to chronic stress during the gestational period, and the effect of this stress was evaluated histometrically on the progression of ligature-induced bone loss in their adult offspring.

MATERIAL AND METHODS

After confirming pregnancy, half of the pregnant rats were randomly designated as control animals (no stress regimen was imposed), and the other half was submitted to a chronic stress model (immobilization at cold temperature) between the 7th and the 18th gestational day. After birth, 12 male rats delivered by stressed mothers - Group 1 (G1) - and 12 male rats delivered by non-stressed mothers - Group 2 (G2) - were selected. When birthed rats reached 250 g of body weight, a silk ligature was placed around their maxillary right second molar in order to induce bone loss. The non-ligated left side served as a control. Sixty days later, these animals were sacrificed by anaesthetic overdose. After routine laboratorial processing, images of the histological sections were digitized and submitted for histometric measurement using two parameters: histological attachment loss and bone loss.

RESULTS

On the ligated side, G1 presented with greater histological attachment and bone loss than G2 (p<0.05). On the non-ligated control side, neither of the groups presented with alterations in these parameters (p>0.05).

CONCLUSION

The chronic stress regimen imposed on pregnant rats produced a greater progression of ligature-induced bone loss in their adult offspring.

Should neonates sleep alone?

BACKGROUND

Maternal-neonate separation (MNS) in mammals is a model for studying the effects of stress on the development and function of physiological systems. In contrast, for humans, MNS is a Western norm and standard medical practice. However, the physiological impact of this is unknown. The physiological stress-response is orchestrated by the autonomic nervous system and heart rate variability (HRV) is a means of quantifying autonomic nervous system activity. Heart rate variability is influenced by level of arousal, which can be accurately quantified during sleep. Sleep is also essential for optimal early brain development.

METHODS

To investigate the impact of MNS in humans, we measured HRV in 16 2-day-old full-term neonates sleeping in skin-to-skin contact with their mothers and sleeping alone, for 1 hour in each place, before discharge from hospital. Infant behavior was observed continuously and manually recorded according to a validated scale. Cardiac interbeat intervals and continuous electrocardiogram were recorded using two independent devices. Heart rate variability (taken only from sleep states to control for level of arousal) was analyzed in the frequency domain using a wavelet method.

RESULTS

Results show a 176% increase in autonomic activity and an 86% decrease in quiet sleep duration during MNS compared with skin-to-skin contact.

CONCLUSIONS

Maternal-neonate separation is associated with a dramatic increase in HRV power, possibly indicative of central anxious autonomic arousal. Maternal-neonate separation also had a profoundly negative impact on quiet sleep duration. Maternal separation may be a stressor the human neonate is not well-evolved to cope with and may not be benign.

Impact of childhood trauma on functionality and quality of life in HIV-infected women

BACKGROUND

While there are many published studies on HIV and functional limitations, there are few in the context of early abuse and its impact on functionality and Quality of Life (QoL) in HIV.

METHODS

The present study focused on HIV in the context of childhood trauma and its impact on functionality and Quality of Life (QoL) by evaluating 85 HIV-positive (48 with childhood trauma and 37 without) and 52 HIV-negative (21 with childhood trauma and 31 without) South African women infected with Clade C HIV. QoL was assessed using the Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q), the Patient's Assessment of Own Functioning Inventory (PAOFI), the Activities of Daily Living (ADL) scale and the Sheehan Disability Scale (SDS). Furthermore, participants were assessed using the Center for Epidemiologic Studies Depression Scale (CES-D) and the Childhood Trauma Questionnaire (CTQ).

RESULTS

Subjects had a mean age of 30.1 years. After controlling for age, level of education and CES-D scores, analysis of covariance (ANCOVA) demonstrated significant individual effects of HIV status and childhood trauma on self-reported QoL. No significant interactional effects were evident. Functional limitation was, however, negatively correlated with CD4 lymphocyte count.

CONCLUSIONS

In assessing QoL in HIV-infected women, we were able to demonstrate the impact of childhood trauma on functional limitations in HIV.

Defensive sexualization: a neurobiologically informed explanatory model

Sexualization is a defense mechanism frequently referred to in clinical psychoanalytic literature. Despite this, there is no research linking the theoretical nature of this observed phenomenon to social or neurobiological theory. This discussion paper proposes an interaction between social learning and neural maturation in the development of sexualized tendencies. When anxiety within peer interactions is alleviated repeatedly through sexualized behavior, learned associations develop. This explanation allows understanding and empathy for individuals demonstrating a broad spectrum of sexualized responses since such learning is argued to be functional within their historic social climate.

Effects of maternal L-tryptophan depletion and corticosterone administration on neurobehavioral adjustments in mouse dams and their adolescent and adult daughters

Major depressive disorder (MDD), a pathology characterized by mood and neurovegetative disturbances, depends on a multi-factorial contribution of individual predisposition (e.g., diminished serotonergic transmission) and environmental factors (e.g., neonatal abuse or neglect). Despite its female-biased prevalence, MDD basic research has mainly focused on male rodents. Most of present models of depression are also devalued due to the fact that they typically address only one of the aforementioned pathogenetic factors. In this paper we first describe the basic principles behind mouse model development and evaluation and then articulate that current models of depression are intrinsically devalued due to poor construct and/or external validity. We then report a first attempt to overcome this limitation through the design of a mouse model in which the genetic and the environmental components of early risk factors for depression are mimicked together. Environmental stress is mimicked through the supplementation of corticosterone in the maternal drinking water while biological predisposition is mimicked through maternal access to an L-tryptophan (the serotonin precursor) deficient diet during the first week of lactation. CD1 dams and their offspring exposed to the L-tryptophan deficient diet (T) and to corticosterone (80mg/l; C) were compared to animal facility reared (AFR) subjects. T and C mice served as intermediate reference groups. Adolescent TC offspring, compared to AFR mice, showed decreased time spent floating in the forced-swim test and increased time spent in the open sectors of an elevated 0-maze. Adult TC offspring showed reduced preference for novelty, decreased breakpoints in the progressive ratio operant procedure and major alterations in central BDNF levels and altered HPA regulation. The route of administration and the possibility to control the independent variables predisposing to depressive-like symptoms disclose novel avenues towards the development of animal models with increased external and construct validity. Furthermore, the observation that, compared to adult subjects, adolescent mice display an opposite profile suggests that peri-pubertal developmental processes may interact with neonatal predispositions to calibrate the adult abnormal phenotype.

Illogical thinking and thought disorder in maltreated children

OBJECTIVE

To examine illogical thinking in children from low-income families with and without histories of child maltreatment.

METHOD

Maltreated (n = 91) and nonmaltreated (n = 43) school-age children individually participated in a story game designed to elicit speech samples. Children were instructed to listen to two recorded stories and prompted to retell the story; they then were asked to create their own story from possible topics. Child behavior ratings on the Child Behavior Checklist were completed by research assistants following 35 hours of observation.

RESULTS

Maltreated children exhibited more illogical thinking than did nonmaltreated children, and the level of illogical thinking in maltreated children was in the clinically pathological range. The occurrence of multiple subtypes of maltreatment and the chronicity of the maltreatment also were associated with illogical thinking. Dissociation did not differ between groups, although it was related to illogical thinking.

CONCLUSION

The ability to formulate ideas and communicate them logically is compromised in children who have been maltreated. These results extend prior research on selective attentional processes and negativity biases in maltreated children.

Posttraumatic stress disorder in anorexia nervosa

OBJECTIVES

Comorbidity among eating disorders, traumatic events, and posttraumatic stress disorder (PTSD) has been reported in several studies. The main objectives of this study were to describe the nature of traumatic events experienced and to explore the relationship between PTSD and anorexia nervosa (AN) in a sample of women.

METHODS

Eight hundred twenty-four participants from the National Institutes of Health-funded Genetics of Anorexia Nervosa Collaborative Study were assessed for eating disorders, PTSD, and personality characteristics.

RESULTS

From a final sample of 753 women with AN, 13.7% (n = 103) met Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria for PTSD. The sample mean age was 29.5 (standard deviation = 11.1) years. In pairwise comparisons across AN subtypes, the odds of having a PTSD diagnosis were significantly lower in individuals with restricting AN than individuals with purging AN without binge eating (odds ratio = 0.49, 95% confidence interval = 0.30-0.80). Most participants with PTSD reported the first traumatic event before the onset of AN (64.1%, n = 66). The most common traumatic events reported by those with a PTSD diagnosis were sexually related traumas during childhood (40.8%) and during adulthood (35.0%).

CONCLUSIONS

AN and PTSD do co-occur, and traumatic events tend to occur before the onset of AN. Clinically, these results underscore the importance of assessing trauma history and PTSD in individuals with AN and raise the question of whether specific modifications or augmentations to standard treatment for AN should be considered in a subgroup to address PTSD-related psychopathology.

Aspects of psychodynamic neuropsychiatry II: psychical locality and biology: toward the neurobiology of psychotherapy

Throughout his career, Freud believed that psychiatry in general and psychoanalysis in particular would one day be rooted in anatomical/biological ground. He felt confidant that such ground would replace the psychological understanding on which he had been forced to base most of his clinical theory and practice. He felt confidant that one day psychotherapy would be more "scientific." This article seeks to demonstrate that this day is arriving. A clinical case is presented where assessment and formulation are largely based on neurobiology, where treatment was conducted less in accord with psychodynamic theory than neurodynamic data of anatomy and biology.

Predicting cortisol stress responses in older individuals: influence of serotonin receptor 1A gene (HTR1A) and stressful life events

Considerable variability in the activity of the hypothalamus-pituitary-adrenal (HPA) axis in response to stress has been found in quantitative genetic studies investigating healthy individuals suggesting that at least part of this variance is due to genetic factors. Since the HPA axis is regulated by a neuronal network including amygdala, hippocampus, prefrontal cortex as well as brainstem circuits, the investigation of candidate genes that impact neurotransmitter systems related to these brain regions might further elucidate the genetic underpinnings of the stress response. However, aside from genetic risk factors, past stressful life events might also result in long-term adjustments of HPA axis reactivity. Here, we investigated the effects of the -1019 G/C polymorphism in the HTR1A gene encoding the serotonin (5-HT) receptor 1A (5-HT(1A)) and stressful life events experienced during childhood and adolescence on changes in cortisol levels in response to the Trier Social Stress Test (TSST) in a sample of healthy older adults (N=97). Regression analyses revealed a significant effect of HTR1A genotype with the G allele being associated with a less pronounced stress response. In addition, an inverse relationship between past stressful life events and cortisol release but no gene × environment interaction was detected. The results further underscore the crucial role of functional serotonergic genetic variation as well as stressful events during critical stages of development on the acute stress response later in life.

[Neurobiological consequences of child sexual abuse: a systematic review]

OBJECTIVE

The results of several studies suggest that there is a critical timeframe during development in which experiences of maltreatment and sexual abuse may lead to permanent or long-lasting neurobiological changes that particularly affect the hypothalamus-pituitary-adrenal axis response. The aim of the present study was to provide an updated review on the main neurobiological consequences of child sexual abuse.

METHODS

We selected articles published between January 1999 and January 2010 in English or Spanish that focused on the neurobiological consequences of child sexual abuse available through Medline, Scopus and Web of Science. We also examined the references in published articles on the consequences of sexual victimization in childhood.

RESULTS

In this review we included 34 studies on neurobiological consequences, indicating different kinds of effects, namely: neuroendocrine, structural, functional and neuropsychological consequences, which affect a large number of victims.

CONCLUSIONS

The existing body of work on the neurobiological consequences of maltreatment shows the need to consider maltreatment and child sexual abuse as health problems that affect different areas of victims' lives, which would in turn favor the development of intervention and treatment programs that take these multiple effects into account.

Effects of an early handling-like procedure and individual housing on anxiety-like behavior in adult C57BL/6J and DBA/2J mice

Manipulations of rearing conditions have been used to examine the effects of early experience on adult behavior with varying results. Evidence suggests that postnatal days (PND) 15-21 are a time of particular susceptibility to environmental influences on anxiety-like behavior in mice. To examine this, we subjected C57BL/6J and DBA/2J mice to an early handling-like procedure. Pups were separated from dams from PND 12-20 for 30 minutes daily or received standard care. On PND 21, pups were weaned and either individually- or group-housed. On PND 60, anxiety-like behavior was examined on the elevated zero-maze. Although individually-housed animals took longer to enter an open quadrant of the maze, they spent more time in the open than group-housed animals. Additionally, we observed a trend of reduced anxiety-like behavior in C57BL/6J, but not DBA/2J mice that underwent the handling-like procedure.

A novel BDNF polymorphism affects plasma protein levels in interaction with early adversity in rhesus macaques

Early stressful events can increase vulnerability for psychopathology, although knowledge on the effectors is still limited. In this report we describe the characterization of a single nucleotide polymorphism (SNP) in rhesus macaques, which results in a Val to Met transition in the pro-BDNF domain, similar to a well described variant in the human gene. Further, we tested the hypothesis that peripheral levels of BDNF, which is involved in the response to stress and in the pathophysiology of anxiety and depression, might be differentially affected in a non-human primate model of early adverse rearing in a genotype-dependent manner. Males and females rhesus macaques reared either with their mothers (MR), in peer-only groups (PR), or in a "surrogate/peer-reared" (SPR) condition with limited peer interactions, were used as experimental subjects. BDNF levels were determined at baseline on postnatal days (PND) 14, 30 and 60 by means of specific ELISA procedure. Data indicate that BDNF levels were increased as a result of peer-rearing and that this increase was moderated by the presence of the SNP. Overall these data indicate that a SNP, which results in a Val to Met transition in the pro-BDNF domain, is present in rhesus macaques and is able to affect BDNF peripheral levels, thus making this primate model a fundamental tool to study gene by environment interactions involving the BDNF gene.

Annual Research Review: Epigenetic mechanisms and environmental shaping of the brain during sensitive periods of development

Experiences during early development profoundly affect development of the central nervous system (CNS) to impart either risk for or resilience to later psychopathology. Work in the developmental neuroscience field is providing compelling data that epigenetic marking of the genome may underlie aspects of this process. Experiments in rodents continue to show that experiences during sensitive periods of development influence DNA methylation patterns of several genes. These experience-induced DNA methylation patterns represent stable epigenetic modifications that alter gene transcription throughout the lifespan and promote specific behavioral outcomes. We discuss the relevance of these findings to humans, and also briefly discuss these findings in the broader contexts of cognition and psychiatric disorder. We conclude by discussing the implications of these observations for future research.