Expertise solicited for Early Childhood Education Curriculum design
Manitoba-based Red River College, in partnership with University of Toronto’s
|Renewal dates||2007, 2012|
|Supporters||The Alva Foundation George Weston Limited Great-West Life, London Life and Canada Life The Joan and Clifford Hatch Foundation The W. Garfield Weston Foundation (1 Anonymous Donor)|
|Behavioural, developmental, molecular and evolutionary biology; behavioural genetics; epigenetics; cognitive and developmental neuroscience; biological, cognitive and developmental psychology; psychiatry; biological anthropology; epidemiology; public and environmental health; social biomedical science|
Researchers with the program in Child & Brain Development want to know how adversity and enrichment in early childhood affect mental, physical and emotional health throughout a lifetime, and how the problems caused by early adversity can be abated or reversed.
This program has led the way in moving beyond the debate about “nature vs. nurture,” and instead has helped establish that it is interactions among genes and environments during early childhood that guide human development.
The program examines the neurobiological mechanisms that are governed by those gene-environment interactions and how they determine individual differences in children’s development and health. Researchers are also concerned with the larger societal differences in outcomes when children grow up in poverty and when they are reared in more supportive, sustaining environments.
The Child & Brain Development program has significantly increased knowledge about the way early experiences influence biological development and lead to health differences over time. Program members conduct basic, field and clinical research and come from a wide range of disciplines, including neurobiology, epidemiology, paediatrics, molecular genetics, psychiatry, psychology and anthropology.
They study not only the complex interactions of genes with children’s early environments, but also the neural processes and molecular pathways by which those interactions act on development.
The work of program fellows has galvanized scientific interest in the importance of early life experience. Increased understanding of biological embedding is helping them to test interventions that prevent or moderate the negative impact of early adversity, better understand its effects across multiple generations, and determine the optimal timing of education for children.
For example, Associate Fellow Ronald Barr developed an education intervention that makes parents aware that severe shaking of infants can lead to brain damage or even death. The intervention is now widely used in hospitals in Canada and the US and has helped to reduce the incidence of shaken baby syndrome.
The program in Population Health, the precursor to Child & Brain Development, had a strong impact in the field, culminating in the publication of Why are Some People Healthy and Others Not?, an influential book which for the first time laid out the broad case for population health and was widely taught and reviewed.
The program was founded in 2003 under the name Experience-based Brain and Biological Development, and is in its third five-year cycle. The current scientific agenda focuses on research to address the mediating, neurodevelopmental processes within the brain that likely underlie how genes and environments work together to affect individual trajectories of development and health.
Researchers with the program have made pioneering contributions to the study of the interplay between genes and the environment, including epigenetics. They have mapped, defined and modelled development and health disparities in human populations, and established animal models to simulate and explain the interaction of genes and environments in the genesis of illness and disordered development.
Senior Fellow Michael Meaney worked with rats to show that the environment did in fact affect how genes were expressed. He examined rat pups who suffered stress because they were neglected (not licked) by their mothers. In the neglected pups the switch that turns on a gene that encodes a neuroreceptor associated with the stress response was “turned down,” making the rats more susceptible to the effects of stress. Meaney later found the same epigenetic change in humans who were neglected or abused in childhood.
Meaney and Senior Fellow Marla Sokolowski have now extended this work into a human sample of at-risk mothers and infants in the Maternal Adversity, Vulnerabilitiy and Neurodevelopment Project. Clear evidence has begun to emerge from this project implicating genetic differences in the calibration of infants’ responses to both negative and positive environmental settings.
An early study of adults raised in low socioeconomic circumstances showed that the genes responsible for regulating the stress hormone cortisol were less active, and the genes responsible for inflammation were more active. These findings help to explain how adverse early experiences can lead to a lifelong increase in the risk of certain chronic diseases related to stress and inflammation. Senior Fellow and program Co-Director W. Thomas Boyce and Clyde Hertzman described the phenomenon in a widely cited paper.
But not all children are affected by stress in the same way. Boyce and co-author Bruce J. Ellis of the University of Arizona suggested that some children are “dandelions,” who will do reasonably well no matter the stress in their environment. Other “orchid” children will do very well in a nurturing environment, but poorly when faced with a poor environment.
Senior Fellow Stephen Suomi found support for the hypothesis among young rhesus macaques. He discovered that some did indeed have constitutional differences that made them thrive in supportive, predictable settings—doing better than their more robust peers—but caused them to fare worse than those peers in more stressful contexts.
New techniques for measuring physiological changes have boosted this avenue of research in humans. Senior Fellow Chuck Nelson and colleagues have recently built a sophisticated neuroimaging lab in Dhaka, Bangladesh, that is allowing them to examine the consequences of a range of adversities in young children living in the slums of that city.
Associate Fellow Megan Gunner contributed to the creation of therapeutic interventions to help mitigate or reverse the heightened stress response of children in foster care who suffered early abuse. Some of her other research indicates parents lose their ability to buffer or prevent stress hormone responses in their children when they reach early adolescence. This work is important because affective disorders (such as depression and bipolar disorder) rise during early adolescence, which may reflect the loss of a strong external regulator of cortisol.
In 2011 program members organized an Arthur M. Sackler Colloquium with the National Academy of Sciences, which resulted in a special edition of the Proceedings of the National Academy of Sciences edited by program Co-Directors Boyce (University of British Columbia & University of California San Francisco ) and Marla Sokolowski (University of Toronto), and Advisory Committee member Gene Robinson. It was the first volume of collected research to provide a substantial and comprehensive picture of the interaction between experience and biology in the early years.
Recently, Boyce and Mike Kobor examined how epigenetic processes may underlie the biological embedding of early life adversity that are linked to health outcomes later in life. These epigenetic processes may help explain individual variations in the strengths of the linkages, as well as how risk and protections can be passed down through generations.
Senior Fellow Takao Hensch has produced groundbreaking work in the timing of events at the molecular level. He found changes associated with circadian “clock genes” that are involved in the opening and closing of critical periods in brain development. He and other fellows have also experimented with ways to re-open critical periods for those whose development has been impaired. For example, Hensch and colleagues have used a drug to restore plasticity in the brains of mice and correct amblyopia, a condition in which information from one eye is not correctly processed in the brain.
Hensch and CBD Senior Fellow Janet Werker also published a landmark chapter in the Annual Review of Psychology in which they reviewed the literature on speech perception development in humans within the context of Hensch’s mechanistic model of critical periods, which was developed using molecular and cellular techniques with animals. This paper represents the first time there has been a full synthesis of the fields of language development and critical period biology, a synthesis made possible by their collaboration within the CIFAR Network.
In groundbreaking work, Fellow Daniela Kaufer has uncovered the molecular mechanism behind the infertility induced in rats by chronic stress, and identified a potential target for treatment. She and her colleagues have shown the crucial role of the peptide RFRP3, also known as gonadotropin inhibitory hormone, which acts as an inhibitory switch on the reproductive axis. Chronic stress increases the levels of RFRP3 expression in the brain, leading to decreased sexual interest and decreased likelihood of pregnancy when engaged in mating. This finding could lead to a treatment for stress-induced human infertility.
University of British Columbia, BC Children’s Hospital
Queen Mary, University of London
Hospital for Sick Children
The Hospital for Sick Children, University of Toronto
University of Minnesota
University of California, Berkeley
University of British Columbia
University of Lethbridge
University of Toronto at Mississauga
University of British Columbia
National Institutes of Health
University of British Columbia
University of California, San Fransisco
Max Planck Institute of Psychiatry
University of Illinois Urbana-Champaign
Advisory Committee Chair
King's College London
CIFAR Senior Fellows Michael Meaney (Douglas Hospital Research Centre) and
Following a conversation with CIFAR president Chaviva Hošek, The Globe
In collaboration with UBC’s Human Early Learning Partnership, CIFAR Senior
CIFAR Fellow Douglas Willms (University of New Brunswick) is elected
To see whether stressors influence parental behaviour, Senior Fellow Michael
In conjunction with his role as head of the Center
CIFAR Senior Fellow Janet Werker (University of British Columbia) reveals
CIFAR Senior Fellow Janet Werker (University of British Columbia), a
The program recruits molecular geneticist Joel Levine (University of Toronto
The World Health Organization International Commission on the Social Determinants
To tackle the incidence of Shaken Baby Syndrome (SBS), CIFAR
CIFAR Senior Fellow Michael Kobor (University of British Columbia) helps
A striking study by CIFAR Senior Fellow Janet Werker (University
CIFAR Senior Fellows Clyde Hertzman and Tom Boyce (both University
CIFAR Senior Fellows Marla Sokolowski (University of Toronto) and Michael
The program successfully holds a prestigious Arthur M. Sackler Colloquium
CIFAR Senior Fellows Clyde Hertzman (University of British Columbia), Tom
CIFAR Senior Fellows Stephen Suomi (National Institute of Child Health
CIFAR Senior Fellows Takao Hensch (Harvard University) and Janet Werker
CIFAR Fellow Thomas McDade (Northwestern University) shows that contrary to
Manitoba-based Red River College, in partnership with University of Toronto’s Atkinson Centre, assembles a multimedia curriculum resource entitled “The Science of Early Child Development.” The project’s founders credit CIFAR's Fraser Mustard for inspiring the resource. The project translates knowledge about early brain development and population health into an easily accessible and updatable online resource for students and frontline workers. Since its inception, the resource has featured 15 EBBD program fellows and advisors. The World Bank later funded the development of an international edition of the website, which has since been further expanded with support from the Aga Khan University. Both the national and international editions of the resource are currently in high demand.
CIFAR Senior Fellows Michael Meaney (Douglas Hospital Research Centre) and Moshe Szyf (McGill University) are the first to demonstrate that early life events influence adult outcomes via epigenetic remodeling of the genome. Their study, published in prestigious journal Nature Neuroscience, shows that the more a rat pup is licked or groomed by its mother during infancy, the less anxious it grows up to be as an adult. Crucially, this results from a maternal care-dependent change in hippocampal glucocorticoid receptor expression, a key component of the HPA axis, which controls our reaction to stress. More attentive mothering triggers more beneficial changes to the offspring’s epigenome. The study demonstrates unequivocally for the first time that behaviour can regulate the epigenomic state of a gene, and provides evidence to explain how early life events can become biologically embedded for life.
Following a conversation with CIFAR president Chaviva Hošek, The Globe and Mail's Editor in Chief Edward Greenspon commits the Globe to a major focus on early childhood development. This five-part series entitled “Starting from Zero” highlights findings from a number of fascinating child development research projects in Canada, including the work of CIFAR fellows Ronald Barr, Clyde Hertzman, Janet Werker (all University of British Columbia), Richard Tremblay (University of Montreal and Douglas Willms (University of New Brunswick). These feature pieces showcase the originality of the multidisciplinary nature of this program's research projects and help translate key scientific concepts to the public at large.
CIFAR Senior Fellow Clyde Hertzman (University of British Columbia) is the Principal Investigator on a prestigious foundation grant from the Canadian Foundation for Innovation and the British Columbia Knowledge Development Foundation, worth $7.3 million CDN. The grant, which brings together 50 investigators, enables the formation of the Population Health and Learning Observatory (now called Population Data BC), which aims to provide unprecedented access to unique population-wide linked data resources for population health and health services research in Canada and the world.
In collaboration with UBC’s Human Early Learning Partnership, CIFAR Senior Fellow Clyde Hertzman (University of British Columbia) implements the Early Development Instrument (EDI) in British Columbia. The EDI is a detailed checklist designed to evaluate child development in five key areas — physical well-being, social competence, emotional maturity, language and cognitive development, and communication and general knowledge — scoring children as vulnerable or not vulnerable. Initially trialed on five-year-old children in Vancouver, the pilot is quickly implemented B.C.-wide when grouping results by geographic areas reveals striking associations between vulnerability and poorer neighbourhoods. Hertzman is quickly seen as a global leader in population-based assessments of developmental health, leading to his appointment by the World Health Organization as Team Leader of the Global Knowledge Hub in early childhood development, as part of their international commission on the Social Determinants of Health. The EDI is now in place in all jurisdictions in Canada and is spreading rapidly in the U.S.
CIFAR Fellow Douglas Willms (University of New Brunswick) is elected a Fellow of the Royal Society of Canada, an event considered the highest honour attainable by scholars, artists and scientists nationwide. CIFAR Associate Megan Gunnar (University of Minnesota) is invited to share the policy implications of her work on early child development with both the National Council of State Legislators and the Centers for Disease Control. The U.S. National Institutes of Health selects CIFAR Advisor Nancy Adler (University of California San Francisco) as a member of the Advisory Committee to the Director, a prestigious and influential appointment, which serves to advise the NIH Director on policy and planning issues.
CIFAR Senior Fellow Thomas Boyce is successfully recruited from UC Berkeley to the University of British Columbia as a B.C. Leadership Chair in Early Child Development. Interactions with CIFAR members within the program are considered instrumental in bringing this appointment to fruition. Tom Boyce officially joins UBC in 2006 and brings with him a newly funded National Institutes of Health grant entitled “Social disparities in the early neurobiology of stress.” Boyce says “the experience with the Experience-based Brain and Biological Development program made it a natural move.”
To see whether stressors influence parental behaviour, Senior Fellow Michael Meaney (Douglas Hospital Research Centre) characterizes rat mothers as either high or low in maternal instinct based on licking and grooming of newborn pups. After the pups are weaned he re-breeds the same females but exposes them to a stressful stimulus for a seven-day period while pregnant. Mothers that had once scored as having high maternal instinct scored low following exposure to stress. Importantly, once their pups reached adulthood they too had poor maternal instincts, showing a cross generational effect. A final re-breeding in which no stressful stimuli is applied demonstrates that the previous episode of stress triggered long-lasting changes in behaviour as the mothers (and the pups in adulthood) continue to exhibit low maternal instinct even following a stress-free pregnancy. The study is important because it shows that the effects of environmental adversity are transmitted across generations via a non-genomic mechanism involving maternal care.
In conjunction with his role as head of the Center of Excellence on Early Child Development, CIFAR Fellow Richard Tremblay (University of Montreal), along with Program Director Ronald Barr (University of British Columbia), furthers the ongoing development of a freely accessible, web-based encyclopedia of early child development. This online tool, which the two program members co-edit, offers cutting edge, research-based information on early childhood development topics. Aimed primarily at policy makers, professionals and educated parents, this site uses international experts on early childhood development to synthesize current knowledge on specific topics. Available in four languages and receiving more than 1,000 hits daily, the encyclopedia is considered one of the best electronic sources for recent findings in early childhood development topics.
Shaken baby syndrome (SBS), the most common form of child abuse, is typically seen in infants less than six months of age, the same age at which a natural increase in crying occurs. To determine whether crying is a trigger for SBS, CIFAR Program Director Ronald Barr (University of British Columbia) compares the age at hospitalization of over 270 infants with SBS, with the developmental time period in which infants exhibit a normal increase in crying. His study shows that both the cry curve and SBS curve start at 2-3 weeks of age, exhibit a strong peak prior to a decline to baseline by 36 weeks of age. The detected lag in the peaks of the two curves has since been shown to arise due to the fact that many SBS infants are exposed to repeated bouts of shaking prior to hospitalization. In knowing that crying can trigger SBS, researchers now hope to develop opportunities for preventive intervention.
CIFAR Senior Fellow Janet Werker (University of British Columbia) reveals that four- and six-month-old infants are able to discriminate English from French, simply by viewing silently presented articulations. Strikingly, by eight months of age, only bilingual (English-French) infants continue to succeed at the task; monolingual babies are no longer able to spot a difference. These findings identify a surprisingly early preparedness for visual language discrimination in infants, and highlight an infants' ability to retain only the perceptual sensitivities that are necessary.
CIFAR Senior Fellow Janet Werker (University of British Columbia), a developmental psychologist, and CIFAR Senior Fellow Takao Hensch (Harvard University), a molecular and cellular biologist, team up to acquire a prestigious $1 million grant from the Human Frontier Science Program. They credit discussion and brainstorming with CIFAR fellows as a key to their success. The grant takes advantage of their multidisciplinary approach by including both epigenetic and human behaviour components. The grant funds basic science studies investigating the central neural signaling pathways involved in the acquisition of language and communicative behaviour in animal models and humans. The fellows have since published a number of high profile papers on topics including the impact of antidepressants during pregnancy on infant speech perception (see 2012) and the acquisition of absolute pitch in adulthood (see 2013).
W. Weikum et al., “Prenatal exposure to antidepressants and depressed maternal mood alter trajectory of infant speech perception,” in G. Robinson (Ed.) “The Biological Embedding of Early Social Adversity: From Fruit Flies to Kindergarteners,” Supplement to Proceedings of the National Academy of Sciences, vol. 109, supp. 2, pp. 17143-17308, Arthur M. Sackler Colloquium of the National Academy of Sciences (October 16, 2012).
Fellows celebrate the recruitment of leading geneticist Marla Sokolowski (University of Toronto) to the program. Sokolowski, a molecular biologist who discovered the foraging gene, is considered a pioneer in the genetic and molecular underpinnings of food-related behaviour in fruit flies. While perhaps a surprising model of interest for the program, the fruit fly is invaluable to genetic studies because of its genetic similarity to humans and its rapid ability to reproduce, allowing multigenerational studies in a short time. Sokolowski plans to use the fruit fly models to study the genetic and neuroplastic links between early life adversity and adult health outcomes. For more information, please watch the video to the left of Marla Sokolowski's 2013 interview on TVO's The Agenda with Steve Paikin.
The program recruits molecular geneticist Joel Levine (University of Toronto Mississauga) and developmental biologist David Clayton (Queen Mary, University of London). The two senior fellows aim to decipher the molecular and cellular processes underlying experience-dependent changes in gene expression and brain function, particularly in the context of social interaction and behaviour. Clayton's work focuses on zebra finches while Levine primarily studies fruit flies. Both are useful models in epigenetic studies. For more information, please see this video by the University of Illinois at Urbana-Champaign about Clayton's research on song birds and this 2013 PNAS Science Sessions podcast with Levine about fruit flies.
The World Health Organization International Commission on the Social Determinants of Health publishes its final report, “Closing the gap in a generation: Health equity through action on the social determinants of health." Under the leadership of CIFAR Senior Fellow Clyde Hertzman, Canada is the primary knowledge contributor of one of the report’s key chapters, “Equity from the Start,” which is devoted entirely to early child development. Based on the findings, the report recommends that WHO member countries “commit to and implement a comprehensive approach to early life, building on existing child survival programs and extending interventions in early life to include social/emotional and language/cognitive development.”
Building on their fascinating Nature Neuroscience study involving maternal rat care (see 2004), CIFAR Senior Fellows Michael Meaney (Douglas Hospital Research Centre) and Moshe Szyf (McGill University) translate their work to humans, demonstrating that early life adversity may epigenetically influence subsequent responsivity in the adult brain. Childhood abuse is known to alter the HPA axis, the brain’s key stress response system, and to cause an increased risk of suicide. However, prior to these two hallmark studies, the biological mechanisms to explain these connections was unclear. In looking at adult brain tissue from suicide victims (or individuals who died suddenly without a history of child abuse), the researchers identify that the epigenetic changes controlling the expression of ribosomal RNA and cortisol receptor genes differ systematically amongst individuals with a history of childhood abuse. The findings implicate the epigenetic modulation of rRNA in the pathophysiology of suicide, as well as the role of parental care in the epigenetic regulation of stress responsivity in humans. They highlight the possibility that suicide victims are burdened long before they decide to commit suicide.
P. McGowan et al., “Epigenetic regulation of the glucocorticoid receptor in human brain associates with childhood abuse,” Nature Neuroscience, vol. 12, pp. 342-348 (February 22, 2009). doi:10.1038/nn.2270
To tackle the incidence of Shaken Baby Syndrome (SBS), CIFAR Senior Fellow Ronald Barr (University of British Columbia) develops "The Period of PURPLE Crying," an educational booklet and DVD designed to teach parents about the normalcy of infant crying and the dangers associated with shaking. Two randomized controlled trials show that the materials increased parental understanding regarding infant crying and improved behaviours considered important for SBS prevention (e.g. walking away during inconsolable crying). The approach is now being utilized in over a 1,000 hospitals in Canada and the U.S., as well as in hospitals in Japan and Australia.
R.G. Barr et al., “Do educational materials change knowledge and behaviour about crying and shaken baby syndrome? A randomized controlled trial,” Canadian Medical Association Journal, vol. 180, no. 7, pp. 727-733 (March 31, 2009) doi: 10.1503/cmaj.081419
R.G. Barr et al., “Effectiveness of Educational Materials Designed to Change Knowledge and Behaviors Regarding Crying and Shaken-Baby Syndrome in Mothers of Newborns: A Randomized, Controlled Trial,” Pediatrics, vol. 123, no. 3, pp. 972-980 (March 1, 2009). doi: 10.1542/peds.2008-0908
CIFAR Senior Fellow Michael Kobor (University of British Columbia) helps explain why children raised in unfavourable socio-economic circumstances display an increased susceptibility to chronic diseases of aging in their 50s and 60s. Kobor and colleagues show that a low socio-economic early life environment appears to trigger a defensive epigenetic adaptation through a down-regulation of genes involved in the stress response and an up regulation of genes involved in pro-inflammatory signaling. While in the short-term these adaptations may help the individual deal with adversity, in the long run they take a toll on the body, likely contributing to an enhanced susceptibility to chronic disease.
CIFAR Senior Fellow and program Co-Director Marla Sokolowski (University of Toronto) and colleagues untangle a mechanism that makes ants adjust their behavior according to environmental cues. The ants they study can change roles between majors who defend the nest, or minors who forage for food, depending on environmental cues including food availability. The researchers identify the foraging gene (originally identified by Sokolowski in fruit flies), and an enzyme encoded by the foraging gene called PKG, as biological mediators of this behavioural shift. Majors and minors display distinct differences in PKG activity and in the spatial distribution of foraging protein in the brain (see inset picture). Manipulation of foraging gene or PKG activity levels can also trigger behavioural switching. This study is one of the first to identify the actual biological mechanisms underpinning an environment-induced change in behaviour.
A striking study by CIFAR Senior Fellow Janet Werker (University of British Columbia) identifies that babies are already familiar with specific languages at birth. The researchers give babies a pacifier connected to a computer to measure sucking rate and then expose them to a variety of languages. An increase in sucking indicates an interest in the language being heard. Babies sucked most when they heard the language their mother had regularly spoken during pregnancy; for example, English versus Tagalog or Chinese. Babies born from bilingual mothers who spoke two languages regularly throughout pregnancy, responded with equal interest to both languages. Strikingly, babies from bilingual mothers were able to differentiate one language from another; babies increased their sucking rate when hearing a familiar language until they became disinterested and stopped, but once another language was introduced, they started fervently sucking again, showing they could identify the switch from one language to another.
CIFAR Senior Fellows Clyde Hertzman and Tom Boyce (both University of British Columbia) publish a paper in the Annual Review of Public Health about the way social environments and experiences get under the skin early in life to affect the course of human development. This publication is the first of its kind to show how the relationships among population health, early human development and developmental neurobiology are of paramount importance to the field of public health.
CIFAR Senior Fellows Tom Boyce, Clyde Hertzman and Michael Kobor (all University of British Columbia) as well as CIFAR Global Scholar Jelena Obradović (Stanford University) travel to Karachi, Pakistan to explore collaborating with the Aga Khan University. This visit results in a Grand Challenges Canada grant to Obradović, to study the impact of early, developmental interventions on the executive function (a measure of cognitive capacity) of infants and toddlers in rural Pakistan. In collaboration with Aga Khan’s Aisha Yousafzai, the researchers hope to provide novel neurobiological evidence that interventions in the lives of children in the developing world can influence basic neural processes. The study now involves CIFAR Senior Fellow Charles Nelson (Harvard University) who is providing expertise on electroencephalographic measures of prefrontal neural functions. The initial visit also results in a pilot study to assess the impact of the implementation of the Early Development Instrument (see 2005) in a large jurisdiction of rural Pakistan.
CIFAR Senior Fellows Marla Sokolowski (University of Toronto) and Michael Meaney (Douglas Hospital Research Centre) publish a study showing a link between a genetic variation, mothering capacity and a mother’s own early life adversity. In conjunction with the Maternal Adversity, Vulnerability and Neurodevelopment project in human children, the researchers show that variations in the serotonin transporter gene – a key gene for developmental and mental health – affect maternal sensitivity and behaviour towards six-month-old infants when the early experience of the mother is taken into account. Mothers with a history of abuse in their own childhoods and a specific variation of the serotonin transporter gene looked away from their babies more frequently than mothers with the same variation who had no history of abuse, or mothers who had a variation of the gene considered to be more protective. This finding may help explain why some people are more sensitive to abuse or postpartum depression than others. Since this publication the researchers have identified other genetic variations in genes associated with the dopaminergic and oxytocin systems, which also appear to link to mothering capacity.
The program successfully holds a prestigious Arthur M. Sackler Colloquium entitled "The Biological Embedding of Early Social Adversity: From Fruit Flies to Kindergartners," with sponsorship from CIFAR Advisor and National Academy of Science member Gene Robinson. The topic is inspired by the program’s observation that socio-economic position is the single most powerful determinant of health and development in humans and that differential exposure to early childhood adversities contributes strongly to resultant social disparities. Held in California, the colloquium features presentations from fellows in the program as well as other leading scientists investigating the biology of social stratification and the ways in which socially partitioned adversities affect neurobiological and genomic processes. The symposium enables the program to share its cutting edge research and insight with a world class, cross disciplinary assembly of basic, biomedical and social scientists.
“The Biological Embedding of Early Social Adversity: From Fruit Flies to Kindergarteners,” Supplement to Proceedings of the National Academy of Sciences, vol. 109, supp. 2, pp. 17143-17308, Arthur M. Sackler Colloquium of the National Academy of Sciences (October 16, 2012).
The world's first evidence that social circumstances early in life — socioeconomic and psychosocial — can influence the genome through epigenetic processes arises from two collaborative publications authored by CIFAR fellows. The first study identifies a differential methylation pattern (a type of epigenetic modulator which influences how much or how little a gene is expressed) in adolescents whose parents reported high levels of stress during their children’s early lives, as compared to adolescents whose parents did not. The second study assessed DNA from participants of the 1958 British Birth Cohort, a group who had previously been shown to have socio-economic gradients in health, learning and development. The paper identified an association between differential methylation of adult DNA and childhood socio-economic position. These studies are crucial because they identify epigenetic modifications as a plausible basic mechanism of biological embedding, and as such provide clear evidence that nature and nurture are inextricably connected in human development, leaving behind the nature versus nurture debate.
N. Borghol et al., “Associations with early-life socio-economic position in adult DNA methylation,” International Journal of Epidemiology, vol. 41, no. 1, pp. 62-74 (February 2012) doi: 10.1093/ije/dyr147
M. Essex et al., “Epigenetic Vestiges of Early Developmental Adversity: Childhood Stress Exposure and DNA Methylation in Adolescence,” Child Development, vol. 84, no. 1, pp. 58-75 (January/February 2013) doi: 10.1111/j.1467-8624.2011.01641.x
CIFAR Senior Fellows Clyde Hertzman (University of British Columbia), Tom Boyce (University of California San Francisco), Marla Sokolowski (University of Toronto) and Ronald Barr (University of British Columbia) are invited to form part of a Royal Society of Canada & Canadian Academy of Health Sciences Expert Panel on Early Childhood Development. The panel is convened to provide the Canadian public with a consensus document of scientific evidence on how early biological, social and environmental factors interact to influence long-term health outcomes. The resulting report is now a widely used tool for those concerned with early childhood development.
CIFAR Senior Fellows Stephen Suomi (National Institute of Child Health and Human Development) and Moshe Szyf (McGill University) show that maternal rearing environment directly influences genomic methylation patterns in rhesus macaques. Monkeys raised for the first six months by their mothers showed differences compared with monkeys reared by an inanimate surrogate. The two groups had distinctly different methylation patterns in blood (lymphocytes) and brain (frontal cortex) DNA as young adults. These findings demonstrate the concept of biological embedding in animals that are closely related to humans. Maternal rearing triggered different methylation patterns in common regions of DNA from both brain and blood samples, as well as tissue-specific changes. This finding suggests that the biological embedding of early life adversity is both system-wide and genome-wide, a particularly relevant observation for human epigenetics studies where access to brain tissue is difficult.
Following the 2011 Sackler colloquium, CIFAR fellows contribute a special issue to Proceedings of the National Academy of Sciences, one of world's most-cited multidisciplinary scientific serials. The volume, entitled, "The Biological Embedding of Early Social Adversity: From Fruit Flies to Kindergarteners," contains 25 articles written mostly by CIFAR fellows in the Child & Brain Development program from a variety of disciplines, and spanning a range of topics. For example, the research covered links between antidepressant use during pregnancy and changes in the way infants perceived speech, and the impact of early life nutritional adversity on subsequent exploratory and risk-taking behaviour as adults in fruit flies. Papers also covered epigenomic remodeling as a result of early life socioeconomic status or early life psychosocial factors and the behavioural adaptation of kindergartners to social stratification and classroom climate.
CIFAR Senior Fellows Takao Hensch (Harvard University) and Janet Werker (University of British Columbia) are able to re-open a learning window in adults and allow them to nearly acquire absolute pitch. Absolute pitch is the ability to accurately identify a musical note without a reference point, and the critical period for learning it usually closes after about the age of seven. The researchers found that giving the drug valproate, in conjunction with a note recognition training program, reinstates plasticity for absolute pitch in adults. Critical periods – a fixed window of time during which an organism has a heightened sensitivity to an environmental stimulus required to develop a particular skill – are a key focus of the program, since they have a lasting effect on the development of brain function and behaviour. This work is important because it suggests a way that perceptual capabilities might be reinstated in individuals who would otherwise never have them: for example, individuals who had hearing loss or blindness corrected late in life.
For more information, please see this interview with CIFAR Senior Fellow Takao Hensch on National Public Radio.
CIFAR Fellow Thomas McDade (Northwestern University) shows that contrary to previous reports, early experience appears to affect the association between stress and inflammation in adulthood. McDade finds that people exposed to low levels of microbes in infancy show enhanced sensitivity to the pro-inflammatory effects of stress as adults. The results suggest that higher levels of microbial exposure in infancy may serve to buffer the adverse health effects of pro-inflammatory stressors in adulthood, raising the question of whether highly hygienic western societies may actually be doing their children a disservice.
CIFAR Senior Fellow Megan Gunnar (University of Minnesota) and CIFAR Advisor Charles Nelson (Harvard University) identify a deficit in executive function (a measure of cognitive capacity) in 10 and 11 year old children who were adopted as infants or toddlers. The researchers test brain electrical activity during two specific attention tasks in both adopted children and non-adopted children raised in households with similar income and education levels. Adopted children are found to display alterations in sustaining attention and executive attention, findings which agree with previous work identifying a link between suboptimal conditions early in life with an impact on brain regions involved in behaviour regulation. These findings have significant implications for a child’s potential school achievement and may help explain the achievement gap associated with children who have experienced adversity in early life.
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