1 707 134 BY WHAT MOLECULAR MECHANISMS DO SOCIAL DETERMINANTS IMPACT CARDIOMETABOLIC RISK? WHILE IT IS WELL KNOWN FROM NUMEROUS EPIDEMIOLOGIC INVESTIGATIONS THAT SOCIAL DETERMINANTS (SOCIOECONOMIC, ENVIRONMENTAL, AND PSYCHOSOCIAL FACTORS EXPOSED TO OVER THE LIFE-COURSE) CAN DRAMATICALLY IMPACT CARDIOVASCULAR HEALTH, THE MOLECULAR MECHANISMS BY WHICH SOCIAL DETERMINANTS LEAD TO POOR CARDIOMETABOLIC OUTCOMES ARE NOT WELL UNDERSTOOD. THIS REVIEW COMPREHENSIVELY SUMMARIZES A VARIETY OF CURRENT TOPICS SURROUNDING THE BIOLOGICAL EFFECTS OF ADVERSE SOCIAL DETERMINANTS (I.E., THE BIOLOGY OF ADVERSITY), LINKING TRANSLATIONAL AND LABORATORY STUDIES WITH EPIDEMIOLOGIC FINDINGS. WITH A STRONG FOCUS ON THE BIOLOGICAL EFFECTS OF CHRONIC STRESS, WE HIGHLIGHT AN ARRAY OF STUDIES ON MOLECULAR AND IMMUNOLOGICAL SIGNALING IN THE CONTEXT OF SOCIAL DETERMINANTS OF HEALTH (SDOH). THE MAIN TOPICS COVERED INCLUDE BIOMARKERS OF SYMPATHETIC NERVOUS SYSTEM AND HYPOTHALAMIC-PITUITARY-ADRENAL AXIS ACTIVATION, AND THE ROLE OF INFLAMMATION IN THE BIOLOGY OF ADVERSITY FOCUSING ON GLUCOCORTICOID RESISTANCE AND KEY INFLAMMATORY CYTOKINES LINKED TO PSYCHOSOCIAL AND ENVIRONMENTAL STRESSORS (PSES). WE THEN FURTHER DISCUSS THE EFFECT OF SDOH ON IMMUNE CELL DISTRIBUTION AND CHARACTERIZATION BY SUBSET, RECEPTOR EXPRESSION, AND FUNCTION. LASTLY, WE DESCRIBE EPIGENETIC REGULATION OF THE CHRONIC STRESS RESPONSE AND EFFECTS OF SDOH ON TELOMERE LENGTH AND AGING. ULTIMATELY, WE HIGHLIGHT CRITICAL KNOWLEDGE GAPS FOR FUTURE RESEARCH AS WE STRIVE TO DEVELOP MORE TARGETED INTERVENTIONS THAT ACCOUNT FOR SDOH TO IMPROVE CARDIOMETABOLIC HEALTH FOR AT-RISK, VULNERABLE POPULATIONS. 2023 2 4985 36 PATHWAYS TO AGING: THE MITOCHONDRION AT THE INTERSECTION OF BIOLOGICAL AND PSYCHOSOCIAL SCIENCES. COMPELLING EVIDENCE SUGGESTS THAT BOTH BIOLOGICAL AND PSYCHOSOCIAL FACTORS IMPACT THE PROCESS OF AGING. HOWEVER, OUR UNDERSTANDING OF THE DYNAMIC INTERPLAY AMONG BIOLOGICAL AND PSYCHOSOCIAL FACTORS ACROSS THE LIFE COURSE IS STILL FRAGMENTARY. FOR EXAMPLE, IT NEEDS TO BE ESTABLISHED HOW THE INTERACTION OF INDIVIDUAL FACTORS (E.G., GENETIC AND EPIGENETIC ENDOWMENT AND PERSONALITY), BEHAVIORAL FACTORS (E.G., PHYSICAL ACTIVITY, DIET, AND STRESS MANAGEMENT), AND PSYCHOSOCIAL EXPERIENCES (E.G., SOCIAL SUPPORT, WELL-BEING, SOCIOECONOMIC STATUS, AND MARRIAGE) IN PERINATAL, CHILDHOOD, AND ADULTHOOD INFLUENCE HEALTH ACROSS THE AGING CONTINUUM. THIS PAPER AIMS TO OUTLINE POTENTIAL INTERSECTION POINTS SERVING AS AN INTERFACE BETWEEN BIOLOGICAL AND PSYCHOSOCIAL FACTORS, WITH AN EMPHASIS ON THE MITOCHONDRION. MITOCHONDRIA ARE CELLULAR ORGANELLES WHICH PLAY A CRITICAL ROLE IN CELLULAR SENESCENCE. BOTH CHRONIC EXPOSURE TO PSYCHOSOCIAL STRESS AND GENETIC-BASED MITOCHONDRIAL DYSFUNCTION HAVE STRIKINGLY SIMILAR BIOLOGICAL CONSEQUENCES; BOTH PREDISPOSE INDIVIDUALS TO ADVERSE AGE-RELATED HEALTH DISORDERS AND EARLY MORTALITY. EXPLORING THE INTERACTIVE NATURE OF THE FACTORS RESULTING IN PATHWAYS TO NORMAL HEALTHY AGING, AS WELL AS THOSE LEADING TO MORBIDITY AND EARLY MORTALITY, WILL CONTINUE TO ENHANCE OUR ABILITY TO TRANSLATE RESEARCH INTO EFFECTIVE PRACTICES THAT CAN BE IMPLEMENTED THROUGHOUT THE LIFE COURSE TO OPTIMISE THE AGING PROCESS. 2011 3 4591 36 NARRATIVE REVIEW OF THE COMPLEX INTERACTION BETWEEN PAIN AND TRAUMA IN CHILDREN: A FOCUS ON BIOLOGICAL MEMORY, PRECLINICAL DATA, AND EPIGENETIC PROCESSES. THE INCIDENCE AND COLLECTIVE IMPACT OF EARLY ADVERSE EXPERIENCES, TRAUMA, AND PAIN CONTINUE TO INCREASE. THIS UNDERSCORES THE URGENT NEED FOR TRANSLATIONAL EFFORTS BETWEEN CLINICAL AND PRECLINICAL RESEARCH TO BETTER UNDERSTAND THE UNDERLYING MECHANISMS AND DEVELOP EFFECTIVE THERAPEUTIC APPROACHES. AS OUR UNDERSTANDING OF THESE ISSUES IMPROVES FROM STUDIES IN CHILDREN AND ADOLESCENTS, WE CAN CREATE MORE PRECISE PRECLINICAL MODELS AND ULTIMATELY TRANSLATE OUR FINDINGS BACK TO CLINICAL PRACTICE. A MULTIDISCIPLINARY APPROACH IS ESSENTIAL FOR ADDRESSING THE COMPLEX AND WIDE-RANGING EFFECTS OF THESE EXPERIENCES ON INDIVIDUALS AND SOCIETY. THIS NARRATIVE REVIEW AIMS TO (1) DEFINE PAIN AND TRAUMA EXPERIENCES IN CHILDHOOD AND ADOLESCENTS, (2) DISCUSS THE RELATIONSHIP BETWEEN PAIN AND TRAUMA, (3) CONSIDER THE ROLE OF BIOLOGICAL MEMORY, (4) DECIPHER THE RELATIONSHIP BETWEEN PAIN AND TRAUMA USING PRECLINICAL DATA, AND (5) EXAMINE THE ROLE OF THE ENVIRONMENT BY INTRODUCING THE IMPORTANCE OF EPIGENETIC PROCESSES. THE ULTIMATE SCOPE IS TO BETTER UNDERSTAND THE WIDE-RANGING EFFECTS OF TRAUMA, ABUSE, AND CHRONIC PAIN ON CHILDREN AND ADOLESCENTS, HOW THEY OCCUR, AND HOW TO PREVENT OR MITIGATE THEIR EFFECTS AND DEVELOP EFFECTIVE TREATMENT STRATEGIES THAT ADDRESS BOTH THE UNDERLYING CAUSES AND THE ASSOCIATED PHYSIOLOGICAL AND PSYCHOLOGICAL EFFECTS. 2023 4 6119 28 THE EPIGENETIC IMPACTS OF SOCIAL STRESS: HOW DOES SOCIAL ADVERSITY BECOME BIOLOGICALLY EMBEDDED? EPIGENETIC MECHANISMS ARE IMPLICATED IN THE PROCESSES THROUGH WHICH SOCIAL STRESSORS ERODE HEALTH IN HUMANS AND OTHER ANIMALS. HERE I REVIEW PROGRESS IN ELUCIDATING THE BIOLOGICAL PATHWAYS UNDERLYING THE SOCIAL GRADIENT IN HEALTH, WITH PARTICULAR EMPHASIS ON HOW BEHAVIORAL STRESSES INFLUENCE EPIGENOMIC VARIATION LINKED TO HEALTH. THE EVIDENCE THAT EPIGENETIC CHANGES ARE INVOLVED IN EMBEDDING OF SOCIAL STATUS-LINKED CHRONIC STRESS IS REVIEWED IN THE CONTEXT OF CURRENT KNOWLEDGE ABOUT BEHAVIOR WITHIN ANIMAL DOMINANCE HIERARCHIES AND THE IMPACTS OF SOCIAL POSITION ON BEHAVIORS THAT AFFECT HEALTH. THE ROLES OF EPIGENETIC MECHANISMS IN RESPONSES TO TRAUMA AND THE EVIDENCE FOR THEIR INVOLVEMENT IN INTERGENERATIONAL TRANSMISSION OF THE BIOLOGICAL IMPACTS OF TRAUMATIC STRESS ARE ALSO CONSIDERED. TAKEN TOGETHER, THE EMERGING INSIGHTS HAVE IMPORTANT IMPLICATIONS FOR DEVELOPMENT OF STRATEGIES TO IMPROVE SOCIETAL HEALTH AND WELL-BEING. 2016 5 6026 40 THE BIOLOGY OF STRESS INTOLERANCE IN PATIENTS WITH CHRONIC PAIN-STATE OF THE ART AND FUTURE DIRECTIONS. STRESS HAS BEEN CONSISTENTLY LINKED TO NEGATIVE IMPACTS ON PHYSICAL AND MENTAL HEALTH. MORE SPECIFICALLY, PATIENTS WITH CHRONIC PAIN EXPERIENCE STRESS INTOLERANCE, WHICH IS AN EXACERBATION OR OCCURRENCE OF SYMPTOMS IN RESPONSE TO ANY TYPE OF STRESS. THE PATHOPHYSIOLOGICAL MECHANISMS UNDERLYING THIS PHENOMENON REMAIN UNSOLVED. IN THIS STATE-OF-THE-ART PAPER, WE SUMMARISED THE ROLE OF THE AUTONOMIC NERVOUS SYSTEM (ANS) AND HYPOTHALAMUS-PITUITARY-ADRENAL (HPA) AXIS, THE TWO MAJOR STRESS RESPONSE SYSTEMS IN STRESS INTOLERANCE. WE PROVIDED INSIGHTS INTO SUCH MECHANISMS BASED ON EVIDENCE FROM CLINICAL STUDIES IN BOTH PATIENTS WITH CHRONIC PAIN, SHOWING DYSREGULATED STRESS SYSTEMS, AND HEALTHY CONTROLS SUPPORTED BY PRECLINICAL STUDIES, HIGHLIGHTING THE LINK BETWEEN THESE SYSTEMS AND SYMPTOMS OF STRESS INTOLERANCE. FURTHERMORE, WE EXPLORED THE POSSIBLE REGULATING ROLE FOR (EPI)GENETIC MECHANISMS INFLUENCING THE ANS AND HPA AXIS. THE LINK BETWEEN STRESS AND CHRONIC PAIN HAS BECOME AN IMPORTANT AREA OF RESEARCH AS IT HAS THE POTENTIAL TO INFORM THE DEVELOPMENT OF INTERVENTIONS TO IMPROVE THE QUALITY OF LIFE FOR INDIVIDUALS LIVING WITH CHRONIC PAIN. AS STRESS HAS BECOME A PREVALENT CONCERN IN MODERN SOCIETY, UNDERSTANDING THE CONNECTION BETWEEN STRESS, HPA AXIS, ANS, AND CHRONIC HEALTH CONDITIONS SUCH AS CHRONIC PAIN IS CRUCIAL TO IMPROVE PUBLIC HEALTH AND WELL-BEING. 2023 6 5164 43 PRECLINICAL AND CLINICAL EVIDENCE OF DNA METHYLATION CHANGES IN RESPONSE TO TRAUMA AND CHRONIC STRESS. EXPOSURE TO CHRONIC STRESS, EITHER REPEATED SEVERE ACUTE OR MODERATE SUSTAINED STRESS, IS ONE OF THE STRONGEST RISK FACTORS FOR THE DEVELOPMENT OF PSYCHOPATHOLOGIES SUCH AS POST-TRAUMATIC STRESS DISORDER AND DEPRESSION. CHRONIC STRESS IS LINKED WITH SEVERAL LASTING BIOLOGICAL CONSEQUENCES, PARTICULARLY TO THE STRESS ENDOCRINE SYSTEM BUT ALSO AFFECTING INTERMEDIATE PHENOTYPES SUCH AS BRAIN STRUCTURE AND FUNCTION, IMMUNE FUNCTION, AND BEHAVIOR. ALTHOUGH GENETIC PREDISPOSITION CONFERS A PROPORTION OF THE RISK, THE MOST RELEVANT MOLECULAR MECHANISMS DETERMINING THOSE SUSCEPTIBLE AND RESILIENT TO THE EFFECTS OF STRESS AND TRAUMA MAY BE EPIGENETIC. EPIGENETICS REFERS TO THE MECHANISMS THAT REGULATE GENOMIC INFORMATION BY DYNAMICALLY CHANGING THE PATTERNS OF TRANSCRIPTION AND TRANSLATION OF GENES. MOUNTING EVIDENCE FROM PRECLINICAL RODENT AND CLINICAL POPULATION STUDIES STRONGLY SUPPORT THAT EPIGENETIC MODIFICATIONS CAN OCCUR IN RESPONSE TO TRAUMATIC AND CHRONIC STRESS. HERE, WE DISCUSS THIS LITERATURE EXAMINING STRESS-INDUCED EPIGENETIC CHANGES IN PRECLINICAL MODELS AND CLINICAL COHORTS OF STRESS AND TRAUMA OCCURRING EARLY IN LIFE OR IN ADULTHOOD. WE HIGHLIGHT THAT A COMPLEX RELATIONSHIP BETWEEN THE TIMING OF ENVIRONMENTAL STRESSORS AND GENETIC PREDISPOSITIONS LIKELY MEDIATE THE RESPONSE TO CHRONIC STRESS OVER TIME, AND THAT A BETTER UNDERSTANDING OF EPIGENETIC CHANGES IS NEEDED BY FURTHER INVESTIGATIONS IN LONGITUDINAL AND POSTMORTEM BRAIN CLINICAL COHORTS. 2017 7 1938 35 EPIDEMIOLOGIC EVIDENCE FOR ASSOCIATION BETWEEN ADVERSE ENVIRONMENTAL EXPOSURES IN EARLY LIFE AND EPIGENETIC VARIATION: A POTENTIAL LINK TO DISEASE SUSCEPTIBILITY? A GROWING BODY OF EVIDENCE SUGGESTS THAT THE RISK OF DEVELOPMENT AND PROGRESSION OF A VARIETY OF HUMAN CHRONIC DISEASES DEPENDS ON EPIGENETIC MODIFICATIONS TRIGGERED BY ENVIRONMENTAL CUES DURING EARLY LIFE SENSITIVE STAGES. EXPOSURES TO ENVIRONMENTAL FACTORS SUCH AS ADVERSE NUTRITIONAL, PSYCHOLOGICAL, AND SOCIAL CONDITIONS, AS WELL AS POLLUTANTS AND SUBSTANCE ABUSE IN EARLY LIFE, HAVE BEEN SHOWN TO BE IMPORTANT DETERMINANTS OF EPIGENETIC PROGRAMMING OF CHRONIC PATHOLOGICAL CONDITIONS IN HUMAN POPULATIONS. OVER THE PAST YEARS, IT HAS BECOME INCREASINGLY CLEAR DUE TO THE EPIGENOME-WIDE ASSOCIATION STUDIES (EWASS) THAT EARLY LIFE ADVERSE ENVIRONMENTAL EVENTS MAY TRIGGER WIDESPREAD AND PERSISTENT ALTERATIONS IN TRANSCRIPTIONAL PROFILING. SEVERAL CANDIDATE GENES HAVE BEEN IDENTIFIED UNDERLYING THESE ASSOCIATIONS. IN THIS CONTEXT, DNA METHYLATION IS THE MOST INTENSIVELY STUDIED EPIGENETIC PHENOMENON. IN THIS REVIEW, THE CLINICAL AND EPIDEMIOLOGICAL EVIDENCE FOR THE ROLE OF EPIGENETIC FACTORS IN MEDIATING THE LINK BETWEEN EARLY LIFE EXPERIENCES AND LONG-TERM HEALTH OUTCOMES ARE SUMMARIZED. 2015 8 5316 32 PSYCHOLOGICAL STRESS IN EARLY LIFE AS A PREDISPOSING FACTOR FOR THE DEVELOPMENT OF CHRONIC PAIN: CLINICAL AND PRECLINICAL EVIDENCE AND NEUROBIOLOGICAL MECHANISMS. A WEALTH OF RESEARCH OVER THE PAST 2 DECADES HAS EXPANDED OUR UNDERSTANDING OF THE IMPACT OF EARLY-LIFE ADVERSITY ON PHYSIOLOGICAL FUNCTION AND, CONSEQUENTLY, HEALTH AND WELLBEING IN LATER LIFE. EARLY-LIFE ADVERSITY INCREASES THE RISK OF DEVELOPING A NUMBER OF DISORDERS, SUCH AS CHRONIC PAIN, FIBROMYALGIA, AND IRRITABLE BOWEL SYNDROME. ALTHOUGH MUCH OF THE RESEARCH HAS EXAMINED THE IMPACT OF PHYSICAL MALTREATMENT, AN INCREASING NUMBER OF STUDIES HAVE BEEN PUBLISHED OVER THE PAST FEW YEARS EXAMINING THE EFFECT OF CHILDHOOD PSYCHOLOGICAL STRESS AND TRAUMA ON THE DEVELOPMENT OF VARIOUS TYPES OF CHRONIC PAIN CONDITIONS. WE REVIEW THE CLINICAL AND PRECLINICAL DATA EXAMINING THE LINK AMONG EARLY-LIFE PSYCHOLOGICAL STRESS, ALTERED NOCICEPTIVE BEHAVIOR, AND CHRONIC PAIN IN LATER LIFE. EVIDENCE SUPPORTING A ROLE FOR CERTAIN KEY NEUROBIOLOGICAL SUBSTRATES, INCLUDING THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS; MONOAMINERGIC, OPIOIDERGIC, ENDOCANNABINOID AND IMMUNE SYSTEMS; AND EPIGENETIC MECHANISMS IN THE ASSOCIATION BETWEEN EARLY-LIFE PSYCHOLOGICAL STRESS AND CHRONIC PAIN, IS PROVIDED. GREATER UNDERSTANDING OF THE IMPACT OF EARLY-LIFE STRESS MAY INFORM THE DEVELOPMENT OF PERSONALIZED TREATMENTS FOR CHRONIC PAIN IN LATER LIFE AND STRATEGIES TO PREVENT ITS ONSET IN SUSCEPTIBLE INDIVIDUALS. (C) 2016 WILEY PERIODICALS, INC. 2017 9 5829 28 STRESS, PSYCHIATRIC DISORDERS, MOLECULAR TARGETS, AND MORE. MENTAL HEALTH IS CENTRAL TO NORMAL HEALTH OUTCOMES. A WIDELY ACCEPTED THEORY IS THAT CHRONIC PERSISTENT STRESS DURING ADULTHOOD AS WELL AS DURING EARLY LIFE TRIGGERS ONSET OF NEUROPSYCHIATRIC AILMENTS. HOWEVER, QUESTIONS RELATED TO HOW THAT OCCURS, AND WHY ARE SOME INDIVIDUALS RESISTANT TO STRESS WHILE OTHERS ARE NOT, REMAIN UNANSWERED. AN INTEGRATED, MULTISYSTEMIC STRESS RESPONSE INVOLVING NEUROINFLAMMATORY, NEUROENDOCRINE, EPIGENETIC AND METABOLIC CASCADES HAVE BEEN SUGGESTED TO HAVE CAUSATIVE LINKS. SEVERAL THEORIES HAVE BEEN PROPOSED OVER THE YEARS TO CONCEPTUALIZE THIS LINK INCLUDING THE CYTOKINE HYPOTHESIS, THE ENDOCRINE HYPOTHESIS, THE OXIDATIVE STRESS HYPOTHESIS AND THE OXIDO-NEUROINFLAMMATION HYPOTHESIS. THE DATA DISCUSSED IN THIS REVIEW DESCRIBES POTENTIAL BIOCHEMICAL BASIS OF THE LINK BETWEEN STRESS, AND STRESS-INDUCED NEURONAL, BEHAVIORAL AND EMOTIONAL DEFICITS, PROVIDING INSIGHTS INTO POTENTIALLY NOVEL DRUG TARGETS. 2019 10 5813 31 STRESS AND ASTHMA: NOVEL INSIGHTS ON GENETIC, EPIGENETIC, AND IMMUNOLOGIC MECHANISMS. IN THE UNITED STATES THE ECONOMICALLY DISADVANTAGED AND SOME ETHNIC MINORITIES ARE OFTEN EXPOSED TO CHRONIC PSYCHOSOCIAL STRESSORS AND DISPROPORTIONATELY AFFECTED BY ASTHMA. CURRENT EVIDENCE SUGGESTS A CAUSAL ASSOCIATION BETWEEN CHRONIC PSYCHOSOCIAL STRESS AND ASTHMA OR ASTHMA MORBIDITY. RECENT FINDINGS SUGGEST POTENTIAL MECHANISMS UNDERLYING THIS ASSOCIATION, INCLUDING CHANGES IN THE METHYLATION AND EXPRESSION OF GENES THAT REGULATE BEHAVIORAL, AUTONOMIC, NEUROENDOCRINE, AND IMMUNOLOGIC RESPONSES TO STRESS. THERE IS ALSO EVIDENCE SUGGESTING THE EXISTENCE OF SUSCEPTIBILITY GENES THAT PREDISPOSE CHRONICALLY STRESSED YOUTH TO BOTH POST-TRAUMATIC STRESS DISORDER AND ASTHMA. IN THIS REVIEW WE CRITICALLY EXAMINE PUBLISHED EVIDENCE AND SUGGEST FUTURE DIRECTIONS FOR RESEARCH IN THIS FIELD. 2014 11 2724 38 EXPERIENCE-SENSITIVE EPIGENETIC MECHANISMS, DEVELOPMENTAL PLASTICITY, AND THE BIOLOGICAL EMBEDDING OF CHRONIC DISEASE RISK. A WIDE RANGE OF DEVELOPMENTAL, NUTRITIONAL, ENVIRONMENTAL, AND SOCIAL FACTORS AFFECT THE BIOLOGICAL ACTIVITIES OF EPIGENETIC MECHANISMS. THESE FACTORS CHANGE SPATIOTEMPORAL PATTERNS OF GENE EXPRESSION IN A VARIETY OF DIFFERENT WAYS AND BRING SIGNIFICANT IMPACTS TO BEAR ON DEVELOPMENT, PHYSIOLOGY, AND DISEASE RISK THROUGHOUT THE LIFE COURSE. ABUNDANT EVIDENCE DEMONSTRATES THAT BEHAVIORAL STRESSORS AND ADVERSE NUTRITIONAL CONDITIONS ARE PARTICULARLY POTENT INDUCERS OF EPIGENETIC CHANGES AND ENHANCERS OF CHRONIC DISEASE RISKS. RECENT INSIGHTS FROM BOTH HUMAN CLINICAL STUDIES AND RESEARCH WITH MODEL ORGANISMS FURTHER INDICATE THAT SUCH EXPERIENCE-DEPENDENT CHANGES TO THE EPIGENOME CAN BE TRANSMITTED THROUGH THE GERMLINE ACROSS MULTIPLE GENERATIONS, WITH IMPORTANT CONSEQUENCES FOR THE HERITABILITY OF BOTH ADAPTIVE AND MALADAPTIVE PHENOTYPES. EPIGENETICS RESEARCH THUS OFFERS MANY POSSIBILITIES FOR DEVELOPING INFORMATIVE BIOMARKERS OF ACQUIRED CHRONIC DISEASE RISK AND DETERMINING THE EFFECTIVENESS OF PREVENTIVE AND THERAPEUTIC INTERVENTIONS. MOREOVER, THE EXPERIENCE-SENSITIVE NATURE OF THESE DISEASE RISKS RAISES IMPORTANT QUESTIONS ABOUT SOCIETAL AND INDIVIDUAL RESPONSIBILITIES FOR THE PREVENTION OF ILL-HEALTH AND THE PROMOTION OF WELL-BEING DURING DEVELOPMENT, ACROSS THE LIFE COURSE AND BETWEEN GENERATIONS. BETTER UNDERSTANDING OF HOW EPIGENETIC MECHANISMS REGULATE DEVELOPMENTAL PLASTICITY AND MEDIATE THE BIOLOGICAL EMBEDDING OF CHRONIC DISEASE RISKS IS THEREFORE LIKELY TO SHED IMPORTANT NEW LIGHT ON THE NATURE OF THE PATHOPHYSIOLOGICAL MECHANISMS LINKING SOCIAL AND HEALTH INEQUALITIES, AND WILL HELP TO INFORM PUBLIC POLICY INITIATIVES IN THIS AREA. CONFLICT OF INTEREST: THE AUTHOR HAS DECLARED NO CONFLICTS OF INTEREST FOR THIS ARTICLE. 2015 12 634 41 BIOLOGICAL EMBEDDING OF EARLY-LIFE ADVERSITY AND A SCOPING REVIEW OF THE EVIDENCE FOR INTERGENERATIONAL EPIGENETIC TRANSMISSION OF STRESS AND TRAUMA IN HUMANS. SEVERE OR CHRONIC STRESS AND TRAUMA CAN HAVE A DETRIMENTAL IMPACT ON HEALTH. EVIDENCE SUGGESTS THAT EARLY-LIFE ADVERSITY CAN BECOME BIOLOGICALLY EMBEDDED AND HAS THE POTENTIAL TO INFLUENCE HEALTH OUTCOMES DECADES LATER. EPIGENETICS IS ONE MECHANISM THAT HAS BEEN IMPLICATED IN THESE LONG-LASTING EFFECTS. OBSERVATIONAL STUDIES IN HUMANS INDICATE THAT THE EFFECTS OF STRESS COULD EVEN PERSIST ACROSS GENERATIONS, ALTHOUGH WHETHER OR NOT EPIGENETIC MECHANISMS ARE INVOLVED REMAINS UNDER DEBATE. HERE, WE PROVIDE AN OVERVIEW OF STUDIES IN ANIMALS AND HUMANS THAT DEMONSTRATE THE EFFECTS OF EARLY-LIFE STRESS ON DNA METHYLATION, ONE OF THE MOST WIDELY STUDIED EPIGENETIC MECHANISMS, AND SUMMARIZE FINDINGS FROM ANIMAL MODELS DEMONSTRATING THE INVOLVEMENT OF EPIGENETICS IN THE TRANSMISSION OF STRESS ACROSS GENERATIONS. WE THEN DESCRIBE THE RESULTS OF A SCOPING REVIEW TO DETERMINE THE EXTENT TO WHICH THE TERMS INTERGENERATIONAL OR TRANSGENERATIONAL HAVE BEEN USED IN HUMAN STUDIES INVESTIGATING THE TRANSMISSION OF TRAUMA AND STRESS VIA EPIGENETIC MECHANISMS. WE END WITH A DISCUSSION OF KEY AREAS FOR FUTURE RESEARCH TO ADVANCE UNDERSTANDING OF THE ROLE OF EPIGENETICS IN THE LEGACY EFFECTS OF STRESS AND TRAUMA. 2023 13 6211 37 THE INTERPLAY BETWEEN OXIDATIVE STRESS, EXERCISE, AND PAIN IN HEALTH AND DISEASE: POTENTIAL ROLE OF AUTONOMIC REGULATION AND EPIGENETIC MECHANISMS. OXIDATIVE STRESS CAN BE INDUCED BY VARIOUS STIMULI AND ALTERED IN CERTAIN CONDITIONS, INCLUDING EXERCISE AND PAIN. ALTHOUGH MANY STUDIES HAVE INVESTIGATED OXIDATIVE STRESS IN RELATION TO EITHER EXERCISE OR PAIN, THE LITERATURE PRESENTS CONFLICTING RESULTS. THEREFORE, THIS REVIEW CRITICALLY DISCUSSES EXISTING LITERATURE ABOUT THIS TOPIC, AIMING TO PROVIDE A CLEAR OVERVIEW OF KNOWN INTERACTIONS BETWEEN OXIDATIVE STRESS, EXERCISE, AND PAIN IN HEALTHY PEOPLE AS WELL AS IN PEOPLE WITH CHRONIC PAIN, AND TO HIGHLIGHT POSSIBLE CONFOUNDING FACTORS TO KEEP IN MIND WHEN REFLECTING ON THESE INTERACTIONS. IN ADDITION, AUTONOMIC REGULATION AND EPIGENETIC MECHANISMS ARE PROPOSED AS POTENTIAL MECHANISMS OF ACTION UNDERLYING THE INTERPLAY BETWEEN OXIDATIVE STRESS, EXERCISE, AND PAIN. THIS REVIEW HIGHLIGHTS THAT THE RELATION BETWEEN OXIDATIVE STRESS, EXERCISE, AND PAIN IS POORLY UNDERSTOOD AND NOT STRAIGHTFORWARD, AS IT IS DEPENDENT ON THE CHARACTERISTICS OF EXERCISE, BUT ALSO ON WHICH POPULATION IS INVESTIGATED. TO BE ABLE TO COMPARE STUDIES ON THIS TOPIC, STRICT GUIDELINES SHOULD BE DEVELOPED TO LIMIT THE EFFECT OF SEVERAL CONFOUNDING FACTORS. THIS WAY, THE TRUE INTERPLAY BETWEEN OXIDATIVE STRESS, EXERCISE, AND PAIN, AND THE UNDERLYING MECHANISMS OF ACTION CAN BE REVEALED AND VALIDATED VIA INDEPENDENT STUDIES. 2020 14 754 51 CARDIOVASCULAR ADAPTATIONS TO PARTICLE INHALATION EXPOSURE: MOLECULAR MECHANISMS OF THE TOXICOLOGY. AMBIENT AIR, OCCUPATIONAL SETTINGS, AND THE USE AND DISTRIBUTION OF CONSUMER PRODUCTS ALL SERVE AS CONDUITS FOR TOXICANT EXPOSURE THROUGH INHALATION. WHILE THE PULMONARY SYSTEM REMAINS A PRIMARY TARGET FOLLOWING INHALATION EXPOSURE, CARDIOVASCULAR IMPLICATIONS ARE EXCEPTIONALLY CULPABLE FOR INCREASED MORBIDITY AND MORTALITY. THE EPIDEMIOLOGICAL EVIDENCE FOR CARDIOVASCULAR DYSFUNCTION RESULTING FROM ACUTE OR CHRONIC INHALATION EXPOSURE TO PARTICULATE MATTER HAS BEEN WELL DOCUMENTED, BUT THE MECHANISMS DRIVING THE RESULTING DISTURBANCES REMAIN ELUSIVE. IN THE CURRENT REVIEW, WE AIM TO SUMMARIZE THE CELLULAR AND MOLECULAR MECHANISMS THAT ARE DIRECTLY LINKED TO CARDIOVASCULAR HEALTH FOLLOWING EXPOSURE TO A VARIETY OF INHALED TOXICANTS. THE PURPOSE OF THIS REVIEW IS TO PROVIDE A COMPREHENSIVE OVERVIEW OF THE BIOCHEMICAL CHANGES IN THE CARDIOVASCULAR SYSTEM FOLLOWING PARTICLE INHALATION EXPOSURE AND TO HIGHLIGHT POTENTIAL BIOMARKERS THAT EXIST ACROSS MULTIPLE EXPOSURE PARADIGMS. WE ATTEMPT TO INTEGRATE THESE MOLECULAR SIGNATURES IN AN EFFORT TO PROVIDE DIRECTION FOR FUTURE INVESTIGATIONS. THIS REVIEW ALSO CHARACTERIZES HOW MOLECULAR RESPONSES ARE MODIFIED IN AT-RISK POPULATIONS, SPECIFICALLY THE IMPACT OF ENVIRONMENTAL EXPOSURE DURING CRITICAL WINDOWS OF DEVELOPMENT. MATERNAL EXPOSURE TO PARTICULATE MATTER DURING GESTATION CAN LEAD TO FETAL EPIGENETIC REPROGRAMMING, RESULTING IN LONG-TERM DEFICITS TO THE CARDIOVASCULAR SYSTEM. IN BOTH DIRECT AND INDIRECT (GESTATIONAL) EXPOSURES, CONNECTING THE BIOCHEMICAL MECHANISMS WITH FUNCTIONAL DEFICITS OUTLINES PATHWAYS THAT CAN BE TARGETED FOR FUTURE THERAPEUTIC INTERVENTION. ULTIMATELY, FUTURE INVESTIGATIONS INTEGRATING "OMICS"-BASED APPROACHES WILL BETTER ELUCIDATE THE MECHANISMS THAT ARE ALTERED BY XENOBIOTIC INHALATION EXPOSURE, IDENTIFY BIOMARKERS, AND GUIDE IN CLINICAL DECISION MAKING. 2020 15 3582 30 IMPACT OF PRENATAL AND EARLY LIFE ENVIRONMENTAL EXPOSURES ON NORMAL HUMAN DEVELOPMENT. THE GLOBAL BURDEN AND PATTERN OF DISEASE HAS CHANGED IN RECENT DECADES, WITH FEWER EARLY CHILDHOOD DEATHS AND LONGER LIVES COMPLICATED BY CHRONIC DISEASE. DISRUPTION OF NORMAL HUMAN GROWTH AND DEVELOPMENT BY ADVERSE ENVIRONMENTAL EXPOSURES, ESPECIALLY DURING FOETAL DEVELOPMENT AND EARLY POSTNATAL LIFE INCREASE LIFE-LONG RISK OF CHRONIC DISEASE. THE DEVELOPMENTAL TIMING AND METHOD OF ADVERSE EXPOSURE DETERMINES THE LIKELY IMPACT ON HEALTH AND DEVELOPMENT. WHILE MANY ORGAN SYSTEMS ARE STRUCTURALLY AND FUNCTIONALLY MATURE AT BIRTH, THE CNS, RESPIRATORY AND IMMUNE SYSTEMS ARE NOT AND UNDERGO PROLONGED PERIODS OF POSTNATAL GROWTH AND DEVELOPMENT. AS SUCH, THESE ORGAN SYSTEMS ARE VULNERABLE TO ADVERSE EFFECTS OF BOTH PRENATAL AND POSTNATAL ENVIRONMENTAL EXPOSURES. WHILE THE PRECISE MECHANISMS UNDERLYING CHRONIC DISEASE ARE UNKNOWN, EPIGENETIC MECHANISMS AND THE INDUCTION OF OXIDATIVE STRESS ARE LIKELY TO BE INVOLVED. AN UNDERSTANDING OF THESE PROCESSES IS NECESSARY TO DEVELOP MITIGATION STRATEGIES AIMED AT REDUCING CHRONIC DISEASE PREVALENCE. 2021 16 6034 44 THE CHALLENGE BY MULTIPLE ENVIRONMENTAL AND BIOLOGICAL FACTORS INDUCE INFLAMMATION IN AGING: THEIR ROLE IN THE PROMOTION OF CHRONIC DISEASE. THE AGING PROCESS IS DRIVEN BY MULTIPLE MECHANISMS THAT LEAD TO CHANGES IN ENERGY PRODUCTION, OXIDATIVE STRESS, HOMEOSTATIC DYSREGULATION AND EVENTUALLY TO LOSS OF FUNCTIONALITY AND INCREASED DISEASE SUSCEPTIBILITY. MOST AGED INDIVIDUALS DEVELOP CHRONIC LOW-GRADE INFLAMMATION, WHICH IS AN IMPORTANT RISK FACTOR FOR MORBIDITY, PHYSICAL AND COGNITIVE IMPAIRMENT, FRAILTY, AND DEATH. AT ANY AGE, CHRONIC INFLAMMATORY DISEASES ARE MAJOR CAUSES OF MORBIMORTALITY, AFFECTING UP TO 5-8% OF THE POPULATION OF INDUSTRIALIZED COUNTRIES. SEVERAL ENVIRONMENTAL FACTORS CAN PLAY AN IMPORTANT ROLE FOR MODIFYING THE INFLAMMATORY STATE. GENETICS ACCOUNTS FOR ONLY A SMALL FRACTION OF CHRONIC-INFLAMMATORY DISEASES, WHEREAS ENVIRONMENTAL FACTORS APPEAR TO PARTICIPATE, EITHER WITH A CAUSATIVE OR A PROMOTIONAL ROLE IN 50% TO 75% OF PATIENTS. SEVERAL OF THOSE CHANGES DEPEND ON EPIGENETIC CHANGES THAT WILL FURTHER MODIFY THE INDIVIDUAL RESPONSE TO ADDITIONAL STIMULI. THE INTERACTION BETWEEN INFLAMMATION AND THE ENVIRONMENT OFFERS IMPORTANT INSIGHTS ON AGING AND HEALTH. THESE CONDITIONS, OFTEN DEPENDING ON THE INDIVIDUAL'S SEX, APPEAR TO LEAD TO DECREASED LONGEVITY AND PHYSICAL AND COGNITIVE DECLINE. IN ADDITION TO BIOLOGICAL FACTORS, THE ENVIRONMENT IS ALSO INVOLVED IN THE GENERATION OF PSYCHOLOGICAL AND SOCIAL CONTEXT LEADING TO STRESS. POOR PSYCHOLOGICAL ENVIRONMENTS AND OTHER SOURCES OF STRESS ALSO RESULT IN INCREASED INFLAMMATION. HOWEVER, THE MECHANISMS UNDERLYING THE ROLE OF ENVIRONMENTAL AND PSYCHOSOCIAL FACTORS AND NUTRITION ON THE REGULATION OF INFLAMMATION, AND HOW THE RESPONSE ELICITED FOR THOSE FACTORS INTERACT AMONG THEM, ARE POORLY UNDERSTOOD. WHEREAS CERTAIN DELETERIOUS ENVIRONMENTAL FACTORS RESULT IN THE GENERATION OF OXIDATIVE STRESS DRIVEN BY AN INCREASED PRODUCTION OF REACTIVE OXYGEN AND NITROGEN SPECIES, ENDOPLASMIC RETICULUM STRESS, AND INFLAMMATION, OTHER FACTORS, INCLUDING NUTRITION (POLYUNSATURATED FATTY ACIDS) AND BEHAVIORAL FACTORS (EXERCISE) CONFER PROTECTION AGAINST INFLAMMATION, OXIDATIVE AND ENDOPLASMIC RETICULUM STRESS, AND THUS AMELIORATE THEIR DELETERIOUS EFFECT. HERE, WE DISCUSS PROCESSES AND MECHANISMS OF INFLAMMATION ASSOCIATED WITH ENVIRONMENTAL FACTORS AND BEHAVIOR, THEIR LINKS TO SEX AND GENDER, AND THEIR OVERALL IMPACT ON AGING. 2020 17 2638 26 EPIGENOME: BIOSENSOR OF CUMULATIVE EXPOSURE TO CHEMICAL AND NONCHEMICAL STRESSORS RELATED TO ENVIRONMENTAL JUSTICE. UNDERSTANDING DIFFERENTIAL DISEASE SUSCEPTIBILITY REQUIRES NEW TOOLS TO QUANTIFY THE CUMULATIVE EFFECTS OF ENVIRONMENTAL STRESS. EVIDENCE SUGGESTS THAT SOCIAL, PHYSICAL, AND CHEMICAL STRESSORS CAN INFLUENCE DISEASE THROUGH THE ACCUMULATION OF EPIGENETIC MODIFICATIONS. GEOGRAPHICALLY STABLE EPIGENETIC ALTERATIONS COULD IDENTIFY PLAUSIBLE MECHANISMS FOR HEALTH DISPARITIES AMONG THE DISADVANTAGED AND POOR. RELATIONS BETWEEN NEIGHBORHOOD-SPECIFIC EPIGENETIC MARKERS AND DISEASE WOULD IDENTIFY THE MOST APPROPRIATE TARGETS FOR MEDICAL AND ENVIRONMENTAL INTERVENTION. COMPLEX INTERACTIONS AMONG GENES, THE ENVIRONMENT, AND DISEASE REQUIRE THE EXAMINATION OF HOW EPIGENETIC CHANGES REGULATE SUSCEPTIBILITY TO ENVIRONMENTAL STRESSORS. PROGRESS IN UNDERSTANDING DISPARITIES IN DISEASE SUSCEPTIBILITY MAY DEPEND ON ASSESSING THE CUMULATIVE EFFECT OF ENVIRONMENTAL STRESSORS ON GENETIC SUBSTRATES. WE HIGHLIGHT KEY CONCEPTS REGARDING THE INTERFACE BETWEEN ENVIRONMENTAL STRESS, EPIGENETICS, AND CHRONIC DISEASE. 2014 18 6189 43 THE IMPACT OF LIFE STRESS ON HALLMARKS OF AGING AND ACCELERATED SENESCENCE: CONNECTIONS IN SICKNESS AND IN HEALTH. CHRONIC STRESS IS A RISK FACTOR FOR NUMEROUS AGING-RELATED DISEASES AND HAS BEEN SHOWN TO SHORTEN LIFESPAN IN HUMANS AND OTHER SOCIAL MAMMALS. YET HOW LIFE STRESS CAUSES SUCH A VAST RANGE OF DISEASES IS STILL LARGELY UNCLEAR. IN RECENT YEARS, THE IMPACT OF STRESS ON HEALTH AND AGING HAS BEEN INCREASINGLY ASSOCIATED WITH THE DYSREGULATION OF THE SO-CALLED HALLMARKS OF AGING. THESE ARE BASIC BIOLOGICAL MECHANISMS THAT INFLUENCE INTRINSIC CELLULAR FUNCTIONS AND WHOSE ALTERATION CAN LEAD TO ACCELERATED AGING. HERE, WE REVIEW CORRELATIONAL AND EXPERIMENTAL LITERATURE (PRIMARILY FOCUSING ON EVIDENCE FROM HUMANS AND MURINE MODELS) ON THE CONTRIBUTION OF LIFE STRESS - PARTICULARLY STRESS DERIVED FROM ADVERSE SOCIAL ENVIRONMENTS - TO TRIGGER HALLMARKS OF AGING, INCLUDING CELLULAR SENESCENCE, STERILE INFLAMMATION, TELOMERE SHORTENING, PRODUCTION OF REACTIVE OXYGEN SPECIES, DNA DAMAGE, AND EPIGENETIC CHANGES. WE ALSO EVALUATE THE VALIDITY OF STRESS-INDUCED SENESCENCE AND ACCELERATED AGING AS AN ETIOPATHOLOGICAL PROPOSITION. FINALLY, WE HIGHLIGHT CURRENT GAPS OF KNOWLEDGE AND FUTURE DIRECTIONS FOR THE FIELD, AND DISCUSS PERSPECTIVES FOR TRANSLATIONAL GEROSCIENCE. 2023 19 1248 35 CURRENT EVIDENCE FOR BIOLOGICAL BIOMARKERS AND MECHANISMS UNDERLYING ACUTE TO CHRONIC PAIN TRANSITION ACROSS THE PEDIATRIC AGE SPECTRUM. CHRONIC PAIN IS HIGHLY PREVALENT IN THE PEDIATRIC POPULATION. MANY FACTORS ARE INVOLVED IN THE TRANSITION FROM ACUTE TO CHRONIC PAIN. CURRENTLY, THERE ARE CONCEPTUAL MODELS PROPOSED, BUT THEY LACK A MECHANISTICALLY SOUND INTEGRATED THEORY CONSIDERING THE STAGES OF CHILD DEVELOPMENT. OBJECTIVE BIOMARKERS ARE CRITICALLY NEEDED FOR THE DIAGNOSIS, RISK STRATIFICATION, AND PROGNOSIS OF THE PATHOLOGICAL STAGES OF PAIN CHRONIFICATION. IN THIS ARTICLE, WE SUMMARIZE THE CURRENT EVIDENCE ON MECHANISMS AND BIOMARKERS OF ACUTE TO CHRONIC PAIN TRANSITIONS IN INFANTS AND CHILDREN THROUGH THE DEVELOPMENTAL LENS. THE GOAL IS TO IDENTIFY GAPS AND OUTLINE FUTURE DIRECTIONS FOR BASIC AND CLINICAL RESEARCH TOWARD A DEVELOPMENTALLY INFORMED THEORY OF PAIN CHRONIFICATION IN THE PEDIATRIC POPULATION. AT THE OUTSET, THE IMPORTANCE OF OBJECTIVE BIOMARKERS FOR CHRONIFICATION OF PAIN IN CHILDREN IS OUTLINED, FOLLOWED BY A SUMMARY OF THE CURRENT EVIDENCE ON THE MECHANISMS OF ACUTE TO CHRONIC PAIN TRANSITION IN ADULTS, IN ORDER TO CONTRAST WITH THE DEVELOPMENTAL MECHANISMS OF PAIN CHRONIFICATION IN THE PEDIATRIC POPULATION. EVIDENCE IS PRESENTED TO SHOW THAT CHRONIC PAIN MAY HAVE ITS ORIGIN FROM INSULTS EARLY IN LIFE, WHICH PRIME THE CHILD FOR THE DEVELOPMENT OF CHRONIC PAIN IN LATER LIFE. FURTHERMORE, AVAILABLE GENETIC, EPIGENETIC, PSYCHOPHYSICAL, ELECTROPHYSIOLOGICAL, NEUROIMAGING, NEUROIMMUNE, AND SEX MECHANISMS ARE DESCRIBED IN INFANTS AND OLDER CHILDREN. IN CONCLUSION, FUTURE DIRECTIONS ARE DISCUSSED WITH A FOCUS ON RESEARCH GAPS, TRANSLATIONAL AND CLINICAL IMPLICATIONS. UTILIZATION OF DEVELOPMENTAL MECHANISMS FRAMEWORK TO INFORM CLINICAL DECISION-MAKING AND STRATEGIES FOR PREVENTION AND MANAGEMENT OF ACUTE TO CHRONIC PAIN TRANSITIONS IN CHILDREN, IS HIGHLIGHTED. 2023 20 585 32 BEHAVIORAL PERINATOLOGY: BIOBEHAVIORAL PROCESSES IN HUMAN FETAL DEVELOPMENT. BEHAVIORAL PERINATOLOGY IS AS AN INTERDISCIPLINARY AREA OF RESEARCH THAT INVOLVES CONCEPTUALIZATION OF THEORETICAL MODELS AND CONDUCT OF EMPIRICAL STUDIES OF THE DYNAMIC TIME-, PLACE-, AND CONTEXT-DEPENDENT INTERPLAY BETWEEN BIOLOGICAL AND BEHAVIORAL PROCESSES IN FETAL, NEONATAL, AND INFANT LIFE USING AN EPIGENETIC FRAMEWORK OF DEVELOPMENT. THE BIOBEHAVIORAL PROCESSES OF PARTICULAR INTEREST TO OUR RESEARCH GROUP RELATE TO THE EFFECTS OF MATERNAL PRE- AND PERINATAL STRESS AND MATERNAL-PLACENTAL-FETAL STRESS PHYSIOLOGY. WE PROPOSE THAT BEHAVIORAL PERINATOLOGY RESEARCH MAY HAVE IMPORTANT IMPLICATIONS FOR A BETTER UNDERSTANDING OF THE PROCESSES THAT UNDERLIE OR CONTRIBUTE TO THE RISK OF THREE SETS OF OUTCOMES: PREMATURITY, ADVERSE NEURODEVELOPMENT, AND CHRONIC DEGENERATIVE DISEASES IN ADULTHOOD. BASED ON OUR UNDERSTANDING OF THE ONTOGENY OF HUMAN FETAL DEVELOPMENT AND THE PHYSIOLOGY OF PREGNANCY AND FETAL DEVELOPMENT, WE HAVE ARTICULATED A NEUROBIOLOGICAL MODEL OF PRE- AND PERINATAL STRESS. OUR MODEL PROPOSES THAT CHRONIC MATERNAL STRESS MAY EXERT A SIGNIFICANT INFLUENCE ON FETAL DEVELOPMENTAL OUTCOMES. MATERNAL STRESS MAY ACT VIA ONE OR MORE OF THREE MAJOR PHYSIOLOGICAL PATHWAYS: NEUROENDOCRINE, IMMUNE/INFLAMMATORY, AND VASCULAR. WE FURTHER SUGGEST THAT PLACENTAL CORTICOTROPIN-RELEASING HORMONE (CRH) MAY PLAY A CENTRAL ROLE IN COORDINATING THE EFFECTS OF ENDOCRINE, IMMUNE/INFLAMMATORY, AND VASCULAR PROCESSES ON FETAL DEVELOPMENTAL OUTCOMES. FINALLY, WE HYPOTHESIZE THAT THE EFFECTS OF MATERNAL STRESS ARE MODULATED BY THE NATURE, DURATION, AND TIMING OF OCCURRENCE OF STRESS DURING GESTATION. IN THIS PAPER, WE ELABORATE ON THE CONCEPTUAL AND EMPIRICAL BASIS FOR THIS MODEL, HIGHLIGHT SOME RELEVANT ISSUES AND QUESTIONS, AND MAKE RECOMMENDATIONS FOR FUTURE RESEARCH IN THIS AREA. 2002