Prenatal tobacco exposure, maternal postnatal nicotine dependence and adolescent risk for nicotine dependence: Birth cohort study

Through a teratological lens: A narrative review of exposure to stress and drugs of abuse during pregnancy on neurodevelopment

Teratological research shows that both prenatal stress and prenatal substance exposure have a significant impact on neurodevelopmental outcomes in children. Using human research, the purpose of this narrative review is to explore the degree to which these exposures may represent complex prenatal and postnatal risks for the development of cognition and behavior in children. An understanding of the HPA axis and its function during pregnancy as well as the types and operationalization of prenatal stress provide a context for understanding the direct and indirect mechanisms by which prenatal stress affects brain and behavior development. In turn, prenatal substance exposure studies are evaluated for their importance in understanding variables that indicate a potential interaction with prenatal stress including reactivity to novelty, arousal, and stress reactivity during early childhood. The similarities and differences between prenatal stress exposure and prenatal substance exposure on neurodevelopmental outcomes including arousal and emotion regulation, cognition, behavior, stress reactivity, and risk for psychopathology are summarized. Further considerations for teratological studies of prenatal stress and/or substance exposure include identifying and addressing methodological challenges, embracing the complexity of pre-and postnatal environments in the research, and the importance of incorporating parenting and resilience into future studies.

Black Father's Influence on Adverse Pregnancy Outcomes in the United States: A Narrative Synthesis of Literature

Few studies have investigated paternal characteristics in relationship with adverse pregnancy outcomes, and results are inconsistent. The purpose of this study was to review studies examining associations between characteristics of Black fathers and adverse pregnancy outcomes in the United States. A systematic narrative synthesis was conducted of research studies examining paternal characteristics of Black fathers in association with adverse pregnancy outcomes: preterm birth, hypertensive disorders of pregnancy, gestational diabetes, spontaneous abortion, and maternal mortality. Seven databases (Academic Search Premier, CINHAL, CENTRAL, ClinicalTrials.gov, Embase, PubMed, and Web of Science) were searched for original research articles from inception to February 2023. Articles were excluded if they (a) were in a language other than English, (b) did not describe original research, (c) included a geographic region outside of the United States, (d) did not include adverse maternal outcomes as a study outcome, (e) did not describe race of fathers in the study sample, and (f) did not describe a paternal characteristic of Black fathers. The search resulted in 210 articles. Six studies were included in the final review; five studies examined associations between paternal characteristics of Black fathers and preterm birth, finding significantly increased odds of preterm birth among births with Black fathers. Among births with non-Hispanic Black paternity, the odds of hypertensive disorders of pregnancy were reduced or not significantly associated. Researchers should continue to explore paternal factors that influence pregnancy outcomes in racial/ethnic-specific models to identify optimal intervention strategies to improve disparities in maternal and child health outcomes.

Utility of the Zebrafish Model for Studying Neuronal and Behavioral Disturbances Induced by Embryonic Exposure to Alcohol, Nicotine, and Cannabis

It is estimated that 5% of pregnant women consume drugs of abuse during pregnancy. Clinical research suggests that intake of drugs during pregnancy, such as alcohol, nicotine and cannabis, disturbs the development of neuronal systems in the offspring, in association with behavioral disturbances early in life and an increased risk of developing drug use disorders. After briefly summarizing evidence in rodents, this review focuses on the zebrafish model and its inherent advantages for studying the effects of embryonic exposure to drugs of abuse on behavioral and neuronal development, with an emphasis on neuropeptides known to promote drug-related behaviors. In addition to stimulating the expression and density of peptide neurons, as in rodents, zebrafish studies demonstrate that embryonic drug exposure has marked effects on the migration, morphology, projections, anatomical location, and peptide co-expression of these neurons. We also describe studies using advanced methodologies that can be applied in vivo in zebrafish: first, to demonstrate a causal relationship between the drug-induced neuronal and behavioral disturbances and second, to discover underlying molecular mechanisms that mediate these effects. The zebrafish model has great potential for providing important information regarding the development of novel and efficacious therapies for ameliorating the effects of early drug exposure.

Prenatal nicotine exposure during pregnancy results in adverse neurodevelopmental alterations and neurobehavioral deficits

Maternal tobacco use and nicotine exposure during pregnancy have been associated with adverse birth outcomes in infants and can lead to preventable pregnancy complications. Exposure to nicotine and other compounds in tobacco and electronic cigarettes (e-cigarettes) has been shown to increases the risk of miscarriage, prematurity, stillbirth, low birth weight, perinatal morbidity, and sudden infant death syndrome (SIDS). Additionally, recent data provided by clinical and pre-clinical research demonstrates that nicotine exposure during pregnancy may heighten the risk for adverse neurodevelopmental disorders such as Attention-Deficit Hyperactivity (ADHD), anxiety, and depression along with altering the infants underlying brain circuitry, response to neurotransmitters, and brain volume. In the United States, one in 14 women (7.2%) reported to have smoked cigarettes during their pregnancy with the global prevalence of smoking during pregnancy estimated to be 1.7%. Approximately 1.1% of women in the United States also reported to have used e-cigarettes during the last 3 months of pregnancy. Due to the large percentage of women utilizing nicotine products during pregnancy in the United States and globally, this review seeks to centralize pre-clinical and clinical studies focused on the neurobehavioral and neurodevelopmental complications associated with prenatal nicotine exposure (PNE) such as alterations to the hypothalamic-pituitary-adrenal (HPA) axis and brain regions such as the prefrontal cortex (PFC), ventral tegmental area (VTA), nucleus accumbens (NA), hippocampus, and caudate as well as changes to nAChR and cholinergic receptor signaling, long-term drug seeking behavior following PNE, and other related developmental disorders. Current literature analyzing the association between PNE and the risk for offspring developing schizophrenia, attention-deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), anxiety, and obesity will also be discussed.

Pregnant and postnatal women's experiences of interacting with health care providers about their tobacco smoking: a qualitative systematic review

OBJECTIVE

The objective of this review was twofold: (i) to comprehensively identify the best available evidence about the experiences of women who smoked tobacco during pregnancy or postnatally (or both) concerning health care providers' interactions with them about their smoking, when such interactions occurred during contact for prenatal or postnatal health care in any health care setting; and (ii) to synthesize the research findings for recommendations to strengthen health care providers' interventions regarding smoking during pregnancy and smoking during the postnatal period.

INTRODUCTION

Maternal tobacco smoking during pregnancy and maternal tobacco smoking postnatally pose serious health risks for the woman, fetus, and offspring, whereas maternal smoking cessation has beneficial health effects. Given the importance of health care providers' interactions with pregnant and postnatal women for smoking cessation care, it is essential to understand women's experiences of such interactions.

INCLUSION CRITERIA

Studies considered for this review had qualitative research findings about the experiences of women who smoked tobacco during pregnancy or postnatally (or both) in relation to health care providers' interactions with them about their smoking.

METHODS

The review was conducted using the JBI approach to qualitative systematic reviews. Published studies were sought through 6 academic databases (eg, CINAHL, MEDLINE). Unpublished studies were searched in 6 gray literature sources (eg, ProQuest Dissertations and Theses, Google Scholar). Reference lists of retrieved records were also searched. The searches occurred in October and November 2020; no country, language, or date limits were applied. Study selection involved title and abstract screening, full-text examination, and critical appraisal of all studies that met the inclusion criteria for the review. Study characteristics and research findings were extracted from the included studies. Study selection and extraction of findings were conducted by two reviewers independently; differences between reviewers were resolved through consensus. The research findings were categorized, and the categories were aggregated into a set of synthesized findings. The synthesized finding were assigned confidence scores. The categories and finalized synthesized findings were agreed upon by all reviewers.

RESULTS

The 57 included studies varied in qualitative research designs and in methodological quality (from mostly low to high). There were approximately 1092 eligible participants, and 250 credible and unequivocal research findings. The research findings yielded 14 categories and 6 synthesized findings with low to very low confidence scores. Some women who smoked tobacco during pregnancy and some women who smoked tobacco postnatally lacked supportive interactions by health care providers regarding their smoking; other women experienced supportive interactions by health care providers. Women were adversely impacted when health care providers' interactions lacked supportiveness, and were beneficially impacted when interactions were supportive. Women varied in openness to health care providers' interactions regarding their smoking, from not being receptive to being accepting, and some women wanted meaningful health care provider interactions.

CONCLUSIONS

Although confidence in the synthesized findings is low to very low, the evidence indicates that supportive health care provider interactions may facilitate positive smoking behavior change in pregnancy and postnatally. It is recommended that health care providers implement accepted clinical practice guidelines with women who smoke prenatally or postnatally, using an approach that is person-centered, emotionally supportive, engaging (eg, understanding), and non-authoritarian.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42020178866.

The Understanding of Maternal Smoking among Women who were Smoking or had Quit Smoking during Pregnancy

Background

Maternal tobacco smoking during pregnancy is associated with adverse health effects for the woman, fetus, and child, including such serious effects as preterm birth, low birth weight, stillbirth, and neonatal and sudden infant death. Smoking cessation during pregnancy reduces health risks.

Purpose

In order to support pregnant women to quit smoking, it is essential to know determinants of quitting smoking in pregnancy. The purpose of this research was to examine women's understanding of maternal smoking, in terms of their beliefs, in relation to quitting smoking during pregnancy.

Methods

The study was a cross-sectional survey with anonymous questionnaires. The sample consisted of 161 pregnant and postnatal women who were continuing or had continued to smoke during pregnancy or had quit smoking during pregnancy. Logistic regression was used to determine the impact of women's understanding of maternal smoking on quitting smoking in pregnancy.

Results

A large majority of the women had low to moderate understanding of maternal smoking. Those with higher levels of understanding were more likely to quit smoking during pregnancy than were those with a low level of understanding. Not having children prior to the current pregnancy or childbirth also increased the likelihood of quitting smoking during pregnancy while being without a partner combined with having a longer duration of smoking decreased the likelihood of quitting smoking during pregnancy.

Conclusion

As a modifiable factor, pregnant women's understanding of maternal smoking can be readily targeted with informational interventions in an effort to help them quit smoking.

Prenatal alcohol and tobacco exposures and the risk of cannabis use in offspring: Findings from a population-based cohort study

BACKGROUND

There is a paucity of prospective longitudinal studies examining the associations between maternal use of alcohol and tobacco during pregnancy and the risk of cannabis use in offspring. The aim of this study was to examine the association between prenatal alcohol and tobacco exposures and offspring cannabis use.

METHODS

Data were from the Raine Study, a longitudinal prospective birth cohort based in Western Australia. Cannabis use at 17 years of age was measured with a self-reported questionnaire developed to capture risky behaviors in adolescents. Associations between prenatal alcohol and tobacco exposures and the risk of cannabis use in offspring were examined using log-binomial regression models, computing relative risk (RR). We also computed the E-values (E) to estimate the extent of unmeasured confounding.

RESULTS

After adjusting for potential confounders, we observed increased risks of cannabis use in offspring exposed to first trimester prenatal alcohol use (RR = 1.38, 95% CI: 1.09-1.75; E = 2.10, CI:1.40) and tobacco use (RR = 1.42, 95% CI: 1.08-1.86; E = 2.19, CI:1.37) as well as third trimester prenatal alcohol use (RR = 1.39, 95% CI: 1.09-1.79; E = 2.13, CI:1.40) and tobacco use (RR = 1.39, 95% CI: 1.09-1.79; E = 2.21, CI:1.34]. We also noted dose-response associations in which risk estimates in offspring increased with the level of exposures to prenatal alcohol and tobacco use.

CONCLUSION

These findings provide epidemiological evidence for effects of prenatal alcohol and tobacco exposures on offspring cannabis use. Although these results should be confirmed by other studies, the present study adds to the mounting evidence suggesting that women should be encouraged to abstain from alcohol and tobacco during pregnancy.

Prenatal nicotine alters development of the laterodorsal tegmentum: Possible role for attention-deficit/hyperactivity disorder and drug dependence

As we cycle between the states of wakefulness and sleep, a bilateral cholinergic nucleus in the pontine brain stem, the laterodorsal tegmentum (LDT), plays a critical role in controlling salience processing, attention, behavioral arousal, and electrophysiological signatures of the sub- and microstates of sleep. Disorders involving abnormal alterations in behavioral and motivated states, such as drug dependence, likely involve dysfunctions in LDT signaling. In addition, as the LDT exhibits connectivity with the thalamus and mesocortical circuits, as well as receives direct, excitatory input from the prefrontal cortex, a role for the LDT in cognitive symptoms characterizing attention-deficit/hyperactivity disorder (ADHD) including impulsivity, inflexibility, and dysfunctions of attention is suggested. Prenatal nicotine exposure (PNE) is associated with a higher risk for later life development of drug dependence and ADHD, suggesting alteration in development of brain regions involved in these behaviors. PNE has been shown to alter glutamate and cholinergic signaling within the LDT. As glutamate and acetylcholine are major excitatory mediators, these alterations would likely alter excitatory output to target regions in limbic motivational circuits and to thalamic and cortical networks mediating executive control. Further, PNE alters neuronal development and transmission within prefrontal cortex and limbic areas that send input to the LDT, which would compound effects of differential processing within the PNE LDT. When taken together, alterations in signaling in the LDT are likely to play a role in negative behavioral outcomes seen in PNE individuals, including a heightened risk of drug dependence and ADHD behaviors.

Syndemics of Sexually Transmitted Infections in a Sample of Racially Diverse Pregnant Young Women

Introduction

Syndemic theory posits that poor health outcomes co-occur and amplify each other in the context of harmful conditions that must be addressed simultaneously to improve health equity. This analysis identifies perinatal syndemic factors and examine how factors are related to STI in a sample of racially diverse young pregnant women.

Methods

Pregnant participants (n = 61) ages 14–21 from racially diverse backgrounds were recruited from a prenatal clinic for an ongoing longitudinal study between October 2019-February 2020. Participants completed a tablet survey assessing pregnancy intention, psychosocial factors (e.g., depression, stress, partner violence, pregnancy history) and consented to provide access to their medical records for STI and clinical urine samples screened for tobacco and cannabis use. Latent class analysis (LCA) was used to examine probabilities of co-occurring Syndemic indicators.

Results

Half of the women were Black (52%) and primigravida (54%). Three classes were identified in the LCA, two of them reflecting syndemics related to STI from the medical record. The largest class was half Black (51%), with a high rate of STI (65%), and was characterized by factors including depressive symptoms (93%), stress (64%), and substance use (65% cannabis, 82% tobacco). Additionally, the class with the highest rates of STI (74%) also had higher rates of partner violence (48%), morning sickness (100%), and prenatal cannabis use (63%).

Conclusion

Findings indicate evidence of a syndemic related to increased STI. A longitudinal evaluation of syndemics in this cohort may inform appropriately tailored intervention strategies to promote perinatal health in racially diverse young pregnant populations.

Prenatal Tobacco Exposure and the Risk of Tobacco Smoking and Dependence in Offspring: a Systematic Review and Meta-Analysis

BACKGROUND

There is some compelling, though not comprehensive, epidemiological evidence which suggests an association between prenatal tobacco exposure and tobacco smoking/dependence in offspring. We conducted a systematic review and meta-analysis to identify the magnitude and consistency of associations reported between prenatal tobacco exposure and subsequent tobacco smoking/dependence in offspring.

METHODS

Using the PRISMA guideline, we systematically searched PubMed, SCOPUS, EMBASE and Psych-INFO to identify relevant studies. The methodological quality of all identified studies was checked by the Newcastle-Ottawa Scale. Inverse variance weighted random effects meta-analysis was used to estimate pooled risk ratio (RR) and 95 % confidence intervals (CI). We stratified outcomes by tobacco smoking initiation, lifetime tobacco smoking, current tobacco smoking and tobacco dependence. We further performed subgroup and leave-one-out sensitivity analyses. The protocol of this review was registered in the PROSPERO.

RESULTS

Twenty-six cohort and one case-control study were included in the final meta-analysis. We found elevated pooled risks of tobacco smoking initiation [RR = 2.08, (95 % CI: 1.18-3.68)], ever tobacco smoking [RR = 1.21, (95 % CI: 1.05-1.38)], current tobacco smoking [RR = 1.70, (95 % CI: 1.48-1.95)] and tobacco dependence [RR = 1.50, (95 % CI: 1.31-1.73)] in offspring exposed to maternal prenatal tobacco use compared to non-exposed. We also noted higher risk estimate of current tobacco smoking in offspring exposed to heavy prenatal tobacco smoking [RR = 1.68, (95 % CI: 1.26-2.23)] when compared to prenatal exposure to lighter tobacco use [RR = 1.39, (95 % CI: 1.09-1.78)]. There was no association observed between paternal smoking during pregnancy and tobacco smoking in offspring.

CONCLUSION

Offspring exposed to maternal prenatal tobacco smoking are at an increased risk of tobacco smoking/dependence, indicating that tobacco smoking cessation during gestation may be imperative to reduce these risks in offspring.

Prenatal exposure to maternal, but not paternal, tobacco smoking is associated with smoking in adolescence

BACKGROUND

Mounting epidemiological evidence suggests an association between prenatal tobacco exposure and an increased risk of tobacco smoking in offspring. However, it is uncertain whether the association is due to the intrauterine or shared environmental exposures.

METHODS

Study participants were from the Raine Study, a prospective birth cohort study based in Perth, Western Australia (N = 2730). Tobacco smoking in adolescents, at age 17 years, was measured using a self-reported questionnaire. Log-binomial regression was used to estimate the relative risks (RRs) of tobacco smoking in offspring exposed to maternal prenatal tobacco use during the first and third trimesters of pregnancy. We have also calculated the E-values to investigate the potential effect of unmeasured confounding. Paternal smoking during pregnancy was used as a negative control for comparison.

RESULTS

A total of 1210 mothers-offspring pairs were included in the final analysis. After controlling for potential confounders, we found increased risks of tobacco smoking in offspring exposed to maternal prenatal tobacco use during the first trimester [RR 1.50 (95% CI: 1.13-1.97)] (E-value for point estimate = 2.37) and during both trimesters of pregnancy [RR 1.41 (95% CI: 1.03-1.89)] (E-value for point estimate = 2.17). However, we found insufficient statistical evidence for an association between paternal smoking during pregnancy and risk of tobacco smoking in offspring [RR 1.18 (95% CI: 0.84-1.67)].

CONCLUSION

Maternal prenatal tobacco exposure was associated with an increased risk of tobacco smoking in offspring at the age of 17 years. Tobacco smoking cessation at the early stages of gestation may reduce the risk of tobacco smoking in the next generation.

Prenatal exposure to tobacco and cannabis, early cannabis initiation, and daily dual use of combustible cigarettes and cannabis during young adulthood

INTRODUCTION

Daily combustible cigarette use is common among cannabis users, and dual use of cigarettes and cannabis is associated with detrimental outcomes. This study addresses gaps in the literature by examining data from the prenatal and adolescent phases of a prospective, longitudinal study to predict adult daily dual use.

METHODS

Young adult offspring (M age = 22.8 years, 53% female) from a prenatal cohort reported on combustible cigarette and cannabis use (N = 500, 58% Black, 42% White). Pathways to daily dual use were modeled using variables from the gestational and adolescent phases of the study including prenatal tobacco, alcohol, and cannabis exposures; ages at initiation of cigarettes and cannabis; and adolescent learning/memory, impulsivity, and behavior problems.

RESULTS

Prenatal cannabis and tobacco use were not directly linked to adult daily dual use of cannabis and tobacco. However, structural equation modeling revealed three significant indirect pathways from prenatal cigarette and cannabis exposures to adult daily dual use of cigarettes and cannabis via early cigarette initiation, early cannabis initiation, and adolescent behavior problems.

CONCLUSIONS

This study identified pathways from prenatal cannabis and tobacco exposure to adult daily dual use, in addition to clarifying adolescent outcomes that may be part of the pathways. In a climate of growing acceptance of cannabis use and increasing legalization of recreational use, these findings serve as a warning that early exposure to cannabis may have an important role in shaping long-term dual use of tobacco and cannabis.

Challenges Experienced by Women Who Smoke During Pregnancy or Postnatally

Maternal smoking during pregnancy and maternal smoking postnatally are important public health concerns worldwide. Smoking adversely affects the woman's general health and is causally related to pregnancy complications and serious health outcomes for the child, such as stillbirth, preterm delivery, low birth weight, and sudden infant death. The purpose of this research was to examine maternal smoking through a quantitative descriptive survey of 164 women, 120 who were pregnant and 44 who were postnatal. Women experienced barriers to quitting smoking, including dealing with stress, being exposed to smokers, not being ready to quit, not knowing how to quit, not looking for or not being able to find information about smoking or quitting smoking, and lacking adequate social and healthcare provider support. On the other hand, women revealed characteristics that suggest they might have had improved potential for quitting smoking, including having negative feelings about smoking, having cut down on smoking, smoking at a low level, having made quit attempts, thinking it would not be hard to quit smoking, being in the preparation stage of behavioral change, and thinking their healthcare providers (HCPs) would help them if they decided to quit. Taken together, those findings suggest that HCPs could offer important assistance to help women achieve smoking cessation. However, more research needs to be conducted to clarify the role and effectiveness of various HCPs in smoking cessation interventions and to identify measures to strengthen their provision of such interventions.

Factors associated with maintenance of smoking cessation in adolescents after implementation of tobacco pricing policy in South Korea: Evidence from the 11th Youth Health Behavior Survey

As a part of Korea's smoking cessation policy, the price of tobacco was increased in January 2015. Initially, the smoking rate among adolescents began to decrease. The current data, however, show that the adolescent smoking rate is on the rise. Alongside price policies, there is a need to further understand additional preventive measures that promote successful smoking cessation by identifying the factors that influence maintenance of smoking cessation in adolescents. This study aimed to identify the factors that influence smoking cessation in adolescents after attempting smoking cessation after increase in tobacco price. The study used large-scale, nationwide, secondary data obtained from the Korean Youth Risk Behavior Web-Based Survey. The sample included a total of 627 subjects who reported an attempt to quit smoking after the tobacco price increased. Descriptive statistics, t test, the χ² test, and multiple logistic regression were used. The results showed that household economic status, school type, suicidal ideation, experience of exposure to secondhand smoke at home, and experience of witnessing teaching staff smoking were significant factors related to maintenance of smoking cessation among adolescents. To increase the success rate of smoking cessation, future intervention programs should include school environment structure and address emotional and psychological issues such as suicide.

Trajectories of pre- and postnatal co-use of cannabis and tobacco predict co-use and drug use disorders in adult offspring

Co-use of cannabis and tobacco is increasingly common among women and is associated with tobacco and cannabis dependence and poorer cessation outcomes. However, no study has examined maternal patterns of co-use over time, or the impact of maternal co-use on co-use and drug problems in adult offspring. Pregnant women (M age = 23, range = 18-42; 52% African American, 48% White) were asked about substance use during each trimester of pregnancy, and at 8 and 18 months, 3, 6, 10, 14, 16, and 22 years postpartum. We examined patterns of any maternal cigarette and cannabis use during pregnancy and the postpartum years. As young adults (M age = 22.8 years, range = 21-26), 603 offspring completed the Diagnostic Interview Schedule (DIS). Growth mixture modeling (GMM) was used to identify four maternal trajectories through 16 years postpartum: (1) no co-use (66%), (2) decreasing co-use (16%), (3) postpartum-only co-use (11%), and (4) chronic co-use (7%). Offspring whose mothers were in the decreasing co-use group (co-users primarily during prenatal and preschool periods) were more likely to be co-users than the offspring of non-co-users. Offspring whose mothers were chronic co-users of cigarettes and cannabis were more than twice as likely to have a drug use disorder than young adults whose mothers were not co-users. The results of this study highlight the heterogeneity in maternal co-use of tobacco and cannabis over time, with some women quitting during pregnancy but resuming co-use in the postpartum, and other women co-using during pregnancy but desisting co-use over time. Maternal trajectories of co-use were associated with inter-generational transfer of risk for substance use and dependence in adult offspring.

Neuroendocrine and immune pathways from pre- and perinatal stress to substance abuse

Early life adversity is a documented risk factor for substance abuse and addiction. The pre- and perinatal period (i.e., from implantation, through pregnancy, to 6 months of age) is a critical period marked by high biological plasticity and vulnerability, making perinatal stress a particularly robust form of adversity. The neuroendocrine and immune systems are key mechanisms implicated in the transmission of addiction risk. We review animal and human studies that provide preliminary evidence for links between perinatal stress, neuroendocrine and immune dysregulation, and risk for substance abuse and addiction. A translational neuroscience perspective is employed to elucidate pre- and perinatally-induced biological mechanisms linked to addiction and discuss implications for prevention and intervention efforts. Significant evidence supports associations between pre- and perinatal stress and dysregulation of the hypothalamic-pituitary-adrenal axis and immune systems as well as links between neuroendocrine/immune functioning and addiction risk. More work is needed to explicitly examine the interplay between pre- and perinatal stress and neuroendocrine/immune disruptions that together heighten substance abuse risk. Future work is needed to fully understand how pre- and perinatal stress induces biological alterations to predispose individuals to higher risk for addiction. Such knowledge will strengthen theoretically-driven and empirically-supported prevention efforts for substance abuse and addiction.

Prenatal exposures to tobacco and cannabis: Associations with adult electronic cigarette use

INTRODUCTION

Prenatal exposures to tobacco and cannabis are associated with combustible cigarette use. This study evaluated pathways from these prenatal exposures to adult electronic cigarette use. We tested whether there were indirect effects of these prenatal exposures via childhood behavior dysregulation, early tobacco use, and adolescent tobacco dependence.

METHODS

Telephone interviews were conducted with 427 adult offspring (22-33 years old) from 3 prenatal cohorts with trimester-specific data on exposures to tobacco, alcohol, and cannabis. The offspring were 59% Black and 41% White (61% female). Prenatal exposures included quantity/frequency of tobacco, alcohol, and cannabis use by mothers during the first trimester. Using logistic regression and structural equation modeling, we examined the effects of gestational exposures on adult electronic cigarette use via early cigarette use (prior to age 14), controlling for covariates of combustible and electronic cigarette use.

RESULTS

There were no effects of childhood behavioral dysregulation on electronic cigarette use. However, there was a significant indirect effect of prenatal exposures to tobacco and cannabis on electronic cigarette use via early adolescent combustible cigarette use and adolescent risk for tobacco dependence.

CONCLUSIONS

One implication of these findings is that the inter-generational risk for tobacco use conferred via gestational exposures to tobacco and cannabis generalizes to novel products such as electronic cigarettes. These results have implications for public health, as more women use cannabis and co-use cigarettes and cannabis during pregnancy.

Alpha6-Containing Nicotinic Acetylcholine Receptors Mediate Nicotine-Induced Structural Plasticity in Mouse and Human iPSC-Derived Dopaminergic Neurons

Midbrain dopamine (DA) neurons are considered a critical substrate for the reinforcing and sensitizing effects of nicotine and tobacco dependence. While the role of the α4 and β2 subunit containing nicotinic acetylcholine receptors (α4β2^∗nAChRs) in mediating nicotine effects on DA release and DA neuron activity has been widely explored, less information is available on their role in the morphological adaptation of the DA system to nicotine, eventually leading to dysfunctional behaviors observed in nicotine dependence. In particular, no information is available on the role of α6^∗nAChRs in nicotine-induced structural plasticity in rodents and no direct evidence exists regarding the occurrence of structural plasticity in human DA neurons exposed to nicotine. To approach this problem, we used two parallel in vitro systems, mouse primary DA neuron cultures from E12.5 embryos and human DA neurons differentiated from induced pluripotent stem cells (iPSCs) of healthy donors, identified using TH⁺ immunoreactivity. In both systems, nicotine 1–10 μM produced a dose-dependent increase of maximal dendrite length, number of primary dendrites, and soma size when measured after 3 days in culture. These effects were blocked by pretreatments with the α6^∗nAChR antagonists α-conotoxin MII and α-conotoxin PIA, as well as by the α4β2nAChR antagonist dihydro-β-erythroidine (DHβE) in both mouse and human DA neurons. Nicotine was also ineffective when the primary DA neurons were obtained from null mutant mice for either the α6 subunit or both the α4 and α6 subunits of nAChR. When pregnant mice were exposed to nicotine from gestational day 15, structural plasticity was also observed in the midbrain DA neurons of postnatal day 1 offspring only in wild-type mice and not in both null mutant mice. This study confirmed the critical role of α4α6^∗nAChRs in mediating nicotine-induced structural plasticity in both mouse and human DA neurons, supporting the translational relevance of neurons differentiated from human iPSCs for pharmacological studies.