Chapter 9 Developmental Exposure to Cannabinoids Causes Subtle and Enduring Neurofunctional Alterations

Influence of prenatal cannabinoid exposure on early development and beyond

Public perception surrounding whether cannabis use is harmful during pregnancy often diverges greatly from the recommendations of doctors and healthcare providers. In contrast to the medical guidance of abstinence before, during, and after pregnancy, many women of reproductive age believe cannabis use during pregnancy is associated with little potential harm. Legalization and social cues support public perceptions that cannabis use during pregnancy is safe. Moreover, pregnant women may consider cannabis to be a safe alternative for treating pregnancy related ailments, including morning sickness. Compounding the problem is a lack of medical and federal guidance on safe, low, or high-risk levels of cannabis use. These issues mirror the continuing debate surrounding alcohol use and health, in particular, whether there are safe or lower risk levels of alcohol consumption during pregnancy. Clinical studies to date suffer from several limitations. First, most human studies are correlative in nature, meaning that causal associations cannot be made between in utero cannabis exposure and health and behavioral outcomes later in life. Due to obvious ethical constraints, it is not possible to randomly assign pregnant mothers to cannabis or other drug exposure conditions-a requirement needed to establish causality. In addition, clinical studies often lack quantitative information on maternal exposure (i.e., dose, frequency, and duration), include a small number of individuals, lack replication of outcome measures across cohorts, rely on self-report to establish maternal drug use, and suffer from unmeasured or residual confounding factors. Causal associations between maternal cannabis exposure and offspring outcomes are possible in preclinical cohorts but there is a large amount of heterogeneity across study designs and developmental differences between rodents and humans may limit translatability. In this review, we summarize research from human and preclinical models to provide insight into potential risks associated with prenatal cannabinoid exposure (PCE). Finally, we highlight gaps in knowledge likely to contribute to the growing divide between medical guidance and public attitudes regarding cannabis use during pregnancy.

Maternal Marijuana Exposure, Feto-Placental Weight Ratio, and Placental Histology

OBJECTIVE

Marijuana use is associated with placenta-mediated adverse pregnancy outcomes including fetal growth restriction, but the mechanism remains uncertain. The objective was to evaluate the association between maternal marijuana use and the feto-placental weight ratio (FPR). Secondarily, we aimed to compare placental histology of women who used marijuana to those who did not.

STUDY DESIGN

This was a secondary analysis of singleton pregnancies enrolled in a multicenter and case-control stillbirth study. Prior marijuana use was detected by electronic medical record abstraction or cord homogenate positive for 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid. Prior tobacco use was detected by self-report or presence of maternal serum cotinine. Stillbirths and live births were considered separately. The primary outcome was FPR. Association of marijuana use with FPR was estimated with multivariable linear modeling adjusted for fetal sex, preterm birth, and tobacco use. Comparisons between groups for placental histology were made using Chi-square and stratified by live birth and stillbirth, term and preterm deliveries, and fetal sex.

RESULTS

Of 1,027 participants, 224 were stillbirths and 803 were live births. Overall, 41 (4%) women used marijuana during the pregnancy. The FPR ratio was lower among exposed offspring but reached statistical significance only for term stillbirths (mean 6.84 with marijuana use vs. mean 7.8 without use, p < 0.001). In multivariable modeling, marijuana use was not significantly associated with FPR (p = 0.09). There were no differences in histologic placental features among those with and without marijuana use overall or in stratified analyses.

CONCLUSION

Exposure to marijuana may not be associated with FPR. Similarly, there were no placental histologic features associated with marijuana exposure. Further study of the influence of maternal marijuana use on placental development and function is warranted to better understand the association between prenatal marijuana use and poor fetal growth.

KEY POINTS

· Maternal marijuana exposure was not associated with the feto-placental weight ratio.. · Marijuana exposure was not associated with differences in placental histology.. · Concerning trend toward lower feto-placental weight ratios among marijuana-exposed stillbirths..

The Term Newborn: Prenatal Substance Exposure

Care for pregnant patients with substance use disorder must be provided in a nonjudgmental manner with recognition of addiction as a chronic medical illness in order to establish a therapeutic relationship and improve outcomes. All pregnant patients should be screened for substance use during prenatal care. Screening can be accomplished through several validated screening tools. Patients who screen positive need to be evaluated and referred for treatment as appropriate. This article reviews specific adverse perinatal outcomes associated with the use of a variety of substances and provides guidance on exposure with continued breastfeeding.

Lasting effects of prenatal exposure to Cannabis in the retina of the offspring: an experimental study in mice

Background

Prenatal exposure to Cannabis is a worldwide growing problem. Although retina is part of the central nervous system, the impact of maternal Cannabis use on the retinal development and its postnatal consequences remains unknown. As the prenatal period is potentially sensitive in the normal development of the retina, we hypothesized that recreational use of Cannabis during pregnancy may alter retina structure in the offspring. To test this, we developed a murine model that mimics human exposure in terms of dose and use.

Methods

Pregnant BalbC mice were exposed daily for 5 min to Cannabis smoke (0.2 g of Cannabis) or filtered air, from gestational day 5 to 18 (N = 10/group). After weaning period, pups were separated and examined weekly. On days 60, 120, 200, and 360 after birth, 10 pups from each group were randomly selected for Spectral Domain Optical Coherence Tomography (SD-OCT) analysis of the retina. All retina layers were measured and inner, outer, and total retina thickness were calculated. Other 37 mice from both groups were sacrificed on days 20, 60, and 360 for retinal stereology (total volume of the retina and volume fraction of each retinal layer) and light microscopy. Means and standard deviations were calculated and MANOVA was performed.

Results

The retina of animals which mother was exposed to Cannabis during gestation was 17% thinner on day 120 (young adult) than controls (P = 0.003) due to 21% thinning of the outer retina (P = 0.001). The offspring of mice from the exposed group presented thickening of the IS/OS in comparison to controls on day 200 (P < 0.001). In the volumetric analyzes by retinal stereology, the exposed mice presented transitory increase of the IS/OS total volume and volume fraction on day 60 (young adult) compared to controls (P = 0.008 and P = 0.035, respectively). On light microscopy, exposed mice presented thickening of the IS/OS on day 360 (adult) compared to controls (P = 0.03).

Conclusion

Gestational exposure to Cannabis smoke may cause structural changes in the retina of the offspring that return to normal on mice adulthood. These experimental evidences suggest that children and young adults whose mothers smoked Cannabis during pregnancy may require earlier and more frequent clinical care than the non-exposed population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40942-021-00314-8.

Cannabis Use in Pregnant and Breastfeeding Women: Behavioral and Neurobiological Consequences

Nowadays, cannabis is the most consumed illicit drug. The global prevalence of the use of cannabis in 2017 was estimated in 188 million of people, 3.8% of worldwide population. Importantly, the legalization of cannabis in different countries, together with the increase in the apparent safety perception, may result in a great variety of health problems. Indeed, an important concern is the increase in cannabis use among pregnant and breastfeeding women, especially since the content of delta9-tetrahidrocannabinol (THC) is currently around 2-fold higher than it was 15-20 years ago. The purpose of this study was to review cannabis use during pregnancy and breastfeeding including epidemiological aspects, therapeutic or preventive strategies, and experimental considerations and results from animal models of perinatal cannabis exposure to analyze the underlying neurobiological mechanisms and to identify new therapeutic approaches. A recent report revealed that among pregnant women aged 15-44, last month cannabis use prevalence was over 4.9%, raising to 8.5% in the 18-25-year-old age range. Pre- and post-natal exposure to cannabis may be associated with critical alterations in the newborn infants that are prolonged throughout childhood and adolescence. Briefly, several reports revealed that perinatal cannabis exposure was associated with low birth weight, reduction in the head circumference, cognitive deficits (attention, learning, and memory), disturbances in emotional response leading to aggressiveness, high impulsivity, or affective disorders, and higher risk to develop a substance use disorder. Furthermore, important neurobiological alterations in different neuromodulatory and neurotransmission systems have been associated with cannabis consumption during pregnancy and lactation. In spite of the evidences pointing out the negative behavioral and neurobiological consequences of cannabis use in pregnant and breastfeeding women, there are still limitations to identify biomarkers that could help to establish preventive or therapeutic approaches. It is difficult to define the direct association specifically with cannabis, avoiding other confusing factors, co-occurrence of other drugs consumption (mainly nicotine and alcohol), lifestyle, or socioeconomic factors. Therefore, it is necessary to progress in the characterization of short- and long-term cannabis exposure-related disturbances.

Prenatal cannabinoid exposure and altered neurotransmission

Marijuana is one of the most commonly used illicit drugs worldwide. In addition, use of synthetic cannabinoids is increasing, especially among adolescents and young adults. Although human studies have shown that the use of marijuana during pregnancy leads to adverse behavioral effects, such as deficiencies in attention and executive function in affected offspring, the rate of marijuana use among pregnant women is steadily increasing. Various aspects of human behavior including emotion, learning, and memory are dependent on complex interactions between multiple neurotransmitter systems that are especially vulnerable to alterations during the developmental period. Thus, exploration of neurotransmitter changes in response to prenatal cannabinoid exposure is crucial to develop an understanding of how homeostatic imbalance and various long-term neurobehavioral deficits manifest following the abuse of marijuana or other synthetic cannabinoids during pregnancy. Current literature confirms that vast alterations to neurotransmitter systems are present following prenatal cannabinoid exposure, and many of these alterations within the brain are region specific, time-dependent, and sexually dimorphic. In this review, we aim to provide a summary of observed changes to various neurotransmitter systems following cannabinoid exposure during pregnancy and to draw possible correlations to reported behavioral alterations in affected offspring.

Cannabinoid exposure during pregnancy and its impact on immune function

Cannabinoids are the most commonly abused illicit drugs worldwide. While cannabis can be beneficial for certain heath conditions, abuse of potent synthetic cannabinoids has been on the rise. Exposure to cannabinoids is also prevalent in women of child-bearing age and pregnant women. These compounds can cross the placental barrier and directly affect the fetus. They mediate their effects primarily through G-protein coupled cannabinoid receptors, CB1 and CB2. In addition to significant neurological effects, cannabinoids can trigger robust immunomodulation by altering cytokine levels, causing apoptosis of lymphoid cells and inducing suppressor cells of the immune system. Profound effects of cannabinoids on the immune system as discussed in this review, suggest that maternal exposure during pregnancy could lead to dysregulation of innate and adaptive immune system of developing fetus and offspring potentially leading to weakening of immune defenses against infections and cancer later in life. Emerging evidence also indicates the underlying role of epigenetic mechanisms causing long-lasting impact following cannabinoid exposure in utero.

Use of paracetamol, ibuprofen or aspirin in pregnancy and risk of cerebral palsy in the child

Background

It has been debated whether mild analgesics, mainly paracetamol, adversely affect aspects of neurodevelopment. We examined whether mother's use of paracetamol, aspirin or ibuprofen in pregnancy is associated with increased risk of cerebral palsy (CP) in the child.

Method

We included 185 617 mother-child pairs from the Danish National Birth Cohort and the Norwegian Mother and Child Cohort Study. We created harmonized definitions of analgesic use in pregnancy, as well as indications for analgesic use and other potential confounders. Children with CP were identified in nationwide registers. We estimated the average causal effect of analgesics on risk of CP using marginal structural models with stabilized inverse probability weights.

Results

Paracetamol use was reported in 49% of all pregnancies, aspirin in 3% and ibuprofen in 4%. Prenatal exposure to paracetamol ever in pregnancy was associated with increased risk of overall CP [adjusted odds ratio (aOR) 1.3, 95% confidence interval (CI): 1.0-1.7] and unilateral spastic CP (aOR 1.5, 95% CI: 1.0-2.2). The association appeared to be driven by an increased risk of unilateral spastic CP in children exposed in second trimester (aOR 1.6, 95% CI: 1.0-2.5). Children ever prenatally exposed to aspirin in pregnancy had an elevated risk of bilateral spastic CP (aOR 2.4, 95% CI: 1.1-5.3) compared with unexposed.

Conclusion

We observed an increased risk of spastic CP in children prenatally exposed to paracetamol and aspirin. Although we controlled for several important indications for analgesic use, we cannot exclude the possibility of confounding by underlying diseases.

Autism Spectrum Disorders: Potential Neuro-Psychopharmacotherapeutic Plant-Based Drugs

Over the years, scientific researches have validated the healing benefits of many psychopharmacotherapeutic plant-based drugs to ameliorate psychiatric disorders. In contrast, the use of chemical procedures to isolate and purify specific compounds from plants that have been used to treat autism spectrum disorders (ASDs) and its clinical features may contribute to improve the quality of life of many patients. Also, herbal pharmacological treatments could improve the core symptoms of autism with fewer side effects. This review will focus on the uses and actions of phytopharmaceuticals in the behavioral conditions of ASDs. A large number of natural compound-based plant drugs have been tested in murine models of autism and in clinical trials with remarkable success in reversing the core and associated behaviors with autism such as flavonoids, cannabinoids, curcuminoids, piperine, resveratrol, and bacosides. This plant-based drug alternative is safer given that many psychiatric disorders and neurodegenerative pathologies do not often respond well to currently prescribed medications or have significant side effects. However, it is noteworthy to consider the need for large clinical trials to determine safety and efficacy. Many results are based on case reports or small size samples, and often the studies are open label. Standardization of procedures (i.e., purity and concentrations) and quality controls are strictly required to ensure the absence of side effects.

Marijuana use during and after pregnancy and association of prenatal use on birth outcomes: A population-based study

BACKGROUND

We sought to describe the correlates of marijuana use during and after pregnancy, and to examine the independent relationship between prenatal marijuana use and infant outcomes.

STUDY DESIGN

We used state-specific data from the Pregnancy Risk Assessment Monitoring System (N = 9013) to describe correlates of self-reported prenatal and postpartum marijuana use. We estimated differences in mean infant birth weight and gestational age among prenatal marijuana users and nonusers, controlling for relevant covariates (i.e., cigarette smoking).

RESULTS

Respectively, 4.2% (95% CI: 3.8-4.7) and 6.8% (95% CI: 6.0-7.7) of women reported using marijuana during and after pregnancy. Compared to nonusers, prenatal marijuana users were more likely to be ≤24 years; non-Hispanic white, not married, have <12 years of education, have Medicaid/IHS/Other insurance, be on WIC during pregnancy, have annual household income <$20,000, cigarette smokers, and alcohol drinkers during pregnancy (p-values < 0.05). After adjustment, no differences in gestational age or birthweight were observed. Postpartum users were more likely to smoke cigarettes (48.7% vs. 20.3%), experience postpartum depressive symptoms (14.0% vs. 9.0%), and breastfeed for <8 weeks (34.9% vs. 18.1%).

CONCLUSION

Co-use of substances was common among prenatal and postpartum marijuana users. Prenatal marijuana use was not independently associated with lower average birthweight or gestational age. Postpartum marijuana use was associated with depressive symptoms and shorter breastfeeding duration. Surveillance of marijuana use among pregnant and postpartum women is critical to better understanding the relationship of marijuana use with birth outcomes, and postpartum experiences such as depression and breastfeeding.

Psychoactive drug exposure during breastfeeding: a critical need for preclinical behavioral testing

Breastfeeding women are excluded from clinical trials of psychoactive drugs because of ethical concerns. Animal testing, which often is predictive of adverse effects in humans, represents the only avenue available for assessing drug safety for human offspring exposed to drugs during lactation. I determined whether behavioral outcomes for children exposed during breastfeeding to antidepressants, anxiolytics, antipsychotics, anti-seizure medications, analgesics, sedatives, and marijuana can be predicted by rodent studies of offspring exposed to drugs during lactation. Animal data were available for only 10 of 80 CNS-active drugs canvassed. Behavioral deficits in adolescence or adulthood in rats and mice after various drug exposures during lactation included reductions in sexual behavior, increased anxiety, hyperactivity, and impaired learning and memory. Whether similar adverse effects will emerge in adulthood in children exposed to drugs during breastfeeding is unknown. Rodent research has the potential to forecast impairments in breastfed children long before information emerges from post-marketing reports and should be prioritized during preclinical drug evaluation by the FDA for new drugs and for drugs currently prescribed off-label for lactating women.

Endocannabinod Signal Dysregulation in Autism Spectrum Disorders: A Correlation Link between Inflammatory State and Neuro-Immune Alterations

Several studies highlight a key involvement of endocannabinoid (EC) system in autism pathophysiology. The EC system is a complex network of lipid signaling pathways comprised of arachidonic acid-derived compounds (anandamide, AEA) and 2-arachidonoyl glycerol (2-AG), their G-protein-coupled receptors (cannabinoid receptors CB1 and CB2) and the associated enzymes. In addition to autism, the EC system is also involved in several other psychiatric disorders (i.e., anxiety, major depression, bipolar disorder and schizophrenia). This system is a key regulator of metabolic and cellular pathways involved in autism, such as food intake, energy metabolism and immune system control. Early studies in autism animal models have demonstrated alterations in the brain's EC system. Autism is also characterized by immune system dysregulation. This alteration includes differential monocyte and macrophage responses, and abnormal cytokine and T cell levels. EC system dysfunction in a monocyte and macrophagic cellular model of autism has been demonstrated by showing that the mRNA and protein for CB2 receptor and EC enzymes were significantly dysregulated, further indicating the involvement of the EC system in autism-associated immunological disruptions. Taken together, these new findings offer a novel perspective in autism research and indicate that the EC system could represent a novel target option for autism pharmacotherapy.

Role of Endocannabinoids on Neuroinflammation in Autism Spectrum Disorder Prevention

Autism Spectrum Disorder (ASD) disease has become a mounting socio-economical alarm around the world. Neuroinflammtion had been shown in postmortem brain specimens from ASD patients. The Endocannabinoids System (ES) consists of a family of locally produced, short-lived, endogenous, phospholipid-derived agonists (endocannabinoids) that control energy balance and body composition. The growing number of medical benefits of ES, such as their ability to regulate processes like neuroinflammation, neurogenesis and memory, raise the question of their potential role as a preventive treatment of ASD. To test this hypothesis, basic and clinical studies allow us a thorough investigation of the role of ES in the pathogenesis of ASD. This hypothesis will help to understand the mechanism of ES and its role in ASD.

Prenatal cannabis exposure - The "first hit" to the endocannabinoid system

As more states and countries legalize medical and/or adult recreational marijuana use, the incidences of prenatal cannabis exposure (PCE) will likely increase. While young people increasingly view marijuana as innocuous, marijuana preparations have been growing in potency in recent years, potentially creating global clinical, public health, and workforce concerns. Unlike fetal alcohol spectrum disorder, there is no phenotypic syndrome associated with PCE. There is also no preponderance of evidence that PCE causes lifelong cognitive, behavioral, or functional abnormalities, and/or susceptibility to subsequent addiction. However, there is compelling circumstantial evidence, based on the principles of teratology and fetal malprogramming, suggesting that pregnant women should refrain from smoking marijuana. The usage of marijuana during pregnancy perturbs the fetal endogenous cannabinoid signaling system (ECSS), which is present and active from the early embryonic stage, modulating neurodevelopment and continuing this role into adulthood. The ECSS is present in virtually every brain structure and organ system, and there is also evidence that this system is important in the regulation of cardiovascular processes. Endocannabinoids (eCBs) undergird a broad spectrum of processes, including the early stages of fetal neurodevelopment and uterine implantation. Delta-9-tetrahydrocannabinol (THC), the psychoactive chemical in cannabis, enters maternal circulation, and readily crosses the placental membrane. THC binds to CB receptors of the fetal ECSS, altering neurodevelopment and possibly rewiring ECSS circuitry. In this review, we discuss the Double-Hit Hypothesis as it relates to PCE. We contend that PCE, similar to a neurodevelopmental teratogen, delivers the first hit to the ECSS, which is compromised in such a way that a second hit (i.e., postnatal stressors) will precipitate the emergence of a specific phenotype. In summary, we conclude that perturbations of the intrauterine milieu via the introduction of exogenous CBs alter the fetal ECSS, predisposing the offspring to abnormalities in cognition and altered emotionality. Based on recent experimental evidence that we will review here, we argue that young women who become pregnant should immediately take a "pregnant pause" from using marijuana.

Acetaminophen Use for Fever in Children Associated with Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) is characterized by persistent deficits in social communication and restrictive behavior, interests, and activities. Our previous case-control study showed that use of acetaminophen at age 12-18 months is associated with increased likelihood for ASD (OR 8.37, 95% CI 2.08-33.7). In this study, we again show that acetaminophen use is associated with ASD (p = 0.013). Because these children are older than in our first study, the association is reversed; fewer children with ASD vs. non-ASD children use acetaminophen as a "first choice" compared to "never use" (OR 0.165, 95% CI 0.045, 0.599). We found significantly more children with ASD vs. non- ASD children change to the use of ibuprofen when acetaminophen is not effective at reducing fever (p = 0.033) and theorize this change in use is due to endocannabinoid system dysfunction. We also found that children with ASD vs. non-ASD children are significantly more likely to show an increase in sociability when they have a fever (p = 0.037) and theorize that this increase is due to anandamide activation of the endocannabinoid system in ASD children with low endocannabinoid tone from early acetaminophen use. In light of this we recommend that acetaminophen use be reviewed for safety in children.

The Medicinal Cannabis Treatment Agreement: Providing Information to Chronic Pain Patients Through a Written Document

AIM

Pain practitioners would seem to have an obligation to understand and inform their patients on key issues of the evidence base on cannabinoid therapeutics. One way to fulfill this obligation might be to borrow from concepts developed in the prescription of opioids: the use of a written agreement to describe and minimize risks. Regrettably, the widespread adoption of opioids was undertaken while harmful effects were minimized; obviously, no one wants to repeat this misstep.

OBJECTIVE

This article describes a method of educating patients in a manner analogous to other treatment agreements.

BACKGROUND

Surveys have demonstrated that pain is the most common indication for medical use of cannabis. As more individuals gain access to this botanical product through state ballot initiatives and legislative mandate, the pain specialist is likely to be confronted by patients either seeking such treatment where permitted, or otherwise inquiring about its potential benefits and harms, and alternative pharmaceuticals containing cannabinoids.

METHODS

PubMed searches were conducted using the following keywords: cannabis guidelines, harmful effects of cannabis, medical marijuana, medicinal cannabis, opioid cannabis interaction, cannabis dependence and cannabis abuse

RESULTS

: The authors selected individual tenets a medicinal cannabis patient would be asked to review and acknowledge via signature.

CONCLUSIONS

Undoubtedly, the knowledge base concerning risks will be an iterative process as we learn more about the long-term use of medicinal cannabis. But we should start the process now so that patients may be instructed about our current conception of what the use of medicinal cannabis entails.

Drugs of Abuse in Human Milk Purchased via the Internet

BACKGROUND

Human milk purchased via the Internet poses a potential risk of recipient infant exposure to drugs, but this risk has not been quantitated by research. Our objective was to test milk we purchased via the Internet for 13 common classes of drugs of abuse to explore the extent of possible exposure to recipient infants.

MATERIALS AND METHODS

Samples (n = 102) of milk purchased via the Internet were tested for 13 groups of drugs that are commonly abused using immunoassay screening to identify suspected positives, followed by liquid chromatography/tandem mass spectrometry or gas chromatography/mass spectrometry for confirmation. Sellers' advertisements were abstracted for statements about drug use or abstinence.

RESULTS

Most (71%) sellers stated in their advertisement that they abstained from some type(s) of drugs (prescription or illicit), but 29% indicated nothing about drug use or abstinence. No sellers admitted to illicit drug use in their advertisement. No samples tested positive for the selected drugs of interest (prevalence = 0%; 95% confidence interval, 0.0, 2.9).

CONCLUSIONS

We did not detect any of the selected drugs in 102 milk samples. Our sample was too small to detect less commonly used drugs and to provide a narrow confidence interval around the prevalence estimate and did not include milk shared at no cost. Thus, these findings are exploratory and cannot rule out the possibility of drugs being present in other milk available via the Internet.

ABM clinical protocol #21: guidelines for breastfeeding and substance use or substance use disorder, revised 2015

A central goal of The Academy of Breastfeeding Medicine is the development of clinical protocols for managing common medical problems that may impact breastfeeding success. These protocols serve only as guidelines for the care of breastfeeding mothers and infants and do not delineate an exclusive course of treatment or serve as standards of medical care. Variations in treatment may be appropriate according to the needs of an individual patient.

Developmental consequences of fetal exposure to drugs: what we know and what we still must learn

Most drugs of abuse easily cross the placenta and can affect fetal brain development. In utero exposures to drugs thus can have long-lasting implications for brain structure and function. These effects on the developing nervous system, before homeostatic regulatory mechanisms are properly calibrated, often differ from their effects on mature systems. In this review, we describe current knowledge on how alcohol, nicotine, cocaine, amphetamine, Ecstasy, and opiates (among other drugs) produce alterations in neurodevelopmental trajectory. We focus both on animal models and available clinical and imaging data from cross-sectional and longitudinal human studies. Early studies of fetal exposures focused on classic teratological methods that are insufficient for revealing more subtle effects that are nevertheless very behaviorally relevant. Modern mechanistic approaches have informed us greatly as to how to potentially ameliorate the induced deficits in brain formation and function, but conclude that better delineation of sensitive periods, dose-response relationships, and long-term longitudinal studies assessing future risk of offspring to exhibit learning disabilities, mental health disorders, and limited neural adaptations are crucial to limit the societal impact of these exposures.

It's not your mother's marijuana: effects on maternal-fetal health and the developing child

Pro-marijuana advocacy efforts exemplified by the "medical" marijuana movement, coupled with the absence of conspicuous public health messages about the potential dangers of marijuana use during pregnancy, could lead to greater use of today's more potent marijuana, which could have significant short- and long-term consequences. This article reviews the current literature regarding the effects of prenatal marijuana use on the pregnant woman and her offspring.

Prenatal cannabis exposure and infant outcomes: overview of studies

Accumulating evidence from both human and preclinical studies indicates maternal substance use during pregnancy can affect fetal development, birth weight and infant outcomes. Thus, the prenatal period can be regarded as an important and potentially sensitive period of development. In this manuscript, an updated overview of studies on prenatal cannabis exposure in humans is presented, including recent studies conducted within the Generation R study. Findings on fetal growth, birth outcomes, early neonatal behavior and infant behavior and cognitive development are discussed in detail. Preclinical evidence and potential mechanisms are described as well, and recommendations for future studies are provided. It is concluded that evidence seems to suggest that fetal development is affected by prenatal maternal cannabis use, while findings on effects on infant behavior or cognition are inconsistent. Beyond infancy, subtle differences may be found in specific cognitive or behavioral outcomes, although replication studies in which pregnant women and their fetuses are exposed to current and probably higher levels of Δ9-tetrahydrocannabinol and novel designs are needed to come to firm conclusions.

The endocannabinoid system: an emotional buffer in the modulation of memory function

Extensive evidence indicates that endocannabinoids modulate cognitive processes in animal models and human subjects. However, the results of endocannabinoid system manipulations on cognition have been contradictory. As for anxiety behavior, a duality has indeed emerged with regard to cannabinoid effects on memory for emotional experiences. Here we summarize findings describing cannabinoid effects on memory acquisition, consolidation, retrieval and extinction. Additionally, we review findings showing how the endocannabinoid system modulates memory function differentially, depending on the level of stress and arousal associated with the experimental context. Based on the evidence reviewed here, we propose that the endocannabinoid system is an emotional buffer that moderates the effects of environmental context and stress on cognitive processes.

The transfer of drugs and therapeutics into human breast milk: an update on selected topics

Many mothers are inappropriately advised to discontinue breastfeeding or avoid taking essential medications because of fears of adverse effects on their infants. This cautious approach may be unnecessary in many cases, because only a small proportion of medications are contraindicated in breastfeeding mothers or associated with adverse effects on their infants. Information to inform physicians about the extent of excretion for a particular drug into human milk is needed but may not be available. Previous statements on this topic from the American Academy of Pediatrics provided physicians with data concerning the known excretion of specific medications into breast milk. More current and comprehensive information is now available on the Internet, as well as an application for mobile devices, at LactMed (http://toxnet.nlm.nih.gov). Therefore, with the exception of radioactive compounds requiring temporary cessation of breastfeeding, the reader will be referred to LactMed to obtain the most current data on an individual medication. This report discusses several topics of interest surrounding lactation, such as the use of psychotropic therapies, drugs to treat substance abuse, narcotics, galactagogues, and herbal products, as well as immunization of breastfeeding women. A discussion regarding the global implications of maternal medications and lactation in the developing world is beyond the scope of this report. The World Health Organization offers several programs and resources that address the importance of breastfeeding (see http://www.who.int/topics/breastfeeding/en/).

The endocannabinoid system as a possible target to treat both the cognitive and emotional features of post-traumatic stress disorder (PTSD)

Post-traumatic stress disorder (PTSD) is a psychiatric disorder of significant prevalence and morbidity, whose pathogenesis relies on paradoxical changes of emotional memory processing. An ideal treatment would be a drug able to block the pathological over-consolidation and continuous retrieval of the traumatic event, while enhancing its extinction and reducing the anxiety symptoms. While the latter benefit from antidepressant medications, no drug is available to control the cognitive symptomatology. Endocannabinoids regulate affective states and participate in memory consolidation, retrieval, and extinction. Clinical findings showing a relationship between Cannabis use and PTSD, as well as changes in endocannabinoid activity in PTSD patients, further suggest the existence of a link between endocannabinoids and maladaptive brain changes after trauma exposure. Along these lines, we suggest that endocannabinoid degradation inhibitors may be an ideal therapeutic approach to simultaneously treat the emotional and cognitive features of PTSD, avoiding the unwanted psychotropic effects of compounds directly binding cannabinoid receptors.

Tonic and transient endocannabinoid regulation of AMPAergic miniature postsynaptic currents and homeostatic plasticity in embryonic motor networks

Endocannabinoid signaling has been shown to mediate synaptic plasticity by retrogradely inhibiting presynaptic transmitter release in several systems. We found that endocannabinoids act tonically to regulate AMPA miniature postsynaptic current (mPSC) frequency in embryonic motor circuits of the chick spinal cord. Further, strong postsynaptic depolarizations also induced a short-lived endocannabinoid-mediated suppression of mEPSC frequency. Unlike many previous studies, endocannabinoid signaling was not found to influence evoked transmitter release. The results suggest a special role for spontaneous glutamatergic mPSCs and their control by endocannabinoids in the developing spinal cord. We determined that blocking endocannabinoid signaling, which increases spontaneous glutamatergic release, increased spontaneous network activity in vitro and in vivo. Previous work in spinal motoneurons had shown that reducing spontaneous network activity (SNA) chronically in vivo led to homeostatic increases in AMPA and GABA mPSC amplitude (homeostatic synaptic plasticity). Blocking endocannabinoid signaling in vivo, and thus increasing SNA, triggered compensatory decreases of both AMPA and GABA mPSC amplitudes. These findings, combined with previous results, are consistent with the idea that this form of homeostatic synaptic plasticity is a bidirectional process in the living embryo. Together, our results suggest a role for tonic signaling of endocannabinoids as a potential mechanism to regulate the level of SNA, which is known to be critical for synaptic maturation in the embryonic spinal cord.

The endocannabinoid transport inhibitor AM404 differentially modulates recognition memory in rats depending on environmental aversiveness

Cannabinoid compounds may influence both emotional and cognitive processes depending on the level of environmental aversiveness at the time of drug administration. However, the mechanisms responsible for these responses remain to be elucidated. The present experiments investigated the effects induced by the endocannabinoid transport inhibitor AM404 (0.5-5 mg/kg, i.p.) on both emotional and cognitive performances of rats tested in a Spatial Open Field task and subjected to different experimental settings, named High Arousal (HA) and Low Arousal (LA) conditions. The two different experimental conditions influenced emotional reactivity independently of drug administration. Indeed, vehicle-treated rats exposed to the LA condition spent more time in the center of the arena than vehicle-treated rats exposed to the HA context. Conversely, the different arousal conditions did not affect the cognitive performances of vehicle-treated animals such as the capability to discriminate a spatial displacement of the objects or an object substitution. AM404 administration did not alter locomotor activity or emotional behavior of animals exposed to both environmental conditions. Interestingly, AM404 administration influenced the cognitive parameters depending on the level of emotional arousal: it impaired the capability of rats exposed to the HA condition to recognize a novel object while it did not induce any impairing effect in rats exposed to the LA condition. These findings suggest that drugs enhancing endocannabinoid signaling induce different effects on recognition memory performance depending on the level of emotional arousal induced by the environmental conditions.

Neonatal drug withdrawal

Maternal use of certain drugs during pregnancy can result in transient neonatal signs consistent with withdrawal or acute toxicity or cause sustained signs consistent with a lasting drug effect. In addition, hospitalized infants who are treated with opioids or benzodiazepines to provide analgesia or sedation may be at risk for manifesting signs of withdrawal. This statement updates information about the clinical presentation of infants exposed to intrauterine drugs and the therapeutic options for treatment of withdrawal and is expanded to include evidence-based approaches to the management of the hospitalized infant who requires weaning from analgesics or sedatives.

Altering endocannabinoid neurotransmission at critical developmental ages: impact on rodent emotionality and cognitive performance

The endocannabinoid system shows functional activity from early stages of brain development: it plays an important role in fundamental developmental processes such as cell proliferation, migration, and differentiation, thus shaping brain organization during pre- and postnatal life. Cannabis sativa preparations are among the illicit drugs most commonly used by young people, including pregnant women. The developing brain can be therefore exposed to cannabis preparations during two critical periods: first, in offspring of cannabis-using mothers through perinatal and/or prenatal exposure; second, in adolescent cannabis users during neural maturation. In the last decade, it has become clear that the endocannabinoid system critically modulates memory processing and emotional responses. Therefore, it is well possible that developmental exposure to cannabinoid compounds induces enduring changes in behaviors and neural processes belonging to the cognitive and emotional domains. We address this issue by focusing on rodent studies, in order to provide a framework for understanding the impact of cannabinoid exposure on the developing brain.

The endocannabinoid system in the regulation of emotions throughout lifespan: a discussion on therapeutic perspectives

Alterations in emotion regulation processes may form the basis of psychopathologies. The endocannabinoid (eCB) system, composed of endogenous ligands, the enzymatic machinery in charge of their metabolism and the specific metabotropic receptors, has emerged as a major neuromodulatory system critically involved in the control of emotional homeostasis and stress responsiveness. Data from animal models indicate that the eCB system plays a key role in brain development, and is probably involved in the control of emotional states from early developmental stages. The present review summarizes the latest information on the role of the eCB system in emotionality and anxiety-related disorders throughout the lifespan. Putative therapeutic strategies based on the pharmacological modulation of this system will be discussed. Given the fact that the pharmacological modulation of the eCB system has recently arisen as a promising strategy in the management of anxiety and mood disorders, the potential efficacy of this pharmacological approach (i.e. blockers of the catabolic pathway) will be discussed, as well as pharmacological alternatives such as modulators of cannabinoid receptors other than the classical CB1 receptor, or administration of other plant-derived compounds (e.g. cannabidiol).

Cannabis in sport: anti-doping perspective

Since 2004, when the World Anti-Doping Agency assumed the responsibility for establishing and maintaining the list of prohibited substances and methods in sport (i.e. the Prohibited List), cannabinoids have been prohibited in all sports during competition. The basis for this prohibition can be found in the World Anti-Doping Code, which defines the three criteria used to consider banning a substance. In this context, we discuss the potential of cannabis to enhance sports performance, the risk it poses to the athlete's health and its violation of the spirit of sport. Although these compounds are prohibited in-competition only, we explain why the pharmacokinetics of their main psychoactive compound, Δ(9)-tetrahydrocannabinol, may complicate the results management of adverse analytical findings. Passive inhalation does not appear to be a plausible explanation for a positive test. Although the prohibition of cannabinoids in sports is one of the most controversial issues in anti-doping, in this review we stress the reasons behind this prohibition, with strong emphasis on the evolving knowledge of cannabinoid pharmacology.

Effects of the analgesic acetaminophen (Paracetamol) and its para-aminophenol metabolite on viability of mouse-cultured cortical neurons

Acetaminophen has been used as an analgesic for more than a hundred years, but its mechanism of action has remained elusive. Recently, it has been shown that acetaminophen produces analgesia by the activation of the brain endocannabinoid receptor CB1 through its para-aminophenol (p-aminophenol) metabolite. The objective of this study was to determine whether p-aminophenol could be toxic for in vitro developing mouse cortical neurons as a first step in establishing a link between acetaminophen use and neuronal apoptosis. We exposed developing mouse cortical neurons to various concentrations of drugs for 24 hr in vitro. Acetaminophen itself was not toxic to developing mouse cortical neurons at therapeutic concentrations of 10-250 μg/ml. However, concentrations of p-aminophenol from 1 to 100 μg/ml produced significant (p < 0.05) loss of mouse cortical neuron viability at 24 hr compared to the controls. The naturally occurring endocannabinoid anandamide also caused similar 24-hr loss of cell viability in developing mouse cortical neurons at concentrations from 1 to 100 μg/ml, which indicates the mechanism of cell death could be through the cannabinoid receptors. The results of our experiments have shown a detrimental effect of the acetaminophen metabolite p-aminophenol on in vitro developing cortical neuron viability which could act through CB1 receptors of the endocannabinoid system. These results could be especially important in recommending an analgesic for children or individuals with traumatic brain injury who have developing cortical neurons.

Lasting impacts of prenatal cannabis exposure and the role of endogenous cannabinoids in the developing brain

Cannabis is the most commonly used illicit substance among pregnant women. Human epidemiological and animal studies have found that prenatal cannabis exposure influences brain development and can have long-lasting impacts on cognitive functions. Exploration of the therapeutic potential of cannabis-based medicines and synthetic cannabinoid compounds has given us much insight into the physiological roles of endogenous ligands (endocannabinoids) and their receptors. In this article, we examine human longitudinal cohort studies that document the long-term influence of prenatal exposure to cannabis, followed by an overview of the molecular composition of the endocannabinoid system and the temporal and spatial changes in their expression during brain development. How endocannabinoid signaling modulates fundamental developmental processes such as cell proliferation, neurogenesis, migration and axonal pathfinding are also summarized.

Developmental consequences of perinatal cannabis exposure: behavioral and neuroendocrine effects in adult rodents

RATIONALE

Cannabis is the most commonly used illicit drug among pregnant women. Since the endocannabinoid system plays a crucial role in brain development, maternal exposure to cannabis derivatives might result in long-lasting neurobehavioral abnormalities in the exposed offspring. It is difficult to detect these effects, and their underlying neurobiological mechanisms, in clinical cohorts, because of their intrinsic methodological and interpretative issues.

OBJECTIVES

The present paper reviews relevant rodent studies examining the long-term behavioral consequences of exposure to cannabinoid compounds during pregnancy and/or lactation.

RESULTS

Maternal exposure to even low doses of cannabinoid compounds results in atypical locomotor activity, cognitive impairments, altered emotional behavior, and enhanced sensitivity to drugs of abuse in the adult rodent offspring. Some of the observed behavioral abnormalities might be related to alterations in stress hormone levels induced by maternal cannabis exposure.

CONCLUSIONS

There is increasing evidence from animal studies showing that cannabinoid drugs are neuroteratogens which induce enduring neurobehavioral abnormalities in the exposed offspring. Several preclinical findings reviewed in this paper are in line with clinical studies reporting hyperactivity, cognitive impairments and altered emotionality in humans exposed in utero to cannabis. Conversely, genetic, environmental and social factors could also influence the neurobiological effects of early cannabis exposure in humans.

Effect of hydrolysis on identifying prenatal cannabis exposure

Identification of prenatal cannabis exposure is important due to potential cognitive and behavioral consequences. A two-dimensional gas chromatography-mass spectrometry method for cannabinol, Delta(9)-tetrahydrocannabinol (THC), 11-hydroxy-THC (11-OH-THC), 8beta,11-dihydroxy-THC, and 11-nor-9-carboxy-THC (THCCOOH) quantification in human meconium was developed and validated. Alkaline, enzymatic, and enzyme-alkaline tandem hydrolysis conditions were optimized with THC- and THCCOOH-glucuronide reference standards. Limits of quantification ranged from 10 to 15 ng/g, and calibration curves were linear to 500 ng/g. Bias and intra-day and inter-day imprecision were <12.3%. Hydrolysis efficiencies were analyte-dependent; THC-glucuronide was effectively cleaved by enzyme, but not base. Conversely, THCCOOH-glucuronide was most sensitive to alkaline hydrolysis. Enzyme-alkaline tandem hydrolysis maximized efficiency for both glucuronides. Identification of cannabinoid-positive meconium specimens nearly doubled following alkaline and enzyme-alkaline hydrolysis. Although no 11-OH-THC glucuronide standard is available, enzymatic hydrolysis improved 11-OH-THC detection in authentic specimens. Maximal identification of cannabis-exposed neonates and the widest range of cannabis biomarkers are achieved with enzyme-alkaline tandem hydrolysis.