Cocaine-induced neurodevelopmental deficits and underlying mechanisms

Evaluation of histological and ultrastructural changes provoked by prenatal tramadol on postnatal cortical cerebellar neuronal development in rats: possible implication of Ki67, GFAP and MicroRNA-7/P53 signalling trajectories

Tramadol is a novel centrally acting analgesic. Despite, its implementation during pregnancy may impair neuronal survival and synaptic development in neonatal cerebella. The current investigation assessed the histological and ultrastructural alterations in postnatal cortical cerebellar neuronal development induced by prenatal tramadol. 30 offsprings were divided to control group I: fifteen pups born to mothers given saline from D10 till D21 of gestation. Tramadol-treated group II: fifteen pups born to mothers received tramadol HCL (50 mg/kg/day) from D10 till D21 of gestation. Pups were categorized into three subgroups (a, b, and c) and offered for sacrifice on the seventh, fourteenth and twenty-first post-natal days. Light microscopic examination revealed the overcrowding and signs of red degeneration affecting purkinje cell layer. Neurodegenerative signs of both purkinje and granule cell neurons were also confirmed by TEM in form of chromatin condensation, dilated Golgi channels, disrupted endoplasmic reticulum, marked infolding of the nuclear envelope and decrease in granule cell precursors. In addition, the astrocytic processes and terminal nerve axons appeared with different degrees of demyelination and decreased number of oligodendrocytes and degenerated mitochondria. Furthermore, group II exhibited an increase in P53 immune expression. The area percentage of apoptotic cells detected by TUNEL assay was significantly increased. Besides to the significant decrease of Ki67 immunoreactivity in the stem neuronal cell progenitors. Quantitative PCR results showed a significant decline in micro RNA7 gene expression in tramadol treated groups resulting in affection of multiple target genes in P53 signaling pathways, improper cortical size and defect in neuronal development.

Ethical Principles Do Not Support Mandatory Preanesthesia Pregnancy Screening Tests: A Narrative Review

Respect for patient autonomy is a pillar of medical ethics, manifested predominantly through informed consent. Mandatory (routine) nonconsented preoperative urine pregnancy testing does not adequately respect patient autonomy, is potentially coercive, and has the potential to cause harm medically, psychologically, socially, and financially. Inaccuracies in pregnancy testing can result in false-positive and false-negative results, especially in early pregnancy. There is substantial scientific evidence that anesthesia is not harmful to the fetus, raising the question of whether pregnancy testing provides substantial benefit to the patient. Not performing a preanesthesia pregnancy test has not been associated with significant medicolegal consequences. We review the ethical implications of mandatory preanesthesia pregnancy testing in light of these facts.

Prenatal cocaine exposure and self-reported behavioral adjustments from ages 12 to 21: environmental pathways

BACKGROUND

In a birth-cohort study, we followed offspring with prenatal cocaine exposure (PCE) to investigate longitudinal associations of PCE with self-reported behavioral adjustment from early adolescence to emerging adulthood (EA). Environmental pathways (family functioning, non-kinship care, maltreatment) were specified as potential mediators of PCE.

METHODS

Participants were 372 (190 PCE; 47% male), primarily Black, low socioeconomic status, enrolled at birth. Internalizing and externalizing behaviors were assessed using Youth Self-Report at ages 12 and 15 and Adult Self-Report at age 21. Extended random-intercept cross-lagged panel modeling was used to account for potential bidirectional relationships between internalizing and externalizing behaviors over time, examining potential mediators.

RESULTS

Adjusting for covariates, significant indirect effects were found for each mediator at different ages. For family functioning, these were both internalizing (β = 0.83, p = 0.04) and externalizing behaviors (β = 1.58, p = 0.02) at age 12 and externalizing behaviors at age 15 (β = 0.51, p = 0.03); for non-kinship care, externalizing behaviors at ages 12 (β = 0.63, p = 0.02) and 15 (β = 0.20, p = 0.03); and for maltreatment, both internalizing and externalizing behaviors at ages 15 (β = 0.64, p = 0.02 for internalizing; β = 0.50, p = 0.03 for externalizing) and 21 (β = 1.39, p = 0.01 for internalizing; β = 1.11, p = 0.01 for externalizing). Direct associations of PCE with internalizing and externalizing behaviors were not observed, nor cross-lagged relationships between internalizing and externalizing behaviors.

CONCLUSIONS

Negative associations of PCE with behavioral adjustment persist into EA via environmental pathways, specifying intervention points to disrupt adverse pathways toward healthy development.

Epigenetic inheritance of phenotypes associated with parental exposure to cocaine

Parental exposure to drugs of abuse induces changes in the germline that can be transmitted across subsequent generations, resulting in enduring effects on gene expression and behavior. This transgenerational inheritance involves a dynamic interplay of environmental, genetic, and epigenetic factors that impact an individual's vulnerability to neuropsychiatric disorders. This chapter aims to summarize recent research into the mechanisms underlying the inheritance of gene expression and phenotypic patterns associated with exposure to drugs of abuse, with an emphasis on cocaine. We will first define the epigenetic modifications such as DNA methylation, histone post-translational modifications, and expression of non-coding RNAs that are impacted by parental cocaine use. We will then explore how parental cocaine use induces heritable epigenetic changes that are linked to alterations in neural circuitry and synaptic plasticity within reward-related circuits, ultimately giving rise to potential behavioral vulnerabilities. This discussion will consider phenotypic differences associated with gestational as well as both maternal and paternal preconception drug exposure and will emphasize differences based on offspring sex. In this context, we explore the complex interactions between genetics, epigenetics, environment, and biological sex. Overall, this chapter consolidates the latest developments in the multigenerational effects and long-term consequences of parental substance abuse.

Perinatal Psychoactive Substances Use: A Rising Perinatal Mental Health Concern

Introduction: A significant increase in psychoactive drugs use was observed in women of childbearing age and during the perinatal period worldwide. Yet, the use of illicit drugs, alcohol and tobacco during pregnancy is a serious health risk for the mother, developing fetus and newborn. Methods: This review of current trends and consequences of psychoactive substance use in the general population and in pregnant women was conducted using the English and French literature published during the years 2000 to 2022, supplemented by guidelines, meta-analyses and reviews. Results: According to current rates of prenatal substances use, it was calculated that 380,000 offspring were exposed to illicit substances, more than 500,000 to alcohol and over one million to tobacco during uterine life. Alarmingly, drug-related pregnancy-associated mortality has shown a staggering 190% rise between 2010 and 2019 in the USA. Different drugs of abuse, when used during pregnancy, increase the risk of stillbirth, neonatal abstinence syndrome and sudden infant death. Adverse effects on pregnancy include premature rupture of membranes, placental abruption, preterm birth, low birth space? weight and small-for-gestational-age infants. There is also an increased risk of morbidity and mortality for the pregnant women. Long-term negative adverse effects of perinatal exposure to substances also include a number of neurocognitive, behavioral and emotional dysfunctions in infants. Each type of substance has its own specificities, which will be briefly summarized. Conclusion: All childbearing age women must be informed about the potential harm of the prenatal use of psychoactive substances and should be encouraged to stop their use when pregnancy is planned and, at least, when pregnancy is known. Questioning women about their alcohol consumption should be systematic at the first prenatal visit and then at every prenatal visit until delivery. Multidisciplinary prevention approaches as well as intervention measures targeted to each type of psychoactive substance can save mothers’ lives and mitigate serious adversities to the offspring.

Cognitive and functional outcomes at age 21 after prenatal cocaine/polydrug exposure and foster/adoptive care

OBJECTIVE

Prenatal cocaine exposure (PCE) has been linked to specific cognitive deficits and behavioral outcomes through early adolescence but there is little information on adult outcomes nor on the relationship of environmental interventions, such as foster/adoptive care, to outcomes.

METHODS

At 21 years, data were available on 325 young adults, [163 PCE and 162 non-exposed (NCE)], primarily African-American, with low SES, who were followed from birth in a prospective longitudinal cohort study. Participants were administered the Wechsler Abbreviated Scale of Intelligence (WASI-II) and surveyed regarding high school completion, problematic substance use, and incarceration/probation history. In the PCE group, 32 remained in non-kinship foster/adoptive care (PCE/FA) from early in life (< 4 years) to 17 years. Group differences were examined through t-tests, MANOVA/ MANCOVA with post-hoc analyses, comparing outcomes and environmental correlates of young adults with PCE vs. NCE, as well as outcomes of PCE young adults in non-kinship foster/adoptive care (PCE/ FA) vs. PCE in birth/kinship care and NCE young adults.

RESULTS

At 21 years, young adults with PCE had lower mean Full Scale (83.7 ± 10.4 vs. 87.3 ± 12.5, p < .01) and Perceptual Reasoning IQs (87.3 ± 11.5 vs. 91.4 ± 13.9, (p < .02), lower high school completion rates (75% vs. 86%, p < .02), and were marginally more likely to have been on probation than NCE young adults, but did not differ in Verbal IQ, self-report of problematic substance use or incarceration. Young adults with PCE in F/A had similar lower IQ scores but had better verbal skills and high school graduation rates that did not differ from NCE young adults (80.6 vs 86.2%, p > .05). They had higher drug exposure at birth and more experiences of maltreatment (p's < 0.05) but their home environment quality was better and lead levels lower (p's < 0.05) than those of young adults with PCE in birth/kinship care.

CONCLUSIONS

Young adults with PCE had lower Perceptual Reasoning and Full-Scale IQ scores, independent of caregiving placement, compared to non-exposed young adults. Young adults with PCE placed in non-kinship foster/adoptive care had lower lead levels, more stimulating home environments, better vocabulary skills and were more likely to graduate from high school than those in birth/kinship care,but were not different in their self-report of problematic substance use, or experiences of incarceration or probation. Our data suggest that some cognitive deficits observed in young adults with PCE may be biologically based, but that some functional outcomes can be modified through environmental interventions. Our data also reflect the complexity of disentangling the effects of teratologic exposures on long term outcomes across a variety of domains and the need for studies of children in the foster care system.

Prenatal cannabis use and its impact on offspring neuro-behavioural outcomes: A systematic review

Introduction

Cannabis is a widely used substance in pregnancy, yet there is a paucity of literature addressing the neuro-behavioural consequences for prenatally exposed children. Our systematic review synthesizes currently available data for the impact of prenatal cannabis use on offspring intelligence and cognitive functioning.

Methods

MEDLINE, EMBASE, PsychINFO, CINAHL, and Clinicaltrials.gov were searched. Observational studies comparing prenatal cannabis use to controls were included. Offspring neuro-behavioural outcomes were grouped in prespecified domains of (1) intelligence and (2) cognitive functioning. Random-effect models were performed for meta-analyses when at least three studies reported the same outcome. All others were summarized qualitatively. GRADE (Grading of Recommendations, Assessment, Development and Evaluations) framework was used to assess evidence certainty.

Results

Of the 1982 reviewed studies (n = 523,107 patients), 28 were included. Significant heterogeneity and cohort redundancy limited meta-analysis. Very low-quality evidence from pooled analyses showed no significant associations between prenatal cannabis exposure and attention [standardized mean difference = -0.27 (95% CI = -0.60 to 0.07)], global intelligence quotient [-0.16 (-0.42 to 0.10)], reading [-0.05 (-0.29 to 0.20)], written comprehension [-0.09 (-0.40 to 0.22)], spelling [-0.04 (-0.26 to 0.17)], and mathematics [-0.01 (-0.15 to 0.13)]. No significant associations were found between prenatal cannabis exposure for all other outcomes. Individual studies reported significant differences between the heavy use groups and non-exposed, although this did not prove to be significant when outcomes were pooled.

Conclusions

The current review did not find a clear association between prenatal cannabis use and offspring neuro-behavioural outcomes. However, evidence was low quality and heterogenous. Further prospective investigation is needed to elucidate any potential association between prenatal cannabis use and long-term neuro-developmental outcomes.

Prenatal cocaine exposure and substance use disorder in emerging adulthood at age 21

BACKGROUND

Prenatal cocaine exposure (PCE) has been associated with child and adolescent externalizing behaviors and early substance use, yet few studies investigated its association with substance use disorder (SUD) in emerging adults. The present study examined the association of PCE with SUD in emerging adulthood, and whether childhood externalizing behaviors and adolescent substance use mediated the relationship.

METHODS

Participants were 367 (187 PCE; 53% female) adults at age 21, primarily urban African American who were recruited at birth. PCE and exposure to alcohol, tobacco, and marijuana were determined using biologic assays for drug metabolites and/or maternal self-report at birth. Offspring externalizing problems were assessed using the Youth Self-Report at age 12, substance use and substance use-related problems via biologic assays and/or self-report at age 15, and SUD determined using DSM-5 diagnostic criteria at age 21.

RESULTS

About 32.3% of the emerging adults were determined to have marijuana use disorder, 30.3% tobacco use disorder, and 15.5% alcohol use disorder. PCE was related to greater externalizing behaviors at age 12 (β = 0.12, p = .042), which in turn was related to SUD (β = 0.22, p = .008). PCE was also related to substance use, mainly marijuana, at age 15 (β = 0.22, p = .011), which was related to SUD (β = 0.51, p < .001). Total indirect effects including these two pathways were significant (β = 0.19, p = .002).

CONCLUSIONS

PCE may increase risk for SUD in emerging adulthood through childhood externalizing behaviors and adolescent substance use.

Prenatal and Postnatal Cocaine Enhances the Induction and Expression of Locomotor Sensitization to Nicotine in Male Rats

INTRODUCTION

Several studies mention that early consumption of cannabis, alcohol, or even cocaine is related to an increase in the prevalence of daily consumption of tobacco in adulthood. However, other factors, such as genetic comorbidity, social influences, and even molecular, neurochemical, and behavioral alterations induced by prenatal and postnatal cocaine exposure, could also explain these observations, since these factors together increase the vulnerability of the offspring to the reinforcing effects of nicotine. The objective of this study was to determine the effect of prenatal and postnatal exposure to cocaine on nicotine-induced locomotor sensitization in young and adult rats.

AIMS AND METHODS

The study was divided into two stages: prenatal and postnatal. In the prenatal stage, a group of pregnant female Wistar rats was administered cocaine daily from day GD0 to GD21 (cocaine preexposure group), and another group of pregnant female rats was administered saline daily (saline preexposure group). Of the litters resulting from the cocaine preexposed and saline preexposed pregnant female groups, in the postnatal stage, only the male rats were used for the recording of the locomotor activity induced by different doses of nicotine (0.2, 0.4, and 0.6 mg/kg) during the induction and expression of locomotor sensitization at different postnatal ages (30, 60, 90, and 120 days).

RESULTS

Prenatal and postnatal cocaine exposure enhanced nicotine-induced locomotor activity and locomotor sensitization.

CONCLUSIONS

This suggests that prenatal and postnatal cocaine exposure can result in increased vulnerability to other drugs of abuse, such as nicotine, in humans.

IMPLICATIONS

Several studies have shown that the abuse of a drug, such as cannabis, alcohol, or even cocaine, at an early age can progress to more severe levels of use of other drugs, such as nicotine, to adulthood. Our data are consistent with this hypothesis, since prenatal and postnatal cocaine exposure enhanced the nicotine-induced increase in locomotor activity and locomotor sensitization. This suggests that prenatal and postnatal exposure to cocaine enhances the drug's salience.

Psychotropic drug abuse in pregnancy and its impact on child neurodevelopment: A review

Substance abuse by women of child-bearing age and fetal in utero drug exposure has increased in the number of infants born with health issues. Prenatal exposure to psychoactive substances can lead to neurological and neurodevelopmental deficits later in life. Useful data concerning the effects of psychoactive drugs on fetal neurodevelopmental status are sparse. Understanding the neurodevelopmental consequences of prenatally drug-exposed children has become a pressing global concern. The aim of this review is to gather current evidence and information on neurodevelopmental outcomes of in utero drug exposure. A literature search was performed on the PubMed, Scopus, and Google Scholar databases using the terms “psychotropic drugs”, “neurodevelopmental consequences”, “prenatal drug exposure”, and “pregnancy”. Available studies on in utero drug exposure were reviewed and found to support the idea that some degree of health issues are present in fetuses and children. Different psychoactive substances have profound neurodevelopmental consequences, such as structural brain changes, poor attention span, Down syndrome, attention deficit hyperactivity disorder, autism spectrum disorder, imbalances in neurotransmitter levels, and many structural deficits. The pervasive use of psychoactive drugs in women of child-bearing age is an important health concern. Further scientific efforts are needed to investigate the effect of prenatal exposure to psychoactive drugs on children.

Prenatal methamphetamine exposure causes dysfunction in glucose metabolism and low birthweight

Methamphetamine (METH) is a psychostimulant drug that induces addiction. Previous epidemiological studies have demonstrated that maternal METH abuse during pregnancy causes low birthweight (LBW) in the offspring. As a source of essential nutrients, in particular glucose, the placenta plays a key role in fetal development. LBW leads to health problems such as obesity, diabetes, and neurodevelopmental disorders (NDDs). However, the detailed mechanism underlying offspring's LBW and health hazards caused by METH are not fully understood. Therefore, we investigated the effects of prenatal METH exposure on LBW and fetal-placental relationship by focusing on metabolism. We found dysfunction of insulin production in the pancreas of fetuses exposed to METH. We also found a reduction of the glycogen cells (GCs) storing glycogens in the junctional zone of placenta, all of which suggest abnormal glucose metabolism affects the fetal development. These results suggest that dysfunction in fetal glucose metabolism may cause LBW and future health hazards. Our findings provide novel insights into the cause of LBW via the fetal-placental crosstalk.

Maternal Exposure and Neonatal Effects of Drugs of Abuse

The public health crisis of pregnant women being exposed to drugs of abuse and of its impact on their unborn children continues to grow at an alarming rate globally. The state of pregnancy is unique, with physiological changes that can lead to changes in the way drugs are handled by the body in both pharmacokinetics and response. These changes place the pregnant woman, fetus, and newborn infant at risk, as many of these drugs can cross the placenta and into breast milk. The substances most commonly linked to harmful effects include alcohol, tobacco, cannabis, stimulants, and opioids. The pharmacological and toxicological changes caused by in utero exposure or breastfeeding exposure are difficult to study, and the full extent of the mechanisms involved are not fully understood. However, these changes can significantly affect the risks of substance abuse and influence optimal treatment of pregnant women with a substance use disorder. In addition, newborns who were exposed to drugs of abuse in utero can experience withdrawal syndromes. Pharmacological management in infants is used to guide and treat withdrawal symptoms, with the goal being to improve the infant's sleep, eating, and comfort. Several barriers may prevent pregnant women from seeking help for substance use, including stigma and interactions with the legal system. Understanding changes in pharmacology, including pharmacokinetic changes that happen during pregnancy, is essential for anticipating the extent of maternal exposure and neonatal adverse effects.

Exposures influencing the developing central autonomic nervous system

Autonomic nervous system function is critical for transition from in-utero to ex-utero life and is associated with neurodevelopmental and neuropsychiatric outcomes later in life. Adverse prenatal and neonatal conditions and exposures can impair or alter ANS development and, as a result, may also impact long-term neurodevelopmental outcomes. The objective of this article is to provide a broad overview of the impact of factors that are known to influence autonomic development during the fetal and early neonatal period, including maternal mood and stress during and after pregnancy, fetal growth restriction, congenital heart disease, toxic exposures, and preterm birth. We touch briefly on the typical development of the ANS, then delve into both in-utero and ex-utero maternal and fetal factors that may impact developmental trajectory of the ANS and, thus, have implications in transition and in long-term developmental outcomes. While many types of exposures and conditions have been shown to impact development of the autonomic nervous system, there is still much to be learned about the mechanisms underlying these influences. In the future, more advanced neuromonitoring tools will be required to better understand autonomic development and its influence on long-term neurodevelopmental and neuropsychological function, especially during the fetal period.

Prenatal and postnatal cocaine exposure enhances the induction and expression of locomotor sensitization to cocaine in rats

Prenatal and postnatal exposure to cocaine can affect the development and function of the central nervous system in offspring. It also produces changes in cocaine-induced dopamine release and increases cocaine self-administration and cocaine-induced conditioned place preference. Further, prenatal cocaine exposure involves greater risk for development of a substance use disorder in adolescents. Therefore, the objective of this study was to determine the effect of prenatal and postnatal cocaine exposure on locomotor sensitization in rats. A group of pregnant female Wistar rats were administered daily from day GD0 to GD21 with cocaine (cocaine pre-exposure group) and another group pregnant female rats were administered daily with saline (saline pre-exposure group). During lactation (PND0 to PND21) pregnant rats also received cocaine administration or saline, respectively. Of the litters resulting of the cocaine pre-exposed and saline pre-exposed pregnant female groups, only the male rats were used for the recording of the locomotor activity induced by different doses of cocaine (1, 5, 10, 20 and 40 mg/Kg/day) during the induction and expression of locomotor sensitization at different postnatal ages (30, 60, 90 and 120 days), representative of adolescence and adult ages. The study found that prenatal and postnatal cocaine exposure enhanced locomotor activity and locomotor sensitization, and such increase was dose- and age-dependent. This suggests that prenatal and postnatal cocaine exposure can result in increased vulnerability to cocaine abuse in young and adult humans.

Life-long impairment of glucose homeostasis upon prenatal exposure to psychostimulants

Maternal drug abuse during pregnancy is a rapidly escalating societal problem. Psychostimulants, including amphetamine, cocaine, and methamphetamine, are amongst the illicit drugs most commonly consumed by pregnant women. Neuropharmacology concepts posit that psychostimulants affect monoamine signaling in the nervous system by their affinities to neurotransmitter reuptake and vesicular transporters to heighten neurotransmitter availability extracellularly. Exacerbated dopamine signaling is particularly considered as a key determinant of psychostimulant action. Much less is known about possible adverse effects of these drugs on peripheral organs, and if in utero exposure induces lifelong pathologies. Here, we addressed this question by combining human RNA-seq data with cellular and mouse models of neuroendocrine development. We show that episodic maternal exposure to psychostimulants during pregnancy coincident with the intrauterine specification of pancreatic β cells permanently impairs their ability of insulin production, leading to glucose intolerance in adult female but not male offspring. We link psychostimulant action specifically to serotonin signaling and implicate the sex-specific epigenetic reprogramming of serotonin-related gene regulatory networks upstream from the transcription factor Pet1/Fev as determinants of reduced insulin production.

Prenatal Environment That Affects Neuronal Migration

Migration of neurons starts in the prenatal period and continues into infancy. This developmental process is crucial for forming a proper neuronal network, and the disturbance of this process results in dysfunction of the brain such as epilepsy. Prenatal exposure to environmental stress, including alcohol, drugs, and inflammation, disrupts neuronal migration and causes neuronal migration disorders (NMDs). In this review, we summarize recent findings on this topic and specifically focusing on two different modes of migration, radial, and tangential migration during cortical development. The shared mechanisms underlying the NMDs are discussed by comparing the molecular changes in impaired neuronal migration under exposure to different types of prenatal environmental stress.

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.

Epigenetic effects of paternal cocaine on reward stimulus behavior and accumbens gene expression in mice

Paternal cocaine use causes phenotypic alterations in offspring behavior and associated neural processing. In rodents, changes in first generation (F1) offspring include drug reward behavior, circadian timing, and anxiety responses. This study, utilizing a murine (C57BL/6J) oral cocaine model, examines the effects of paternal cocaine exposure on fundamental characteristics of offspring reward responses, including: 1) the extent of cocaine-induced effects after different durations of sire drug withdrawal; 2) sex- and drug-dependent differences in F1 reward preference; 3) effects on second generation (F2) cocaine preference; and 4) corresponding changes in reward area (nucleus accumbens) mRNA expression. We demonstrate that paternal cocaine intake over a single ˜40-day spermatogenic cycle significantly decreased cocaine (but not ethanol or sucrose) preference in a sex-specific manner in F1 mice from sires mated 24 h after drug withdrawal. However, F1 offspring of sires bred 4 months after withdrawal did not exhibit altered cocaine preference. Altered cocaine preference also was not observed in F2's. RNASeq analyses of F1 accumbens tissue revealed changes in gene expression in male offspring of cocaine-exposed sires, including many genes not previously linked to cocaine addiction. Enrichment analyses highlight genes linked to CNS development, synaptic signaling, extracellular matrix, and immune function. Expression correlation analyses identified a novel target, Fam19a4, that may negatively regulate many genes in the accumbens, including genes already identified in addiction. Collectively, these results reveal that paternal cocaine effects in F1 offspring may involve temporally limited epigenetic germline effects and identify new genetic targets for addiction research.

An examination of the association between prenatal cocaine exposure and brain activation measures of arousal and attention in young adults: An fMRI study using the Attention Network Task

Prenatal drug exposure, including cocaine, alcohol, marijuana, and tobacco, is associated with deficits in behavioral regulation and attention. Using fMRI, the objective of this study was to characterize the association between prenatal cocaine exposure (PCE) and the underlying neural substrates associated with behavioral outcomes of attention. Forty-seven young adults were recruited for this study from the ongoing Maternal Health Practices and Child Development (MHPCD) Project, a longitudinal study of the effects of PCE on growth, behavior, and cognitive function. Three groups were compared: 1) prenatal exposure to cocaine, alcohol, marijuana, and tobacco (CAMT, n = 15), 2) prenatal exposure to alcohol, marijuana, and tobacco (AMT, n = 17), and 3) no prenatal exposure to drugs (Controls, n = 15). Subjects were frequency matched on gender, race, handedness, and 15-year IQ. This study used the theoretical model proposed by Posner and Peterson (1990), which posits three dissociable components of attention: alerting, orienting, and executive attention. Subjects completed a functional MRI (fMRI) scan while performing the Attention Network Task, a validated neuroimaging measure of the 3-network model of attention. Behavioral and fMRI data revealed no associations between PCE and task accuracy, speed of processing, or activation in key brain regions associated with each of the attention networks. The results of this study show that any subtle differences in brain function associated with PCE are not detectable using the ANT task and fMRI. These results should be interpreted in the context of other studies that have found associations between PCE and arousal with emotionally arousing stimuli, compared to this study that found no associations using emotionally neutral stimuli.

Prenatal cocaine exposure disrupts the dopaminergic system and its postnatal responses to cocaine

Impaired attention is the hallmark consequence of prenatal cocaine exposure (PCE), affecting brain development, learning, memory and social adaptation starting at an early age. To date, little is known about the brain structures and neurochemical processes involved in this effect. Through focusing on the visual system and employing zebrafish as a model, we show that PCE reduces expression of dopamine receptor Drd1, with levels reduced in the optic tectum and other brain regions, but not the telencephalon. Organism-wide, PCE results in a 1.7-fold reduction in the expression of the dopamine transporter (dat), at baseline. Acute cocaine administration leads to a 2-fold reduction in dat in drug-naive larvae but not PCE fish. PCE sensitizes animals to an anxiogenic-like behavioral effect of acute cocaine, bottom-dwelling, while loss of DAT due to genetic knockout (DATKO) leads to bottom-dwelling behavior at baseline. Neuronal calcium responses to visual stimuli in both PCE and DATKO fish show tolerance to acute cocaine in the principal regions of visual attention, the telencephalon and optic tectum. The zebrafish model can provide a sensitive assay by which to elucidate the molecular mechanisms and brain region-specific consequences of PCE, and facilitate the search for effective therapeutic solutions.

Reversal Learning Deficits Associated with Increased Frontal Cortical Brain-Derived Neurotrophic Factor Tyrosine Kinase B Signaling in a Prenatal Cocaine Exposure Mouse Model

Prenatal cocaine exposure remains a major public health concern because of its adverse impact on cognitive function in children and adults. We report that prenatal cocaine exposure produces significant deficits in reversal learning, a key component of cognitive flexibility, in a mouse model. We used an olfactory reversal learning paradigm and found that the prenatally cocaine-exposed mice showed a marked failure to learn the reversed paradigm. Because brain-derived neurotrophic factor (BDNF) is a key regulator of cognitive functions, and because prenatal cocaine exposure increases the expression of BDNF and the phosphorylated form of its receptor, tyrosine kinase B (TrkB), we examined whether BDNF-TrkB signaling is involved in mediating the reversal learning deficit in prenatally cocaine-exposed mice. Systemic administration of a selective TrkB receptor antagonist restored normal reversal learning in prenatally cocaine-exposed mice, suggesting that increased BDNF-TrkB signaling may be an underlying mechanism of reversal learning deficits. Our findings provide novel mechanistic insights into the reversal learning phenomenon and may have significant translational implications because impaired cognitive flexibility is a key symptom in psychiatric conditions of developmental onset.