Limited bedding and nesting increases ethanol drinking in female rats

Prenatal opioid exposure (POE) and postnatal adverse experiences are early life adversities (ELA) that often co-occur and increase problematic alcohol (EtOH) drinking during adolescence. We investigated the relationship between POE, postnatal adversity, and adolescent EtOH drinking in rats. We also sought to determine whether ELAs affect alpha-adrenoceptor density in the brain because the noradrenergic system is involved in problematic alcohol drinking and its treatment. We hypothesized that the combination of POE and postnatal adversity will increase alcohol drinking in rats compared to rats with exposure to either adversity alone or to control. We also predicted that POE and postnatal adversity would increase α1-adrenoceptor density and decrease α2-adrenoceptor density in brain to confer a stress-responsive phenotype. Pregnant rats received morphine (15 mg/kg/day) or saline via subcutaneous minipumps from gestational day 9 until birth. Limited bedding and nesting (LBN) procedures were introduced from postnatal day (PD) 3-11 to mimic early life adversity-scarcity. Offspring rats (PD 31-33) were given opportunities to drink EtOH (20 %, v/v) using intermittent-access, two-bottle choice (with water) procedures. Rats given access to EtOH were assigned into sub-groups that were injected with either yohimbine (1 mg/kg, ip) or vehicle (2 % DMSO, ip) 30 min prior to each EtOH access session to determine the effects of α2-adrenoceptor inhibition on alcohol drinking. We harvested cortices, brainstems, and hypothalami from EtOH-naïve littermates on either PD 30 or PD 70 and conducted radioligand receptor binding assays to quantify α1- and α2-adrenoceptor densities. Contrary to our hypothesis, only LBN alone increased EtOH intake in female adolescent rats compared to female rats with POE. Neither POE nor LBN affected α1- or α2-adrenoceptor densities in the cortex, brainstem, or hypothalamus of early- or late-aged adolescent rats. These results suggest a complex interaction between ELA type and sex on alcohol drinking.

[Formula: see text] Neural and behavioral indicators of cognitive control in preschoolers with and without prenatal opioid exposure

Prenatal opioid exposure is one consequence of the opioid epidemic, but effects on child development remain poorly understood. There is emerging evidence that children exposed to opioids in utero exhibit elevated emotional and behavioral problems, which may be partially due to alterations in cognitive control. Using multiple methods (i.e., neuropsychological, behavioral, and event-related potential [ERP] assessments), the present study examined differences in emotional, behavioral, and cognitive control difficulties in preschool-aged children with (n = 21) and without (n = 23) prenatal opioid exposure (Mage = 4.30, SD = 0.77 years). Child emotional and behavioral problems were measured with a caregiver questionnaire, indicators of cognitive control were measured using developmentally appropriate behavioral (i.e., delay discounting, Go/No-Go) and neuropsychological (i.e., Statue) tasks, and electroencephalogram was recorded to error and correct responses in a Go/No-Go task. ERP analyses focused on the error-related negativity (ERN), an ERP that reflects error monitoring, and correct-response negativity (CRN), a component reflecting performance monitoring more generally. Opioid exposure was associated with elevated difficulties across domains and a blunted ERN, reflecting altered cognitive control at the neural level, but groups did not significantly differ on behavioral measures of cognitive control. These result replicate prior studies indicating an association between prenatal opioid exposure and behavioral problems in preschool-aged children. Further, our findings suggest these differences may be partially due to children with prenatal opioid exposure exhibiting difficulties with cognitive control at the neural level. The ERN is a potential target for future research and intervention efforts to address the sequelae of prenatal opioid exposure.

Opioid-induced dysbiosis of maternal gut microbiota during gestation alters offspring gut microbiota and pain sensitivity

There has been a rapid increase in neonates born with a history of prenatal opioid exposure. How prenatal opioid exposure affects pain sensitivity in offspring is of interest, as this may perpetuate the opioid epidemic. While few studies have reported hypersensitivity to thermal pain, potential mechanisms have not been described. This study posits that alterations in the gut microbiome may underly hypersensitivity to pain in prenatally methadone-exposed 3-week-old male offspring, which were generated using a mouse model of prenatal methadone exposure. Fecal samples collected from dams and their offspring were subjected to 16s rRNA sequencing. Thermal and mechanical pain were assessed using the tail flick and Von Frey assays. Transcriptomic changes in whole brain samples of opioid or saline-exposed offspring were investigated using RNA-sequencing, and midbrain sections from these animals were subjected to qPCR profiling of genes related to neuropathic and inflammatory pain pathways. Prenatal methadone exposure increased sensitivity to thermal and mechanical pain and elevated serum levels of IL-17a. Taxonomical analysis revealed that prenatal methadone exposure resulted in significant alterations in fecal gut microbiota composition, including depletion of Lactobacillus, Bifidobacterium, and Lachnospiracea sp and increased relative abundance of Akkermansia, Clostridium sensu stricto 1, and Lachnoclostridium. Supplementation of the probiotic VSL#3 in dams rescued hypersensitivity to thermal and mechanical pain in prenatally methadone-exposed offspring. Similarly, cross-fostering prenatally methadone-exposed offspring to control dams also attenuated hypersensitivity to thermal pain in opioid-exposed offspring. Modulation of the maternal and neonatal gut microbiome with probiotics resulted in transcriptional changes in genes related to neuropathic and immune-related signaling in whole brain and midbrain samples of prenatally methadone-exposed offspring. Together, our work provides compelling evidence of the gut-brain-axis in mediating pain sensitivity in prenatally opioid-exposed offspring.

Developmental implications of prenatal opioid exposure among school-aged children: a mixed methods and community-initiated analysis

BACKGROUND

Growing research points to potential long-term developmental implications of prenatal opioid exposure for children. Yet, polysubstance use and adverse childhood experiences are raised as potential confounders. Further, there is a lack of data on school-age children and the children's strengths.

METHODS

Parents and caregivers of children with prenatal opioid exposure worked with the study team to design, collect, and descriptively analyze mixed method data. Data were collected through survey (n = 148) and two focus groups (n = 15) from a convenience sample in mostly West Virginia and Massachusetts.

RESULTS

Nearly half of the children in the sample were diagnosed with multiple developmental delays, behavioral health conditions, and specific learning disorders. Roughly 85% of children have behavioral challenges. Associations between prenatal opioid exposure and negative developmental outcomes did not vary by type of opioid nor by polysubstance use, while controlling for adverse childhood experiences. Importantly, over 80% of families also reported their child's strengths, including empathy, social magnetism, and their resilience.

CONCLUSIONS

The challenges for children born with prenatal opioid exposure may extend into school-age. The results are consistent with prior research on younger children, suggesting a need for best practices for caring for these children beyond the neonatal stage.

A 12-month follow-up of infant neurodevelopmental outcomes of prenatal opioid exposure and polysubstance use

BACKGROUND

Prenatal opioid exposure has been associated with developmental deficits during infancy, but the literature is limited by simple group comparisons and lack of appropriate controls. Previously published research with the current sample documented unique associations between prenatal opioid exposure and developmental outcomes at three and six months, but less is known about associations later in infancy.

METHOD

The current study examined pre- and postnatal opioid and polysubstance exposure as predictors of parent-reported developmental status at 12 months of age. Participants were 85 mother-child dyads, oversampled for mothers taking opioid treatment medications during pregnancy. Maternal opioid and polysubstance use were reported using the Timeline Follow-Back Interview during the third trimester of pregnancy or up to one month postpartum and updated through the child's first year of life. Seventy-eight dyads participated in a 12-month assessment, including 68 with parent-reported developmental status on Ages and Stages Questionnaire.

RESULTS

At 12 months, average developmental scores fell within normal ranges and prenatal opioid exposure was not significantly related to any developmental outcomes. However, more prenatal alcohol exposure was significantly related to worse problem-solving scores, and this relationship remained after controlling for adjusted age and other substance exposure.

CONCLUSION

Although findings await replication with larger samples and more comprehensive measures, results suggest that unique developmental risks of prenatal opioid exposure may not persist through the first year of life. Effects of prenatal exposure to co-occurring teratogens, such as alcohol, may become apparent as children exposed to opioids develop.

Effects of prenatal opioid exposure on synaptic adaptations and behaviors across development

In this review, we focus on prenatal opioid exposure (POE) given the significant concern for the mental health outcomes of children with parents affected by opioid use disorder (OUD) in the view of the current opioid crisis. We highlight some of the less explored interactions between developmental age and sex on synaptic plasticity and associated behavioral outcomes in preclinical POE research. We begin with an overview of the rich literature on hippocampal related behaviors and plasticity across POE exposure paradigms. We then discuss recent work on reward circuit dysregulation following POE. Additional risk factors such as early life stress (ELS) could further influence synaptic and behavioral outcomes of POE. Therefore, we include an overview on the use of preclinical ELS models where ELS exposure during key critical developmental periods confers considerable vulnerability to addiction and stress psychopathology. Here, we hope to highlight the similarity between POE and ELS on development and maintenance of opioid-induced plasticity and altered opioid-related behaviors where similar enduring plasticity in reward circuits may occur. We conclude the review with some of the limitations that should be considered in future investigations. This article is part of the Special Issue on 'Opioid-induced addiction'.

The Effects of Opioid Use during Pregnancy on Infant Health and Well-Being

In this study, we estimate the first causal effects of in utero opioid exposure on infant health at birth and child protective services reports. We employ maternal fixed-effects models using linked administrative data capturing 259,723 infants born to 176,224 mothers enrolled in Medicaid between 2010 and 2019. Our preferred specifications suggest that neonatal abstinence syndrome and NICU admission bear strong associations with prenatal opioid exposure, concentrated on illicit and medication assisted treatment (MAT) exposure in the first and third trimesters. We find that prenatal opioid exposure is associated with increased CPS reports, low birth weight, preterm birth, and small for gestational age, though these measures are less sensitive with respect to the timing of exposure. While we detect relatively smaller effects of non-MAT prescription opioid exposure on NAS, NICU admission, low birthweight, these effects are not trivial, suggesting that medical professionals should consider balancing the potential for adverse side effects of infants with the benefits of pain management for pregnant women.

Verbal and nonverbal memory in school-aged children born to opioid-dependent mothers

BACKGROUND

The potential long-term developmental effects of prenatal methadone and buprenorphine exposure during pregnancy are still largely unknown.

AIMS

We investigated memory function in school-aged children of women enrolled in opioid maintenance therapy (OMT) during pregnancy.

STUDY DESIGN

Prospective longitudinal cohort study.

SUBJECTS

Participants included 41 children (aged 9-11 years), 20 of which had histories of prenatal methadone or buprenorphine exposure.

OUTCOME MEASURES

Verbal and non-verbal memory function was assessed using four subtests from the Test of Memory and Learning - Second edition (TOMAL-2).

RESULTS

The OMT group scored lower on both the two non-verbal as well as the two verbal memory tasks, all p-values <.05. Group differences remained for three out of the four subtests after controlling for general IQ. Including maternal tobacco use during pregnancy increased the explanatory power of the model, R² change of 0.07, p = .04.

CONCLUSIONS

Children prenatally exposed to methadone or buprenorphine had significantly lower memory performance, however, this association may in part be explained by maternal tobacco use during pregnancy. Consequently, smoking cessation programs should be systematically integrated into opioid maintenance therapy programs for pregnant women.

Thalamocortical functional connectivity in infants with prenatal opioid exposure correlates with severity of neonatal opioid withdrawal syndrome

PURPOSE

Prenatal opioid exposure (POE) is a growing public health concern due to its associated adverse outcomes including neonatal opioid withdrawal syndrome (NOWS). The aim of this study was to assess alterations in thalamic functional connectivity in neonates with POE using resting-state functional magnetic resonance imaging (rs-fMRI) and identify whether these altered connectivity measures were associated with NOWS severity.

METHODS

In this prospective, IRB-approved study, we performed rs-fMRI in 19 infants with POE and 20 healthy control infants without POE. Following standard pre-processing, we performed seed-based functional connectivity analysis with the right and left thalamus as the regions of interest. We performed post hoc analysis in the prenatal opioid exposure group to identify associations of altered thalamocortical connectivity with severity of NOWS. P value of < .05 was considered statistically significant.

RESULTS

There were several regions of significantly altered thalamic to cortical functional connectivity in infants with POE compared to the healthy infants. Distinct regions of thalamocortical functional connectivity correlated with maximum modified Finnegan score. Association between thalamocortical connectivity and severity of NOWS was nominally modified by maternal psychological conditions and polysubstance use.

CONCLUSION

Our findings reveal prenatal opioid exposure-related alterations in thalamic functional connectivity in the infant brain that are correlated with severity of NOWS. Future studies may benefit from evaluation of thalamocortical resting state functional connectivity in infants with POE to help  stratify risk of long term neurodevelopmental outcomes.

Co-occurrence of preconception maternal childhood adversity and opioid use during pregnancy: Implications for offspring brain development

Understanding of the effects of in utero opioid exposure on neurodevelopment is a priority given the recent dramatic increase in opioid use among pregnant individuals. However, opioid abuse does not occur in isolation-pregnant individuals abusing opioids often have a significant history of adverse experiences in childhood, among other co-occurring factors. Understanding the specific pathways in which these frequently co-occurring factors may interact and cumulatively influence offspring brain development in utero represents a priority for future research in this area. We highlight maternal history of childhood adversity (CA) as one such co-occurring factor that is more prevalent among individuals using opioids during pregnancy and which is increasingly shown to affect offspring neurodevelopment through mechanisms beginning in utero. Despite the high incidence of CA history in pregnant individuals using opioids, we understand very little about the effects of comorbid prenatal opioid exposure and maternal CA history on fetal brain development. Here, we first provide an overview of current knowledge regarding effects of opioid exposure and maternal CA on offspring neurodevelopment that may occur during gestation. We then outline potential mechanistic pathways through which these factors might have interactive and cumulative influences on offspring neurodevelopment as a foundation for future research in this area.

Prenatal exposure to opioids: Associations between the caregiving environment and externalizing behaviors

Maternal opioid use during pregnancy is a rapidly growing public health crisis and is associated with a range of adverse developmental outcomes including externalizing behaviors among exposed children. Recent work has highlighted the role of indirect pathways from prenatal opioid exposure to behavioral outcomes through aspects of the caregiving environment, including parenting. This review highlights maternal sensitivity and related aspects of the caregiving environment that may impact the development of externalizing behaviors among children with a history of prenatal exposure to opioids. We conclude by providing suggestions for future directions in research examining development among children with prenatal opioid exposure.

Infant neurodevelopmental outcomes of prenatal opioid exposure and polysubstance use

BACKGROUND

Prenatal opioid exposure has been linked to adverse birth outcomes and delays in infant development. Existing literature is limited by a simple group-differences approach as well as inadequate controls for sociodemographic factors and polysubstance exposure co-occurring with prenatal opioid use.

METHOD

The current study assessed cumulative opioid exposure (duration of prescribed and illicit opioid use) as a predictor of infant birth outcomes and mother-reported developmental status at three and six months of age, controlling for polysubstance exposure. Participants were predominantly low-income pregnant and peripartum women, oversampled for mothers receiving medication-assisted treatment (MAT) for opioid use disorder. Prenatal opioid and non-opioid substance use were reported by mothers using a Timeline Follow-Back Interview completed during the third trimester and updated postnatally (infant age six months).

RESULTS

Developmental scores were in the normal range. However, total opioid exposure was positively related to premature birth and inversely related to mother-reported developmental status in specific domains. Associations with three-month fine motor skills and six-month communication skills were robust to controls for polysubstance exposure and sociodemographic covariates.

CONCLUSIONS

Results suggest unique effects of prenatal opioid exposure on the early development of fine motor and communication skills. Similar findings were obtained for prescribed and illicit opioid use, underscoring developmental risks of both MAT and untreated substance use. Exploratory analyses investigating type and timing of MAT suggest directions for future research.

Neonatal sleep development and early learning in infants with prenatal opioid exposure

The aim of this chapter is to examine the role of sleep and cognition in the context of the cumulative risk model examining samples of at-risk infants and maternal-infant dyads. The cumulative risk model posits that non-optimal developmental outcomes are the result of multiple factors in a child's life including, but not limited to, prenatal teratogenic exposures, premature birth, family socioeconomic status, parenting style and cognitions as well as the focus of this volume, sleep. We highlight poor neonatal sleep as both an outcome of perinatal risk as well as a risk factor to developing attentional and cognitive capabilities during early childhood. Outcomes associated with and contributing to poor sleep and cognition during infancy are examined in relation to other known risks in our clinical population. Implications of this research and recommendations for interventions for this population are provided.

Prenatally buprenorphine-exposed children: health to 3 years of age

Our prospective study is among the first attempts to examine the health of prenatally buprenorphine-exposed children after neonatal age and to determine the types of child maltreatment in this patient group. The study population included 102 children (61/41 Caucasian males/females) who had a positive urine screen for buprenorphine as a newborn. In addition to buprenorphine, the children were also prenatally exposed to other substances. The data were collected by pediatricians in follow-up visits until 3 years of age and from medical records. Ten prenatally buprenorphine-exposed children (10 %) had some birth defect. The study children had slightly more major anomalies than newborns on average in Finland (3.4 %). Eye disorders (nystagmus, opticus atrophy, and strabismus) occurred in 11 % of children. One child was diagnosed with hepatitis C transmission. One female died of sudden infant death syndrome (SIDS), and one male died of congenital heart disease. Pediatricians submitted altogether 70 reports to child welfare services of suspected maltreatment. Of these reports, 45 (64 %) involved medical neglect. Physical abuse was suspected in four reports.

CONCLUSION

We suggest that prenatally buprenorphine-exposed children have several types of problems with their health at toddler age and that they are susceptible to child maltreatment, especially to medical neglect.