Long-term effects of prenatal drug exposure on the neural correlates of memory at encoding and retrieval

Early emotional caregiving environment and associations with memory performance and hippocampal volume in adolescents with prenatal drug exposure

Early adversities, including prenatal drug exposure (PDE) and a negative postnatal emotional caregiving environment, impact children's long-term development. The protracted developmental course of memory and its underlying neural systems offer a valuable framework for understanding the longitudinal associations of pre- and postnatal factors on children with PDE. This study longitudinally examines memory and hippocampal development in 69 parent-child dyads to investigate how the early caregiving emotional environment affects children with PDE's neural and cognitive systems. Measures of physical health, drug exposure, caregiver stress, depression, and distress were collected between 0 and 24 months At age 14 years, adolescents completed multiple measures of episodic memory, and at ages 14 and 18 years, adolescents underwent magnetic resonance imaging (MRI) scans. Latent constructs of episodic memory and the caregiving environment were created using Confirmatory Factor Analysis. Multiple regressions revealed a negative emotional caregiving environment during infancy was associated with poor memory performance and smaller left hippocampal volumes at 14 years. Better memory performance at 14 years predicted larger right hippocampal volume at 18 years. At 18 years, the association between the emotional caregiving environment and hippocampal volume was moderated by sex, such that a negative emotional caregiving environment was associated with larger left hippocampal volumes in males but not females. Findings suggest that the postnatal caregiving environment may modulate the effects of PDE across development, influencing neurocognitive development.

An intergenerational lifespan perspective on the neuroscience of prenatal substance exposure

Prenatal substance exposure has the potential to impact a variety of domains, with neurobiological effects that last throughout the lifespan. Different substances may impact the brain in both specific and diffuse ways; however, the aberrant neural outcomes following exposure tend to coalesce in three areas: (1) sensorimotor development; (2) arousal, motivation, and reward; and (3) executive functioning, impulse control, and emotion regulation. This manuscript represents a summary and update of a previous review (Morie et al., 2019). We organize this piece by domain and summarize data from published neuroimaging studies that examine the neural correlates of prenatal exposure across developmental stages. While the published neuroimaging literature in the area of prenatal exposure has a range of sampling concerns that may limit generalizability as well as longitudinal prediction, the findings to date do point to domains of interest warranting further study. With this caveat, we synthesize the extant findings to describe ways in which prenatal substance exposure is associated with developmental psychopathology and implicated in potentially aberrant behavioral patterns beginning in infancy and persisting through childhood, adolescence, adulthood, and even parenthood. We also examine how substance abuse may impact parenting behaviors that in turn influences infant and child behavior in ways that may be additive or obscure the direct teratological effects of prenatal exposure. Given this observation, we offer an additional intergenerational lens through which prenatal substance exposure should be studied.

Hippocampal functional connectivity development during the first two years indexes 4-year working memory performance

The hippocampus is a key limbic region involved in higher-order cognitive processes including learning and memory. Although both typical and atypical functional connectivity patterns of the hippocampus have been well-studied in adults, the developmental trajectory of hippocampal connectivity during infancy and how it relates to later working memory performance remains to be elucidated. Here we used resting state fMRI (rsfMRI) during natural sleep to examine the longitudinal development of hippocampal functional connectivity using a large cohort (N = 202) of infants at 3 weeks (neonate), 1 year, and 2 years of age. Next, we used multivariate modeling to investigate the relationship between both cross-sectional and longitudinal growth in hippocampal connectivity and 4-year working memory outcome. Results showed robust local functional connectivity of the hippocampus in neonates with nearby limbic and subcortical regions, with dramatic maturation and increasing connectivity with key default mode network (DMN) regions resulting in adult-like topology of the hippocampal functional connectivity by the end of the first year. This pattern was stabilized and further consolidated by 2 years of age. Importantly, cross-sectional and longitudinal measures of hippocampal connectivity in the first year predicted subsequent behavioral measures of working memory at 4 years of age. Taken together, our findings provide insight into the development of hippocampal functional circuits underlying working memory during this early critical period.

Generational Effects of Opioid Exposure

The inheritance of substance abuse, including opioid abuse, may be influenced by genetic and non-genetic factors related to the environment, such as stress and socioeconomic status. These non-genetic influences on the heritability of a trait can be attributed to epigenetics. Epigenetic inheritance can result from modifications passed down from the mother, father, or both, resulting in either maternal, paternal, or parental epigenetic inheritance, respectively. These epigenetic modifications can be passed to the offspring to result in multigenerational, intergenerational, or transgenerational inheritance. Human and animal models of opioid exposure have shown generational effects that result in molecular, developmental, and behavioral alterations in future generations.

Prenatal drug exposure from infancy through emerging adulthood: Results from neuroimaging

Prenatal drug exposure may have important repercussions across the lifespan for cognition and behavior. While alcohol is a recognized teratogen, the influences of other substances may also be substantial. The neural underpinnings of the influences of prenatal drug exposure have been examined using longitudinal approaches and multiple imaging techniques. Here we review the existing literature on the neural correlates of prenatal drug exposure. We focused the review on studies that have employed functional neuroimaging and electroencephalography and on substances other than alcohol. We also framed the review through the lens of four developmental life stages (infancy, childhood, adolescence and emerging adulthood). We included papers that have examined any drug use, including tobacco, opiates, cocaine, marijuana, methamphetamines, or polysubstance use. Data suggest that prenatal drug exposure has long-lasting, deleterious influences on cognition and reward processing in infancy and childhood that persist into adolescence and emerging adulthood and may underlie some behavioral tendencies, such as increased externalizing and risk-taking behaviors, seen in these groups.