White-matter crossing-fiber microstructure in adolescents prenatally exposed to cocaine

Abstract

Background Prenatal cocaine exposure (PCE) is associated with risk-taking behaviors, including increased initiation of substance use in adolescence. The neurobiological underpinnings of these behaviors in adolescents with PCE are not well understood. The goal of this study was to compare diffusion-weighted imaging data between adolescents with and without PCE using crossing-fiber models, which may provide more comprehensive estimates of white-matter microstructure within regions of multiple (e.g., primary and secondary) fiber orientations. Methods Thirty-nine PCE individuals and 17 comparably aged prenatally non-drug-exposed (NDE) youths were recruited from a longitudinal cohort followed since birth. White matter was examined using tensor-derived and crossing-fiber models. Whole-brain investigations were performed, as were analyses on seven white-matter regions, which included the splenium, body and genu of the corpus callosum, bilateral cingulum, and the right and left superior longitudinal fasciculus (SLF). Results Whole-brain analyses revealed no group differences. However, ROI analyses for anisotropy estimates derived from the crossing-fiber model revealed significant group differences for secondary fibers, with reduced anisotropy among PCE adolescents compared to prenatally non-exposed youth in the right cingulum and the left SLF, and increased anisotropy in the genu. Conclusions Our findings suggest that white-matter differences in PCE adolescents are subtle and localized primarily within secondary fiber orientations, perhaps arising from altered white-matter development.

Substance abuse and white matter: Findings, limitations, and future of diffusion tensor imaging research

“…For cocaine, there is also evidence that cocaine use affects white matter microstructure. Compared to adolescents who had not been exposed to cocaine prenatally, exposed adolescents had lower FA in the cingulum and superior longitudinal fasciculus (Morie et al, 2017). The notion that cocaine induces microstructural white matter changes is corroborated by a recent preliminary longitudinal study.…”

“…Such a negative association has not always been found, however. Interestingly, cocaine abuse is associated with higher FA in certain regions of the brain, and lower FA in other areas (Morie et al, 2017;Romero et al, 2010). Although preliminary, such studies raise the possibility that the mechanism by which cocaine affects the brain may be different than that of other substances.…”

Substance‐use initiation moderates the effect of stress on white‐matter microstructure in adolescents

“…Though the current hypothesis has yet to be addressed, previous studies have found no differences in primary white-matter anisotropy between prenatally cocaine-exposed and non-exposed adolescents within brain regions that overlapped within this study. 24…”

“…As described previously 24 , forty contiguous slices parallel to the AC-PC line were acquired using two 3T Siemens Trio scanners with the following parameters: TR=7400ms; TE=115; B values=0, 1000s/mm 2 ; bandwidth=1396 Hz/px; directions=32 [+0]; matrix=128×128; FOV=256×256mm 2 ; slice thickness=3.0mm; averages=2. Due to an equipment upgrade, nine participants were scanned on one Siemens 3T Trio system, and remaining subjects were scanned on another Siemens 3T Trio system.…”

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

“…PCE status has been associated with increased substance-use initiation in the early teen years of adolescence (Delaney-Black et al, 2011; Minnes et al, 2014), even when controlling for environmental factors (Richardson et al, 2013). Non-behaviorally based investigations into brain structure reveal altered blood flow in PCE adolescents (Rao et al, 2007) and alterations in white matter in prenatally tobacco-exposed adolescents (Jacobsen et al, 2007a) and in prenatally cocaine-exposed adolescents (Morie et al, 2017). It is important to understand the relationship between brain and behavior in prenatally drug-exposed adolescents.…”