Sex-Specific Whole-Transcriptome Analysis in the Cerebral Cortex of FAE Offspring

Late-term moderate prenatal alcohol exposure impairs tactile, but not spatial, discrimination in a T-maze continuous performance task in juvenile rats

Existing maze apparatuses used in rodents often exclusively assess spatial discriminability as a means to evaluate learning impairments. Spatial learning in such paradigms is reportedly spared by moderate prenatal alcohol exposure in rats, suggesting that spatial reinforcement alone is insufficient to delineate executive dysfunction, which consistently manifests in humans prenatally-exposed to alcohol. To address this, we designed a single-session continuous performance task in the T-maze apparatus that requires rats to discriminate within and between simultaneously-presented spatial (left or right) and tactile (sandpaper or smooth) stimuli for food reinforcement across four sequential discrimination stages: simple discrimination, intradimensional reversal 1, extradimensional shift, and intradimensional reversal 2. This design incorporates elements of working memory, attention, and goal-seeking behavior which collectively contribute to the executive function construct. Here, we found that rats prenatally-exposed to alcohol performed worse in both the tactile intradimensional reversal and extradimensional shift; alternatively, rats prenatally-exposed to alcohol acquired the extradimensional shift faster when shifting from the tactile to spatial dimension. In line with previous work, moderate prenatal alcohol exposure spared specifically spatial discrimination in this paradigm. However, when tactile stimuli were mapped into the spatial dimension, rats prenatally-exposed to alcohol required more trials to discriminate between the dimensions. We demonstrate that tactile stimuli can be operantly employed in a continuous performance T-maze task to detect discriminatory learning impairments in rats exposed to moderate prenatal alcohol. The current paradigm may be useful for assessing features of executive dysfunction in rodent models of fetal alcohol spectrum disorders.

Peripheral blood transcriptomic profiling of molecular mechanisms commonly regulated by binge drinking and placebo effects

Molecular responses to alcohol consumption are dynamic, context-dependent, and arise from a complex interplay of biological and external factors. While many have studied genetic risk associated with drinking patterns, comprehensive studies identifying dynamic responses to pharmacologic and psychological/placebo effects underlying binge drinking are lacking. We investigated transcriptome-wide response to binge, medium, and placebo alcohol consumption by 17 healthy heavy social drinkers enrolled in a controlled, in-house, longitudinal study of up to 12 days. Using RNA-seq, we identified 251 and 13 differentially expressed genes (DEGs) in response to binge drinking and placebo, respectively. Eleven protein-coding DEGs had very large effect sizes in response to binge drinking (Cohen's d > 1). Furthermore, binge dose significantly impacted the Cytokine-cytokine receptor interaction pathway (KEGG: hsa04060) across all experimental sequences. Placebo also impacted hsa04060, but only when administered following regular alcohol drinking sessions. Similarly, medium-dose and placebo commonly impacted KEGG pathways of Systemic lupus erythematosus, Neutrophil extracellular trap formation, and Alcoholism based on the sequence of drinking sessions. These findings together indicate the "dose-extending effects" of placebo at a molecular level. Furthermore, besides supporting alcohol dose-specific molecular changes, results suggest that the placebo effects may induce molecular responses within the same pathways regulated by alcohol.

Prenatal alcohol exposure alters expression of genes involved in cell adhesion, immune response, and toxin metabolism in adolescent rat hippocampus

Prenatal alcohol exposure (PAE) can result in mild to severe consequences for children throughout their lives, with this range of symptoms referred to as Fetal Alcohol Spectrum Disorders (FASD). These consequences are thought to be linked to changes in gene expression and transcriptional programming in the brain, but the identity of those changes, and how they persist into adolescence are unclear. In this study, we isolated RNA from the hippocampus of adolescent rats exposed to ethanol during prenatal development and compared gene expression to controls. Briefly, dams were either given free access to standard chow ad libitum (AD), pair-fed a liquid diet (PF) or were given a liquid diet with ethanol (6.7% ethanol, ET) throughout gestation (gestational day (GD) 0-20). All dams were given control diet ad libitum beginning on GD 20 and throughout parturition and lactation. Hippocampal tissue was collected from adolescent male and female offspring (postnatal day (PD) 35-36). Exposure to ethanol caused widespread downregulation of many genes as compared to control rats. Gene ontology analysis demonstrated that affected pathways included cell adhesion, toxin metabolism, and immune responses. Interestingly, these differences were not strongly affected by sex. Furthermore, these changes were consistent when comparing ethanol-exposed rats to pair-fed controls provided with a liquid diet and those fed ad libitum on a standard chow diet. We conclude from this study that changes in genetic architecture and the resulting neuronal connectivity after prenatal exposure to alcohol continue through adolescent development. Further research into the consequences of specific gene expression changes on neural and behavioral changes will be vital to our understanding of the FASD spectrum of diseases.

Clinical Diagnosis and Management of Fetal Alcohol Spectrum Disorder and Sensory Processing Disorder in Children

Fetal alcohol spectrum disorder (FASD) is commonly misdiagnosed because of the complexity of presentation and multiple diagnostic criteria. FASD includes four categorical entities (fetal alcohol syndrome, partial fetal alcohol syndrome, alcohol related neurodevelopmental disorder, and alcohol related birth defects). The four FASD diagnostic criteria are facial dysmorphology, growth deficiency, central nervous system dysfunction, and prenatal alcohol exposure. Sensory processing disorders (SPDs) are common in FASD and are observed as inappropriate behavioral responses to environmental stimuli. These can be either a sensory-based motor disorder, sensory discrimination disorder, or sensory modulation disorder. A child with SPD may experience challenges with their fine motor coordination, gross motor coordination, organizational challenges, or behavioral regulation impairments. FASD requires a multidimensional approach to intervention. Although FASD cannot be cured, symptoms can be managed with sleep-based therapies, sensory integration, and cognitive therapies. This paper reviews SPDs in FASD and the interventions that can be used by practitioners to help improve their therapeutic management, although it is unlikely that any single intervention will be the right choice for all patients.

Peripheral blood transcriptomic profiling indicates molecular mechanisms commonly regulated by binge-drinking and placebo-effects

Molecular changes associated with alcohol consumption arise from complex interactions between pharmacological effects of alcohol, psychological/placebo context surrounding drinking, and other environmental and biological factors. The goal of this study was to tease apart molecular mechanisms regulated by pharmacological effects of alcohol - particularly at binge-drinking, from underlying placebo effects. Transcriptome-wide RNA-seq analyses were performed on peripheral blood samples collected from healthy heavy social drinkers (N=16) enrolled in a 12-day randomized, double-blind, cross-over human laboratory trial testing three alcohol doses: Placebo, moderate (0.05g/kg (men), 0.04g/kg (women)), and binge (1g/kg (men), 0.9g/kg (women)), administered in three 4-day experiments, separated by minimum of 7-day washout periods. Effects of beverage doses on the normalized gene expression counts were analyzed within each experiment compared to its own baseline using paired-t-tests. Differential expression of genes (DEGs) across experimental sequences in which each beverage dose was administered, as well as responsiveness to regular alcohol compared to placebo (i.e., pharmacological effects), were analyzed using generalized linear mixed-effects models. The 10% False discovery rate-adjusted DEGs varied across experimental sequences in response to all three beverage doses. We identified and validated 22 protein coding DEGs potentially responsive to pharmacological effects of binge and medium doses, of which 11 were selectively responsive to binge dose. Binge-dose significantly impacted the Cytokine-cytokine receptor interaction pathway (KEGG: hsa04060) across all experimental-sequences that it was administered in, and during dose-extending placebo. Medium dose and placebo impacted pathways hsa05322, hsa04613, and hsa05034, in the first two and last experimental sequences, respectively. In summary, our findings add novel, and confirm previously reported data supporting dose-dependent effects of alcohol on molecular mechanisms and suggest that the placebo effects may induce molecular responses within the same pathways regulated by alcohol. Innovative study designs are required to validate molecular correlates of placebo effects underlying drinking.