Verbal Learning and Memory in Cannabis and Alcohol Users: An Event-Related Potential Investigation

Aims: Long-term heavy use of cannabis and alcohol are known to be associated withmemory impairments. In this study, we used event-related potentials to examine verballearning and memory processing in a commonly used behavioral task.Method: We conducted two studies: first, a small pilot study of adolescent males,comprising 13 Drug-Naive Controls (DNC), 12 heavy drinkers (HD) and 8 cannabis users(CU). Second, a larger study of young adults, comprising 45 DNC (20 female), 39 HD (16female), and 20 CU (9 female). In both studies, participants completed a modified verballearning task (the Rey Auditory Verbal Learning Test, RAVLT) while brain electrical activitywas recorded. ERPs were calculated for words which were subsequently rememberedvs. those which were not remembered, and for presentations of learnt words, previouslyseen words, and new words in a subsequent recognition test. Pre-planned principalcomponents analyses (PCA) were used to quantify the ERP components in these recalland recognition phases separately for each study.Results: Memory performance overall was slightly lower than published norms usingthe standardized RAVLT delivery, but was generally similar and showed the expectedchanges over trials. Few differences in performance were observed between groups; anotable exception was markedly poorer delayed recall in HD relative to DNC (Study 2).PCA identified components expected from prior research using other memory tasks. Atencoding, there were no between-group differences in the usual P2 recall effect (larger forrecalled than not-recalled words). However, alcohol-related differences were observed ina larger P540 (indexing recollection) in HD than DNC, and cannabis-related differenceswere observed in a smaller N340 (indexing familiarity) and a lack of previously seen > newwords effect for P540 in Study 2.Conclusions: This study is the first examination of ERPs in the RAVLT in healthycontrol participants, as well as substance-using individuals, and represents an importantadvance in methodology. The results indicate alterations in recognition memoryprocessing, which even if not manifesting in overt behavioral impairment, underline thepotential for brain dysfunction with early exposure to alcohol and cannabis

Early influences on cardiovascular and renal development

The hypothesis that a developmental component plays a role in subsequent disease initially arose from epidemiological studies relating birth size to both risk factors for cardiovascular disease and actual cardiovascular disease prevalence in later life. The findings that small size at birth is associated with an increased risk of cardiovascular disease have led to concerns about the effect size and the causality of the associations. However, recent studies have overcome most methodological flaws and suggested small effect sizes for these associations for the individual, but an potential important effect size on a population level. Various mechanisms underlying these associations have been hypothesized, including fetal undernutrition, genetic susceptibility and postnatal accelerated growth. The specific adverse exposures in fetal and early postnatal life leading to cardiovascular disease in adult life are not yet fully understood. Current studies suggest that both environmental and genetic factors in various periods of life may underlie the complex associations of fetal growth retardation and low birth weight with cardiovascular disease in later life. To estimate the population effect size and to identify the underlying mechanisms, well-designed epidemiological studies are needed. This review is focused on specific adverse fetal exposures, cardiovascular adaptations and perspectives for new studies. Copyrigh

tDCS effects on task-related activation and working memory performance in traumatic brain injury: A within group randomized controlled trial

Non-invasive transcranial direct current stimulation (tDCS) has been reported to facilitate working memory in normal adults. There is some evidence in people with Traumatic Brain Injury (TBI) but overall evidence is mixed. This study aimed to address shortcomings of prior study designs in TBI to examine whether a single dose of tDCS would lead to benefits in working memory. Thirty people with severe, chronic TBI were administered a single session of either anodal tDCS (2 mA for 20 min) or sham tDCS (2 mA for 30 s), in a counterbalanced order, over the left parietal cortex while performing 1-back and 2-back working memory tasks. Skin conductance levels were examined as a measure of task activated arousal, a possible functional analogue of cortical excitability. We found that tDCS led to no improvements in accuracy on the working memory tasks. A slight increase in variability and reaction time with tDCS was related to decreased task activated arousal. Overall, this study yielded no evidence that a single session of tDCS can facilitate working memory for people with TBI

Fetal growth restriction, catch-up growth and the early origins of insulin resistance and visceral obesity

There is an association between growing slowly before birth, accelerated growth in early postnatal life and the emergence of insulin resistance, visceral obesity and glucose intolerance in adult life. In this review we consider the pathway through which intrauterine growth restriction (IUGR) leads to the initial increase in insulin sensitivity and to catch-up growth. We also discuss the importance of the early insulin environment in determining later visceral adiposity and the intrahepatic mechanisms that may result in the emergence of glucose intolerance in a subset of IUGR infants. We present evidence that a key fetal adaptation to poor fetal nutrition is an upregulation of the abundance of the insulin receptor in the absence of an upregulation of insulin signalling in fetal skeletal muscle. After birth, however, there is an upregulation in the abundance of the insulin receptor and the insulin signalling pathway in the IUGR offspring. Thus, the origins of the accelerated postnatal growth rate experienced by IUGR infants lie in the fetal adaptations to a poor nutrient supply. We also discuss how the intracellular availability of free fatty acids and glucose within the visceral adipocyte and hepatocyte in fetal and neonatal life are critical in determining the subsequent metabolic phenotype of the IUGR offspring. It is clear that a better understanding of the relative contributions of the fetal and neonatal nutrient environment to the regulation of key insulin signalling pathways in muscle, visceral adipose tissue and the liver is required to support the development of evidence-based intervention strategies and better outcomes for the IUGR infant.Janna L. Morrison, Jaime A. Duffield, Beverly S. Muhlhausler, Sheridan Gentili, Isabella C. McMille

Glucocorticoids in Pediatric Gastrointestinal Disorders

3Pediatric Inflammatory Bowel Disease Inflammatory bowel diseases (IBDs) are the most frequent chronic gastrointestinal disorders in pediatric age. They include two disease entities – Crohn’s disease (CD) and ulcerative colitis (UC) – which, although different in their pathogenesis, show common clinical characteristics such as chronic inflammation at different levels of the gastrointestinal tract and alternation between active and inactive phases. The incidence of IBD is increasing in recent years, particularly among children and adolescents, and it is currently estimated that 20–30 % of patients with IBD experience the onset of symptoms when they are under 20 years of age [1–3]. In childhood, IBDs are gener- ally more extended, more severe, and progress more rapidly than in adulthood. Moreover, therapy in children with IBD is more aggressive than in adults: Indeed, about 80 % of children need steroids, and about 30 % are subjected to an intestinal resection during a 5-year follow-up. Quality of life is severely affected in IBD, espe- cially for pediatric patients, owing to the chronic character of the disease that implies frequent hospitalizations and aggressive therapies, with a significant risk of side effects and a considerable impact on health care costs. IBD can result in loss of education and difficulty in gaining employment or insurance; overall, 15 % of patients with IBD are unable to work after 5–10 years of disease. Depressive disorders and low social func- tioning are also common among these patients, and the disease can also cause growth failure or retarded sexual development in young people [4–7]. It was recently reported that the mean individual annual costs in European countries amount to US$6,000 for CD and$4,600 for UC, and pediatric cases cost even more than adult ones [8].nonenoneDe Iudicibus, Sara; Martelossi, Stefano; Decorti, GiulianaDE IUDICIBUS, Sara; Martelossi, Stefano; Decorti, Giulian