Developmental Changes of Prefrontal Activation in Humans: A Near-Infrared Spectroscopy Study of Preschool Children and Adults

Previous morphological studies indicated that development of the human prefrontal cortex (PFC) appears to continue into late adolescence. Although functional brain imaging studies have sought to determine the time course of functional development of the PFC, it is unclear whether the developmental change occurs after adolescence to adulthood and when it achieves a peak because of the narrow or discontinuous range in the participant's age. Moreover, previous functional studies have not focused on the anterior frontal region, that is, the frontopolar regions (BA9/10). Thus, the present study investigated the developmental change in frontopolar PFC activation associated with letter fluency task by using near-infrared spectroscopy (NIRS), in subjects from preschool children to adults. We analyzed the relative concentration of hemoglobin (ΔHb) in the prefrontal cortex measured during the activation task in 48 typically-developing children and adolescents and 22 healthy adults. Consistent with prior morphological studies, we found developmental change with age in the children/adolescents. Moreover, the average Δoxy-Hb in adult males was significantly larger than that in child/adolescent males, but was not true for females. These data suggested that functional development of the PFC continues into late adolescence. Although the developmental change of the frontopolar PFC was independent of gender from childhood to adolescence, in adulthood a gender difference was shown

Neutralization of hepatitis B virus with vaccine-escape mutations by hepatitis B vaccine with large-HBs antigen

優れたB型肝炎予防ワクチン開発に成功 --既存ワクチンの弱点克服へ--. 京都大学プレスリリース. 2022-09-07.Although the current hepatitis B (HB) vaccine comprising small-HBs antigen (Ag) is potent and safe, attenuated prophylaxis against hepatitis B virus (HBV) with vaccine-escape mutations (VEMs) has been reported. We investigate an HB vaccine consisting of large-HBsAg that overcomes the shortcomings of the current HB vaccine. Yeast-derived large-HBsAg is immunized into rhesus macaques, and the neutralizing activities of the induced antibodies are compared with those of the current HB vaccine. Although the antibodies induced by the current HB vaccine cannot prevent HBV infection with VEMs, the large-HBsAg vaccine-induced antibodies neutralize those infections. The HBV genotypes that exhibited attenuated neutralization via these vaccines are different. Here, we show that the HB vaccine consisting of large-HBsAg is useful to compensate for the shortcomings of the current HB vaccine. The combined use of these HB vaccines may induce antibodies that can neutralize HBV strains with VEMs or multiple HBV genotypes

The effectiveness of exercise programs accessible from home on children's and adolescents' emotional well‐being: Systematic review & meta‐analysis

Abstract Background The current systematic review and meta‐analysis aimed to explore the evidence base to date for exercise interventions/interventions that aim to increase physical activity using a modality that can be accessed from home (i.e., online or video‐based programs), and its effects on anxiety and depression in children and adolescents. Methods A broad search was conducted using six databases (PubMed, Web of Science, CINAHL, PsychINFO, ERIC and Scopus) on February 23, 2022. Studies with children or adolescents between the ages 5 and 18 years were included. Of the 2527 records that were identified, nine studies met the full‐inclusion criteria. Their quality was assessed by two independent researchers using the Cochrane risk‐of‐bias tool for randomized trials (RoB 2) and Quality Assessment Tool for Before‐After (Pre‐Post) Studies with No Control Group. Meta analyses were conducted for studies that specifically assessed anxiety and depression. Results The overall results indicated that there is some evidence suggesting the positive effects of exercise interventions delivered online in reducing children's and adolescents' anxiety (d = −0.99, 95% confidence interval [CI]: −1.12 to −0.86). Meanwhile, there seems to be insufficient evidence for its efficacy in reducing low mood (d = −0.42; 95% CI: −0.84 to 0.01). Motivational and coaching based interventions to increase levels of physical activity may be limited in their efficacy, whilst having children exercise along with a video or live sessions online appears promising. Conclusion The current preliminary review revealed potential benefits of at‐home interventions that had children and adolescents exercise along with a video in improving anxiety

Deficient neural activity subserving decision-making during reward waiting time in intertemporal choice in adult attention-deficit hyperactivity disorder.

Impulsivity, which significantly affects social adaptation, is an important target behavioral characteristic in interventions for attention-deficit hyperactivity disorder (ADHD). Typically, people are willing to wait longer to acquire greater rewards. Impulsivity in ADHD may be associated with brain dysfunction in decision-making involving waiting behavior under such situations. We tested the hypothesis that brain circuitry during a period of waiting (i.e., prior to the acquisition of reward) is altered in adults with ADHD

Preliminary evidence of altered neural response during intertemporal choice of losses in adult attention-deficit hyperactivity disorder.

Impulsive behaviours are common symptoms of attention-deficit hyperactivity disorder (ADHD). Although previous studies have suggested functional models of impulsive behaviour, a full explanation of impulsivity in ADHD remains elusive. To investigate the detailed mechanisms behind impulsive behaviour in ADHD, we applied an economic intertemporal choice task involving gains and losses to adults with ADHD and healthy controls and measured brain activity by functional magnetic resonance imaging. In the intertemporal choice of future gains, we observed no behavioural or neural difference between the two groups. In the intertemporal choice of future losses, adults with ADHD exhibited higher discount rates than the control participants. Furthermore, a comparison of brain activity representing the sensitivity of future loss in the two groups revealed significantly lower activity in the striatum and higher activity in the amygdala in adults with ADHD than in controls. Our preliminary findings suggest that an altered size sensitivity to future loss is involved in apparent impulsive choice behaviour in adults with ADHD and shed light on the multifaceted impulsivity underlying ADHD

Grand average waveforms of ΔHb during the letter fluency task.

<p>Upper: male, lower: female, right: adult group, left: child/adolescent group. Line: red, oxyhemoglobin; blue, deoxyhemoglobin. The period of the activation task is between the two dotted lines.</p

A multicohort, longitudinal study of cerebellar development in attention deficit hyperactivity disorder

Contains fulltext : 196109pub.pdf (postprint version ) (Open Access

The mean ΔHb of the hemispheres in each group.

<p>Left: Δoxy-Hb, right: Δdeoxy-Hb, blue: male, red: female. The average Δoxy-Hb in the adult group was significantly larger than that in the child/adolescent group for male (F(1,30) = 11.55, p<.01). Moreover, for the adult group the average Δoxy-Hb in male was significantly larger than that in female (F(1,19) = 16.15, p<.01).</p