Methylphenidate Normalizes Fronto-Striatal Underactivation During Interference Inhibition in Medication-Naïve Boys with Attention-Deficit Hyperactivity Disorder

Youth with attention deficit hyperactivity disorder (ADHD) have deficits in interference inhibition, which can be improved with the indirect catecholamine agonist methylphenidate (MPH). Functional magnetic resonance imaging was used to investigate the effects of a single dose of MPH on brain activation during interference inhibition in medication-naïve ADHD boys. Medication-naïve boys with ADHD were scanned twice, in a randomized, double-blind design, under either a single clinical dose of MPH or placebo, while performing a Simon task that measures interference inhibition and controls for the oddball effect of low-frequency appearance of incongruent trials. Brain activation was compared within patients under either drug condition. To test for potential normalization effects of MPH, brain activation in ADHD patients under either drug condition was compared with that of healthy age-matched comparison boys. During incongruent trials compared with congruent–oddball trials, boys with ADHD under placebo relative to controls showed reduced brain activation in typical areas of interference inhibition, including right inferior prefrontal cortex, left striatum and thalamus, mid-cingulate/supplementary motor area, and left superior temporal lobe. MPH relative to placebo upregulated brain activation in right inferior prefrontal and premotor cortices. Under the MPH condition, patients relative to controls no longer showed the reduced activation in right inferior prefrontal and striato-thalamic regions. Effect size comparison, furthermore, showed that these normalization effects were significant. MPH significantly normalized the fronto-striatal underfunctioning in ADHD patients relative to controls during interference inhibition, but did not affect medial frontal or temporal dysfunction. MPH therefore appears to have a region-specific upregulation effect on fronto-striatal activation

Metagenomic analysis of the microbial community in fermented grape marc reveals that Lactobacillus fabifermentans is one of the dominant species: insights into its genome structure

Grape marc used for the production of distilled beverages undergoes prolonged storage which allows alcoholic fermentation to occur. Harsh conditions including low pH, limited oxygen and nutrients, temperature fluctuations, and high ethanol concentrations imposed by that environment create a strong selective pressure on microorganisms. A detailed characterization of the bacterial community during two time points of the fermentation process was performed using high-throughput sequencing of the V3-V6 16S rDNA hypervariable regions. The results revealed a marked reduction in the number of bacterial species after 30 days of incubation and made it possible to identify those species that are able to grow in that extreme environment. The genome sequence of Lactobacillus fabifermentans, one of the dominant species identified, was then analyzed using shotgun sequencing and comparative genomics. The results revealed that it is one of the largest genomes among the Lactobacillus sequenced and is characterized by a large number of genes involved in carbohydrate utilization and in the regulation of gene expression. The genome was shaped through a large number of gene duplication events, while lateral gene transfer contributed to a lesser extent with respect to other Lactobacillus species. According to genomic analysis, its carbohydrate utilization pattern and ability to form biofilm are the main genetic traits linked to the adaptation the species underwent permitting it to grow in fermenting grape marc