BACKGROUND: Intellectual disability is a neurodevelopmental disorder characterized by significant impairments in intellectual functioning and adaptive behavior. Cognitive flexibility and attention are crucial cognitive domains often affected in children with intellectual disability. This case report explores the novel use of transcranial alternating current stimulation, a noninvasive brain stimulation technique, to enhance these cognitive functions. The study\'s novelty lies in its focus on alpha-wave frequency transcranial alternating current stimulation targeting specific Brodmann areas and its potential sustained impact on cognitive flexibility and attention in the pediatric population with intellectual disability.
METHODS: The case study involved two elementary school students, both 7 years old with mild intellectual disability, one male and one female, both with Turkic ethnicity, from Shahid Fahmideh School for Exceptional Children in Khosrowshah, Iran. Both participants underwent a 2-week intervention with daily 20-minute sessions of transcranial alternating current stimulation at an alpha-wave frequency (10 Hz), targeting Brodmann areas F3 and P3. Cognitive flexibility and attention were assessed using the Wisconsin Card Sorting Test and the Clock Test, administered at four time points: pre-intervention, week 1, week 2, and 1 month post-intervention. Statistical analysis showed significant improvements in both Wisconsin Card Sorting Test and Clock Test scores for both participants compared with baseline, with sustained enhancement over time.
CONCLUSIONS: The findings from this case report indicate that transcranial alternating current stimulation may be a promising intervention for improving cognitive flexibility and attention in children with intellectual disability. The significant and sustained improvements observed suggest that transcranial alternating current stimulation could have a meaningful clinical impact on the cognitive development of this population. However, further research is needed to confirm the efficacy of transcranial alternating current stimulation and to explore its broader applicability and long-term effects in larger, more diverse populations.

(1) Background: Inhibitory and rewarding processes that mediate attentional biases to addiction-related cues may slightly differ between patients suffering from alcohol use (AUD) or gambling (GD) disorder. (2) Methods: 23 AUD inpatients, 19 GD patients, and 22 healthy controls performed four separate Go/NoGo tasks, in, respectively, an alcohol, gambling, food, and neutral long-lasting cueing context during the recording of event-related potentials (ERPs). (3) Results: AUD patients showed a poorer inhibitory performance than controls (slower response latencies, lower N2d, and delayed P3d components). In addition, AUD patients showed a preserved inhibitory performance in the alcohol-related context (but a more disrupted one in the food-related context), while GD patients showed a specific inhibitory deficit in the game-related context, both indexed by N2d amplitude modulations. (4) Conclusions: Despite sharing common addiction-related mechanisms, AUD and GD patients showed different patterns of response to (non-)rewarding cues that should be taken into account in the therapeutic context.

Inhibitory control impairment in alcohol use disorder (AUD) may indicate detrimental effects of chronic alcohol use on different functional systems in the brain, but the current studies lack consistency. This study aims to identify the most consistent response inhibition-related brain dysfunction based on existing data.
We performed systematic searches of the PubMed, Embase, Web of Science, and PsychINFO databases for available studies. Anisotropic effect-size signed differential mapping was used to quantitatively analyze the differences in response inhibition-related brain activation between AUD patients and HCs. Meta regression was used to explore the relationship between brain alterations and clinical variables.
The brain hypoactivation or hyperactivation in AUD patients compared with HCs during the response inhibition tasks was mainly located in the prefrontal cortex including the superior frontal gyrus, inferior frontal gyrus, and middle frontal gyrus, anterior cingulate gyrus (ACC), superior temporal gyrus, occipital gyrus, and somatosensory areas including postcentral gyrus and supramarginal gyrus. The meta-regression revealed that older patients were more likely to present activation in the left superior frontal gyrus when performing the response inhibition tasks.
The response inhibitive dysfunctions in a distinct prefrontal-cingulate cortices may presumably reflect the core impairment in cognitive control abilities. Dysfunction in the occipital gyrus and somatosensory areas may indicate an abnormal motor-sensory and visual function in AUD. Such functional abnormalities may represent neurophysiological correlates of the executive deficits observed in AUD patients. This study has been registered in PROSPERO (number CRD42022339384).

Undesirable ammonium concentrations can lead to unstable anaerobic digestion processes, and Methanosarcina spp. are the representative methanogens under inhibition. However, no known work seems to exist for directly exploring the detailed metabolic regulation of pure cultured representative Methanosarcina spp. to ammonium inhibition. We used transcriptomics and proteomics to profile the metabolic regulation of Methanosarcina barkeri to 1, 4, and 7 g N/L of total ammoniacal nitrogen (TAN), where free ammonia concentrations were between 1.5 and 36.1 mg N/L. At the initial stages of ammonium inhibition, the genes participating in the acquisition and assimilation of reduced nitrogen sources showed significant upregulation where the minimal fold change of gene transcription was about 2. Apart from nitrogen metabolism, the transcription of some genes in methanogenesis also significantly increased at the initial stages. For example, the genes encoding alternative heterodisulfide reductase subunits (HdrAB), energy-converting hydrogenase subunit (EchC), and methanophenazine-dependent hydrogenase subunits (VhtAC) were significantly upregulated by at least 2.05 times. For the element translocation at the initial stages, the genes participating in the uptake of ferrous iron, potassium ion, and molybdate were significantly upregulated with a minimal fold change of 2.10. As the cultivation proceeded, the gene encoding the cell division protein subunit (FtsH) was significantly upregulated by 13.0 times at 7 g N/L of TAN; meanwhile, an increment in OD600 was observed at the terminal sampling point of 7 g N/L of TAN. The present study explored the metabolic regulation of M. barkeri in stress response, protein synthesis, signal transduction, nitrogen metabolism, methanogenesis, and element translocation. The results would contribute to the understanding of the metabolic effects of ammonium inhibition on methanogens and have significant practical implication in inhibited anaerobic digestion.

Isovalerate is one of the key intermediates during anaerobic digestion treating protein-containing waste/wastewater. Investigating the effect of different kinds of inhibitors on isovalerate-degrading microbial community is necessary to develop measures for improving the effectiveness of the treatment plants. In the present study, dynamic changes in the isovalerate-degrading microbial community in presence of inhibitors (ammonium, sulfide, mixed ammonium and sulfide, and chlortetracycline (CTC)) were investigated using high-throughput sequencing of 16S rRNA gene. Our observations showed that the isovalerate-degrading microbial community responded differently to different inhibitors and that the isovalerate degradation and gas production were strongly repressed by each inhibitor. We found that sulfide inhibited both isovalerate oxidation followed by methanogenesis, while ammonium, mixed ammonium and sulfide, and CTC mainly inhibited isovalerate oxidation. Genera classified into Proteobacteria and Chloroflexi were less sensitive to inhibitors. The two dominant genera, which are potential syntrophic isovalerate oxidizers, exhibited different responses to inhibitors that the unclassified_Peptococcaceae_3 was more sensitive to inhibitors than the unclassified_Syntrophaceae. Upon comparison to acetoclastic methanogen Methanosaeta, hydrogenotrophic methanogens Methanoculleus and Methanobacterium were less sensitive to inhibitors.

In anaerobic digestion, propionate is a key intermediate whose degradation is thermodynamically challenging and accumulation is detrimental to the process. Many wastewater streams contain antibiotics due to its globally increasing use, and these compounds can inhibit methane production. However, the effect of antibiotics on propionate degradation in anaerobic digestion remains unclear. In this study, the influence of two antibiotics (chlortetracycline [CTC] and enrofloxacin [EFX]) on biogas production and mesophilic propionate-degrading microbial community was investigated. CTC strongly repressed propionate oxidation, acetate utilization, and methane production, while EFX only inhibited propionate oxidation and methane production to a lesser extent. Microbial community analyses showed that syntrophic propionate-oxidizing bacteria (SPOB) Syntrophobacter had strong tolerance to both CTC and EFX. CTC inhibition mainly acted on the activity of acetate-oxidizing bacteria (Mesotoga, Geovibrio, Tepidanaerobacter, unclassified Bacteroidetes, and unclassified Clostridia) and acetoclastic methanogen, while EFX inhibition applied to the SPOB Smithella and acetoclastic methanogen. Network analysis further indicated that more complicated correlation among bacterial genera occurred in CTC treatments. These results suggested that CTC and EFX inhibited propionate degradation via different mechanisms, which was the result of joint action by antibiotics and microbial interactions.

Investigating the effects of different kinds of inhibitors on the activity and structure of acetate-degrading microbial community involved in methane fermentation is critically important for developing countermeasures to make the fermentation process stable under different inhibitory conditions. In the present study, a mesophilic chemostat fed with acetate as the sole carbon source was constructed. Microbial community analysis based on high-throughput sequencing of 16S rRNA revealed that Methanothrix was the dominant methanogen and a variety of bacteria including acetate-oxidizing bacteria such as Tepidanaerobacter, Mesotoga, Geovibrio, and Geobacter were found. The activity and dynamic changes of the acetate-degrading microbial community under different inhibitory conditions were investigated. Addition of 600 mg L-1 ammonium and 150 mg L-1 sulfide reduced nearly half of the biogas production. The response of microbial community to sulfide inhibition was quicker than ammonium but the structure could recover in a short time. Addition of 8 mg L-1 chlortetracycline (CTC) and 160 mg L-1 enrofloxacin (EFX) exhibited a similar inhibitory effect on biogas production, with approximately 35% reduction. Compared to ammonium and sulfide, antibiotics showed stronger selective inhibition on some bacterial species. The genera related to acetate-oxidizing and sulfate-reducing bacteria showed stronger tolerance to CTC, which may be due to their low growth rates. Network analysis suggested that some genera which had close phylogenic relationship and similar functions showed constant positive correlation under different inhibitory conditions.

Event-related fMRI studies have explored emotion inhibitory processes in alexithymic individuals and have demonstrated abnormal BOLD activations in the processing of emotional stimuli. So far, no study has explored the relationship between the alexithymic trait and the general inhibition process, namely utilizing stimuli devoid of emotional valence. In this study 26 healthy subjects were administered the Toronto Alexithymic Scale (TAS-20) questionnaire to measure the alexithymic trait and performed an event related Go/Nogo task build up with letters during fMRI acquisition. We found no correlation between the TAS-20 z-score and the reaction times during the Go/Nogo task. Conversely, we observed a positive correlation between the degree of alexithymic trait -measured with the TAS-20 and the Nogo-Go activation of the right Inferior Frontal Gyrus and the right pre-Supplementary Motor Area. These data suggest that the general process of response inhibition may be modulated by the individual degree of alexithymic trait. We propose that such a relationship could reflect a compensatory mechanism implemented by participants with higher degree of alexithymic trait to reach a correct inhibition.

According to the balance model of self-regulation, dysfunction of the inhibitory control and reward processing might be a behavioral marker for addiction and problematic behaviors. Although several studies have separately examined the inhibitory control or reward processing of individuals exhibiting problematic Internet use (PIU), no study has explored these two functions simultaneously to examine the potential imbalance of these functions. This study aimed to investigate whether the self-regulatory failure of PIU individuals results from deficits in both inhibitory control [indexed with the stop signal reaction time (SSRT) in a stop signal task] and risk taking with losses (measured as the acceptance rates of risky gables or the ratio of win/loss in a mixed gambles task). The results revealed that PIU individuals, compared with controls, showed decreased SSRT and increased error rates as well as reduced risk taking with losses. Correlational analyses revealed a significant positive relationship between the SSRT and risk taking with losses. These findings suggest that both the inhibitory control and reward functions are impaired in PIU individuals and reveal an association between these two systems. These results strengthen the balance model of self-regulation theory\'s argument that deficits in inhibitory control and risk taking with losses may assist in identifying risk markers for early diagnosis, progression, and prediction of PIU.

Like drug addiction, pathological gambling (PG) has been associated with impairments in executive functions and alterations in dopaminergic functioning; however, the role of dopamine (DA) in the executive profile of PG remains unclear. The aim of this study was to identify whether the DRD2/ANKK1 Taq1A-rs1800497 and the DAT1-40 bp VNTR polymorphisms are associated with cognitive flexibility (measured by Wisconsin Card Sorting Test (WCST) and Trail Making Test (TMT)) and inhibition response (measured by Stroop Color and Word Test (SCWT)), in a clinical sample of 69 PG patients. Our results showed an association between DA functioning and cognitive flexibility performance. The Taq1A A1+ (A1A2/A1A1) genotype was associated with poorer TMT performance (p<0.05), while DAT1 9-repeat homozygotes displayed better WCST performance (p<0.05) than either 10-repeat homozygotes or heterozygotes. We did not find any association between the DRD2 or DAT1 polymorphisms and the inhibition response. These results suggested that pathological gamblers with genetic predispositions toward lower availability of DA and D2 receptor density are at a higher risk of cognitive flexibility difficulties. Future studies should aim to shed more light on the genetic mechanisms underlying the executive profile in PG.