Sensory Recruitment Revisited: Ipsilateral V1 Involved in Visual Working Memory.

The "sensory recruitment hypothesis" posits an essential role of sensory cortices in working memory, beyond the well-accepted frontoparietal areas. Yet, this hypothesis has recently been challenged. In the present study, participants performed a delayed orientation recall task while high-spatial-resolution 3 T functional magnetic resonance imaging (fMRI) signals were measured in posterior cortices. A multivariate inverted encoding model approach was used to decode remembered orientations based on blood oxygen level-dependent fMRI signals from visual cortices during the delay period. We found that not only did activity in the contralateral primary visual cortex (V1) retain high-fidelity representations of the visual stimuli, but activity in the ipsilateral V1 also contained such orientation tuning. Moreover, although the encoded tuning was faded in the contralateral V1 during the late delay period, tuning information in the ipsilateral V1 remained sustained. Furthermore, the ipsilateral representation was presented in secondary visual cortex (V2) as well, but not in other higher-level visual areas. These results thus supported the sensory recruitment hypothesis and extended it to the ipsilateral sensory areas, which indicated the distributed involvement of visual areas in visual working memory.

TRIM31 promotes the progression of oral squamous cell carcinoma through upregulating AKT phosphorylation and subsequent cellular glycolysis.

The regulation of protein kinase B (AKT) phosphorylation by Tripartite motif-containing protein 31 (TRIM31) is implicated as an essential mechanism in the progression of many malignant tumors. Nevertheless, the function of the TRIM31/AKT pathway in oral squamous cell carcinoma (OSCC) remains elusive. Here, immunohistochemistry analysis of human OSCC tissue microarrays indicated significantly higher levels of TRIM31 and phosphorylated AKT (p-AKT) in OSCC tumors than in adjacent tissue samples. Also, we detected a positive association between TRIM31 expression and clinical OSCC development. In in vitro studies, TRIM31 knockdown severely impaired OSCC cell growth, invasion, and migration. By contrast, TRIM31 overexpression improved these cell behaviors, while subsequent AKT inhibition abrogated the effect. In vivo tumorigenesis experiments using nude mice also validated the effects of TRIM31/AKT signaling in tumor growth. Furthermore, TRIM31 upregulation facilitated glucose uptake, as well as lactate and adenosine triphosphate production of OSCC cells, while such positive effects on glycolysis and malignant cell phenotypes were reversed by treatment with AKT or glycolysis inhibitors. In conclusion, TRIM31 may improve OSCC progression by enhancing AKT phosphorylation and subsequent glycolysis. Hence, TRIM31 has the potential as a treatment target in OSCC.

Atypically larger variability of resource allocation accounts for visual working memory deficits in schizophrenia.

Working memory (WM) deficits have been widely documented in schizophrenia (SZ), and almost all existing studies attributed the deficits to decreased capacity as compared to healthy control (HC) subjects. Recent developments in WM research suggest that other components, such as precision, also mediate behavioral performance. It remains unclear how different WM components jointly contribute to deficits in schizophrenia. We measured the performance of 60 SZ (31 females) and 61 HC (29 females) in a classical delay-estimation visual working memory (VWM) task and evaluated several influential computational models proposed in basic science of VWM to disentangle the effect of various memory components. We show that the model assuming variable precision (VP) across items and trials is the best model to explain the performance of both groups. According to the VP model, SZ exhibited abnormally larger variability of allocating memory resources rather than resources or capacity per se. Finally, individual differences in the resource allocation variability predicted variation of symptom severity in SZ, highlighting its functional relevance to schizophrenic pathology. This finding was further verified using distinct visual features and subject cohorts. These results provide an alternative view instead of the widely accepted decreased-capacity theory and highlight the key role of elevated resource allocation variability in generating atypical VWM behavior in schizophrenia. Our findings also shed new light on the utility of Bayesian observer models to characterize mechanisms of mental deficits in clinical neuroscience.

Divergent roles of early visual cortex and inferior frontal junction in visual working memory.

BACKGROUND: Recent studies indicate that both prefrontal and visual regions play critical roles in visual working memory (VWM), with prefrontal regions mainly associated with executive functions, and visual cortices linked to representations of memory contents. VWM involves the selective filtering of irrelevant information, yet the specific contributions of the prefrontal regions and visual cortex in this process remain unclear. OBJECTIVE: To understand the dynamic causal roles of prefrontal and visual regions in VWM. METHODS: The differentiation of VWM components was achieved using a computational model that incorporated a swap rate for non-target stimuli. Single-pulse magnetic transcranial stimulation (spTMS) was delivered to the early visual cortex (EVC) and the inferior frontal junction (IFJ) across different phases of an orientation recall task that with or without distractors. RESULTS: Our results indicate that spTMS over the EVC and IFJ influences VWM particularly when distractors are present. VWM precision can be impacted by spTMS applied to either region during the early retention, while spTMS effect is especially prominent when EVC is stimulated during the late retention phase and when directed at the ipsilateral EVC. Conversely, the probability of accurately recalling the target exhibited comparable patterns when spTMS was administered to either the EVC or IFJ. CONCLUSIONS: We highlight the "sensory recruitment" of VWM characterized by critical involvement of EVC particularly in the information-filtering process within VWM. The maintenance of memory content representations necessitates ongoing communication between the EVC and IFJ throughout the entirety of the VWM process in a dynamic pattern.

Evidence Accumulation and Neural Correlates of Uncertainty in Obsessive-Compulsive Disorder.

BACKGROUND: Decision making is frequently associated with risk taking under uncertainty. Elevated intolerance of uncertainty is suggested to be a critical feature of obsessive-compulsive disorder (OCD). However, impairments of latent constructs of uncertainty processing and its neural correlates remain unclear in OCD. METHODS: In 83 participants (24 OCD patients treated with capsulotomy, 28 OCD control participants, and 31 healthy control participants), we performed magnetic resonance imaging using a card gambling task in which participants made decisions whether to bet or not that the next card would be larger than the current one. A hierarchical drift diffusion model was used to dissociate speed and amount of evidence accumulated before a decisional threshold (i.e., betting or no betting) was reached. RESULTS: High uncertainty was characterized by a smaller amount of evidence accumulation (lower thresholds), thus dissociating uncertainty from conflict tasks and highlighting the specificity of this task to test value-based uncertainty. OCD patients exhibited greater caution with poor performance and greater evidence accumulation overall along with slower speed of accumulation, particularly under low uncertainty. Bilateral dorsal anterior cingulate and anterior insula distinguished high- and low-uncertainty decision processes in healthy control participants but not in the OCD groups, indicating impairments in anticipation of differences in outcome variance and salience network activity. There were no behavioral or imaging differences relating to capsulotomy despite improvements in OCD symptoms. CONCLUSIONS: Our findings highlight greater impairments particularly in more certain trials in the OCD groups along with impaired neural differentiation of high and low uncertainty and suggest uncertainty processing as a trait cognitive endophenotype rather than a state-specific factor.

Time-locked acute alpha-frequency stimulation of subthalamic nuclei during the evaluation of emotional stimuli and its effect on power modulation.

Introduction: Deep brain stimulation (DBS) studies in Parkinson's Disease (PD) targeting the subthalamic nucleus (STN) have characterized its spectral properties across cognitive processes. In emotional evaluation tasks, specific alpha frequency (8-12 Hz) event-related de-synchronization (ERD) (reduced power) has been demonstrated. The time-locked stimulation of STN relative to stimuli onset has shown subjective positive valence shifts with 10 Hz but not with 130 Hz. However, neurophysiological effects of stimulation on power modulation have not been investigated. We aim to investigate effects of acute stimulation of the right STN on concurrent power modulation in the contralateral STN and frontal scalp EEG. From our previous study, we had a strong a priori hypothesis that negative imagery without stimulation would be associated with alpha ERD; negative imagery with 130 Hz stimulation would be also associated with alpha ERD given the lack of its effect on subjective valence ratings; negative imagery with 10 Hz stimulation was to be associated with enhanced alpha power given the shift in behavioral valence ratings. Methods: Twenty-four subjects with STN DBS underwent emotional picture-viewing tasks comprising neutral and negative pictures. In a subset of these subjects, the negative images were associated with time-locked acute stimulation at either 10 or 130 Hz. Power of signals was estimated relative to the baseline and subjected to non-parametric statistical testing. Results: As hypothesized, in 130 Hz stimulation condition, we show a decrease in alpha power to negative vs. neutral images irrespective of stimulation. In contrast, this alpha power decrease was no longer evident in the negative 10 Hz stimulation condition consistent with a predicted increase in alpha power. Greater beta power in the 10 Hz stimulation condition along with correlations between beta power across the 10 Hz stimulation and unstimulated conditions suggest physiological and cognitive generalization effects. Conclusion: Acute alpha-specific frequency stimulation presumably was associated with a loss of this expected decrease or desynchronization in alpha power to negative images suggesting the capacity to facilitate the synchronization of alpha and enhance power. Acute time-locked stimulation has the potential to provide causal insights into the spectral frequencies and temporal dynamics of emotional processing.

Assessment of immediate clotting after flapless extraction using piezosurgery or turbine handpiece in patients receiving dual antiplatelet therapy.

PURPOSE: This study aimed to investigate the efficacy of piezosurgery (PI) in promoting immediate clotting after flapless extraction in patients undergoing dual antiplatelet therapy (DAPT). METHODS: In this randomized controlled trial, 80 DAPT patients were equally divided into the PI and turbine handpiece (TH) groups. Accordingly, flapless extraction of a single tooth using PI or TH was performed on each patient, and the immediate clotting status was evaluated. The results of the preoperative hematological examinations, surgery-related variables and postoperative complications were recorded for analysis. RESULTS: Both groups presented with low platelet aggregation and similar coagulation functions. The PI group exhibited a higher proportion of patients with normal intra-alveolar clotting (≤30 min) (70% vs. 40%, P = 0.007) and fewer intraoperative complications (25% vs. 47.5%, P = 0.036) than that in the TH group. Logistic regression analysis indicated that the applied instrument was an independent risk factor for prolonged immediate bleeding (odds ratio = 3.10, 95% confidence interval: 1.20-8.00, P = 0.019). Intergroup differences were insignificant in terms of the other surgery-related variables and postoperative complications, except for the longer surgical duration in the PI group. CONCLUSION: The application of PI may contribute to better immediate clotting in DAPT patients after flapless extraction compared with the use of TH.

Power signatures of habenular neuronal signals in patients with bipolar or unipolar depressive disorders correlate with their disease severity.

The habenula is an epithalamic structure implicated in negative reward mechanisms and plays a downstream modulatory role in regulation of dopaminergic and serotonergic functions. Human and animal studies show its hyperactivity in depression which is curtailed by the antidepressant response of ketamine. Deep brain stimulation of habenula (DBS) for major depression have also shown promising results. However, direct neuronal activity of habenula in human studies have rarely been reported. Here, in a cross-sectional design, we acquired both spontaneous resting state and emotional task-induced neuronal recordings from habenula from treatment resistant depressed patients undergoing DBS surgery. We first characterise the aperiodic component (1/f slope) of the power spectrum, interpreted to signify excitation-inhibition balance, in resting and task state. This aperiodicity for left habenula correlated between rest and task and which was significantly positively correlated with depression severity. Time-frequency responses to the emotional picture viewing task show condition differences in beta and gamma frequencies for left habenula and alpha for right habenula. Notably, alpha activity for right habenula was negatively correlated with depression severity. Overall, from direct habenular recordings, we thus show findings convergent with depression models of aberrant excitatory glutamatergic output of the habenula driving inhibition of monoaminergic systems.

[Seasonal Variation, Source Identification, and Health Risk of PM2.5-bound Metals in Xinxiang].

This study analyzed the seasonal variation, sources, and source-specific health risks of PM2.5-bound metals in Xinxiang city, Henan province. A total of 112 daily PM2.5 samples were collected over four consecutive seasons during 2019-2020. In total, 19 elements were identified using inductively coupled plasma atomic emission spectroscopy (ICP-AES). The annual concentrations of PM2.5 and 11 heavy metals were calculated to be (66.25±35.73) µg·m-3 and (1.32±0.84) µg·m-3, respectively. Strong seasonal variations were observed in PM2.5 concentrations and the concentrations of associated metal elements, with the lowest concentrations all occurring in summer. The highest concentrations of dust-related elements (e.g., Al, Ca, Fe, Mg,and Ti) were recorded in spring, differing significantly from other elements, which all exhibited the highest mass concentrations in winter. The results apportioned from positive matrix factorization (PMF) and potential source contribution function (PSCF) models showed that the major sources of PM2.5-bound elements were Ni-and Co-related emissions (5.8%), motor vehicles (13.7%), Cd-related emissions(5.1%), combustion emissions (18.2%), and dust (57.3%). Health risk models showed that there were no obvious non-carcinogenic risks associated with these metals, because their hazard quotient (HQ) values were all below 1. Lifetime carcinogenic risks of the five apportioned sources were all higher than the acceptable level (1×10-6). Of these five sources, combustion emissions were the largest contributors to cancer risk (8.74×10-6, 36.9%) and non-cancer risk (0.60, 25.6%). This study suggests that control strategies to mitigate exposure risk in Xinxiang should emphasize reducing the sources of combustion emissions.