Subregional thalamic functional connectivity abnormalities and cognitive impairments in first-episode schizophrenia.

BACKGROUND: Previous studies have documented thalamic functional connectivity (FC) abnormalities in schizophrenia, typically examining the thalamus as a whole. The specific link between subregional thalamic FC and cognitive deficits in first-episode schizophrenia (FES) remains unexplored. METHODS: Using data from resting-state functional magnetic resonance imaging, we compared whole-brain FC with thalamic subregions between patients and HCs, and analyzed FC changes in drug-naïve patients separately. We then examined correlations between FC abnormalities with both cognitive impairment and clinical symptoms. RESULTS: A total of 33 FES patients (20 drug-naïve) and 32 age- and sex-matched healthy controls (HCs) were included. Compared to HCs, FES patients exhibited increased FC between specific thalamic subregions and cortical regions, particularly bilateral middle temporal lobe and cuneus gyrus, left medial superior frontal gyrus, and right inferior/superior occipital gyrus. Decreased FC was observed between certain thalamic subregions and the left inferior frontal triangle. These findings were largely consistent in drug-naïve patients. Notably, deficits in social cognition and visual learning in FES patients correlated with increased FC between certain thalamic subregions and cortical regions involving the right superior occipital gyrus and cuneus gyrus. The severity of negative symptoms was associated with increased FC between a thalamic subregion and the left middle temporal gyrus. CONCLUSION: Our findings suggest FC abnormalities between thalamic subregions and cortical areas in FES patients. Increased FC correlated with cognitive deficits and negative symptoms, highlighting the importance of thalamo-cortical connectivity in the pathophysiology of schizophrenia.

Repetitive Transcranial Magnetic Stimulation for Working Memory Deficits in Schizophrenia: A Systematic Review of Randomized Controlled Trials.

Working memory (WM) deficits are a significant component of neurocognitive impairment in individuals with schizophrenia (SCZ). Two previous meta-analyses, conducted on randomized controlled trials (RCTs), examined the effectiveness of repetitive transcranial magnetic stimulation (rTMS) in addressing WM deficits in individuals diagnosed with SCZ. However, the conclusions drawn from these analyses were inconsistent. Additionally, the commonly used random effects (RE) models might underestimate statistical errors, attributing a significant portion of perceived heterogeneity between studies to variations in study quality. Therefore, this review utilized both RE and quality effects (QE) models to assess relevant RCTs comparing TMS with sham intervention in terms of clinical outcomes. A comprehensive literature search was conducted using PubMed and Scopus databases, resulting in the inclusion of 13 studies for data synthesis. Overall, regardless of whether the RE or QE model was used, eligible RCTs suggested that the TMS and sham groups exhibited comparable therapeutic effects after treatment. The current state of research regarding the use of rTMS as a treatment for WM deficits in patients with SCZ remains in its preliminary phase. Furthermore, concerning the mechanism of action, the activation of brain regions focused on the dorsolateral prefrontal cortex and alterations in gamma oscillations may hold significant relevance in the therapeutic application of rTMS for addressing WM impairments. Finally, we believe that the application of closed-loop neuromodulation may contribute to the optimization of rTMS for WM impairment in patients with SCZ.

Cognitive control impairment in ax-continuous performance test in patients with schizophrenia: A pilot EEG study.

OBJECTIVES: This study aimed to investigate the mechanism of cognitive control impairment in patients with schizophrenia (SPs) using electroencephalogram (EEG). METHODS: A total of 17 SPs and 17 healthy controls (HCs) were included in this study. We measured the EEG activity, whereas they performed the AX-continuous performance test which consisted of the preparatory phase and the response phase. The MATRICS Consensus Cognitive Battery (MCCB) was used for cognitive function, and the Positive and Negative Syndrome Scale (PANSS) was used for clinical symptom assessment. A univariate linear regression model was used to explore the relationships among behavioral index, event-related potentials (ERPs), rhythmic oscillation power, and score of MCCB and PANSS. RESULTS: A significant difference was found in response accuracy and reaction time (RT) during the preparatory phase between patients and HCs (p < .05). During the response phase, the SPs exhibited longer RT than the HCs (p < .05). Analysis of the ERPs revealed that the amplitude of P3a on BX clues was significantly smaller in SPs than in HCs (p < .05). Additionally, the midline frontal theta power of neural oscillation was significantly lower in the SPs than in NCs both during the preparatory and response phases. The accuracies on BX clues (r = .694, p = .002) and d'context (r = .698, p = .002) were positively correlated with MCCB scores. CONCLUSION: The present study revealed that patients with schizophrenia have deficits both in proactive and reactive cognitive control, with a greater reliance on reactive control during conflict resolution. The neural mechanisms of the cognitive control impairment may involve the inability to engage additional neural resources for proactive control, and a reduction in frontal midline theta power during both proactive and reactive control. The severity of proactive control impairment is positively correlated with an increased tendency to rely on reactive control.

Efficacy and Safety of Theta Burst vs Repetitive Transcranial Magnetic Stimulation for the Treatment of Depression: A Meta-Analysis of Randomized Controlled Trials.

OBJECTIVES: Theta burst stimulation (TBS) is more energy- and time-efficient than is standard repetitive transcranial magnetic stimulation (rTMS). However, further studies are needed to analyze TBS therapy for its efficacy and safety compared with standard rTMS in treating depression. The aim of this meta-analysis was to compare TBS therapy with standard rTMS treatment regarding their safety and therapeutic effect on individuals with depression. MATERIALS AND METHODS: Six data bases (Wanfang, the China National Knowledge Infrastructure, PubMed, Embase, Cochrane Library, and PsycINFO) were searched from inception till December 20, 2022. Two independent reviewers selected potentially relevant studies on the basis of the inclusion criteria, extracted data, and evaluated the methodologic quality of the eligible trials using the modified ten-item Physiotherapy Evidence Database scale per Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Finally, ten comparable pairs of nine randomized controlled trials (RCTs) were included for meta-analysis. Summary odds ratios (ORs) of the rates of response, remission, and adverse events were simultaneously calculated using quality-effects (QE) and random-effects (RE) models. Changes in depression scores associated with antidepressant effects were expressed using standardized mean differences simultaneously. This study was registered with the International Prospective Register of Systematic Reviews (CRD42022376790). RESULTS: Nine of the 602 RCTs, covering 1124 patients (616 who had TBS protocols applied vs 508 treated using standard rTMS), were included. Differences in response rates between the above two treatment modalities were not significant (OR = 1.01, 95% CI: 0.88-1.16, p = 0.44, I2 = 0%, RE model; OR = 1.07, 95% CI: 0.87-1.32, p = 0.44, I2 = 0%, QE model). Differences in adverse event rates between TBS and standard rTMS groups were not statistically significant. CONCLUSIONS: TBS has similar efficacy and safety to standard rTMS for treating depression. Considering the short duration of daily stimulation sessions, this meta-analysis supports the continued development of TBS for treating depression.

Reduced suicidality after electroconvulsive therapy is linked to increased frontal brain activity in depressed patients: a resting-state fMRI study.

Objective: Suicidality is commonly observed in patients with depressive episodes, and electroconvulsive therapy (ECT) has been found to be effective in treating these patients. However, the role of ECT in suicidality remains unclear. This study used resting-state functional magnetic resonance imaging (rs-fMRI) to explore the changes in brain function before and after ECT in depressed patients with suicidality. Methods: In total, 26 depressed patients with suicidality underwent rs-fMRI at baseline and after 8-12 sessions of ECT. In addition, 32 healthy controls (HCs) matched for age, gender, and educational level underwent rs-fMRI once. The amplitude of low-frequency fluctuations (ALFF), the fractional amplitude of low-frequency fluctuations (fALFF), and regional homogeneity (ReHo) were measured to evaluate whole brain function. Differences between the groups and time points (before and after ECT) were compared. Clinical symptoms were assessed using the 17-item Hamilton Depression Scale (HAMD-17) and Beck Scale for Suicide Ideation (BSSI). Results: At baseline, patients exhibited decreased ALFF in the right postcentral and precentral gyrus and decreased fALFF in the right supramarginal and postcentral gyrus, left superior frontal gyrus (SFG), as well as the superior and middle temporal gyrus compared to HCs. Patients also had lower ReHo in the left amygdala, anterior cingulate, and postcentral gyrus, and in the right thalamus, insula, and postcentral gyrus. They also exhibited higher ALFF in the bilateral temporal gyrus and insula as well as higher fALFF in the cerebellum. Following ECT, fALFF in the left SFG and orbital frontal cortex (OFC) significantly increased and was inversely correlated with the reduction of BSSI scores (r = -0.416, p = 0.048), whereas no correlation was found with changes in HAMD-17scores. Conclusion: Our findings suggest that the left SFG and OFC may play a key role in the mechanism of ECT for suicidality. The decrease of fALFF in the left SFG and OFC may represent a potential mechanism through which ECT effectively treats suicidality in depressed patients.

Adding Far-Red to Red-Blue Light-Emitting Diode Light Promotes Yield of Lettuce at Different Planting Densities.

The economic viability and energy use of vertical farms strongly depend on the efficiency of the use of light. Increasing far-red radiation (FR, 700-800 nm) relative to photosynthetically active radiation (PAR, 400-700 nm) may induce shade avoidance responses including stem elongation and leaf expansion, which would benefit light interception, and FR might even be photosynthetically active when used in combination with PAR. The aims of this study are to investigate the interaction between FR and planting density and to quantify the underlying components of the FR effects on growth. Lettuce (Lactuca sativa cv. Expertise RZ) was grown in a climate chamber under two FR treatments (0 or 52 µmol m-2 s-1) and three planting densities (23, 37, and 51 plants m-2). PAR of 89% red and 11% blue was kept at 218 µmol m-2 s-1. Adding FR increased plant dry weight after 4 weeks by 46-77% (largest effect at lowest planting density) and leaf area by 58-75% (largest effect at middle planting density). Radiation use efficiency (RUE: plant dry weight per unit of incident radiation, 400-800 nm) increased by 17-42% and incident light use efficiency (LUEinc: plant dry weight per unit of incident PAR, 400-700 nm) increased by 46-77% by adding FR; the largest FR effects were observed at the lowest planting density. Intercepted light use efficiency (LUEint: plant dry weight per unit of intercepted PAR) increased by adding FR (8-23%). Neither specific leaf area nor net leaf photosynthetic rate was influenced by FR. We conclude that supplemental FR increased plant biomass production mainly by faster leaf area expansion, which increased light interception. The effects of FR on plant dry weight are stronger at low than at high planting density. Additionally, an increased LUEint may contribute to the increased biomass production.