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"Novák, Tomáš"
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Psilocin, LSD, mescaline, and DOB all induce broadband desynchronization of EEG and disconnection in rats with robust translational validity
2021
Serotonergic psychedelics are recently gaining a lot of attention as a potential treatment of several neuropsychiatric disorders. Broadband desynchronization of EEG activity and disconnection in humans have been repeatedly shown; however, translational data from animals are completely lacking. Therefore, the main aim of our study was to assess the effects of tryptamine and phenethylamine psychedelics (psilocin 4 mg/kg, LSD 0.2 mg/kg, mescaline 100 mg/kg, and DOB 5 mg/kg) on EEG in freely moving rats. A system consisting of 14 cortical EEG electrodes, co-registration of behavioral activity of animals with subsequent analysis only in segments corresponding to behavioral inactivity (resting-state-like EEG) was used in order to reach a high level of translational validity. Analyses of the mean power, topographic brain-mapping, and functional connectivity revealed that all of the psychedelics irrespective of the structural family induced overall and time-dependent global decrease/desynchronization of EEG activity and disconnection within 1–40 Hz. Major changes in activity were localized on the large areas of the frontal and sensorimotor cortex showing some subtle spatial patterns characterizing each substance. A rebound of occipital theta (4–8 Hz) activity was detected at later stages after treatment with mescaline and LSD. Connectivity analyses showed an overall decrease in global connectivity for both the components of cross-spectral and phase-lagged coherence. Since our results show almost identical effects to those known from human EEG/MEG studies, we conclude that our method has robust translational validity.
Journal Article
Transcranial direct current stimulation (tDCS) in the treatment of neuropsychiatric symptoms of long COVID
by
Klírová, Monika
,
Laskov, Olga
,
Stuchlíková, Zuzana
in
692/308/409
,
692/617/375/1367
,
692/699/476/1300
2024
The study aimed to assess the efficacy of transcranial direct current stimulation (tDCS) in the treatment of neuropsychiatric (NP) symptoms of the post-acute sequelae of SARS-CoV-2 infection (PASC), known as the long COVID. A double-blind, randomized, sham-controlled study compared the efficacy and safety of prefrontal cortex active tDCS to sham-tDCS in treating NP-PASC. Patients diagnosed with NP-PASC, with a Fatigue Impact Scale (FIS) score ≥ 40, were eligible for the study. Twenty tDCS sessions were administered within four weeks, with continuous, end-of-treatment, and follow-up measurements. The primary outcome was a change in the FIS at the end-of-treatment, analyzed in the intention-to-treat population. Data from 33 patients assigned to active (n = 16) or sham-tDCS (n = 17) were analyzed. After the treatment, a decrease in the FIS score was more pronounced in the sham than in the active group, yet the intergroup difference was insignificant (11.7 [95% CI −11.1 to 34.5], p = 0.6). Furthermore, no significant intergroup differences were observed regarding anxiety, depression, quality of life, and cognitive performance. The small cohort sample, differences in baseline FIS scores between groups (non-stratified randomization), or chosen stimulation parameters may have influenced our findings. However, it might also be possible that the expected mechanism of action of tDCS is insufficient to treat these conditions.
Journal Article
Assessment of Response to Lithium Maintenance Treatment in Bipolar Disorder: A Consortium on Lithium Genetics (ConLiGen) Report
by
Cheng, Andrew Tai Ann
,
Brichant-Petitjean, Clara
,
Malafosse, Alain
in
Analysis
,
Antimanic Agents - administration & dosage
,
Antimanic Agents - therapeutic use
2013
The assessment of response to lithium maintenance treatment in bipolar disorder (BD) is complicated by variable length of treatment, unpredictable clinical course, and often inconsistent compliance. Prospective and retrospective methods of assessment of lithium response have been proposed in the literature. In this study we report the key phenotypic measures of the \"Retrospective Criteria of Long-Term Treatment Response in Research Subjects with Bipolar Disorder\" scale currently used in the Consortium on Lithium Genetics (ConLiGen) study.
Twenty-nine ConLiGen sites took part in a two-stage case-vignette rating procedure to examine inter-rater agreement [Kappa (κ)] and reliability [intra-class correlation coefficient (ICC)] of lithium response. Annotated first-round vignettes and rating guidelines were circulated to expert research clinicians for training purposes between the two stages. Further, we analyzed the distributional properties of the treatment response scores available for 1,308 patients using mixture modeling.
Substantial and moderate agreement was shown across sites in the first and second sets of vignettes (κ = 0.66 and κ = 0.54, respectively), without significant improvement from training. However, definition of response using the A score as a quantitative trait and selecting cases with B criteria of 4 or less showed an improvement between the two stages (ICC1 = 0.71 and ICC2 = 0.75, respectively). Mixture modeling of score distribution indicated three subpopulations (full responders, partial responders, non responders).
We identified two definitions of lithium response, one dichotomous and the other continuous, with moderate to substantial inter-rater agreement and reliability. Accurate phenotypic measurement of lithium response is crucial for the ongoing ConLiGen pharmacogenomic study.
Journal Article
Combining schizophrenia and depression polygenic risk scores improves the genetic prediction of lithium response in bipolar disorder patients
by
Kelsoe, John
,
Nievergelt, Caroline M
,
McElroy, Susan
in
Bipolar disorder
,
Lithium
,
Schizophrenia
2021
Lithium is the gold standard therapy for Bipolar Disorder (BD) but its effectiveness differs widely between individuals. The molecular mechanisms underlying treatment response heterogeneity are not well understood, and personalized treatment in BD remains elusive. Genetic analyses of the lithium treatment response phenotype may generate novel molecular insights into lithium’s therapeutic mechanisms and lead to testable hypotheses to improve BD management and outcomes. We used fixed effect meta-analysis techniques to develop meta-analytic polygenic risk scores (MET-PRS) from combinations of highly correlated psychiatric traits, namely schizophrenia (SCZ), major depression (MD) and bipolar disorder (BD). We compared the effects of cross-disorder MET-PRS and single genetic trait PRS on lithium response. For the PRS analyses, we included clinical data on lithium treatment response and genetic information for n = 2283 BD cases from the International Consortium on Lithium Genetics (ConLi+Gen; www.ConLiGen.org). Higher SCZ and MD PRSs were associated with poorer lithium treatment response whereas BD-PRS had no association with treatment outcome. The combined MET2-PRS comprising of SCZ and MD variants (MET2-PRS) and a model using SCZ and MD-PRS sequentially improved response prediction, compared to single-disorder PRS or to a combined score using all three traits (MET3-PRS). Patients in the highest decile for MET2-PRS loading had 2.5 times higher odds of being classified as poor responders than patients with the lowest decile MET2-PRS scores. An exploratory functional pathway analysis of top MET2-PRS variants was conducted. Findings may inform the development of future testing strategies for personalized lithium prescribing in BD.
Journal Article
HLA-DRB1 and HLA-DQB1 genetic diversity modulates response to lithium in bipolar affective disorders
by
Brichant-Petitjean, Clara
,
Zagury, Jean-François
,
Nievergelt, Caroline M.
in
631/208
,
631/250
,
631/250/248
2021
Bipolar affective disorder (BD) is a severe psychiatric illness, for which lithium (Li) is the gold standard for acute and maintenance therapies. The therapeutic response to Li in BD is heterogeneous and reliable biomarkers allowing patients stratification are still needed. A GWAS performed by the International Consortium on Lithium Genetics (ConLiGen) has recently identified genetic markers associated with treatment responses to Li in the human leukocyte antigens (HLA) region. To better understand the molecular mechanisms underlying this association, we have genetically imputed the classical alleles of the
HLA
region in the European patients of the ConLiGen cohort. We found our best signal for amino-acid variants belonging to the
HLA-DRB1*11:01
classical allele, associated with a better response to Li (
p
< 1 × 10
−3
; FDR < 0.09 in the recessive model). Alanine or Leucine at position 74 of the HLA-DRB1 heavy chain was associated with a good response while Arginine or Glutamic acid with a poor response. As these variants have been implicated in common inflammatory/autoimmune processes, our findings strongly suggest that HLA-mediated low inflammatory background may contribute to the efficient response to Li in BD patients, while an inflammatory status overriding Li anti-inflammatory properties would favor a weak response.
Journal Article
Lithium response in bipolar disorder is associated with focal adhesion and PI3K-Akt networks: a multi-omics replication study
by
Nievergelt, Caroline M.
,
Wray, Naomi R.
,
Clark, Scott R.
in
631/208/2489
,
692/699/476/1333
,
Behavioral Sciences
2024
Lithium is the gold standard treatment for bipolar disorder (BD). However, its mechanism of action is incompletely understood, and prediction of treatment outcomes is limited. In our previous multi-omics study of the Pharmacogenomics of Bipolar Disorder (PGBD) sample combining transcriptomic and genomic data, we found that focal adhesion, the extracellular matrix (ECM), and PI3K-Akt signaling networks were associated with response to lithium. In this study, we replicated the results of our previous study using network propagation methods in a genome-wide association study of an independent sample of 2039 patients from the International Consortium on Lithium Genetics (ConLiGen) study. We identified functional enrichment in focal adhesion and PI3K-Akt pathways, but we did not find an association with the ECM pathway. Our results suggest that deficits in the neuronal growth cone and PI3K-Akt signaling, but not in ECM proteins, may influence response to lithium in BD.
Journal Article
Underlying pharmacological mechanisms of psilocin-induced broadband desynchronization and disconnection of EEG in rats
by
Lukáš Kadeřábek
,
Martin Kuchař
,
Vlastimil Koudelka
in
Animal models
,
Antipsychotics
,
Clozapine
2023
Psilocybin is one of the most extensively studied psychedelic drugs with a broad therapeutic potential. Despite the fact that its psychoactivity is mainly attributed to the agonism at 5-HT
receptors, it has high binding affinity also to 5-HT
and 5-HT
receptors and indirectly modulates the dopaminergic system. Psilocybin and its active metabolite psilocin, as well as other serotonergic psychedelics, induce broadband desynchronization and disconnection in EEG in humans as well as in animals. The contribution of serotonergic and dopaminergic mechanisms underlying these changes is not clear. The present study thus aims to elucidate the pharmacological mechanisms underlying psilocin-induced broadband desynchronization and disconnection in an animal model.
Selective antagonists of serotonin receptors (5-HT
WAY100635, 5-HT
MDL100907, 5-HT
SB242084) and antipsychotics haloperidol, a D
antagonist, and clozapine, a mixed D
and 5-HT receptor antagonist, were used in order to clarify the underlying pharmacology.
Psilocin-induced broadband decrease in the mean absolute EEG power was normalized by all antagonists and antipsychotics used within the frequency range 1-25 Hz; however, decreases in 25-40 Hz were influenced only by clozapine. Psilocin-induced decrease in global functional connectivity and, specifically, fronto-temporal disconnection were reversed by the 5-HT
antagonist while other drugs had no effect.
These findings suggest the involvement of all three serotonergic receptors studied as well as the role of dopaminergic mechanisms in power spectra/current density with only the 5-HT
receptor being effective in both studied metrics. This opens an important discussion on the role of other than 5-HT
-dependent mechanisms underlying the neurobiology of psychedelics.
Journal Article
Transcranial direct current stimulation and cognitive training in the treatment of cognitive deficit in schizophrenia: a randomized controlled trial
2026
Background
Cognitive impairment is a core feature of schizophrenia spectrum disorders and a major contributor to functional impairment in patients with the disorder. Given the limited effects of pharmacological treatments on cognition, there is an increasing interest in the use of alternative therapeutic approaches, including cognitive training and non-invasive brain stimulation. Our study aimed to evaluate the effectiveness of the combined treatment of tDCS and cognitive training on improving cognitive functions in patients with schizophrenia.
Methods
This one-week, randomized, double-blind, placebo-controlled trial explored the effects of the combined intervention of anodal tDCS to the left dorsolateral prefrontal cortex and computer-based cognitive training on cognitive functions in schizophrenia. 30 clinically stable patients, aged 18 to 50 years, with an ICD-10 diagnosis of schizophrenia were randomized into two groups for five daily sessions of cognitive training and sham or active tDCS. Anodal tDCS (2 mA) was applied with the anode over left DLPFC (F3) and the cathode over the right orbitofrontal region (Fp2). Computer-based cognitive training was used. Cognitive testing was performed using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS, versions A and B).
Results
29 out of the 30 enrolled patients completed the study, and the data was analyzed. Although no statistically significant differences were detected, numerical trends across several RBANS domains (Total Score, Memory, Visuoconstructional, and Language indices) were slightly higher in the active stimulation group. The attention score was numerically higher in the sham group, but also did not reach a statistically significant level.
Conclusions
The combined intervention of tDCS and cognitive training did not demonstrate significant superiority over cognitive training alone. Nevertheless, numerical trends in memory-related domains suggest potential for benefit. These findings contribute to the growing body of research on neuromodulation in schizophrenia, underscoring both the promise and the challenges of implementing combined therapeutic approaches in clinical practice.
Trial registration
The trial was retrospectively registered in the ISRCTN registry (
https://doi.org/10.1186/ISRCTN13247154
) on 18/08/2021.
Journal Article
Investigating the phenotypic and genetic associations between personality traits and suicidal behavior across major mental health diagnoses
by
Brichant-Petitjean, Clara
,
Streit, Fabian
,
Ardau, Raffaella
in
Archives & records
,
Bipolar disorder
,
Consortia
2022
Personality traits influence risk for suicidal behavior. We examined phenotype- and genotype-level associations between the Big Five personality traits and suicidal ideation and attempt in major depressive, bipolar and schizoaffective disorder, and schizophrenia patients (N = 3012) using fixed- and random-effects inverse variance-weighted meta-analyses. Suicidal ideations were more likely to be reported by patients with higher neuroticism and lower extraversion phenotypic scores, but showed no significant association with polygenic load for these personality traits. Our findings provide new insights into the association between personality and suicidal behavior across mental illnesses and suggest that the genetic component of personality traits is unlikely to have strong causal effects on suicidal behavior.
Journal Article
Effects of Normalised SSIM Loss on Super-Resolution Tasks
by
Brožek, Jiří
,
Žáček, Miroslav
,
Hamplová, Adéla
in
Algorithms
,
Datasets
,
Generative adversarial networks
2025
This study proposes a new component of the composite loss function minimised during training of the Super-Resolution (SR) algorithms—the normalised structural similarity index loss , which has the potential to improve the natural appearance of reconstructed images. Deep learning-based super-resolution (SR) algorithms reconstruct high-resolution images from low-resolution inputs, offering a practical means to enhance image quality without requiring superior imaging hardware, which is particularly important in medical applications where diagnostic accuracy is critical. Although recent SR methods employing convolutional and generative adversarial networks achieve high pixel fidelity, visual artefacts may persist, making the design of the loss function during training essential for ensuring reliable and naturalistic image reconstruction. Our research shows on two models—SR and Invertible Rescaling Neural Network (IRN)—trained on multiple benchmark datasets that the function significantly contributes to the visual quality, preserving the structural fidelity on the reference datasets. The quantitative analysis of results while incorporating shows that including this loss function component has a mean 2.88% impact on the improvement of the final structural similarity of the reconstructed images in the validation set, in comparison to leaving it out and 0.218% in comparison when this component is non-normalised.
Journal Article