Biology subjects

Demily, C.

Publications and source records attributed to Demily, C..

3 recordsLinked to original sources

bioRxiv2026

Dissociation Between Genetic Risk and Transcriptional Output in Schizophrenia: A Cross-Tissue Meta-Analysis of CSMD1 and CSMD2 Expression

BackgroundSchizophrenia is a neurodevelopmental disorder shaped by immune-related mechanisms, particularly dysregulated complement-mediated synaptic pruning. Genome-wide association studies have identified CSMD1 as a major schizophrenia risk gene, an association robustly replicated across populations of diverse ancestries. As a complement regulator, CSMD1 further links genetic vulnerability to synaptic refinement processes. However, the transcriptional status of CSMD1 and its homolog CSMD2 in individuals with schizophrenia (SZ individuals) remains poorly characterized. We conducted a meta-analysis of gene-expression datasets to determine whether CSMD1 and CSMD2 are differentially expressed in brain and peripheral tissues, and to assess the concordance between central and peripheral transcriptional signals. MethodsTranscriptional data were obtained from gene expression omnibus. Random-effects meta-analyses were performed on CSMD1 and CSMD2 expression data from 854 postmortem brain samples derived from 348 SZ individuals and 346 healthy controls (HC), and 295 peripheral blood samples from 162 SZ individuals and 133 HC. Sex-stratified analyses and meta-regressions evaluated potential moderators. ResultsIn brain tissues, CSMD2 expression was significantly increased in SZ individuals vs. HC (SMD: 0.22 [0.05; 0.39], adj-p=0.026), whereas CSMD1 showed no differential expression. The female-only meta-analysis revealed nominal CSMD2 overexpression (p=0.037) in brain tissues, not surviving correction. No significant transcriptional differences were detected in peripheral blood. ConclusionIn schizophrenia, our findings point to a dissociation between genetic vulnerability and transcriptional activity within the CSMD gene family. Schizophrenia is associated with selective brain CSMD2 overexpression, contrasting with unchanged CSMD1 transcription and absent peripheral blood alterations. These findings support complement-related dysregulation as a central pathway in schizophrenia.

neuroscience↗

bioRxiv2021

Dissociation of early and late face-related processes in Autism Spectrum Disorder and Williams syndrome

Williams syndrome (WS) and Autism Spectrum Disorders (ASD) are psychiatric conditions associated with atypical but opposite face-to-face interactions patterns: WS patients overly stare at others, ASD individuals escape eye contact. Whether these behaviors result from dissociable visual processes within the occipito-temporal pathways is unknown. Using high-density electroencephalography, multivariate signal processing algorithms and a protocol designed to identify and extract evoked activities sensitive to facial cues, we investigated how WS (N=14), ASD (N=14) and neurotypical subjects (N=14) decode the information content of a face stimulus. We found two neural components in neurotypical participants, both strongest when the eye region was projected onto the subjects fovea, simulating a direct eye contact situation, and weakest over more distant regions, reaching a minimum when the focused region was outside the stimulus face. The first component peaks at 170ms, an early signal known to be implicated in low-level face features. The second is identified later, 260ms post-stimulus onset and is implicated in decoding salient face social cues. Remarkably, both components were found distinctly impaired and preserved in WS and ASD. In WS, we could weakly decode the 170ms signal based on our regressor relative to facial features, probably due to their relatively poor ability to process faces morphology, while the late 260ms component was highly significant. The reverse pattern was observed in ASD participants who showed neurotypical like early 170ms evoked activity but impaired late evoked 260ms signal. Our study reveals a dissociation between WS and ASD patients and point at different neural origins for their social impairments.

neuroscience↗

bioRxiv2021

An eye gaze-modulated neural source highly impaired in autism spectrum disorder

Attention to faces and eye contact are key behaviors for establishing social bonds in humans. In Autism Spectrum Disorders (ASD) a neurodevelopmental disturbance characterized by poor communication skills, impaired face processing and gaze avoidance are critical clinical features for its diagnosis. The biological alterations underlying these impairments are not clear yet. Using high-density electroencephalography coupled with multi-variate pattern classification and group blind source separation methods we searched for face- and face components-related neural signals that could best discriminate neurotypical and ASD visual processing. First, we isolated a face-specific neural signal in the superior temporal sulcus peaking at 240ms after stimulus onset. A machine learning algorithm applied on the extracted neural component reached 74% decoding accuracy at the same latencies, dissociating the neurotypical population from ASD subjects in whom this signal was weak. Further, by manipulating attention to face parts we found that the signal-evoked power in neurotypical subjects varied as a function of the distance of the eyes in the face stimulus with respect to the viewers fovea, i.e. it was strongest when the eyes were projected on the fovea and weakest when projected in the retinal periphery. Such selective face and face-components neural modulations were not found in ASD individuals although they showed typical early face related P100 and the N170 signals. These findings show that dedicated cortical mechanisms related to face perception set neural priority for attention to eyes and that these mechanisms are altered in individuals with ASD.

neuroscience↗