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Tucci, V.

Publications and source records attributed to Tucci, V..

5 recordsLinked to original sources

The Preclinical Animal Network (PCAN): Integrative high-throughput phenotyping of standardized mouse models for Prader-Willi syndrome

The Preclinical Animal Network (PCAN) is a collaborative resource established to advance translational research and therapeutic development for Prader-Willi syndrome (PWS), a rare neurodevelopmental disorder caused by loss of paternally expressed genes on chromosome 15q11-q13. PCAN integrates standardized, high-throughput phenotyping of approximately 1,000 mice across six engineered lines carrying paternal deletions of Ndn, Magel2, Snord116, Ipw, and multigenic loci. Using validated experimental pipelines spanning metabolic, behavioral, and developmental domains, we captured comprehensive phenotypic profiles by applying a statistical variance-decomposition framework to partition genetic and environmental contributions. This analysis provides robust genotype-phenotype maps, revealing shared and model-specific phenotypic effects while accounting for key confounding factors. The PCAN resource provides a framework for evaluating PWS-relevant phenotypes and benchmarking therapeutic strategies. By providing open access to its mouse models, datasets and analytical resources, PCAN enables the research community to apply standardized, reproducible workflows and accelerate the development of targeted, mechanism-based treatments.

genetics↗

Developmental excitation-inhibition imbalance permanently reprograms autism-relevant social brain circuits

An influential theory proposes that an imbalance between excitation and inhibition (E:I) plays a central role in the etiology of autism and related developmental disorders. However, controversy exists as to whether this imbalance is a direct causal mechanism for autism, or a compensatory response to other primary etiological factors. Using chemogenetic manipulations in neonatal mice, we show that a transient E:I imbalance during development is sufficient to permanently reprogram autism-relevant social brain circuits. Chemogenetically manipulated mice exhibit lifelong impairments in sociability, persistent dysregulation of multiple autism-risk synaptic genes, and sustained cortical hyperexcitability in adulthood. Importantly, these social impairments are robustly rescued by pharmacological inhibition of neuronal excitability. Developmental E:I imbalance also disrupts functional connectivity in social brain regions enriched for transcriptionally dysregulated genes, suggesting a convergence of transcriptional and circuit-level pathology. Finally, multivariate modelling shows that behavioral dysfunction in chemogenetically manipulated animals closely associates with disrupted connectivity between prefrontal and mesolimbic dopaminergic regions. Collectively, our findings reconcile conflicting theories in the field and point to activity-dependent transcriptional remodeling as a foundational mechanism by which transient E:I imbalance during development can cause lasting, autism-relevant circuit dysfunction.

neuroscience↗

'SpikeNburst' and 'Nicespike': Advanced Tools for Enhancing and Accelerating In Vitro High-Density Electrophysiology Analysis

High-density multi-electrode arrays (HD-MEAs) enable the recording of in vitro neuronal activity with exceptional spatial and temporal resolution. However, analysing these extensive datasets presents challenges, such as artefact removal, spike sorting, and accurate assessments of neuronal synchronization. Here, we introduce a structured protocol for conducting comprehensive HD-MEA analyses using two Python-based tools: spikeNburst and nicespike. This protocol provides a scalable and systematic approach to processing HD-MEA recordings, ensuring efficient data handling and robust analytical outcomes. The spikeNburst tool incorporates advanced methodologies for spike train filtering, burst and network burst detection, and synchronization analysis. Complementing this, we have implemented a full analysis pipeline in the nicespike tool, featuring GPU-accelerated spike sorting via template matching with Kilosort, enabling accurate identification of neuronal units across multiple electrodes. This protocol ensures more precise analyses by reducing redundancy and overestimation inherent in single-channel approaches. Moreover, both tools offer graphical user and command-line interfaces, ensuring accessibility for diverse user needs. We validated our protocol on in vitro neuronal culture recordings, demonstrating its suitability to identify somatic and dendritic features of neuronal units, characterize bursting behaviour, and quantify synchronization at both unit and network levels. By addressing critical limitations of existing methods, spikeNburst and nicespike provide a robust, scalable, and user-friendly framework for HD-MEA data analysis, enhancing the study of neural network dynamics and single-cell activity in detail.

neuroscience↗

Paternally expressed imprinted Snord116 and Peg3 regulate hypothalamic orexin neurons

Imprinted genes are highly expressed in the hypothalamus; however, whether specific imprinted genes affect hypothalamic neuromodulators and their functions is unknown. It has been suggested that Prader-Willi syndrome (PWS), a neurodevelopmental disorder caused by lack of paternal expression at chromosome 15q11-q13, is characterised by hypothalamic insufficiency. Here, we investigate the role of the paternally expressed Snord116 gene within the context of sleep and metabolic abnormalities of PWS, and we report a novel role of this imprinted gene in the function and organisation of the two main neuromodulatory systems of the lateral hypothalamus (LH), namely, the orexin (OX) and melanin concentrating hormone (MCH) systems. We observe that the dynamics between neuronal discharge in the LH and the sleep-wake states of mice with paternal deletion of Snord116 (PWScrm+/p-) are compromised. This abnormal state-dependent neuronal activity is paralleled by a significant reduction in OX neurons in the LH of mutants. Therefore, we propose that an imbalance between OX- and MCH-expressing neurons in the LH of mutants reflects a series of deficits manifested in the PWS, such as dysregulation of rapid eye movement (REM) sleep, food intake and temperature control.\n\nHighlightsO_LISnord116 regulates neuronal activity in the lateral hypothalamus (LH), which is time-locked with cortical states of sleep.\nC_LIO_LILoss of Snord116 reduces orexin neurons in the LH and affects sleep homeostasis and thermoregulation in mice.\nC_LIO_LISnord116 and Peg3 independently control orexin expression in the LH.\nC_LIO_LIPaternally expressed alleles maximize the patrilineal effects in the control of REM sleep by the LH in mammals.\nC_LI

neuroscience↗

The paternally imprinted gene Snord116 regulates cortical neuronal activity

Prader-Willi syndrome (PWS) is a neurodevelopmental disorder that is characterized by rapid eye movement (REM) sleep abnormalities. The disease is caused by genomic imprinting defects that are inherited through the paternal line. Among the genes located in the PWS region on chromosome 15 (15q11-q13), small nucleolar RNA 116 (Snord116) has been previously associated with intrusions of REM sleep into wakefulness in both humans and mice.\n\nHere, we further explore the processes of sleep regulation by studying the PWScrm+/p- mouse line, which carries a paternal deletion of Snord116. We focused on microstructural electrophysiological components of sleep, such as REM sleep features and sleep spindles within NREM sleep. While the former are thought to contribute to neuronal network formation early in brain development, the latter are markers of thalamocortical processes. Both signals are often compromised in neurodevelopmental disorders and influence functional properties of cortical neurons. Thus, we isolated and characterized the intrinsic activity of cortical neurons using in vitro microelectrode array (MEA) studies.\n\nOur results indicate that the Snord116 gene in mice selectively influences REM sleep properties, such as theta rhythms and the organization of REM episodes throughout sleep-wake cycles. Moreover, sleep spindles present specific abnormalities in PWS model systems, indicating that these features of sleep may translate as potential biomarkers in human PWS. We observed abnormalities in the synchronization of cortical neuronal activity that are accounted for by high levels of norepinephrine.\n\nIn conclusion, our results provide support for an important role of Snord116 in regulating brain activity during sleep and, in particular, cortical neuronal properties, thereby opening new avenues for developing interventions in PWS.\n\nSignificance StatementWe found that the Snord116 gene, a major player in Prader-Willi syndrome (PWS), significantly impacts REM sleep and its regulation. Additionally, we found that sleep spindles, a subtle electroencephalography (EEG) marker that occurs during NREM sleep, are dysregulated in PWS mice that carry a paternal deletion of the Snord116 gene. Using a combination of in vivo and in vitro experiments, we identified sleep features at the network and molecular level that suggest that Snord116 is fundamental in the synchronization of neuronal networks. Our study also provides a new pre-clinical tool to investigate the pathophysiology of sleep in PWS.

neuroscience↗