Biology subjects

Peles, D.

Publications and source records attributed to Peles, D..

6 recordsLinked to original sources

bioRxiv2024

DeePosit: an AI-based tool for detecting mouse urine and fecal depositions from thermal video clips of behavioral experiments

In many mammals, including rodents, social interactions are often accompanied by active urination (micturition), which is considered a mechanism for spatial scent marking. Urine and fecal deposits contain a variety of chemosensory signals that convey information about the individuals identity, genetic strain, social rank, and physiological or hormonal state. Furthermore, scent marking has been shown to be influenced by the social context and by the individuals internal state and experience. Therefore, analyzing scent-marking behavior during social interactions can provide valuable insight into the structure of mammalian social interactions in health and disease. However, conducting such analyses has been hindered by several technical challenges. For example, the widely used void spot assay lacks temporal resolution and is prone to artifacts, such as urine smearing. To solve these issues, recent studies employed thermal imaging for the spatio-temporal analysis of urination activity. However, this method involved manual analysis, which is time-consuming and susceptible to observer bias. Moreover, defecation activity was hardly analyzed by previous studies. In the present study, we integrate thermal imaging with an open-source algorithm based on a transformer-based video classifier for automatic detection and classification of urine and fecal deposits made by male and female mice during various social behavior assays. Our results reveal distinct dynamics of urination and defecation in a test-, strain- and sex-dependent manner, indicating two separate processes of scent marking in mice. We validate this algorithm, termed by us DeePosit, and show that its accuracy is comparable to that of a human annotator and that it is efficient in various setups and conditions. Thus, the method and tools introduced here enable efficient and unbiased automatic spatio-temporal analysis of scent marking behavior in the context of behavioral experiments in small rodents.

animal behavior and cognition↗

bioRxiv2024

Brain Extracellular Matrix implications in multiple neurological disorders are revealed through a meta-analysis of transcriptional changes

Neurological disorders comprise a wide range of illnesses that may affect the central and peripheral nervous systems. Despite diverse etiologies, patients with these disorders may share symptoms. In this study, we aimed to explore potential common mechanisms between seven neurological disorders spanning three categories: neurodegenerative diseases, neuropsychiatric disorders, and neurodevelopmental disorders, by comparing gene expression profiles and focusing on the most prominent dysregulated genes consistently reported within and across disorders. Our results demonstrate 31 genes that are commonly differentially expressed in brain cells and tissues derived from human disease models when compared to healthy controls. These genes were enriched in brain Extracellular Matrix (ECM) pathways, Growth factor binding, Response to acid chemical, and External encapsulating structure. Remarkedly, dysregulation of ECM genes was evident separately in each of the three categories of disorders. This suggests a notable distinction in the brain ECM in disease states. Furthermore, we identified that the most frequently reported genes among all disorders were GFAP, and IFITM3. Key PointsO_LIAnalysis of 41 human studies revealed 31 significantly dysregulated genes shared among seven neurological disorders when compared to healthy controls, spanning three distinct categories: Neurodegenerative diseases, Neuropsychiatric disorders, and Neurodevelopmental disorders. C_LIO_LIThese shared Differentially Expressed Genes (DEGs) demonstrated significant enrichment for Extracellular Matrix (ECM) pathways, Growth factor binding, Response to acid chemical, Blood vessel development, and External encapsulating structure. Particularly, SST and BCL6 were the most frequently reported shared DEGs. C_LIO_LINotably, each of the three categories of neurological disorders exhibited significant cellular component enrichment for ECM pathways. C_LIO_LIIn order to distinguish noise genes (false-positive genes) from disease-relevant genes, we identified the DEGs that were reported the highest number of times per disorder. GFAP, followed by IFITM3, were found to be the most reported genes. C_LIO_LIFurthermore, due to partially shared symptoms, we explored commonalities between Autism Spectrum Disorders (ASD) and Schizophrenia. DEGs shared between both disorders were specifically enriched with ECM pathways, External encapsulating structure, Growth factor binding, Cell adhesion molecule binding, and PI3K-Akt signaling pathway. Noteworthy, IFITM2, HSPB1, IFITM3, HSPA1A, MKNK2, GFAP and COL4A1 were among the most frequently reported shared DEGs. C_LIO_LIThe central aspects of our findings suggest a substantial distinction between the Central Nervous System (CNS) ECM in health and disease. C_LI

neuroscience↗

bioRxiv2023

Ventral dentate gyrus-dominated LFP rhythmicity in the social brain reflects the context of social encounters

Mammalian social behavior is highly context-sensitive. Yet, little is known about the mechanisms that modulate social behavior according to its context. Recent studies have revealed a network of mostly limbic brain regions, here termed the "social brain", which regulates social behavior. We hypothesized that coherent theta and gamma rhythms reflect the organization of the social brain regions into functional networks in a context-dependent manner. To test this concept, we simultaneously recorded extracellular activity from multiple social brain regions in mice performing three social discrimination tasks. Local field potential (LFP) rhythmicity across all tasks was dominated by a general internal state. However, during stimulus investigation LFP rhythmicity was sensitive to stimulus characteristics. Specifically, the pattern of LFP coherence between the various regions reflected mainly the social context. Moreover, we found the ventral dentate gyrus to play a pivotal role in coordinating the context-specific rhythmic activity in the network.

neuroscience↗

bioRxiv2022

Early maturation and hyperexcitability is a shared phenotype of cortical neurons derived from different ASD-causing mutations

Autism Spectrum Disorder (ASD) is characterized mainly by social and sensory-motor abnormal and repetitive behavior patterns. Over hundreds of genes and thousands of genetic variants were reported to be highly penetrant and causative of ASD. Many of these mutations cause comorbidities such as epilepsy and intellectual disabilities (ID). In this study, we measured cortical neurons derived from induced pluripotent stem cells (iPSCs) of patients with four mutations in the genes GRIN2B, SHANK3, UBTF, as well as chromosomal duplication in the 7q11.23 region and compared them to neurons derived from a first-degree relative without the mutation. Using a whole-cell patch-clamp, we observed that the mutant cortical neurons demonstrated hyperexcitability and early maturation compared to control lines. These changes were characterized by increased sodium currents, increased amplitude and rate of excitatory postsynaptic currents (EPSCs), and more evoked action potentials in response to current stimulation in early-stage cell development (3-5 weeks post differentiation). These changes that appeared in all the different mutant lines, together with previously reported data, indicate that an early maturation and hyperexcitability may be a convergent phenotype of ASD cortical neurons.

neuroscience↗

bioRxiv2022

Current progress in understanding Schizophrenia using genomics and pluripotent stem cells: A Meta-analytical overview

Schizophrenia (SCZ) is a highly heritable, polygenic neuropsychiatric disease, which disables the patients as well as decreases their life expectancy and quality of life. Common and Rare variants studies on SCZ subjects have provided more than 100 genomic loci that hold importance in the context of SCZ pathophysiology. Transcriptomic studies from clinical samples have informed about the differentially expressed genes (DEGs) and non-coding RNAs in SCZ patients. Despite these advancements, no causative genes for SCZ were found and hence SCZ is difficult to recapitulate in animal models. In the last decade, induced Pluripotent Stem Cells (iPSCs)-based models have helped in understanding the neural phenotypes of SCZ by studying patient iPSC-derived 2D neuronal cultures and 3D brain organoids. Here, we have aimed to provide a simplistic overview of the current progress and advancements after synthesizing the enormous literature on SCZ genetics and SCZ iPSC-based models. Although further understanding of SCZ genetics and mechanisms using these technological advancements is required, the recent approaches have allowed to delineate important cellular mechanisms and biological pathways affected in SCZ.

neuroscience↗

bioRxiv2022

Monozygotic twins discordant for schizophrenia differ in maturation and synaptic transmission

Schizophrenia affects approximately 1% of the world population. Genetics, epigenetics, and environmental factors are known to play a role in this psychiatric disorder. While there is a high concordance in monozygotic twins, about half of twin pairs are discordant for schizophrenia. We characterized human-induced pluripotent stem cell (iPSC)-derived hippocampal neurons from two pairs of monozygotic twins that are discordant for a schizophrenia diagnosis. We compared the affected and the non-affected siblings and compared all of them to twin sets where none of the siblings suffered from schizophrenia. We found that the neurons derived from the schizophrenia patients were less arborized, were hypoexcitable with immature spike features, and exhibited a significant reduction in synaptic activity with dysregulation in synapse-related genes. Interestingly, the neurons derived from the co-twin siblings who did not have schizophrenia formed another distinct group that was different from the neurons in the group of the affected twin siblings but also different from the neurons in the group of the control twins. The neurons in the unaffected co-twin group were also less arborized than the neurons from controls but more arborized than those from affected siblings. Some of their spike features were immature (but less immature than neurons derived from the affected siblings). Importantly, their synaptic activity was not affected. Since schizophrenia is a genetically complex disorder, our twin study allows the measurement of neuronal phenotypes with a similar genetic background. The differences between the siblings may arise due to changes that occurred after the split of the egg into twins. Therefore, our study confirms that dysregulation of synaptic pathways, as well as changes in the rate of synaptic events, distinguishes between individuals affected with schizophrenia and unaffected individuals, even in those having a very similar genetic background.

neuroscience↗