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Ronnenberg, A.

Publications and source records attributed to Ronnenberg, A..

4 recordsLinked to original sources

Transcriptional dynamics of the oligodendrocyte lineageand its regulation by the brain erythropoietin system

Oligodendrocytes differentiate from oligodendrocyte progenitor cells (OPC) in early postnatal development, but some oligodendrogenesis is maintained throughout adulthood, where oligodendrocyte lineage dynamics may contribute to neuroplasticity, adaptive myelination, and myelin repair. Here, we studied the effect of erythropoietin (EPO) and its receptor (EPOR) on oligodendrocyte lineage dynamics employing murine hippocampus and its myelinated fibers as model region. Using multiple stage-specific markers and single-nuclei-RNA-seq data, we find that EPO stimulates all oligodendroglial lineage cells directly, driving differentiation/maturation. Differential gene expression analysis reveals multiple EPO-regulated mRNAs, including downregulated transcripts for GABA-A receptors, fitting the known inhibition of oligodendrocyte maturation by GABA. Importantly, analogous oligodendrocyte responses are seen when endogenous EPO expression in brain is stimulated by hypoxia. Mice lacking EPOR from mature oligodendrocytes show subtle deficiencies of adult myelination in hippocampal fimbria and mild working memory deficits. These gain- and loss-of-function experiments may further suggest EPO as clinically safe treatment for remyelination therapies.

neuroscience↗

Erythropoietin alleviates intellectual disability and autism-like behavior of mice caused by Zbtb20 haploinsufficiency, a construct-valid model of Primrose syndrome

Among the known genetic causes of syndromic autism spectrum disorders (ASD) are transcription factor deficiencies. In this regard, haploinsufficiency of the zinc finger and broad complex, tramtrack, bric and brac domain-containing protein 20 (ZBTB20) leads to a prototypical clinical picture, referred to as Primrose syndrome, comprising severe ASD symptoms together with intellectual disability. Here, we present a comprehensive behavioral and phenotypical characterization of Zbtb20+/- mice, a construct valid model of this thus far untreatable human condition. Zbtb20+/- mice exhibit diminished sociability, reduced vocalization, distinct repetitive behaviors, impaired cognitive flexibility, hyperactivity and hypoalgesia. Magnetic resonance imaging reveals increased volumes of hippocampus, cerebellum, brain matter, and whole brain, confirmed by postmortem brain weight measurements. Due to our previous observation of enhanced ZBTB20 expression in CA1 pyramidal neurons upon recombinant human erythropoietin (rhEPO) injections, we anticipated a mitigating effect through rhEPO treatment of Zbtb20 deficiency/Primrose syndrome. Indeed, after three weeks of alternate-day rhEPO injections, a remarkable improvement in the behavioral phenotype was observed. Our results highlight rhEPO as a first promising treatment for Primrose syndrome.

neuroscience↗

IntelliR: A comprehensive and standardized pipeline for automated profiling of higher cognition in mice

In the rapidly evolving field of rodent behavior research, observer-independent methods facilitate data collection within a social, stress-reduced, and thus more natural environment. A prevalent system in this research area is the IntelliCage, which empowers experimenters to design individual tasks and higher cognitive challenges for mice, driven by their motivation to access reward. The extensive amount and diversity of data provided by the IntelliCage system explains the growing demand for automated analysis among users. Here, we introduce IntelliR, a standardized pipeline for analyzing raw data generated by the IntelliCage software, as well as novel parameters including the cognition index, which enables comparison of performance across various challenges. With IntelliR, we provide the tools to implement and automatically analyze 3 challenges that we designed, encompassing spatial, episodic-like, and working memory with their respective reversal tests. Using results from 3 independent control cohorts of adult female wildtype mice, we demonstrate their ability to comprehend and learn the tasks, thereby improving their proficiency over time. To validate the sensitivity of our approach for detecting cognitive impairment, we used adult female NexCreERT2xRosa26-eGFP-DTA mice after tamoxifen induced diphtheria toxin-mediated ablation of pyramidal neurons in cortex and hippocampus. We observed deterioration in learning capabilities and cognition index across several tests. IntelliR can be readily integrated into and adapted for individual research, thereby improving time management and reproducibility of data analysis. HIGHLIGHTSO_LIIntelliR is a standardized pipeline for analyzing raw data of IntelliCage software. C_LIO_LIDomains include spatial, episodic-like, and working memory with reversals. C_LIO_LIWT mice (3 cohorts) comprehend, learn and improve proficiency over time. C_LIO_LICognition index permits comparison of performance across cognitive domains. C_LIO_LIMice with ablation of pyramidal neurons decline mainly in working memory. C_LI

animal behavior and cognition↗

Isolated catatonia-like executive dysfunction in micewith forebrain-specific loss of myelin integrity

A key feature of advanced brain aging includes structural defects of intracortical myelin that are associated with secondary neuroinflammation. A similar pathology is seen in specific myelin mutant mice that model advanced brain aging and exhibit a range of behavioral abnormalities. However, the cognitive assessment of these mutants is problematic because myelin-dependent motor-sensory functions are required for quantitative behavioral readouts. To better understand the role of cortical myelin integrity for higher brain functions, we generated mice lacking Plp1, encoding the major integral myelin membrane protein, selectively in ventricular zone stem cells of the mouse forebrain. In contrast to conventional Plp1 null mutants, subtle myelin defects were restricted to the cortex, hippocampus and underlying callosal tracts. Moreover, forebrain-specific Plp1 mutants exhibited no defect of basic motor-sensory performance at any age tested. Surprisingly, several behavioral alterations reported for conventional Plp1 null mice (Gould et al., 2018) were absent and even social interactions appeared normal. However, with novel behavioral paradigms, we determined catatonia-like symptoms and isolated executive dysfunction in both genders. This suggests that loss of myelin integrity has an impact on cortical connectivity and underlies specific defects of executive function. These observations are likewise relevant for human neuropsychiatric conditions and other myelin-related diseases.

neuroscience↗