Biology subjects

Landwehr, A.

Publications and source records attributed to Landwehr, A..

4 recordsLinked to original sources

bioRxiv2026

A Novel Open-Source CellProfiler Pipeline for Automated, User-Friendly Hierarchical and K-Means Clustering of Microglial Morphology

Microglia represent a highly dynamic and heterogeneous cell type that is critically implicated in states of health and pathology. Microglial morphological subgroups have been identified that correspond to functional characteristics determining health-related outcomes. The identification of states based on morphological characteristics will therefore provide invaluable insights into the microglia-specific functional mechanisms driving treatment effects. The application of clustering analyses enables the detection of groupings within samples reflecting differences in morphological features. Here we propose the application of three custom-created modules to be used within the open-source software CellProfiler. These modules enable the automated detection of clusters present within the sample of microglia, as well as the assessment of the abundance of these clusters across conditions. The application of the analysis is conducted in a highly user-friendly manner, with a user interface integrated into the pipeline, enabling the performance of the analysis with only minimal user input. The workflow thereby includes the conduction of an outlier assessment, followed by hierarchical clustering and k-means clustering and the generation of interactive graphs to determine the number of microglia states present in the sample. Bar plots displaying the abundance of the microglia states across conditions included in the sample will be created. This approach will facilitate faster and more comparable detection of microglial morphological clusters across studies.

cell biology↗

bioRxiv2026

Semi-Automated CellProfiler Pipelines for Robust Quantification of Microglial Density, Distribution and Morphology

The field of microglial research has evolved throughout the years. Microglia, the immune cells of the central nervous system, are recognized as highly heterogeneous and dynamic cells, known for modifying their structure and function based on the local context. Investigating microglial density, spatial distribution, and morphological states is important for uncovering their distinct functional states in health and pathology. However, quantifying these features accurately is often a methodological challenge. Fully automated computational approaches often fail to capture subtle biological nuances and complex structural variations. Also, the high diversity of image sets makes it difficult to maintain consistent reliability. In contrast, entirely manual quantification is labor-intensive and prone to observer bias. To bridge this gap, we propose a semi-automated framework using the open-source software CellProfiler. Our workflow is divided into two distinct pipelines designed to combine automation of batch analysis with targeted user oversight, allowing for manual intervention when necessary to ensure maximum accuracy. Both pipelines are capable of recognizing microglial soma and tracing their processes. In the density workflow, it automatically calculates cell density and provides spatial distribution measurements, such as closest-neighbor distance and spacing index. For morphological profiling, it yields extensive structural data, including area, perimeter, convex area, form factor, and various shape descriptors. Furthermore, we demonstrate how researchers can optimize the pipeline settings to accommodate varied image datasets and experimental conditions. We hope this open-source framework can standardize microglial density, distribution, and morphological analysis and reduce systematic bias, providing researchers with a robust tool to better characterize their heterogeneity.

cell biology↗

bioRxiv2026

The antipsychotic drug clozapine suppresses autoimmunity driving psychosis-like behavior in mice

Antipsychotic drugs are the first-line treatment for psychosis yet their mechanism of action remains poorly understood, largely due to the challenge to faithfully model psychosis preclinically. Here, we focus on the emerging concept that psychosis can be caused by brain autoimmunity and present a novel mouse model of anti-N-methyl-D-aspartate-receptor (anti-NMDAR) encephalitis, a condition that manifests with psychosis and autoanti-bodies against the NMDAR. We devised a new mRNA-based approach to immunize mice against the NMDAR. Immunized mice developed psychosis-like behaviors that were caused by anti-NMDAR autoantibodies leading to phagocytosis of NMDARs by brain microglia. The antipsychotic drug clozapine rescued psychosis-like behaviors and, remarkably, reduced anti-NMDAR autoantibody levels and antibody-mediated phagocytosis of NMDARs. The immunomodulatory effects of clozapine were confirmed in a mouse model of systemic lupus erythematosus. Our results demonstrate that clozapine suppresses autoimmunity driving psychosis-like behaviors, raising the possibility that immunomodulation contributes to antipsychotic drug action. HIGHLIGHTSO_LImRNA immunization against the NMDAR induces psychosis-like behavior in mice C_LIO_LIAnti-NMDAR autoantibodies are sufficient for psychosis-like behavior C_LIO_LIMicroglial phagocytosis of NMDARs mediates psychosis-like behavior induced by anti-NMDAR autoanti-bodies. C_LIO_LIClozapine reduces anti-NMDAR autoantibodies, microglial phagocytosis and psychosis-like behavior, consistent with immunomodulation as a potential mechanism of antipsychotic drug action. C_LI

neuroscience↗

bioRxiv2025

Adolescent stress impairs parvalbumin interneurons and their associated perineuronal nets: protective effects of microglia-modulating minocycline treatment

Adolescence is a critical period of brain maturation during which exposure to stress can lead to long-lasting behavioral and neurobiological alterations linked to increased vulnerability to psychiatric disorders. Here, we investigated whether minocycline, a tetracycline antibiotic that modulates microglial activity, could prevent or attenuate the long-term effects of adolescent stress on behavior, parvalbumin (PV)-expressing (+) interneurons (PVIs), perineuronal nets (PNNs), and microglia in adulthood. Male mice were exposed to a 10-day footshock stress protocol during adolescence (postnatal days 31-40) and treated with minocycline (30 mg/kg; i.p.) either during or after stress exposure. Behavioral assessments in adulthood revealed that adolescent stress impaired sociability, social memory, and object recognition memory, which were attenuated by minocycline treatment during or after adolescent stress exposure. Stress also reduced the number of PV+, PNN+, and PV+/PNN+ cells in the prefrontal cortex (PFC) and ventral hippocampus (vHip). These effects were prevented by minocycline administration at both time points. No significant long-lasting changes were observed in microglial number, density, or spatial distribution in either region. However, minocycline treatment modulated microglial morphology in a region- and timing-dependent manner, with increased microglial area observed in the PFC and subtle alterations in circularity in the vHip. These findings suggest that adolescent stress induces enduring impairments in PVIs and behavior, possibly through transient microglial intervention and PNN degradation. Minocycline treatment during or after stress was effective in preventing these changes, supporting its potential as a therapeutic strategy to mitigate the long-term consequences of adolescent stress and to reduce vulnerability to stress-related psychiatric disorders.

neuroscience↗