Biology subjects

Arroyo, D.

Publications and source records attributed to Arroyo, D..

4 recordsLinked to original sources

bioRxiv2025

Dissecting mammalian cortical circuit development at single-cell resolution using inducible barcoded rabies virus

Highly organized circuits of connected neurons enable diverse brain functions. Improper development of these circuits is associated with neurodevelopmental disorders, and understanding how circuits are formed is crucial for unraveling the mechanisms of these diseases. We currently have an incomplete picture of how specific brain circuits develop and how they are affected in disease, because we lack methods to study them at scale and with single-cell resolution. Monosynaptic rabies tracing is the gold standard method to study circuit architecture. However, it suffers from cellular toxicity, low throughput, lack of control over the timing of labeling, and the inability to access the molecular profiles of individual neurons. To address these issues, we developed an inducible barcoded rabies virus (ibRV) to enable temporal-controlled labeling of synaptic circuits followed by high-throughput single-cell genomics readout. ibRV allows for dissecting neuronal circuit changes over time at single-cell and spatial resolution. We applied ibRV to study the development of specific mouse cortical circuits during late prenatal and postnatal life using single-cell genomics and unbiased spatial transcriptomics as readouts. We characterized and quantified developmental connectivity patterns and molecular cascades that underlie their formation. Additionally, we constructed functional in silico circuit models that enable interrogation of circuit function and dysfunction at specific developmental stages. Our study provides novel tools for circuit analysis and can provide new insights into the mechanisms of mammalian brain development.

neuroscience↗

bioRxiv2025

Circuit-specific gene editing for precision modulation of neuronal activity with CRISPR-rabies virus

CRISPR gene editing has revolutionized our ability to study and manipulate specific genes, enabling novel insights into gene function and potential therapies for brain disorders. Recent advances in cell-type-specific regulatory elements and viral delivery systems have made precise in vivo gene editing possible. However, neurons with similar molecular profiles can belong to different circuits, complicating efforts to manipulate circuit function and behavior. To address this, we developed CRISPR-rabies virus (CRV), which leverages the trans-synaptic spread of rabies virus to enable gene editing within anatomically defined neural circuits. By pairing CRV with cell type-specific Cas9 expression, we achieved targeted gene modifications in specific circuits. We demonstrate that CRV can modulate sodium and potassium channel expression in parvalbumin interneurons, thereby effectively regulating synaptic transmission of pyramidal neurons in the CA3 region of the hippocampus. Its compatibility with 3'-capture single-cell RNA-seq allows simultaneous circuit perturbation and molecular profiling. In summary, CRV allows precise circuit-level gene modulation, providing a platform for studying gene function in neural circuits and developing novel gene therapies for brain disorders.

neuroscience↗

bioRxiv2024

Intranasal immunization with CPAF combined with cyclic-di-AMP induces a memory CD4 T cell response and reduces bacterial burden following intravaginal infection with Chlamydia muridarum

Chlamydia trachomatis (Ct) is the most common bacterial sexually transmitted infection globally, and a vaccine is urgently needed to stop transmission and disease. Chlamydial Protease Activity Factor (CPAF) is an immunoprevalent and immunodominant antigen for CD4 T cells and B cells, which makes it a strong vaccine candidate. Due to the tolerogenic nature of the female genital tract (FGT) and its lack of secondary lymphoid tissue, effective induction of protective cell-mediated immunity will likely require potent and safe mucosal adjuvants. To address this need, we produced CPAF in a cell-free protein synthesis platform and adjuvanted it with the TLR9-agonist CpG1826, STING (stimulator of interferon genes) agonist cyclic-di-AMP (CDA), and/or the squalene oil-in-water nanoemulsion, AddaS03. We determined that intranasal immunization with CPAF plus CDA was well tolerated in female mice, induced CD4 T cells that produced IL-17A or IFN{gamma}, significantly reduced bacterial shedding, and shortened the duration of infection in mice intravaginally challenged with Chlamydia muridarum. These data demonstrate the potential for CDA as a mucosal adjuvant for vaccines against Chlamydia genital tract infection.

immunology↗

bioRxiv2018

Robust dynamical invariants in sequential neural activity

By studying different sources of temporal variability in central pattern generator circuits, in this paper we unveil distinct aspects of the instantaneous balance between flexibility and robustness in sequential dynamics -a property that characterizes many systems that display neural rhythms. The level of irregularity and coordination was characterized using intrinsic time references and intervals in long recordings of the pyloric central pattern generator. The analysis demonstrated strong robustness of transient dynamics in keeping not only the activation sequences but also specific cycle-by-cycle temporal relationships in the form of dynamical invariants. The rich dynamics of neurons and connections balance flexibility and coordination to readily negotiate the interactions between neurons and produce the resultant rhythm. In particular, two dynamical invariants were identified between time intervals that build the sequence, existing even outside steady states. We suggest that invariant temporal sequence relationships could be present in other networks, including those related to brain rhythms, and underlie rhythm programming and functionality.

neuroscience↗