Biology subjects

Miranda, G.

Publications and source records attributed to Miranda, G..

4 recordsLinked to original sources

bioRxiv2026

Adapting Social Operant Paradigms to Measure Postpartum Maternal Motivation

Operant paradigms are powerful tools to quantify motivation and reward. Traditionally, operant conditioning research has been limited to food and drug reinforcers. Recent advances in commercially available operant equipment, however, allow for the quantification of social motivation. These operant assays are an improvement over commonly used social preference tasks, as they enable direct measurement of the effort and motivation driving social behavior. Based on a design by Venniro et al. (2020), the MedPC social operant boxes modify the traditional operant box setup for social interactions. The experimental rat can lever-press to raise a door for an interaction with a target rat behind a porous barrier. These social operant boxes have been widely adapted to test social behavior in adult and adolescent rodents and investigate how a range of conditions (e.g. stress, drug taking, etc.) affect social motivation. However, there is a gap in assessing maternal motivation for pups during the postpartum period, despite ample evidence that postpartum social behavior is highly relevant for offspring health outcomes. Here, we detail 3D-printed modifications to the standard Med PC social operant boxes to adapt the social target chamber to safely house neonatal pups. We have also developed testing protocols to assess motivation during the limited postpartum period. These data demonstrate that, with simple modifications to social operant chambers and testing protocols, the field can implement advanced behavioral approaches to directly assess maternal motivation.

animal behavior and cognition↗

bioRxiv2026

Early resource scarcity drives persistent transcriptional changes and vascular remodeling in the female prefrontal cortex

Early childhood poverty is an environmental risk factor for psychiatric and neurodegenerative disorders, yet the cellular mechanisms by which resource scarcity produces persistent brain vulnerability remain poorly understood. The medial prefrontal cortex (mPFC), which regulates executive function and motivated behavior, is sensitive to early environmental conditions. To identify mechanisms linking early resource scarcity to lasting mPFC dysfunction, we used the rat limited bedding and nesting (LBN) model, which recapitulates key features of poverty. Prior work shows LBN disrupts mPFC-mediated behaviors in adulthood, often in a sex-specific manner. Here, we used single-nucleus RNA sequencing (snRNAseq) to identify sex- and cell-type-specific transcriptional alterations in the adult mPFC following brief postnatal LBN exposure or control housing. LBN induced more differentially expressed genes (DEGs) across multiple pyramidal neuron clusters in females than in males. Unexpectedly, the largest transcriptional changes due to LBN occurred in vascular cells in females, whereas male vascular cells exhibited no DEGs. These female-specific vascular genes were enriched for alterations of transcriptional programs regulating angiogenesis and endothelial structure. This molecular profile was orthogonally validated with 3D vascular reconstruction, revealing LBN reduced vascular coverage in the adult female mPFC, driven by decreased vessel volume and shortened vessel length, while males were unaffected. Reduced vascular coverage may constrain metabolic support to this region. The postnatal period is a critical window for vascular maturation, and, taken together, these findings identify persistent, female-specific vascular alterations as a novel and previously unrecognized mechanism through which early resource scarcity may persistently affect brain function and vulnerability.

neuroscience↗

bioRxiv2024

A spatiotemporal atlas of human spermatogenesis based on single-cell transcriptomics and multiplex antibody imaging

Understanding how transcriptional programs are translated into functional protein landscapes within intact tissues remains a major challenge in biology. While single-cell RNA sequencing (scRNA-seq) has enabled high-resolution identification of cellular states, corresponding protein expression within its spatial context remains poorly resolved at scale. Here, we present a scalable framework that integrates scRNA-seq with multiplex immunohistochemistry (mIHC) and automated image analysis to achieve spatially resolved, single-cell-level protein mapping across human spermatogenesis. Using this approach, we quantified the expression of nearly 500 proteins across 12 discrete germ cell states within intact human testis tissue, generating a high-resolution spatiotemporal proteomic atlas. Comparative analysis of mRNA and protein expression revealed widespread temporal discordance, indicating that transcriptional state is not always predictive of protein abundance. Notably, we identify delayed translation of key regulators such as PIWIL4, whose protein expression peaks at later differentiation stages than its mRNA expression. Together, our results establish a generalizable strategy for proteome-wide spatial mapping of single-cell states and demonstrate the importance of integrating protein-level measurements to resolve cellular identity and function in complex tissues.

molecular biology↗

bioRxiv2023

Piezo regulates epithelial topology and promotes precision in organ size control

Mechanosensitive Piezo channels regulate cell division through calcium-mediated activation of ERK signaling or activate Rho signaling to mediate cell extrusion and cell death. However, systems-level functions of Piezo in regulating organogenesis remain poorly understood. Here, we demonstrate that Piezo controls epithelial cell topology to ensure precise organ growth through the integration of live imaging experiments with pharmacological and genetic perturbations and computational modeling. Notably, knockout or knockdown of Piezo led to bilateral asymmetry in wing phenotypes. While pharmacological activation of Piezo stimulated an increase in the frequency of spikes in cytosolic Ca2+, we discovered that Piezo overexpression counterintuitively reduces Ca2+ signaling dynamics. Knockdown of Piezo inhibited proliferation and decreased apoptosis, resulting in an overall increase in epithelial overcrowding. In contrast, either genetic overexpression or pharmacological activation of Piezo increased cell proliferation and cell removal through basal extrusion. Surprisingly, Piezo overexpression increased the hexagonality of cellular topology. To test whether Piezo regulates cell topology, we formulated computational simulations to investigate how expression levels of Piezo protein regulate cell proliferation and apoptosis through modulation of the cut-off tension required for Piezo channel activation. Quantitative analysis validated computational simulation predictions of how perturbations to Piezo impacted epithelial topology. Overall, our findings demonstrate that Piezo promotes robustness in regulating epithelial topology and is necessary for precise organ size control.

developmental biology↗