“Descending Enkephalinergic neurons in Barrington’s nucleus gate sex-biased control of micturition”

Barrington’s nucleus (Bar) is a brainstem hub essential for lower urinary tract (LUT) function, yet the molecular identity and functional specialization of its neuronal subtypes remain poorly defined. Here, we construct a single-nucleus transcriptional atlas of the murine Bar and identify an excitatory Penk-expressing population (Bar-Penk) critical for LUT regulation. Bar-Penk neurons are selectively active during voiding, when the external urethral sphincter (EUS) relaxes, and their optogenetic activation elicits time-locked suppression of EUS activity.

Chemogenetic activation of these neurons induces a sex-specific, aberrant pattern of micturition, whereas targeted ablation impairs voluntary marking behavior in response to female cues. We observe multiple regions involved in visceromotor regulation and behavioral state control that project to Bar-Penk neurons, supporting their role as integrators of internal state and environmental context that drive urinary output. These findings provide new insights into the brainstem circuits that shape reflexive and voluntary micturition and highlight how discrete neuronal subtypes contribute to sexually dimorphic regulation of LUT function.

Christopher Jacobs, Harini Srinivasan, and the Functional Genomics and Bioinformatics Core at Beth Israel Deaconess Medical Center (BIDMC) for their assistance with snRNA-seq analysis; Dr. Da-qing Wang and the BIDMC Transgenic Core Facility for support in generating transgenic mouse lines; Dr. Clif Saper’s Lab for the generous use of shared confocal equipment, as well as BIDMC Confocal Imaging Core and Neurobiology Imaging Facility at Harvard Medical School for imaging resources.

We thank the BIDMC Statistical Support Core for guidance with data analysis, and Dr. Mark Zeidel and members of the lab for helpful feedback and support throughout the project. This work was supported by NIH grants NIDDK P20-DK119789 and R01-DK113030 (to Mark L.

Zeidel, Beth Israel Deaconess Medical Center) and R01-DK125708 (to A.M.J.V.). Division of Nephrology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA Nataliya Klymko, Andrea M. Sartori, Mihoko Leon, Cassandra N.

Seifert, Richard Lee, John C. Verstegen University of Maryland School of Medicine, Baltimore, MD, USA The authors declare no competing interests. Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.