Biology subjects

Biglari, N.

Publications and source records attributed to Biglari, N..

3 recordsLinked to original sources

bioRxiv2026

Wireless Magnetomechanical Stimulation of Targeted Vagal Gut-Brain Circuits

Causal manipulation of gut-brain neural circuits empowers studies of metabolism and interoception. However, the anatomy and cytoarchitecture of peripheral ganglia relaying gut-brain circuits pose challenges to deployment of optical or electrical stimulation probes. To enable implant-free, cell-type specific, and temporally precise control of defined gut-brain pathways, we develop a neuromodulation platform based on magnetic nanodiscs (MNDs) targeted to peripheral neurons via genetically delivered anchoring moieties. The anchored MNDs selectively transduce externally applied weak magnetic fields to mechanical torque, thereby activating endogenous mechanosensitive pathways in specified cell types with sub-second latency. When targeted to nodose ganglia neurons expressing oxytocin or glucagon-like peptide 1 receptors, MND-mediated stimulation enables robust and reversible activation of gut-brain signaling, which engages hindbrain satiety circuits and regulates feeding behavior. These findings establish MND-mediated stimulation as a genetically targetable, implant-free strategy for modulating gut-brain neural circuits and highlight its potential in studies of brain-body physiology and bioelectronic medicines.

bioengineering↗

bioRxiv2023

Projectome-defined subtypes and modular intra-hypothalamic subnetworks of peptidergic neurons

The hypothalamus plays a vital role in coordinating essential neuroendocrine, autonomic, and somatomotor responses for survival and reproduction. While previous studies have explored population-level projections of hypothalamic neurons, the specific innervation patterns of individual hypothalamic axons remain unclear. To understand the organization of hypothalamic axon projections, we conducted a comprehensive reconstruction of single-cell projectomes from 7,180 mouse hypothalamic neurons expressing specific neuropeptides. Our analysis identified 31 distinct subtypes based on projectome-defined characteristics, with many exhibiting long-range axon collateral projections to multiple brain regions. Notably, these subtypes selectively targeted specific subdomains within downstream areas, either unilaterally or bilaterally. Furthermore, we observed that individual peptidergic neuronal types encompassed multiple projectome-defined subtypes, explaining their diverse functional roles. Additionally, by examining intra-hypothalamic axon projections, we uncovered six modular subnetworks characterized by enriched intramodular connections and distinct preferences for downstream targets. This modular organization of the intra-hypothalamic network likely contributes to the coordinated organization of hypothalamic outputs. In summary, our comprehensive projectome analysis reveals the organizational principles governing hypothalamic axon projections, providing a framework for understanding the neural circuit mechanisms underlying the diverse and coordinated functions of the hypothalamus.

neuroscience↗

bioRxiv2019

Rapid, selective and single cell electrical detection of antibiotic resistant bacteria

The rapid increase in antibiotic resistant pathogenic bacteria has become a global threat, which besides the development of new drugs, requires rapid, cheap, scalable, and accurate diagnostics. Label free biosensors relying on electrochemical, mechanical, and mass based detection of whole bacterial cells have attempted to meet these requirements. However, the trade-off between selectivity and sensitivity of such sensors remains a key challenge. In particular, point-of-care diagnostics that are able to reduce and/or prevent unneeded antibiotic prescriptions require highly specific probes with sensitive and accurate transducers that can be miniaturized and multiplexed, and that are easy to operate and cheap. Towards achieving this goal, we present a number of advances in the use of graphene field effect transistors (G-FET) including the first use of peptide probes to electrically detect antibiotic resistant bacteria in a highly specific manner. In addition, we dramatically reduce the needed concentration for detection by employing dielectrophoresis for the first time in a G-FET, allowing us to monitor changes in the Dirac point due to individual bacterial cells. Specifically, we realized rapid binding of bacterial cells to a G-FET by electrical field guiding to the device to realize an overall 3 order of magnitude decrease in cell-concentration enabling a single-cell detection limit, and 9-fold reduction in needed time to 5 minutes. Utilizing our new biosensor and procedures, we demonstrate the first selective, electrical detection of the pathogenic bacterial species Staphylococcus aureus and antibiotic resistant Acinetobacter baumannii on a single platform.

microbiology↗