Biology subjects

Buck, F.

Publications and source records attributed to Buck, F..

4 recordsLinked to original sources

bioRxiv2026

In vitro programming and pseudounipolarization of human iPSC-derived sensory neurons

Ectopic expression of NGN1, BRN3A and ISLET1 (NBI) from a safe harbor locus in induced pluripotent stem cells (iPSCs) yielded robust differentiation into functional sensory neurons (iNBI-SNs) within seven days. Single nucleus transcriptomics identified peripheral sensory neuron profiles of nociceptors and mechanoreceptors. Electrophysiological studies showed that more than 98 % of iNBI-SNs display TTX-resistant sodium currents and that they establish functional connections to excitatory CNS neurons. iNBI-SNs derived from patients with inherited erythromelalgia, a pain disorder associated with gain-of-function mutations in the Nav1.7 sodium channel showed pathologically increased firing rates which could be partially rescued with a Nav1.7 inhibitor. Notably, iNBI-SNs acquire a characteristic pseudounipolar morphology upon co-culture with embryonic rodent DRG cells. Taken together, NBI-based forward programming of iPSCs represents a robust approach for the generation of human sensory neurons suitable for developmental, disease- and therapy-related studies.

neuroscience↗

bioRxiv2026

Overcoming oxygen impermeability in PDMS-free organ-on-a-chip microfluidics with nanoporous thermoplastic

Oxygen availability is a critical yet all-too-often overlooked variable in organ-on-a-chip (OoC) systems. PDMS-based microfluidics remain the most common approach to facilitating oxygen equilibration with the incubator environment, but the materials tendency to ad- and absorb small hydrophobic molecules can pose significant concerns for pharmacological and toxicological studies. Yet there remains a lack of alternative gas-exchange materials feasible for OoC integration, even as the use of thermoplastic microfluidics in particular has otherwise proliferated. Here, we present commercially available track-etched nanoporous polycarbonate (50 nm pores, 1.18% porosity, [~]0.1 {euro}/cm2) as a practical alternative to polydimethylsiloxane (PDMS) for gas exchange in OoC. We show that nanoporous polycarbonate provides a thermoplastic material with an oxygen permeability of 3290 {+/-} 240 fs mol / kg, over an order of magnitude higher than PDMS. We demonstrate integration into existing lamination-based thermoplastic microfluidic fabrication workflows with sustained leak-free operation well above physiologically relevant pressures. We find that nanoporous polycarbonate does not compromise cell viability, but that high water vapor permeance necessitates a high-humidity environment around the device - though thickness-normalized water vapor permeability is notably similar to PDMS. We validate the OoC application with Caco-2 intestinal epithelial cells by monitoring oxygen levels during the critical cell attachment phase, with nanoporous polycarbonate allowing for maintenance of stable oxygen tension, in stark contrast to severe hypoxia in nonporous controls within 30 minutes. We further show that this uncontrolled hypoxia correlates with a time-delayed increase in cellular hypoxia inducible factor-1 reporter expression. Overall, our findings position nanoporous polycarbonate as a low-cost, mechanically robust, and fabrication-friendly alternative that can bring controlled oxygen availability to PDMS-free microfluidics and OoC.

bioengineering↗

bioRxiv2025

FERAL: A Video-Understanding System for Direct Video-to-Behavior Mapping

Quantifying animal behavior often requires segmenting continuous actions into discrete, interpretable states, yet most automated pipelines infer actions from keypoint dynamics and are limited by keypoint tracking quality. Here we present FERAL (Feature Extraction for Recognition of Animal Locomotion), a supervised video-understanding toolkit that maps raw video directly to frame-level behavioral labels, bypassing the keypoint-extraction and pose-classification stages of conventional pipelines. Across benchmarks, FERAL matches or exceeds state-of-the-art pose- and video-based baselines. On the CalMS21 mouse social-interaction benchmark, it exceeds Googles VideoPrism using only a quarter of the training data. FERAL generalizes across species (apes, zebras, mice, ants, flies, and nematodes), recording conditions, and levels of organization, from single animals to social interactions and colony-scale collective behavior. Released as a user-friendly, open-source package, it integrates with existing analysis pipelines. By enabling scalable, species-agnostic behavioral quantification directly from raw video, FERAL broadens the experimental paradigms available for studying animal behavior.

animal behavior and cognition↗

bioRxiv2019

Representation of Visual Landmarks in Retrosplenial Cortex

The process by which visual information is incorporated into the brains spatial framework to represent landmarks is poorly understood. Studies in humans and rodents suggest that retrosplenial cortex (RSC) plays a key role in these computations. We developed an RSC-dependent behavioral task in which head-fixed mice learned the spatial relationship between visual landmark cues and hidden reward locations. Two-photon imaging revealed that these cues served as dominant reference points for most task-active neurons and anchored the spatial code in RSC. Presenting the same environment but decoupled from mouse behavior degraded encoding fidelity. Analyzing visual and motor responses showed that landmark codes were the result of supralinear integration. Surprisingly, V1 axons recorded in RSC showed similar receptive fields. However, they were less modulated by task engagement, indicating that landmark representations in RSC are the result of local computations. Our data provide cellular- and network-level insight into how RSC represents landmarks.

neuroscience↗