Hantak, M. | Search bioRxiv

bioRxiv2023

Implementation and testing of a biohybrid transitionmicroelectrode array for neural recording and modulation

Recent advances in microtissue engineered neural networks have opened avenues for the fabrication of biohybrid intracortical brain implants. To date, however, the experimental validation of these biohybrid implants has been restricted to singularly positioned electrodes, with the functionality confined to optical neuromodulation and neural recording. We present for the first time a biohybrid transition microelectrode array (TMEA) comprising a 4x4 matrix of biohybrid electrodes. These electrodes are expected to project axons into the brain, thereby establishing synaptic connections for electrical readout and excitation. Our device thus offers a promising pathway to leverage organic, endogenous materials in intracortical implants to enhance their biocompatibility as well as their functionality. In particular with respect to functionality, we assume that the spatiotemporal resolution of recorded neural signals may be significantly increased using this technology owing to the size ratios of these biohybrid microelectrodes compared to abiotic ones. Future investigations will therefore focus on the exploitation of the electrode density to further advance brain-computer interface technology.

neuroscience↗

bioRxiv2019

Methods for broad-scale plant phenology assessments using citizen scientists’ photographs

Broad-scale plant flowering phenology data has predominantly come from geographically and taxonomically restricted monitoring networks. However, platforms such as iNaturalist, where citizen scientists upload photographs and curate identifications, provide a promising new source of data. Here we develop a general set of best practices for scoring iNaturalist digital records supporting downstream re-use in phenology studies. We focus on a case study group, Yucca, because it has showy flowers and is well documented on iNaturalist. Additionally, drivers of Yucca phenology are not well-understood despite need for Yucca to synchronize flowering with obligate moth pollinators. Finally, evidence of anomalous flowering events have been recently reported, but the extent of those events is unknown. We use best-practices approach to annotate nearly 9,000 Yucca iNaturalist records, and compare the spatiotemporal coverage of this dataset with other broad-scale monitoring resources. Our findings demonstrate that iNaturalist provides unique phenology information, including delineation of extents of unusual flowering events. We also determine if unusual early flowering events impact later, typical flowering periods. Finally, we adapt a plant phenology global knowledge-store to integrate iNaturalist annotation results, supporting broadest reuse. Our approach has application to other plant groups, leveraging rapidly increasing data resources from iNaturalist to study phenology.

ecology↗