Biology subjects

Jenderny, S.

Publications and source records attributed to Jenderny, S..

3 recordsLinked to original sources

bioRxiv2024

Assembly of a functional neuronal circuit in embryos of an ancestral metazoan is influenced by environmental signals including the microbiome

Understanding how neural populations evolve to give rise to behavior is a major goal in neuroscience. However, the complexity of the nervous system in most invertebrates and vertebrates complicates the deciphering of underlying fundamental processes. Here, we explore the self-assembly of neural circuits in Hydra, an organism with a simple nervous system but no centralized information processing, to improve the understanding of nervous system evolution. The N4 neuronal circuit in embryos develops through activity-driven self-assembly, where neurons in distinct regions increase connectivity and synchronization. Gap junctions and vesicle-mediated communication between neuronal and non-neuronal cells drive rapid assembly, with the embryos prospective oral region exhibiting the highest neuronal density. An artificial electrical circuit-based model demonstrates dynamic increases in synchronization over time, along with predictions for selective dynamic adaptions of connections. Environmental factors, like temperature and an absent microbiome, modify neural architecture, suggesting the existence of a certain plasticity in neural development. We propose that these fundamental features originated in the last common bilaterian ancestor, supporting the hypothesis that the basic architecture of the nervous system is universal.

neuroscience↗

bioRxiv2024

A functional network model for body column neural connectivity in Hydra

Hydra is a non-senescent animal with a relatively small number of cell types and overall low structural complexity, but a surprisingly rich behavioral repertoire. The main drivers of Hydra s behavior are neurons that are arranged in two nerve nets comprising several distinct neuronal populations. Among these populations is the ectodermal nerve net N3 which is located throughout the animal. It has been shown that N3 is necessary and sufficient for the complex behavior of somersaulting and is also involved in Hydra feeding behavior. Despite being a behavioral jack-of-all-trades, there is insufficient knowledge on the coupling structure of neurons in N3, its connectome, and its role in activity propagation and function. We construct a model connectome for the part of N3 located on the body column. Using experimental data on the placement of neuronal somata and the spatial dimensions of the body column, we show that a generative network model combining non-random placement of neuronal somata and the preferred orientation of primary neurites yields good agreement with experimentally observed distributions of connection distances, connection angles, and the number of primary neurites per neuron. Having validated the N3 connectome model in this fashion, we place a simple excitable dynamical model on each node of the body column network and show that it generates directed, short-lived, fast propagating patterns of activity. In addition, by slightly changing the parameters of the dynamical model, the same structural network can also generate persistent activity. Finally, we use a neuromorphic circuit based on the Morris-Lecar model to show that the same structural connectome can, in addition to through-conductance with biologically plausible time scales, also host a dynamical pattern related to the complex behavioral pattern of somersaulting. We speculate that such different dynamical regimes act as dynamical substrates for the different functional roles of N3, allowing Hydra to exhibit behavioral complexity with a relatively simple nervous system that does not possess modules or hubs.

neuroscience↗

bioRxiv2024

Bio-inspired augmented reality: an interactive, digital twin of C. elegans

This work presents a digital twin of the nematode Caenorhabditis elegans (C. elegans), an organism whose biology has been extensively studied. The digital twin can emulate neuronal activity and the corresponding muscle activity, and performs basic locomotion movement. The underlying mathematical model of C. elegans can be realized directly as an electronic circuit and is additionally implemented as a ready-to-use simulation in software. We implemented the digital twin in augmented reality (AR) as a novel format that extends the content of a traditional paper with an interactive visualization in the real world. The figures in the paper are the anchor point for the AR that can be accessed by the readers via an open-source app, which is freely available for tablets, phones, and AR glasses. This enables immersive experiences of the three-dimensional visualization in the real world from a perspective chosen by the reader, supplementing the traditional, flat figure layout of the paper. For researchers, the digital twin further provides a useful tool that is highly relevant and versatile for future developments. At the same time, its manifold possibilities for scientific outreach also aim at making the topic more engaging for a broader audience.

bioengineering↗