Biology subjects

Martinoia, S.

Publications and source records attributed to Martinoia, S..

3 recordsLinked to original sources

bioRxiv2026

Distinct effects of different metabolic stress models on human-derived neuronal networks

Different in vitro models are widely used as experimental platforms to assess neuronal responses to metabolic stress and test potential treatments for patients with ischemic stroke. Results of those studies depend on the stress models used, and the link between cell viability-based readouts and electrophysiological activity remains poorly explored. We investigated the neuronal network activity of human-derived neuronal networks generated from human induced pluripotent stem cells (hiPSCs) under three commonly used metabolic stress models: hypoxia alone, oxygen and glucose deprivation (OGD), and hypoxia combined with different concentrations of glutamate. We aim to clarify the differences between three commonly used in vitro models, including the relation between microscopic and electrophysiological readouts. These conditions produced distinct effects on neuronal network activity. Hypoxia alone induced a progressive decline in activity over time. In contrast, OGD triggered a biphasic response, characterized by an early increase in activity followed by a decline. High concentration glutamate exposure under hypoxia also altered network dynamics, inducing a triphasic pattern consisting of a rapid activity decrease, a transient increase, and a subsequent decline. Across all these pathological conditions, neuronal activity progressively declined and converged toward network failure after prolonged hypoxia. Following reoxygenation, recovery was limited and condition-dependent: hypoxia alone, OGD, and high glutamate conditions showed limited recovery. On the other hand, low glutamate concentration was associated with good recovery. Microscopic assessment revealed that cellular viability was differentially affected across conditions. OGD was associated with the highest levels of cell death, whereas glutamate exposure, particularly at high concentrations, led to a marked reduction in synaptic puncta despite partial preservation of cell viability. These findings highlight that commonly used in vitro ischemia models induce distinct neuronal responses and highlight the importance of integrating electrophysiological and structural analyses to better characterize metabolic stress in human neuronal networks better.

bioengineering↗

bioRxiv2026

Functional human neurospheroids recapitulate key features of cortical complexity

BackgroundThree-dimensional in vitro neuronal cultures have emerged as promising platforms for modelling human brain function and disease under controlled conditions. However, their ability to recapitulate in vivo-like complexity and rich dynamics remains underexplored. In this study, we developed and characterized neurospheroids derived from human induced pluripotent stem cells (hiPSCs) to investigate how key features -- three-dimensionality, cellular heterogeneity, and modular organization -- contribute to replicating brain-like network dynamics. MethodsWe engineered neurospheroids with varying excitatory/inhibitory ratios and assembled them into modular constructs (assembloids), evaluating their electrophysiological activity using high-density micro-electrode arrays. We assessed spontaneous and evoked activity through established metrics of dynamical richness and perturbational complexity. ResultsOur findings show that three-dimensionality and modularity significantly enhance the richness and complexity of network activity, approaching levels observed in vivo, while cellular heterogeneity contribute to functional aspects of the network, such as nuanced activity patterns, dynamical variability, and modular coordination. ConclusionsOur work highlights the critical role of spatial organization in reproducing brain-like activity and provide a foundation for future studies using patient-derived neurospheroids to model disease-specific dynamics.

bioengineering↗

bioRxiv2023

Human-derived cortical neurospheroids coupled to passive, high-density and 3D MEAs: a valid platform for functional tests

With the advent of human-induced pluripotent stem cells (hiPSCs) differentiation protocols, different methods to create in-vitro human-derived neuronal networks have been proposed. Although monolayer cultures represent a valid model, adding three-dimensionality would make them more representative of an in-vivo environment. Thus, human-derived neurospheroids and brain-organoids are becoming increasingly used for in-vitro disease modeling. Achieving control over the final cell composition and investigating the exhibited electrophysiological activity is still a challenge. Thence, platforms capable of measuring and characterizing the functional aspects of these samples are needed. Here, we propose a method to rapid generate neurospheroids of human origin with control over cell composition that can be used for functional investigations. We show a characterization of the electrophysiological activity exhibited by the neurospheroids by presenting for the first-time results from the main micro-electrodes arrays (MEAs) types available on the market (passive electrode, C-MOS electrodes, 3D electrodes). Neurospheroids grown in free culture and transferred on MEA exhibited functional activity that can be chemically and electrically modulated. Our results indicates that this model holds great potential for in-depth study of signal transmission to drug screening, disease modeling and offers a reproducible and stable platform for in-vitro functional testing.

bioengineering↗