Spatiotemporal analysis of 3D human iPSC-derived neural networks using a 3D multi-electrode array

Area of Science:

• Neuroscience
• Biotechnology
• Bioengineering

Background:

• Three-dimensional (3D) neural tissues like organoids and spheroids show promise for modeling brain activity.
• Current electrophysiology techniques struggle to assess functional activity deep within 3D neural tissues.
• Next-generation 3D multi-electrode arrays (MEAs) require advanced computational tools for Z-dimension analysis.

Purpose of the Study:

• To introduce a novel computational analytical pipeline for analyzing 3D neural network activity.
• To assess the development and maturation of neural activity within different Z-axis cross-sections of 3D tissues.
• To investigate region-specific synaptic transmission in engineered 3D neural tissues.

Main Methods:

• Utilized a "bottom-up" 3D MEA integrated with a 3D hydrogel-based tissue of human iPSC-derived neurons and astrocytes.
• Recorded neural activity over ~6.5 weeks, analyzing spiking and bursting activity across vertical electrode positions.
• Applied synchrony analysis and postsynaptic receptor antagonists (bicuculline, AP-5, CNQX) to determine synaptic transmission.

Main Results:

• Characterized the development and maturation of 3D neural activity across Z-axis cross-sections.
• Identified network activity within and between cross-sections using synchrony analysis.
• Demonstrated region-specific preferences for GABA and/or glutamate synaptic transmission, indicating varied network composition.

Conclusions:

• The developed computational pipeline enables functional analysis of entire 3D reconstructed neural tissues.
• This tool is crucial for interpreting network activity in engineered 3D neural models.
• Provides a better understanding of the functional dynamics within modeled organ tissues.