Microstructural and electrophysiological properties of neural tissue are substantially influenced by the immediate extracellular environment wtihin the nervous system. These properties are also arguably the most clinically-relevant and sensitive measures of nerve health. However, the neurological architecture, physiology, and surrounding extracellular matrix are hard to mimic in vitro, and an increasing need for culture platforms that reproduce these complex features has led to the development of 3D cultures and microscale engineered tissues for functional assays. Using a dual hydrogel construct and explants from rat embryonic dorsal root ganglia, we present an in vitro platform for culturing spatially-controlled 3D neurite growth that supports both intracellular and extracellular electrophysiological recordings. Specifically, these 3D neural cultures in hydrogel exhibit both structural and functional characteristics that closely mimic those of sensory peripheral nervous tissue found in vivo. However, the 3D hydrogel constructs allow incorporation of other cell types, fabrication in any geometry, and simultaneous electrical stimulation and probing, providing a viable assay for systematic culture, manipulation, and testing of biomimetic neural growth in any mechanistic study necessitating physiologically-relevant readouts.
