Advantageous environment of micro-patterned, high-density complementary metal–oxide–semiconductor electrode array for spiral ganglion neurons cultured in vitro

Abstract

This study investigated micro-patterned, high-density complementary metal–oxide–semiconductor (CMOS) electrode array to be used as biologically permissive environment for organization, guidance and electrical stimulation of spiral ganglion neurons (SGN). SGNs extracted and isolated from cochleae of P5-P7 rat pups and adult guinea pigs were cultured 1, 4 and 7 days in vitro on glass coverslips (control) and CMOS electrode array. The cultures were analyzed visually and immunohistochemically for SGN presence, outgrowth, neurite alignment, neurite length, neurite asymmetry as well as the contact of a neuronal soma and neurites with the micro-electrodes. Our findings indicate that topographical environment of CMOS chip with micro-patterned pillars enhanced growth, survival, morphology, neural orientation and alignment of SGNs in vitro compared to control. Smaller spacing (0.8–1.6 µm) between protruding pillars on CMOS led SGNs to develop structured and guided neurites oriented along three topographical axes separated by 60°. We found morphological basis for positioning of the micro-electrodes on the chip that was appropriate for direct contact of SGNs with them. This configuration allowed CMOS electrode array to electrically stimulate the SGN whose responses were observed with live Fluo 4 calcium imaging.

Neuronal differentiation of dental pulp stem cells from human permanent and deciduous teeth following coculture with rat auditory brainstem slices

“…Particularly, the observed patterns of calcium intensity matched some previous studies of SGNs calcium imaging. The rapid and steady decline of the intensity was similar to the single pulse of electrical stimulation SGN (Radotić, Braeken, Drviš, Mattotti, & Kovačić, ). The calcium profile that showed peaks with slightly dropped during the elevation of the intensity was matched to veratridine‐induced SGN (Hegarty, Kay, & Green, ).…”

Recent advancements in cell-based models for auditory disorders

“…These developments, along with organ-on-a-chip and other models, have successfully cultured multiple cell lines in parallel. 79 , 92 It appears that many of the early challenges of generating inner ear organoids are being overcome, leading us closer to the mainstream use of these models in the elucidation of novel therapeutics and the pathophysiology of inner ear disease.…”

Guidelines for a Morphometric Analysis of Prokaryotic and Eukaryotic Cells by Scanning Electron Microscopy

“…Neurite number is defined as the number of neurites exiting a single cell body [ 76 ] ( Figure 3 A). In the case of branched cells, a typical descriptor is an average neurite length, defined as the sum of the lengths of all neurites in a single cell divided by the total number of neurites [ 75 , 77 , 78 ]. The measurement of neurite length, which affects networking and signal transmission, can be made by a manual tracing of the entire neurite from the base to its edge with the use of an image analysis software, for example ImageJ (NIH) ( Figure 3 B).…”