A dataset of action potentials recorded from the L5 dorsal rootlet of rat using a multiple electrode array

Introduction: Precurved cochlear implant (CI) electrode arrays were developed in an attempt to improve the auditory outcome of cochlear implantation, which varies greatly. The recent CI532 (Cochlear Corp., Sydney, Australia) may offer further advantages as its electrode array is thinner than previous precurved CI electrode arrays. The aims here were to investigate 1-year postoperative speech recognition, intraoperative electrically evoked compound action potentials (ECAPs), and their possible relation in patients implanted with a CI532 or its predecessor CI512. Methods: A retrospective analysis of data from 63 patients subjected to cochlear implantation at the Karolinska University Hospital, Sweden, was performed. Speech recognition of the implanted ear was evaluated using phonemically balanced monosyllabic Swedish words at 65 dB SPL. ECAPs were evaluated using the intraoperative ECAP threshold across ≥8 electrodes generated by the automated neural response telemetry of the CI. Results: The median aided speech recognition score (SRS) 1 year after implantation was 52% (quartile 1 = 40%, quartile 3 = 60%, n = 63) and did not differ statistically significantly between patients with CI512 (n = 38) and CI532 (n = 25). The mean ECAP threshold was 188 CL (current level; SD = 15 CL, n = 54) intraoperatively and did not differ statistically significantly between patients with CI512 (n = 32) and CI532 (n = 22), but the threshold for each electrode varied more between patients with a CI512 (p < 0.0001). A higher mean ECAP threshold was associated with a worse SRS (Spearman’s ρ = –0.46, p = 0.0004, n = 54). The association remained among those with a CI512 (Spearman’s ρ = –0.62, p = 0.0001, n = 32) when stratified by CI electrode array. Conclusion: No statistically significant difference in speech recognition 1 year after cochlear implantation or in mean threshold of ECAP intraoperatively was found between patients with a CI512 and the more recent, slim CI532, but the ECAP thresholds varied more between those with a CI512. A statistically significant association between SRS and mean ECAP threshold was found, but stratified analysis suggests that the association may be true only for patients with a CI512.

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Skeletal muscles from which the propagation of motor unit action potentials is detectable with a surface electrode array

Electroencephalography and Clinical Neurophysiology ◽

10.1016/0013-4694(87)90005-8 ◽

1987 ◽

Vol 67 (5) ◽

pp. 421-427 ◽

Cited By ~ 62

Author(s):

Tadashi Masuda ◽

Tsugutake Sadoyama

Keyword(s):

Motor Unit ◽

Action Potentials ◽

Skeletal Muscles ◽

Electrode Array ◽

Surface Electrode ◽

Motor Unit Action Potentials ◽

Motor Unit Action ◽

Unit Action

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Functional maps of visual responses with a multiple-electrode array in macaque inferotemporal cortex

Neuroscience Research ◽

10.1016/j.neures.2007.06.985 ◽

2007 ◽

Vol 58 ◽

pp. S214

Author(s):

Manabu Tanifuji ◽

Naohisa Miyakawa ◽

David Blake ◽

Micheal Merzenich

Keyword(s):

Electrode Array ◽

Visual Responses ◽

Inferotemporal Cortex ◽

Multiple Electrode

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Creating Custom Neural Circuits on Multiple Electrode Arrays Utilizing Optical Tweezers for Precise Nerve Cell Placement

Methods and Protocols ◽

10.3390/mps3020044 ◽

2020 ◽

Vol 3 (2) ◽

pp. 44

Author(s):

Frank H. Kung ◽

Ellen Townes-Anderson

Keyword(s):

Optical Tweezers ◽

Neuronal Development ◽

Neural Circuits ◽

Electrode Array ◽

Bipolar Cells ◽

Electrode Arrays ◽

Cell Placement ◽

Multiple Electrode

Precise creation, maintenance, and monitoring of neuronal circuits would facilitate the investigation of subjects such as neuronal development or synaptic plasticity, or assist in the development of neuronal prosthetics. Here we present a method to precisely control the placement of multiple types of neuronal retinal cells onto a commercially available multiple electrode array (MEA), using custom-built optical tweezers. We prepared the MEAs by coating a portion of the MEA with a non-adhesive substrate (Poly (2-hydroxyethyl methacrylate)), and the electrodes with an adhesive cell growth substrate. We then dissociated the retina of adult tiger salamanders, plated them onto prepared MEAs, and utilized the optical tweezers to create retinal circuitry mimicking in vivo connections. In our hands, the optical tweezers moved ~75% of photoreceptors, bipolar cells, and multipolar cells, an average of ~2000 micrometers, at a speed of ~16 micrometers/second. These retinal circuits were maintained in vitro for seven days. We confirmed electrophysiological activity by stimulating the photoreceptors with the MEA and measuring their response with calcium imaging. In conclusion, we have developed a method of utilizing optical tweezers in conjunction with MEAs that allows for the design and maintenance of custom neural circuits for functional analysis.

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