Artificial Vision: The High-Frequency Electrical Stimulation of the Blind Mouse Retina Decay Spike Generation and Electrogenically Clamped Intracellular Ca2+ at Elevated Levels.
Bioengineering (Basel)
; 10(10)2023 Oct 16.
Article
em En
| MEDLINE
| ID: mdl-37892938
ABSTRACT
BACKGROUND:
The electrical stimulation (stim) of retinal neurons enables blind patients to experience limited artificial vision. A rapid response outage of the stimulated ganglion cells (GCs) allows for a low visual sensation rate. Hence, to elucidate the underlying mechanism, we investigated different stim parameters and the role of the neuromodulator calcium (Ca2+).METHODS:
Subretinal stim was applied on retinal explants (blind rd1 mouse) using multielectrode arrays (MEAs) or single metal electrodes, and the GC activity was recorded using Ca2+ imaging or MEA, respectively. Stim parameters, including voltage, phase polarity, and frequency, were investigated using specific blockers.RESULTS:
At lower stim frequencies (<5 Hz), GCs responded synaptically according to the stim pulses (stim biphasic, cathodic-first, -1.6/+1.5 V). In contrast, higher stim frequencies (≥5 Hz) also activated GCs directly and induced a rapid GC spike response outage (<500 ms, MEA recordings), while in Ca2+ imaging at the same frequencies, increased intracellular Ca2+ levels were observed.CONCLUSIONS:
Our study elucidated the mechanisms involved in stim-dependent GC spike response outage sustained high-frequency stim-induced spike outage, accompanied by electrogenically clamped intracellular Ca2+ levels at elevated levels. These findings will guide future studies optimizing stim paradigms for electrical implant applications for interfacing neurons.
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Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2023
Tipo de documento:
Article