TY  - JOUR
A1  - Gerhardt, Matthias
A1  - Groeger, Gillian
A1  - MacCarthy, Niall
T1  - Monopolar vs. bipolar subretinal stimulation-An in vitro study
JF  - Journal of neuroscience methods
N2  - This study uses an in vitro rd10 mouse model to quantify and compare the ability of the monopolar and the (concentric) bipolar electrode configurations for subretinal stimulation. To allow for results which can be directly compared an identical region of the retina was stimulated due to the circumstance that the bipolar electrode configuration allows also for monopolar stimulation, if the concentric counter-electrode is set potential-free (floating). A ganglion cell, located centrally over the bipolar electrode configuration was selected to extracellularly record action potentials during stimulation. To analyse the recorded action potentials, we introduce a new method which combines the advantages of (a) singular value decomposition (SVD) for weighting similar modulation patterns with which the recorded action potentials are characterized and (b) multi curve fitting to identify a common threshold level, required to finally assemble a strength-duration relationship (SDR). By directly comparing the obtained SDR curves, we found that the efficiency of stimulation with the monopolar electrode configuration is significantly higher than with the bipolar electrode configuration. All obtained SDR curves were fitted using the Lapicque model to estimate the chronaxie times and the rheobase currents. Liquid inclusions, eventually separating the retina from the electrodes are discussed to be a major cause for low ganglion cell responses during stimulation with the bipolar electrode configuration.
KW  - SVD
KW  - Subretinal
KW  - Electrodes
KW  - Monopolar
KW  - Bipolar
KW  - Retina
KW  - Ganglion
KW  - Cells
Y1  - 2011
U6  - https://doi.org/10.1016/j.jneumeth.2011.04.017
SN  - 0165-0270
VL  - 199
IS  - 1
SP  - 26
EP  - 34
PB  - Elsevier
CY  - Amsterdam
ER  -