Direct localised measurement of electrical resistivity profile in rat and embryonic chick retinas using a microprobe

Abstract We report an alternative technique to perform a direct and local measurement of electrical resistivities in a layered retinal tissue. Information on resistivity changes along the depth in a retina is important for modelling retinal stimulation by retinal prostheses. Existing techniques for resistivity-depth profiling have the drawbacks of a complicated experimental setup, a less localised resistivity probing and/or lower stability for measurements. We employed a flexible microprobe to measure local resistivity with bipolar impedance spectroscopy at various depths in isolated rat and chick embryo retinas for the first time. Small electrode spacing permitted high resolution measurements and the probe flexibility contributed to stable resistivity profiling. The resistivity was directly calculated based on the resistive part of the impedance measured with the Peak Resistance Frequency (PRF) methodology. The resistivity-depth profiles for both rat and chick embryo models are in accordance with previous mammalian and avian studies in literature. We demonstrate that the measured resistivity at each depth has its own PRF signature. Resistivity profiles obtained with our setup provide the basis for the construction of an electric model of the retina. This model can be used to predict variations in parameters related to retinal stimulation and especially in the design and optimisation of efficient retinal implants.

[1]  C. Karwoski,et al.  Current source-density analysis of light-evoked field potentials in rabbit retina , 1999, Visual Neuroscience.

[2]  R. W. Rodieck.  The vertebrate retina : principles of structure and function , 1973 .

[3]  C. Karwoski,et al.  Current source density (CSD) analysis of retinal field potentials. I. Methodological considerations and depth profiles. , 1994, Journal of neurophysiology.

[4]  D. Norren,et al.  Origin of the electroretinogram in the intact macaque eye—I Principal component analysis , 1985, Vision Research.

[5]  Sverre Grimnes,et al.  Bioimpedance and Bioelectricity Basics , 2000 .

[6]  Werner Kern,et al.  Handbook of Semiconductor Wafer Cleaning Technology: Science, Technology, and Applications , 1994 .

[7]  R. H. Steinberg,et al.  Proximal retinal contribution to the intraretinal 8-Hz pattern ERG of cat. , 1987, Journal of neurophysiology.

[8]  Warren M. Grill,et al.  Polarization of a Spherical Cell in a Nonuniform Extracellular Electric Field , 2005, Annals of Biomedical Engineering.

[9]  T. Ogden,et al.  Avian retina. II. An evaluation of retinal electrical anisotropy. , 1971, Journal of neurophysiology.

[10]  Philippe Renaud,et al.  In Vivo Electrical Impedance Spectroscopy of Tissue Reaction to Microelectrode Arrays , 2009, IEEE Transactions on Biomedical Engineering.

[11]  Huimin Wang,et al.  Analysis of retinal cell development in chick embryo by immunohistochemistry and in ovo electroporation techniques , 2010, BMC Developmental Biology.

[12]  Sverre Grimnes,et al.  History of Bioimpedance and Bioelectricity , 2008 .

[13]  C. Karwoski,et al.  Laminar profile of resistivity in frog retina. , 1985, Journal of neurophysiology.

[14]  Markus Zahn,et al.  Electromagnetic Field Theory: A Problem Solving Approach , 2003 .

[15]  P. Renaud,et al.  Flexible polyimide probes with microelectrodes and embedded microfluidic channels for simultaneous drug delivery and multi-channel monitoring of bioelectric activity. , 2004, Biosensors & bioelectronics.

[16]  E. McAdams,et al.  The linear and non-linear electrical properties of the electrode-electrolyte interface , 1995 .

[17]  W. A. Hagins,et al.  Dark current and photocurrent in retinal rods. , 1970, Biophysical journal.

[18]  F. J. Livesey,et al.  Vertebrate neural cell-fate determination: Lessons from the retina , 2001, Nature Reviews Neuroscience.

[19]  D. Norren,et al.  Origin of the electroretinogram in the intact macaque eye—II Current source-density analysis , 1985, Vision Research.

[20]  R Salvador,et al.  Tissue heterogeneity as a mechanism for localized neural stimulation by applied electric fields , 2007, Physics in medicine and biology.

[21]  A. Cideciyan,et al.  Relation of optical coherence tomography to microanatomy in normal and rd chickens. , 1998, Investigative ophthalmology & visual science.

[22]  P. Jacobs,et al.  Design optimisation of planar electrolytic conductivity sensors , 2006, Medical and Biological Engineering and Computing.

[23]  James Weiland,et al.  Artificial vision: needs, functioning, and testing of a retinal electronic prosthesis. , 2009, Progress in brain research.

[24]  Kenneth S. Cole,et al.  PERMEABILITY AND IMPERMEABILITY OF CELL MEMBRANES FOR IONS , 1940 .

[25]  S. Sadda,et al.  Retinal transplants evaluated by optical coherence tomography in photoreceptor degenerate rats , 2006, Journal of Neuroscience Methods.

[26]  C. Karwoski,et al.  Current-source density analysis of the electroretinogram of the frog: methodological issues and origin of components. , 1996, Journal of the Optical Society of America. A, Optics, image science, and vision.