Screening Transgenic Mouse Models of Human Eye Diseases with CMOS High-Density Microelectrode Arrays
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1
ETH Zurich, Department of Biosystems Science and Engineering, Switzerland
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2
Aarhus University, Department of Biomedicine, Denmark
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3
Friedrich Miescher Institute for Biomedical Research, Neural Circuit Laboratories, Switzerland
Motivation
We aim to correlate the role of genes involved in eye/vision diseases with retinal physiology, and to find accurate functional biomarkers of human diseases.
Direction-selective ganglion cells are a class of retinal neuron that respond asymmetrically to motion (Barlow and Hill 1963). We found that mutations in congenital nystagmus FMRD7 gene selectively abolishes horizontal, but not vertical, direction selectivity in the mammalian retina.
Material and Methods
Animals: Wild type mice (C57BL/6) were obtained from Charles River. FRMD7tm mice refer to the homozygous female or hemizygous male Frmd7tm1a(KOMP)Wtsi mice, which were obtained from the Knockout Mouse Project (KOMP) Repository. Retina preparation: Light-adapted mice were used for recordings. Retinas were isolated under dim red light (FGL610, Thorlabs) in Ringer’s medium (in mM: 110 NaCl, 2.5 KCl, 1 CaCl2, 1.6 MgCl2, 10 d-glucose, 22 NaHCO3) bubbled with 5% CO2 , 95% O2.To secure the retina on the microelectrode array, a permeable membrane (polyester, 10 µm thickness, 0.4 µm pore size) was lightly pressed against the tissue the retina was kept at 35°C and was continuously superfused with Ringer’s medium bubbled with 5% CO2, 95% O2. MEA recording and spike sorting: CMOS-based microelectrode arrays with 26,400 platinum electrodes over an area of 3.85×2.1 mm and 1,024 readout channels and a center-to-center electrode distance of 17.5 µm were used (Muller et al. 2015). For spike sorting we used a fully automatic two-stage procedure that first identified spike templates for each neuron (Marre et al. 2012; Prentice et al. 2011) and then classified each spike using template matching (Franke et al. 2015).
Results
We recorded the spiking activity of retinal ganglion cells in wild type and FRMD7tm mice using microelectrode arrays CMOS-based microelectrode arrays (Fig. 1A). The retina was stimulated with light flashes and bars moving in different directions and at different velocities. Retinas of
FRMD7tm mice responded well to both light flashes and slow and fast motions. In wild-type retinas, we recorded direction-selective responses along both the horizontal and the vertical axes. Strikingly, in FRMD7tm. mice, the fraction of (temporal or nasal) horizontal motion-preferring DS cells decreased by more than 90% compared to wild-type mice (Fig. 1B). Nevertheless, in FRMD7tm mice, the number of vertical motion-preferring direction-selective cells relative to all recorded ganglion cells remained similar to wild-type. Thus, the loss of FRMD7 leads to the specific loss of horizontal direction-selective responses in the retina.
Discussion / Conclusion
We found that FRMD7, a gene responsible for 70% of cases of idiopathic congenital nystagmus in humans, is required in the mouse retina to establish horizontal direction selectivity. CMOS-based high-density microelectrode arrays are a valuable tool (1) for screening mouse models of human diseases, (2) for characterizing accurately a biosample electrophysiological output and (3) for finding biomarkers with clinical relevance.
References:
Barlow HB, and Hill RM. Selective sensitivity to direction of movement in ganglion cells of the rabbit retina. Science 139: 412-414, 1963.
Franke F, Quian Quiroga R, Hierlemann A, and Obermayer K. Bayes optimal template matching for spike sorting - combining fisher discriminant analysis with optimal filtering. Journal of computational neuroscience 38: 439-459, 2015.
Marre O, Amodei D, Deshmukh N, Sadeghi K, Soo F, Holy TE, and Berry MJ, 2nd. Mapping a complete neural population in the retina. J Neurosci 32: 14859-14873, 2012.
Muller J, Ballini M, Livi P, Chen Y, Radivojevic M, Shadmani A, Viswam V, Jones IL, Fiscella M, Diggelmann R, Stettler A, Frey U, Bakkum DJ, and Hierlemann A. High-resolution CMOS MEA platform to study neurons at subcellular, cellular, and network levels. Lab on a chip 15: 2767-2780, 2015.
Prentice JS, Homann J, Simmons KD, Tkacik G, Balasubramanian V, and Nelson PC. Fast, scalable, Bayesian spike identification for multi-electrode arrays. PloS one 6: e19884, 2011.
Figure Legends
(A), Chip micrograph (top) and close-up view of the electrode array (bottom).
(B), Top, polar plots showing the preferred directions (direction of arrow) and direction-selectivity index (length of an arrow) of individual direction-selective retinal ganglion cells in WT and FRMD7tm retinas (DSI> 0.5, each recorded direction-selective retinal ganglion cell is represented by an arrow). The color code shows the different preferred directions (green = superior, blue = nasal, purple = inferior and orange = temporal). Middle, Raster plots showing the spike responses (each black line is a spike) of example DS cells in WT and FRMD7tm retinas in response to motion in eight different directions, indicated by the arrows at the bottom of the plot. Bottom, Polar plots of the normalized mean spike numbers of cells shown in middle panes. The preferred direction and DSI of each cell are shown by the direction and length of the corresponding (color-coded) arrow.
Acknowledgements
Financial support through the ERC Advanced Grant 267351 “NeuroCMOS” and the Swiss National Science Foundation Sinergia Project CRSII3_141801, as well as individual support for R. Diggelmann through a Swiss SystemsX IPhD grant are acknowledged
Keywords:
Disease,
Retina,
screening,
FRMD7,
HD-MEA
Conference:
MEA Meeting 2016 |
10th International Meeting on Substrate-Integrated Electrode Arrays, Reutlingen, Germany, 28 Jun - 1 Jul, 2016.
Presentation Type:
Poster Presentation
Topic:
MEA Meeting 2016
Citation:
Fiscella
M,
Yonehara
K,
Drinnenberg
A,
Franke
F,
Müller
J,
Roska
B and
Hierlemann
A
(2016). Screening Transgenic Mouse Models of Human Eye Diseases with CMOS High-Density Microelectrode Arrays.
Front. Neurosci.
Conference Abstract:
MEA Meeting 2016 |
10th International Meeting on Substrate-Integrated Electrode Arrays.
doi: 10.3389/conf.fnins.2016.93.00091
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Received:
22 Jun 2016;
Published Online:
24 Jun 2016.
*
Correspondence:
Dr. Andreas Hierlemann, ETH Zurich, Department of Biosystems Science and Engineering, Basel, Switzerland, andreas.hierlemann@bsse.ethz.ch