AUTHOR=Zeck Günther 

TITLE=Aberrant Activity in Degenerated Retinas Revealed by Electrical Imaging

JOURNAL=Frontiers in Cellular Neuroscience

VOLUME=10

YEAR=2016

URL=https://www.frontiersin.org/journals/cellular-neuroscience/articles/10.3389/fncel.2016.00025

DOI=10.3389/fncel.2016.00025

ISSN=1662-5102

ABSTRACT=<p>In this review, I present and discuss the current understanding of aberrant electrical activity found in the ganglion cell layer (GCL) of rod-degenerated (<italic>rd</italic>) mouse retinas. The reported electrophysiological properties revealed by electrical imaging using high-density microelectrode arrays can be subdivided between spiking activity originating from retinal ganglion cells (RGCs) and local field potentials (LFPs) reflecting strong trans-membrane currents within the GCL. RGCs in <italic>rd</italic> retinas show increased and rhythmic spiking compared to age-matched wild-type retinas. Fundamental spiking frequencies range from 5 to 15 Hz in various mouse models. The rhythmic RGC spiking is driven by a presynaptic network comprising AII amacrine and bipolar cells. In the healthy retina this rhythm-generating circuit is inhibited by photoreceptor input. A unique physiological feature of <italic>rd</italic> retinas is rhythmic LFP manifested as spatially-restricted low-frequency (5–15 Hz) voltage changes. Their spatiotemporal characterization revealed propagation and correlation with RGC spiking. LFPs rely on gap-junctional coupling and are shaped by glycinergic and by GABAergic transmission. The aberrant RGC spiking and LFPs provide a simple readout of the functionality of the remaining retinal circuitry which can be used in the development of improved vision restoration strategies.</p>