Variability in the firing of retinal ganglion cells of goldfish: A review

The isolated retina of the goldfish has proven a valuable resource for studying the variability of firing of retinal ganglion cells. Three major areas of study are considered here: the variability of maintained discharges, the correlated firing of neighboring ganglion cells, and the variability of responses to light. The sources of variability, its relationship to retinal processing, and its possible functional role in perception are examined through these three aspects of variability. The results are related to similar studies in mammals (mainly cats). This retrospective is biased toward my studies over 30 years.

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Properties of stimulus-dependent synchrony in retinal ganglion cells

Visual Neuroscience ◽

10.1017/s0952523807070757 ◽

2007 ◽

Vol 24 (6) ◽

pp. 827-843 ◽

Cited By ~ 4

Author(s):

SUSMITA CHATTERJEE ◽

DAVID K. MERWINE ◽

FRANKLIN R. AMTHOR ◽

NORBERTO M. GRZYWACZ

Keyword(s):

Ganglion Cell ◽

Retinal Ganglion Cells ◽

Functional Role ◽

Ganglion Cells ◽

Receptive Fields ◽

Rabbit Retina ◽

Retinal Ganglion ◽

Spike Synchrony ◽

Full Field ◽

Dependent Correlation

Neighboring retinal ganglion cells often spike synchronously, but the possible function and mechanism of this synchrony is unclear. Recently, the strength of the fast correlation between ON-OFF directionally selective cells of the rabbit retina was shown to be stimulus dependent. Here, we extend that study, investigating stimulus-dependent correlation among multiple ganglion-cell classes, using multi-electrode recordings. Our results generalized those for directionally selective cells. All cell pairs exhibiting significant spike synchrony did it for an extended edge but rarely for full-field stimuli. The strength of this synchrony did not depend on the amplitude of the response and correlations could be present even when the cells' receptive fields did not overlap. In addition, correlations tended to be orientation selective in a manner predictable by the relative positions of the receptive fields. Finally, extended edges and full-field stimuli produced significantly greater and smaller correlations than predicted by chance respectively. We propose an amacrine-network model for the enhancement and depression of correlation. Such an apparently purposeful control of correlation adds evidence for retinal synchrony playing a functional role in vision.

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Cannabinoids modulate spontaneous synaptic activity in retinal ganglion cells

Visual Neuroscience ◽

10.1017/s0952523811000198 ◽

2011 ◽

Vol 28 (5) ◽

pp. 393-402 ◽

Cited By ~ 22

Author(s):

T. P. MIDDLETON ◽

D. A. PROTTI

Keyword(s):

Synaptic Transmission ◽

Retinal Ganglion Cells ◽

Cannabinoid Receptor ◽

Ganglion Cells ◽

Cell Voltage ◽

Receptor Activation ◽

Synaptic Activity ◽

Retinal Cell ◽

Retinal Ganglion ◽

Retinal Processing

AbstractThe endocannabinoid (ECB) system has been found throughout the central nervous system and modulates cell excitability in various forms of short-term plasticity. ECBs and their receptors have also been localized to all retinal cells, and cannabinoid receptor activation has been shown to alter voltage-dependent conductances in several different retinal cell types, suggesting a possible role for cannabinoids in retinal processing. Their effects on synaptic transmission in the mammalian retina, however, have not been previously investigated. Here, we show that exogenous cannabinoids alter spontaneous synaptic transmission onto retinal ganglion cells (RGCs). Using whole-cell voltage-clamp recordings in whole-mount retinas, we measured spontaneous postsynaptic currents (SPSCs) in RGCs in adult and young (P14–P21) mice. We found that the addition of an exogenous cannabinoid agonist, WIN55212-2 (5 μM), caused a significant reversible reduction in the frequency of SPSCs. This change, however, did not alter the kinetics of the SPSCs, indicating a presynaptic locus of action. Using blockers to isolate inhibitory or excitatory currents, we found that cannabinoids significantly reduced the release probability of both GABA and glutamate, respectively. While the addition of cannabinoids reduced the frequency of both GABAergic and glutamatergic SPSCs in both young and adult mice, we found that the largest effect was on GABA-mediated currents in young mice. These results suggest that the ECB system may potentially be involved in the modulation of signal transmission in the retina. Furthermore, they suggest that it might play a role in the developmental maturation of synaptic circuits, and that exogenous cannabinoids are likely able to disrupt retinal processing and consequently alter vision.

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