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Retinal Ganglion Cells
History
Review of types
Difference of Gaussians (DoG) model for center-surround receptive fields, as developed for cat and applied to primate
Y cell nonlinearity
Comparing M and P cells
History Hartline (1940): extracellular recordings from frog ganglion cell fibers Granit (1947) extracellular recordings from cat retinal ganglion cells
using diffuse stimuli Excitation and inhibition that often cancelled: ill-defined receptive fields
Kuffler’s (1953) discovery of concentric antagonistic center surround organization Used small focused spots to map On and Off center receptive fields
Rodieck’s (1965) Difference of Gaussians (DoG) modelEnroth-Cugell & Robson (1966) linearity of spatial summation, use of sinusoidal gratings to study receptive fields of cat retinal ganglion cells. Numerous studies have applied this approach to study of ganglion cells in several species including macaque monkeys (e.g. Croner & Kaplan, 1995)
Temporal dynamics and impulse response
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Parallel pathways –geniculo-striate pathways in primate
IpRGCs, Dacey et al., 2005)
Midget, On and OFF (70% RGCs)
Parasol, On and Off (10%)
SBS (BY) pathway (On-Off) (8%)
Off BY and melanopsin (0.2% ?
Central retinal projections in primate
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Classifications in primates
Dacey et al., 2005
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Retinal ganglion cell densities (macaque monkey)
Perry & Cowey, Vis Res 1985
Melanopsin ganglion cellin mouse 1-3 % of the population
Webvision
0.2% of the population in NHP & human(Dacey et al., 2005)
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Analysis of center-surround receptive fields
Retinal ganglion cell receptive fieldsCenter-Surround Organization
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On center: Off surround
Recordings in catsEnroth-Cugell & Robson, 1984
Off center: On surround
Enroth-Cugell & Robson, 1984
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Enroth-Cugell & Robson, 1984
Contrast reversal of gratings
Square wave Sine wave
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Enroth-Cugell & Robson, 1984
Cat retinal ganglion cell – spatial “contrast sensitivity”Responsivity = Gain = impulses per sec per unit contrastFilled circles – counterphase gratings, open circles, drifting
gratings
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Martin & Grunert, 2004 Visual NeuroscienceChapter 26.
DoG – macaqueP cell (Croner & Kaplan, 1995, Vision Research)
ParametersRc = center radius at Kc * 1/e (37% Kc)Rs = surround radius at Ks * 1/e (37% Ks)Kc = center sensitivityKs = surround sensitivity
The sensitivity at a point r units from the middle of the receptive fieldS(r)=kc*exp [-(r/rc)2] - ks*exp [-(r/rs)2]
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Linsenmeier et al., 1982
Average cat retinal ganglion cells
Fields are large. A radius of 0.5 deg predicts resolution of around a cycle per degree (cy/deg).
Resolution primate fovea is ~50 cy/deg . About what would the radius of the receptive field be?
Resolution for mouse retina is much less: ~0.1 cy/deg(Koehler et al., 2011 JNP)
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Average macaque ganglion cells - across a large range of eccentricies
Kaplan & Croner, 1995
Difference of Gaussian model for primate ganglion cells –P-cell with red On center, green Off surround
Kaplan & Benardete, 2001
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Dacey, 2000
Surround present in bipolar cells
Davenport et al. 2008, J. Neurosci
Horizontal cell feedback to formsurrounds of bipolar cells which relay signals to ganglion cells.GABA inhibition, or maybe pH?
Macaque retinal ganglion cellsurround – removed by the H+
buffer, HEPES
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Enroth-Cugell et al., 1983
The nonlinearity in Y and Magno cells
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Enroth-Cugell & Robson, 1966
Counter-phase gratings: linear and nonlinear responses: X and Y cells (cats)
Drifting vs stationary gratings – cat Y cell exhibits linear response (F1) to drifing gratings, 2nd harmonic nonlinear response (F2) to counterphase gratings
Frishman & Linsenmeier, J. Physiol. 1982)
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Linsenmeier et al., 1982
Parasol cells in macaque retina have Y-cell physiology.
Crook J D et al. J. Neurosci. 2008;28:11277-11291
©2008 by Society for Neuroscience
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Macaque retinal ganglion cell – Parasol, LGN magno-projecting“Y” cell. This cell also projects to the superior colliculus
Crook et al, 2008J. Neurosci.
Nonlinear subunits in the receptive field
Hochstein & Shapley, J. Physiol. 1976
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Comparing M (Parasol) and P (midget) cells
M vs P-cells
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Midget cells determine human acuity (Dacey, 1993)
?
?
8 %to LGN
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Midget pathwayOverview of retinal circuitsParallel pathways through the retina
Midget, On and Off (70% RGCs)Parasol, On and Off (10%)SMS pathway (On-OFF) (8%) S – Off – and melanopsin (0.2%)
Dacey & Packer, 2003
Nassi & Calloway, 2009
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