1

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

2

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

3

Classifications in primates

Dacey et al., 2005

4

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)

5

Analysis of center-surround receptive fields

Retinal ganglion cell receptive fieldsCenter-Surround Organization

6

On center: Off surround

Recordings in catsEnroth-Cugell & Robson, 1984

Off center: On surround

Enroth-Cugell & Robson, 1984

7

Enroth-Cugell & Robson, 1984

Contrast reversal of gratings

Square wave Sine wave

8

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

9

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]

10

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)

11

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

12

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

13

Enroth-Cugell et al., 1983

The nonlinearity in Y and Magno cells

14

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)

15

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

16

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

17

Comparing M (Parasol) and P (midget) cells

M vs P-cells

18

Midget cells determine human acuity (Dacey, 1993)

?

?

8 %to LGN

19

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