scholarly journals Suppressive Surrounds and Contrast Gain in Magnocellular-Pathway Retinal Ganglion Cells of Macaque

2006 ◽  
Vol 26 (34) ◽  
pp. 8715-8726 ◽  
Author(s):  
S. G. Solomon
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Retinal Ganglion ◽  
Magnocellular Pathway ◽  
Contrast Gain

Contrast gain control in the primate retina: P cells are not X-like, some M cells are

1992 ◽  
Vol 8 (5) ◽  
pp. 483-486 ◽  
Author(s):  
Ethan A. Benardete ◽  
Ehud Kaplan ◽  
Bruce W. Knight
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Temporal Frequency ◽  
Gain Control ◽  
M Cells ◽  
Retinal Ganglion ◽  
M Cell ◽  
Contrast Gain ◽  
Contrast Gain Control ◽  
P Cells

AbstractPrimate retinal ganglion cells that project to the magnocellular layers of the lateral geniculate nucleus (M) are much more sensitive to luminance contrast than those ganglion cells projecting to the parvocellular layers (P). We now report that increasing contrast modifies the temporal-frequency response of M cells, but not of P cells. With rising contrast, the M cells' responses to sinusoidal stimuli show an increasing attenuation at low temporal frequencies while the P cells' responses scale uniformly. The characteristic features of M-cell dynamics are well described by a model originally developed for the X and Y cells of the cat, where the hypothesized nonlinear feedback mechanism responsible for this behavior has been termed the contrast gain control (Shapley & Victor, 1978, 1981; Victor, 1987, 1988). These data provide further physiological evidence that the M-cell pathway differs from the P-cell pathway with regard to the functional elements in the retina. Furthermore, the similarity in dynamics between primate M cells and cat X and Y retinal ganglion cells suggests the possibility that P cells, being different from either group, are a primate specialization not found in the retinae of lower mammals.

The dynamics of primate M retinal ganglion cells

1999 ◽  
Vol 16 (2) ◽  
pp. 355-368 ◽  
Author(s):  
ETHAN A. BENARDETE ◽  
EHUD KAPLAN
Keyword(s):  
Frequency Response ◽  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Temporal Frequency ◽  
Gain Control ◽  
Linear Filter ◽  
M Cells ◽  
Retinal Ganglion ◽  
Contrast Gain ◽  
Contrast Gain Control

The retinal ganglion cells (RGCs) of the primate form at least two classes—M and P—that differ fundamentally in their functional properties. M cells have temporal-frequency response characteristics distinct from P cells (Benardete et al., 1992; Lee et al., 1994). In this paper, we elaborate on the temporal-frequency responses of M cells and focus in detail on the contrast gain control (Shapley & Victor, 1979a,b). Earlier data showed that the temporal-frequency response of M cells is altered by the level of stimulus contrast (Benardete et al., 1992). Higher contrast shifts the peak of the frequency-response curve to higher temporal frequency and produces a phase advance. In this paper, by fitting the data to a linear filter model, the effect of contrast on the temporal-frequency response is subsumed into a change in a single parameter in the model. Furthermore, the model fits are used to predict the response of M cells to steps of contrast, and these predictions demonstrate the dynamic effect of contrast on the M cells' response. We also present new data concerning the spatial organization of the contrast gain control in the primate and show that the signal that controls the contrast gain must come from a broadly distributed network of small subunits in the surround of the M-cell receptive field.

Ganglion cells of a short-wavelength-sensitive cone pathway in New World monkeys: Morphology and physiology

1999 ◽  
Vol 16 (2) ◽  
pp. 333-343 ◽  
Author(s):  
LUIZ CARLOS L. SILVEIRA ◽  
BARRY B. LEE ◽  
ELIZABETH S. YAMADA ◽  
JAN KREMERS ◽  
DAVID M. HUNT ◽  
...  
Keyword(s):  
Retinal Ganglion Cells ◽  
Short Wavelength ◽  
New World ◽  
Ganglion Cells ◽  
Dendritic Tree ◽  
New World Monkeys ◽  
Retinal Ganglion ◽  
Old World ◽  
Contrast Gain ◽  
Cone Pathway

We have studied the morphology and physiology of retinal ganglion cells of a short-wavelength-sensitive cone (SWS-cone) pathway in dichromatic and trichromatic New World anthropoids, the capuchin monkey (Cebus apella) and tufted-ear marmoset (Callithrix jacchus). In Old World anthropoids, in which males and females are both trichromats, blue-ON/yellow-OFF retinal ganglion cells have excitatory SWS-cone and inhibitory middle- and long-wavelength-sensitive (MWS- and LWS-) cone inputs, and have been anatomically identified as small-field bistratified ganglion cells (SB-cells) (Dacey & Lee, 1994). Among retinal ganglion cells of New World monkeys, we find SB-cells which have very similar morphology to such cells in macaque and human; for example, the inner dendritic tree is larger and denser than the outer dendritic tree. We also find blue-on retinal ganglion cells of the capuchin to have physiological responses strongly resembling such cells of the macaque monkey retina; for example, responses were more sustained, with a gentler low frequency roll-off than MC-cells, and no evidence of contrast gain control. There was no difference between dichromatic and trichromatic individuals. The results support the view that SWS-cone pathways are similarly organized in New and Old World primates, consistent with the hypothesis that these pathways form a phylogenetically ancient color system.

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