Receptive Field Properties and Laminar Organization of Lateral Geniculate Nucleus in the Gray Squirrel (Sciurus carolinensis)

2003 ◽  
Vol 90 (5) ◽  
pp. 3398-3418 ◽  
Author(s):  
Stephen D. Van Hooser ◽  
J. Alexander F. Heimel ◽  
Sacha B. Nelson
Keyword(s):  
Receptive Field ◽  
Lateral Geniculate Nucleus ◽  
Spatial Summation ◽  
Field Size ◽  
Gray Squirrel ◽  
Response Latencies ◽  
Laminar Organization ◽  
Contrast Gain ◽  
Lateral Geniculate ◽  
Heterogeneous Class

Physiological studies of the lateral geniculate nucleus (LGN) have revealed three classes of relay neurons, called X, Y, and W cells in carnivores and parvocellular (P), magnocellular (M), and koniocellular (K) in primates. The homological relationships among these cell classes and how receptive field (RF) properties of these cells compare with LGN cells in other mammals are poorly understood. To address these questions, we have characterized RF properties and laminar organization in LGN of a highly visual diurnal rodent, the gray squirrel, under isoflurane anesthesia. We identified three classes of LGN cells. One class found in layers 1 and 2 showed sustained, reliable firing, center-surround organization, and was almost exclusively linear in spatial summation. Another class, found in layer 3, showed short response latencies, transient and reliable firing, center-surround organization, and could show either linear (76%) or nonlinear (24%) spatial summation. A third, heterogeneous class found throughout the LGN but primarily in layer 3 showed highly variable responses, a variety of response latencies and could show either center-surround or noncenter-surround receptive field organization and either linear (77%) or nonlinear (23%) spatial summation. RF sizes of all cell classes showed little dependency on eccentricity, and all of these classes showed low contrast gains. When compared with LGN cells in other mammals, our data are consistent with the idea that all mammals contain three basic classes of LGN neurons, one showing reliable, sustained responses, and center-surround organization (X or P); another showing transient but reliable responses, short latencies, and center-surround organization (Y or M); and a third, highly variable and heterogeneous class of cells (W or K). Other properties such as dependency of receptive field size on eccentricity, linearity of spatial summation, and contrast gain appear to vary from species to species.

Spatial Distribution of Suppressive Signals Outside the Classical Receptive Field in Lateral Geniculate Nucleus

2005 ◽  
Vol 94 (3) ◽  
pp. 1789-1797 ◽  
Author(s):  
Ben S. Webb ◽  
Christopher J. Tinsley ◽  
Christopher J. Vincent ◽  
Andrew M. Derrington
Keyword(s):  
Spatial Distribution ◽  
Receptive Field ◽  
Lateral Geniculate Nucleus ◽  
Spatial Organization ◽  
Temporal Frequency ◽  
Spatial Summation ◽  
Sinusoidal Grating ◽  
Circular Symmetry ◽  
Lateral Geniculate ◽  
Classical Receptive Field

A suppressive surround modulates the responsiveness of cells in the lateral geniculate nucleus (LGN), but we know nothing of its spatial structure or the way in which it combines signals arising from different locations. It is generally assumed that suppressive signals are either uniformly distributed or balanced in opposing regions outside the receptive field. Here, we examine the spatial distribution and summation of suppressive signals outside the receptive field in extracellular recordings from 46 LGN cells in anesthetized marmosets. The receptive field of each cell was stimulated with a drifting sinusoidal grating of the preferred size and spatial and temporal frequency; we probed different positions in the suppressive surround with either a large half-annular grating or a small circular grating patch of the preferred spatial and temporal frequency. In many of the cells with a strong suppressive surround (29/46), the spatial distribution of suppression showed clear deviation from circular symmetry. In the majority of these of cells, suppressive signals were spatially asymmetrical or balanced in opposing areas outside the receptive field. A suppressive area was larger than the classical receptive field itself and spatial summation within and between these areas was nonlinear. There was no bias for suppression to arise from foveal or nasal retina where cone density is higher and no other sign of a systematic spatial organization to the suppressive surround. We conclude that nonclassical suppressive signals in LGN deviate from circular symmetry and are nonlinearly combined.

Light adaptation in cells of macaque lateral geniculate nucleus and its relation to human light adaptation

1983 ◽  
Vol 50 (4) ◽  
pp. 864-878 ◽  
Author(s):  
V. Virsu ◽  
B. B. Lee
Keyword(s):  
Receptive Field ◽  
Lateral Geniculate Nucleus ◽  
Light Adaptation ◽  
Single Cells ◽  
Activity Level ◽  
Field Size ◽  
Adaptation Level ◽  
Response Functions ◽  
Lateral Geniculate ◽  
Intensity Response

Responses of macaque lateral geniculate nucleus (LGN) cells to stimuli of different incremental intensities and wavelength compositions were studied at different levels of light adaptation from scotopic to low photopic levels. Stimuli were large in comparison with receptive-field size. Human increment thresholds were measured for comparison. The strength of responses grew in many cells from threshold up to a saturation level as a logarithmic function of incremental intensity. More complex intensity-response functions were also obtained, particularly from parvocellular layer (PCL) cells, but the shape and slope of the intensity-response function changed as a function of adaptation level only with chromatic backgrounds. As a function of adaptation level, the intensity-response functions shifted along the logarithmic abscissa but not sufficiently for a complete contrast constancy. Thus responses to any constant contrast became smaller when adaptation level decreased. The change from cone to rod responses, when possible, took place without noticeable change in shape of intensity-response functions, and much of the adaptive shift of the functions could be attributed to the change-over between rods and cones. Differences between different cells in light adaptation and dark-adapted sensitivity were large, mostly because of variation in the strength of rod input. The strongest excitatory rod inputs were found in PCL cells activated by short-wavelength light, so that the highest sensitivity at low levels of illumination occurred in blue- and blue-green-sensitive cells. The lowest increment thresholds based on cones matched the thresholds of macaque cone late receptor potentials recorded by Boynton and Whitten (3). They were also similar to human cone thresholds measured psychophysically but only for small stimulus sizes that may approximate the size of the receptive-field centers. Human sensitivity was much higher when measured with large stimulus sizes, indicating integration at post-geniculate neural levels. Light adaptation, as evaluated with respect to contrast constancy and Weber law behavior, was similarly incomplete in monkey single cells and human perception. A few cat LGN cells were studied in a control experiment; results agreed with previous findings. The light adaptation of cat cels was more complete and sensitivity higher than those observed under comparable conditions in macaque single cells and human. The maintained activity level of cells was little affected by the intensity of steady backgrounds. Thus, the steady-state hyper-polarisation of receptors was not transmitted to LGN cells.

Visual signal processing in the macaque lateral geniculate nucleus

2012 ◽  
Vol 29 (2) ◽  
pp. 105-117 ◽  
Author(s):  
THORSTEIN SEIM ◽  
ARNE VALBERG ◽  
BARRY B. LEE
Keyword(s):  
Receptive Field ◽  
Lateral Geniculate Nucleus ◽  
Visual Information ◽  
Field Size ◽  
Visual Signal ◽  
Test Field ◽  
Retinal Ganglion ◽  
Relay Cell ◽  
Firing Rates ◽  
Lateral Geniculate

AbstractComparisons of S- or prepotential activity, thought to derive from a retinal ganglion cell afferent, with the activity of relay cells of the lateral geniculate nucleus (LGN) have sometimes implied a loss, or leak, of visual information. The idea of the “leaky” relay cell is reconsidered in the present analysis of prepotential firing and LGN responses of color-opponent cells of the macaque LGN to stimuli varying in size, relative luminance, and spectral distribution. Above a threshold prepotential spike frequency, called the signal transfer threshold (STT), there is a range of more than 2 log units of test field luminance that has a 1:1 relationship between prepotential- and LGN-cell firing rates. Consequently, above this threshold, the LGN cell response can be viewed as an extension of prepotential firing (a “nonleaky relay cell”). The STT level decreased when the size of the stimulus increased beyond the classical receptive field center, indicating that the LGN cell is influenced by factors other than the prepotential input. For opponent ON cells, both the excitatory and the inhibitory response decreased similarly when the test field size increased beyond the center of the receptive field. These findings have consequences for the modeling of LGN cell responses and transmission of visual information, particularly for small fields. For instance, for LGN ON cells, information in the prepotential intensity–response curve for firing rates below the STT is left to be discriminated by OFF cells. Consequently, for a given light adaptation, the STT improves the separation of the response range of retinal ganglion cells into “complementary” ON and OFF pathways.

Visual receptive-field properties of single neurons in cat's ventral lateral geniculate nucleus

1977 ◽  
Vol 40 (2) ◽  
pp. 390-409 ◽  
Author(s):  
P. D. Spear ◽  
D. C. Smith ◽  
L. L. Williams
Keyword(s):  
Visual Field ◽  
Receptive Field ◽  
Lateral Geniculate Nucleus ◽  
Receptive Fields ◽  
Field Size ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Lower Visual Field ◽  
Visual Receptive Field ◽  
Lateral Geniculate ◽  
Receptive Field Properties

1. Visual receptive-field characteristics were determined for 154 cells in the ventral lateral geniculate nucleus (VLG) of cats anesthetized with nitrous oxide. All cells were verified histologically to be within the VLG. Responses of 182 cells from laminae A and A1 of the dorsal lateral geniculate nucleus (DLG) were tested for comparison. 2. The VLG cells could be grouped into one of seven classes according to their responses to light stimulation. Twenty-seven percent of the cells had uniform receptive fields. They responded maximally to stationary stimuli flashed on or off anywhere within the receptive field and showed no evidence for antagonistic surround mechanisms. About 19.5% of the VLG cells had concentric receptive fields. They were similar to the uniform type, with the addition of a concentric inhibitory surround. Eight percent of the VLG cells had ambient receptive fields. These cells were characterized by an unusually regular maintained discharge which varied in rate in relation to the level of receptive-field illumination or of full-field ambient illumination. About 4% of the VLG cells were movement sensitive. They gave little or no response to stationary stimuli flashed on or off in the receptive field, and responded best to a contour moving across the receptive field in any direction. An additional 2.5% of the VLG cells were direction sensitive. Their response was dependent on the direction of stimulus movement through the receptive field. Sixteen percent of the VLG cells had indefinite receptive fields. They responded to whole-eye illumination or to localized visual-field stimulation; however, specific receptive-field properties could not be adequately defined. Approximately 23% of the VLG cells studied gave no convincing response to visual stimulation. 3. Responses of DLG cells agreed with those reported in previous studies. Almost all (97%) had concentric receptive fields, and a few (3%) had uniform receptive fields with no apparent antagonistic surround. None of the DLG cells had receptive fields like those in the other classes found for VLG cells. 4. The VLG cells tended to have large receptive fields; mean diameter was 10.6 degrees of visual arc. This was substantially larger than the diameter of receptive fields for DLG cells. In addition, VLG cells generally required larger stimuli than DLG cells to respond. There was no consistent relationship between receptive-field size and visual-field eccentricity for VLG cells, in contrast to the DLG. Most (57%) VLG cells were driven only by the contralateral eye, 30% were binocularly driven, and 13% were driven only by the ipsilateral eye. 5. A systematic visuotopic organization was present in the VLG. The lower visual field was represented anteriorly in the nucleus and the upper visual field posteriorly. The vertical meridian was represented along the dorsomedial border of the VLG where it abuts the DLG, and the temporal periphery was represented ventrolaterally. 6. Responses to electrical stimulation of the optic chiasm were studied for 55 VLG cells...

Two Different Types of Y Cells in the Cat Lateral Geniculate Nucleus

2003 ◽  
Vol 90 (3) ◽  
pp. 1852-1864 ◽  
Author(s):  
Chun-I Yeh ◽  
Carl R. Stoelzel ◽  
Jose-Manuel Alonso
Keyword(s):  
Lateral Geniculate Nucleus ◽  
Single Channel ◽  
Receptive Fields ◽  
Spatial Summation ◽  
Field Size ◽  
Lateral Geniculate ◽  
Spatial Parameters ◽  
Latency Response ◽  
X Cells ◽  
Y Cells

The Y pathway in the cat visual system is traditionally viewed as a single channel that originates in the retina. However, most Y cells from the contralateral retina diverge to innervate two different layers of the lateral geniculate nucleus, suggesting a possible channel split: YC (Y geniculate cell in layer C) and YA (Y geniculate cell in layer A). We tested the functional significance of this anatomical divergence by comparing the response properties of simultaneously recorded YC and YA geniculate cells with overlapping receptive fields. Our results demonstrate that YC and YA cells significantly differ in a large number of temporal and spatial parameters including response latency, response transiency, receptive-field size, and linearity of spatial summation. Furthermore, for some of these parameters, the differences between YC and YA cells are as pronounced as the differences between Y and X cells in layer A. These results along with results from previous studies strongly suggest that Y retinal afferents diverge into two separate channels at the level of the thalamus.

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