W-and Y-cells in the C layers of the cat's lateral geniculate nucleus: normal properties and effects of monocular deprivation

1989 ◽  
Vol 61 (1) ◽  
pp. 58-73 ◽  
Author(s):  
P. D. Spear ◽  
M. A. McCall ◽  
N. Tumosa

1. Previous studies have shown that rearing with monocular visual deprivation (MD) produces a loss of Y-cells and a reduction in spatial resolution among X-cells in layers A and A1 of the cat's dorsal lateral geniculate nucleus (dLGN). However, there have been no studies of the effects of visual deprivation on the function of the retinogeniculate W-cell pathway, which terminates in the C layers of the dLGN. It also is not known if Y-cells in the C layers are affected by MD in the same way as Y-cells in the A layers. These questions were addressed by the present experiment. 2. Single-cell recordings were made from the C layers of 5 normal adult cats (112 cells) and from the nondeprived (94 cells) and deprived (95 cells) C layers in 10 cats monocularly deprived by lid suture for 3-7 yr. The cells were classified as X, Y, or W on the basis of their receptive-field properties and responses to electrical stimulation of the optic chiasm. In addition, quantitative measures were made of responses to sine-wave gratings of different spatial frequencies. 3. Receptive-field organization, receptive-field center size, spatial and temporal linearity to counterphased sine-wave gratings, and latency to optic chiasm stimulation were similar for C-layer cells in normal cats and in the deprived and nondeprived layers of MD cats. On the basis of these properties, 23% of normal layer-C cells were classified as Y-cells and 72% were classified as W-cells. The Y-cells tended to be located in the magnocellular division of layer C and most (though not all) W-cells were in the parvocellular division. Normal layers C1 and C2 contained almost exclusively W cells. The incidence of Y and W cells was similar to normal in the nondeprived and deprived C-layers of MD cats. 4. In normal cats, W cells typically had the lowest amplitude first-harmonic (F1) response rates to drifting sine-wave gratings. However, many W cells gave quite brisk responses and, overall, there was no significant difference between F1 response amplitudes of Y and W cells. Response amplitudes of Y- and W-cells in the deprived and nondeprived C-layers of MD cats were not significantly different from normal. 5. Normal Y- and W-cells tended to have low optimal spatial frequencies (0.2 c/deg or lower) and spatial resolutions (generally 0.4-1.6 c/deg) to drifting sine-wave gratings.(ABSTRACT TRUNCATED AT 400 WORDS)

1982 ◽  
Vol 47 (5) ◽  
pp. 869-884 ◽  
Author(s):  
M. Sur ◽  
S. M. Sherman

1. We used standard, single-cell recording techniques to study the response properties of 34 W-cells in the C-laminae of the cat's lateral geniculate nucleus. By W-cell, we mean a poorly responsive geniculate neuron that receives slowly conducting retinal afferents; these are quite distinct from geniculate X- and Y-cells. Our measurements included response latency to optic chiasm stimulation, plots of the receptive-field center, time course of response, and responses to counterphased, sine-wave gratings. This last measurement also involved the determination of contrast sensitivity, which is defined as the inverse of the contrast needed to evoke a threshold response at a particular spatial and temporal frequency of the grating. Many of these responses were compared to those of geniculate X- and Y-cells recorded in the A-laminae. 2. Each of the W-cells responded with a latency of at least 2.0 ms to optic chiasm stimulation, and most (76%) exhibited a latency of at least 2.5 ms. However, only 26 of these W-cells responded to visual stimuli, and these responses were weak or "sluggish," as has been reported previously. Receptive fields of these W-cells tended to be large, compared to those of X- and Y-cells, and included 11 on-center, 13 off-center, and 2 on-off center fields. 3. W-cells exhibited either linear (12 cells) or nonlinear (14 cells) spatial and temporal summation, as determined from their responses to counterphased, sine-wave gratings. Linearity of spatial summation was determined by measuring contrast sensitivity as a function of the grating's spatial phase. The linear W-cells' responses were sinusoidally phase dependent, and the nonlinear W-cells' responses were independent of spatial phase. Linearity of temporal summation was determined by the presence or absence of harmonic distortion in the response relative to the grating's counterphase rate. Linear W-cells responded chiefly at the grating's fundamental temporal frequency, whereas much of the nonlinear W-cells' responses occurred at the second harmonic of the grating's temporal frequency. Thus, nonlinear W-cells exhibited many of the characteristics previously described for Y-cells. 4. Spatial and temporal contrast-sensitivity functions were determined for seven linear and eight nonlinear W-cells. Overall sensitivity values of the linear and nonlinear W-cells were comparable, but these groups differed in terms of the nature of the response component (linear or nonlinear) that was more sensitive. 5. The linear W-cells in our sample included both tonic (comparable to the "sluggish-transient" type of retinal ganglion cells) types, while all nonlinear W-cells were phasic. Otherwise, no difference between linear and nonlinear W-cells was seen for latency to optic chiasm stimulation, receptive-field size, overall contrast sensitivity, responsiveness to visual stimuli, overall spatial resolution, or temporal resolution. 6...


1986 ◽  
Vol 56 (2) ◽  
pp. 523-541 ◽  
Author(s):  
J. S. Tootle ◽  
M. J. Friedlander

We recorded the responses to visual stimulation of single neurons in the A-layers of the dorsal lateral geniculate nucleus (LGNd) of 4- to 5-wk-old kittens and adult cats. Visual stimuli were generated on a cathode-ray tube (CRT) display and consisted of circular spots and annuli whose contrast was twice the threshold for each neuron and was modulated about a background luminance of 28 cd/m2 at 0.5 Hz. Neural responses were collected as interspike intervals and displayed as instantaneous firing rates for individual trials. From the responses to a series of sizes of spot stimuli, area-response functions were constructed and used to derive a quantitative measure of the strength of the receptive field (RF) surround inhibition of each neuron, the spatial density minimum ([SDmin[). To separate neural from optical factors that affect measurements of surround inhibition, published values for the posterior nodal distances of the kitten and adult eye were used to scale stimuli in terms of the retinal area subtended. Of 153 kitten and 95 adult LGNd neurons studied, the responses to a complete series of spot stimuli of different sizes (areas) were obtained for 52 kitten neurons [44 with linear spatial summation (L) and 8 with nonlinear spatial summation (NL)] and 45 adult (24 X-and 21 Y-) neurons. In addition, intracellular recordings were made from 30 of the kitten neurons that were filled iontophoretically with horseradish peroxidase (HRP) and were evaluated structurally. In the adult, neurons were classified as X-or Y-cells on the basis of a battery of physiological properties, including linearity of spatial summation, latency to electrical stimulation of the optic chiasm, and ability to respond reliably to rapidly moving stimuli. Kitten neuronal responses allowed them to be clearly identified as exhibiting linear or nonlinear spatial summation, but application of additional criteria produced ambiguous results for classification into X-or Y-categories. Kitten L or NL neurons showed differences typical of adult X-and Y-cells on some [e.g., RF center size (P less than 0.01)] but not other [e.g., latency to stimulation of optic chiasm (P greater than 0.40)] properties. In addition, by direct comparison of morphological features with these physiological responses, some kitten cells with adult X-cell physiological properties on these tests were found to have typical adult Y-cell somadendritic structure.(ABSTRACT TRUNCATED AT 400 WORDS)


1983 ◽  
Vol 50 (1) ◽  
pp. 240-264 ◽  
Author(s):  
S. C. Mangel ◽  
J. R. Wilson ◽  
S. M. Sherman

We measured response properties of X- and Y-cells from laminae A and A1 of the dorsal lateral geniculate nucleus of monocularly lid-sutured cats at 8, 12, 16, 24, and 52-60 wk of age. Visual stimuli consisted of small spots of light and vertically oriented sine-wave gratings counterphased at a rate of 2 cycles/s. In cats as young as 8 wk of age, nondeprived and deprived neurons could be clearly identified as X-cells or Y-cells with criteria previously established for adult animals. Nonlinear responses of Y-cells from 8- and 12-wk-old cats were often temporally labile; that is, the amplitude of the nonlinear response of nondeprived and deprived cells increased or decreased suddenly. A similar lability was not noted for the linear response component. This phenomenon rarely occurred in older cats. At 8 wk of age, Y-cell proportions (number of Y-cells/total number of cells) in nondeprived and deprived A-laminae were approximately equal. By 12 wk of age and thereafter, the proportion of Y-cells in deprived laminae was significantly lower than that in nondeprived laminae. At no age was there a systematic difference in response properties (spatial resolution, latency to optic chiasm stimulation, etc.) for Y-cells between deprived and nondeprived laminae. Spatial resolution, defined as the highest spatial frequency to which a cell would respond at a contrast of 0.6, was similar for nondeprived and deprived X-cells until 24 wk of age. In these and older cats, the mean spatial resolution of deprived X-cells was lower than that of nondeprived X-cells. This difference was noted first for lamina A1 at 24 wk of age and later for lamina A at 52-60 wk of age. The average latency of X-cells to optic chiasm stimulation was slightly greater in deprived laminae than in nondeprived laminae. No such difference was seen for Y-cells. Cells with poor and inconsistent responses were encountered infrequently but were observed far more often in deprived laminae than in nondeprived laminae. Lid suture appears to affect the development of geniculate X- and Y-cells in very different ways. Not only is the final pattern of abnormalities quite different between these cell groups, but the developmental dynamics of these abnormalities also differ.


1984 ◽  
Vol 52 (5) ◽  
pp. 911-920 ◽  
Author(s):  
J. Frascella ◽  
S. Lehmkuhle

Extracellular responses of Y-cells in the A-laminae and in lamina C of the cat dorsal lateral geniculate nucleus were recorded and compared for several sine-wave grating presentations. Both spatial and temporal contrast sensitivity functions were determined for these cells as well as suprathreshold response functions at 0.2 and 0.4 contrast. Qualitatively, the responses of the lamina C Y-cells were very similar to Y-cells of the A-laminae; differences were of a quantitative nature. At threshold, lamina C Y-cells were more sensitive at all spatial and temporal frequencies tested. Suprathreshold results showed no major differences in fundamental response amplitude between laminar Y-cells. Interlaminar differences were found with respect to second harmonic response amplitude. Lamina C Y-cells gave the largest overall second harmonic response for all stimulus conditions. A trend was observed for these laminar Y-cells such that the second harmonic responses were highest for Y-cells of lamina C, intermediate for lamina A Y-cells, and lowest for those of lamina A1. Based on differences in projection pattern and present electrophysiological results, we conclude that the lamina C Y-cells may represent a population of cells that is distinct from A-laminae Y-cells. These lamina C Y-cells provide a significant input to visual cortex.


Responses to visual stimuli and to electrical stimulation of the optic chiasma were analysed in neurons of the lateral geniculate nucleus, visual cortex and superior colliculus in monocularly deprived cats with different post-deprivation periods. If the cats had both eyes open in their post-deprivation period (1 year) no recovery from the effects of early deprivation was found in the responses of neurones in all 3 visual structures. In cats with a post-deprivation reverse closure we found an increase in the proportion of Y-cells recorded in the early deprived layer of LGN when compared to the Y-cell proportion found in the same layers immediately after the deprived eye was opened. In neurons of the visual cortex and superior colliculus the functional abnormalities remained unaltered. The late closure of the non-deprived eye for up to 3 years did not effect neurons normally activated through that eye. Removal of the non-deprived eye unmasked connections of the deprived eye’s pathway onto neurons in the visual cortex and the superior colliculus. The neurons showed no specificity for the direction of movement or the orientation of visual stimuli. This recovery from deprivation was greater after enucleating the cats at the age of 6 months than at 18 months after birth. In the lateral geniculate nucleus of these cats the proportion of Y-cells in the recorded sample driven by the deprived eye had recovered to the value of normal cats. The difficulties in relating these physiological findings to results from morphological or behavioural studies are discussed.


2014 ◽  
Vol 31 (3) ◽  
pp. 253-261 ◽  
Author(s):  
KEVIN R. DUFFY ◽  
KAITLYN D. HOLMAN ◽  
DONALD E. MITCHELL

AbstractThe parallel processing of visual features by distinct neuron populations is a central characteristic of the mammalian visual system. In the A laminae of the cat dorsal lateral geniculate nucleus (dLGN), parallel processing streams originate from two principal neuron types, called X and Y cells. Disruption of visual experience early in life by monocular deprivation has been shown to alter the structure and function of Y cells, but the extent to which deprivation influences X cells remains less clear. A transcription factor, FoxP2, has recently been shown to selectively label X cells in the ferret dLGN and thus provides an opportunity to examine whether monocular deprivation alters the soma size of X cells. In this study, FoxP2 labeling was examined in the dLGN of normal and monocularly deprived cats. The characteristics of neurons labeled for FoxP2 were consistent with FoxP2 being a marker for X cells in the cat dLGN. Monocular deprivation for either a short (7 days) or long (7 weeks) duration did not alter the density of FoxP2-positive neurons between nondeprived and deprived dLGN layers. However, for each deprived animal examined, measurement of the cross-sectional area of FoxP2-positive neurons (X cells) revealed that within deprived layers, X cells were smaller by approximately 20% after 7 days of deprivation, and by approximately 28% after 7 weeks of deprivation. The observed alteration to the cross-sectional area of X cells indicates that perturbation of this major pathway contributes to the functional impairments that develop from monocular deprivation.


1975 ◽  
Vol 38 (5) ◽  
pp. 1049-1059 ◽  
Author(s):  
K. P. Hoffmann ◽  
S. M. Sherman

1. Recent work has demonstrated at least three distinct inputs to the superior colliculus in normal cats: a) the W-direct retinotectal pathway; b) the Y-direct retinotectal pathway; and c) the Y-indirect pathway which involves Y-cells in retina and lateral geniculate nucleus plus complex cells in cortex, the last being the corticotectal cells. 2. We investigated these inputs in five cats raised with binocular eyelid closure by studying the electrophysiological properties of 164 collicular neurons. After such binocular deprivation, the Y-indirect pathway was missing and the Y-direct pathway appeared reduced, although the W-direct input seemed unaffected. 3. Despite the loss of the Y-indirect input, collicular activation to electrical stimulation of cortex seemed normal in these cats. This suggested that the Y-indirect loop was affected between the optic tract and cortex, and this, in turn, correlated to the previously described reduction in recordable Y-cells from the lateral geniculate nucleus of binocularly deprived cats. 4. We found receptive-field correlates to this loss of Y-direct and Y-indirect input in the binocularly deprived cats. Compared to collicular neurons in normal cats, those in deprived cats exhibited abnormally strong dominance by the contralateral eye, loss of directional selectivity, and loss of responsiveness to fast visual stimuli. 5. These and other data lead to the suggestion that in normal and monocularly deprived cats, the corticotectal input dominates collicular receptive-field properties, whereas in binocularly deprived cats, the remaining retinotectal input dominates these properties.


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