The laminar distribution of retinal fibers in the dorsal lateral geniculate nucleus of the cat: A new interpretation
01 Mar 1970-The Journal of Comparative Neurology (Wiley Subscription Services, Inc., A Wiley Company)-Vol. 138, Iss: 3, pp 339-367
TL;DR: The cell laminae of the lateral geniculate nucleus have been studied in relation to the retinogeniculate degeneration shown by the Nauta method and ventral to lamina A1 three laminaes have been defined.
Abstract: The cell laminae of the lateral geniculate nucleus have been studied in relation to the retinogeniculate degeneration shown by the Nauta method. In agreement with previous accounts laminae A and A1 have been shown to receive contralateral and homolateral inputs respectively. However, ventral to lamina A1 three laminae have been defined. Lamina “C” contains large cells and receives coarse contralateral fibers, lamina “C1” contains smaller cells and receives fine homolateral fibers, while lamina “C2,” which consists of small cells next to the optic tract contains many fibers passing through to other laminae but shows no particular concentration of pericellular degeneration.
The precise relationship between fiber degeneration and cytoarchitectonic borders can be seen only in Nauta sections that have been counterstained by a Nissl method. Such material provides no evidence of any zone where homolateral and contralateral fibers overlap. Between laminae A and A1, and A1 and C there are narrow, relatively cell free zones, which, in many parts of the nucleus, receive no significant retinogeniculate input.
The fiber degeneration appears earliest in the peripheral parts of laminea A and A1, the homolateral degeneration slightly preceding the contralateral degeneration on the third day. The degeneration in the central parts of these laminae appears about 24 hours later and is never as dense. The fine fibers in lamina C1 do not show degeneration clearly until the sixth day.
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TL;DR: Waves are present in the developing retina of higher and lower vertebrates, which suggests that this form of activity may be a common and fundamental mechanism employed in the activity-dependent refinement of early patterns of visual connections.
Abstract: Many pathways in the developing visual system are restructured and become highly organized even before vision occurs. Yet the developmental processes underlying the remodeling of visual connectivity are crucially dependent on retinal activity. Surprisingly, the immature and light-insensitive retina spontaneously generates a pattern of rhythmic bursting activity during the period when the connectivity patterns of retinal ganglion cells are shaped. Spatially, the activity is seen to spread across the retina in the form of waves that bring into synchrony the bursts of neighboring cells. Waves are present in the developing retina of higher and lower vertebrates, which suggests that this form of activity may be a common and fundamental mechanism employed in the activity-dependent refinement of early patterns of visual connections. Unraveling the cues encoded by the waves promises to provide important insights into how interactions driven by specific patterns of activity could lead to the modification of connectivity during development.
545 citations
TL;DR: The aims of this paper are to examine the properties that characterize the neurons of the different classes and to understand what mechanisms might underly the differences; to trace the major central projection of theDifferent cell types and to try to understand their significance for seeing.
492 citations
TL;DR: A spectrum of normal properties is established against which the properties of the LGNd in deprived cats can be compared, and several properties of Xand Y-cell activity of the retina were observed to vary.
Abstract: THE DORSAL lateral geniculate nucleus (LGNd) of the cat is a principal relay nucleus on the direct pathway from the retina to the visual cortex, and several parameters of its organization as a relay are well established. First, relay cells of the LGNd have either onor off-center receptive fields (16), because each relay cell receives direct excitatory drive from either onor off-center retinal ganglion cells (6, 16). Second, retinal ganglion cells fall into two groups (X-cells and Y-cells) according to whether they sum the influences of the center and surround regions of their receptive fields linearly or nonlinearly (8). Most LGNd relay cells can be similarly classified because most receive direct excitatory drive from either Xor Y-type retinal ganglion cells (6). Third, each relay cell receives direct excitatory drive from either fastor slow-conducting retinal afferents, and its own axon is correspondingly either fast or slow conducting (6, 36). The two latter parameters are closely correlated since Y-cells have been shown to have fast axons and Xcells, slow axons (6, 11). The on/off organization is independent of the other two parameters, however. Roth Y-cells and Xcells can have either onor off-center fields. This report examines several features of the LGNd relay in the normal cat, extending previous concepts and establishing a spectrum of normal properties against which the properties of the LGNd in deprived cats (described in the following paper (3W can be compared. First, the separate relay in the LGNd of the Xand Y-cell activity of the retina is described. Second, several properties of Xand Y-cells of the LGNd were observed to vary con-
386 citations
TL;DR: Small lesions were placed in visual cortical areas 17, 18, 19, 20, 21, 7, and Clare‐Bishop in the cat, and the sites of terminal degeneration seen with Fink‐Heimer technique were plotted in thalamus, pretectum and superior colliculus.
Abstract: Small lesions were placed in visual cortical areas 17, 18, 19, 20, 21, 7, and Clare-Bishop in the cat, and the sites of terminal degeneration seen with Fink-Heimer technique were plotted in thalamus, pretectum and superior colliculus. No degeneration was found in these sites after area 20 lesions; lesions in the other cortical areas gave different patterns of degeneration. Two major patterns were present, one from lesions in 17–18, one from lesions in 21, 7 and C-B, with degeneration from 19 forming a transition between the two groups.
Areas 17, 18 and 19 project to the dorsolateral geniculate nuclear complex (LGNd); areas 21, C-B and 7 do not. Area 17 projects to the laminar part, area 18 to both laminar and interlaminar (NIM) parts, and 19 only to NIM. The corticogeniculate projections from all three areas are topically organized anteroposteriorly, and at least that from area 17 is topically organized mediolaterally.
Areas 17 and 18 project topically to a columnar locus of the medial pulvinar (=lateral posterior) nucleus which ventrally includes that area known as the posterior nucleus. Area 19 has a double columnar projection to this part of the thalamus, one in the medial and one in the lateral pulvinar area. The medial column lies medial to that from 17–18, and appears to overlap the termination of the ascending projection from the superior colliculus. Cortical areas 21, C-B and 7 also have a double projection to the pulvinar.
These findings indicate that the corticorecipient neurons in both medial and lateral sectors of the pulvinar are organized so that dorsal neurons are activated by stimuli in upper visual fields (lower retina) and ventral neurons by stimuli in lower fields (upper retina).
Areas 17 and 18 project to the external layer of the ventrolateral geniculate (LGNv) nucleus, 19 to both external and internal layers, and 21, C-B and 7 to internal layer only.
The pretectal projection from 17–18 is limited to its caudal pole chiefly in the posterior pretectal nucleus (NPP), and also in the nucleus of the optic tract (NOT). Area 19 fibers terminate in NPP, NOT and also in the reticular part of the anterior pretectal nucleus (NPAr). Those from 21 and C-B end primarily in NPAr, and from area 7 in both reticular and compact parts of NPA. These corticopretectal systems all appear to be organized topically.
Areas 17, 18 and 19 have a double termination in the superior colliculus, a focal pattern in the superficial layers (chiefly lamina II), and a diffuse pattern in deeper layers (laminae IV, V, VI). The superficial pattern only provides the retinotopical matching with the optic afferents. All other cortical areas project diffusely to the deep layers. After lesions in 21 and C-B, the superficial foci are larger and centered in lamina III; after area 7 lesions this focal degeneration is centered in laminae III and IV and spread over much of the width of the colliculus. Degeneration to pontine nuclei and inferior olive was not examined.
335 citations
TL;DR: In the cat, as in other mammals, development of the retinogeniculate pathway is broadly characterized by an initial period of overlap followed by a period of segregation that gives rise to the adult pattern of afferent input.
Abstract: The prenatal development of connections between the retina and the lateral geniculate nucleus (LGN) was studied by means of the anterograde axonal transport of 3H-amino acids or horseradish peroxidase injected intraocularly in fetal cats older than embryonic day 27 (E27) and in newborn cats. (Gestation is 65 days.) A retinothalamic pathway exists as early as E28, when label can be seen in both ipsilateral and contralateral optic tracts. Afferents from the contralateral eye are the first to invade the anlage of the LGN by E32 with those from the ipsilateral eye following about 3 days later. Initially, the pattern of labeling within the nucleus is uniform, suggesting that the two sets of afferents must share a good deal of territory at early ages. By E47, however, gaps appear in the labeling pattern contralaterally, indicating that afferents from the two eyes are beginning to segregate from each other. Segregation continues so that by E54 it is possible to identify unambiguously regions of the LGN destined to comprise ipsilateral and contralateral eye layers. By birth, afferent input appears adult-like in organization, with the two sets of afferents almost completely segregated from each other into their appropriate layers. Cellular lamination of the nucleus has just commenced, however, thereby lagging the onset of afferent segregation by about 2 weeks. Prenatal development could be followed much more easily in the horizontal than in the coronal plane of section due to the finding here that the LGN is displaced approximately 90 degrees in the horizontal plane between E40 and E60. Measurements of the area occupied by the ipsilateral and contralateral afferents within the LGN indicated that even prior to segregation, the two sets of afferents are not completely intermixed within the LGN. On the contrary, those from the contralateral eye retain almost exclusive control of some territory throughout development. This detail contrasts with development in primates, in which intermixing of afferents from the two eyes is thought to be complete early on (Rakic, P. (1976) Nature 261: 467-471). Nevertheless, in the cat, as in other mammals, development of the retinogeniculate pathway is broadly characterized by an initial period of overlap followed by a period of segregation that gives rise to the adult pattern of afferent input.
324 citations
Cites background from "The laminar distribution of retinal..."
...(C refers to all three C laminae; C, Cl, and C2.)...
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...On the other hand, although the general location of the C layers can be determined here, the pattern of labeling is much less distinct, making the precise subdivision of the C layers into C, Cl, and C2 a difficult task....
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...In the cat, afferents from the contralat- era1 eye innervate layers A, C, and C2; those from the ipsilateral eye terminate in layers Al and Cl (Guillery, 1970; Hickey and Guillery, 1973)....
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...C refers collectively to all three C laminae: C, Cl, and C2....
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...Regions containing radioactive label are sharply delimited, and it is possible to identify unambiguously each LGN layer (A, Al, C, Cl, and C2) (Guillery, 1970) on the basis of the characteristic labeling pattern (Hickey and Guillery, 1973)....
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References
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TL;DR: The original, non-suppressive Natua method for impregenation of terminal degeneration has been modified by the introduction of a potassium permanganate-uranyl nitrate sequence, resulting in a selective impregnation of degenarated axons inclusive of their synaptic thickenings.
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TL;DR: Single-unit recordings in the optic tract and lateral geniculate body of kittens in which one eye had been deprived of vision are described, and an anatomical examination of the visual pathways in these animals are examined.
Abstract: THEIMPORTANCEOFNORMALSENSORYSTIMULATION inthedevelopment and maintenance of the nervous system is now generally recognized. In the visual system this problem has usually been approached by examining the effects of sensory deprivation on structure and behavior (see reviews by Hebb (12) and Riesen (28)). An obvious way of extending this work would be to examine electrophysiologically the functional effects of visual deprivation, but such experiments require some knowledge of normal function. During the last 10 years single-cell responses have been examined and receptive-field arrangements compared at several levels in the cat’s visual pathway: in the retina (Zl), the lateral geniculate body (18), and the visual cortex (17, 19). This information provides the necessary background for a study of the immature and the stimulus-deprived visual system. The results of a physiological and anatomical study of the visual pathways in normal. and visually deprived kittens will be presented in a series of three papers. In the present paper we describe single-unit recordings in the optic tract and lateral geniculate body of kittens in which one eye had been deprived of vision, and an anatomical examination of the visual pathways in these animals. The second paper (20) will describe single-unit recordings in the striate cortex of newborn kittens. The final paper (32) will deal with responses of cells in the visual cortex of visually deprived animals.
1,238 citations
TL;DR: Frozen sections of formalin-fixed brains containing surgical lesions, were treated with 15% ethanol for 0.5 hr, and subsequently treated with 0.05% potassium permanganate for 4–10 min, and covered in neutral synthetic resin.
Abstract: Frozen sections of formalin-fixed brains containing surgical lesions, were treated with 15% ethanol for 0.5 hr., soaked in 0.5% phosphomolybdic acid for 0.25–1.0 hr., and subsequently treated with 0.05% potassium permanganate for 4–10 min. (The duration of the latter treatment is critical and individually variable). Subsequent procedure is as follows: decolorize in a mixture of equal parts of 1% hydroquinone and 1% oxalic acid; wash thoroughly and soak sections in 1.5% silver nitrate for 20–30 min.; ammoniacal silver nitrate (silver nitrate 0.9 g., distilled water 20 ml., pure ethanol 10 ml., strong ammonia 1.8 ml., 2.5% sodium hydroxide 1.5 ml.) 0.5–1.0 min.; reduce in acidified formalin (distilled water 400 ml., pure ethanol 45 ml., 1% citric acid 13.5 ml., 10% formalin 13.5 ml.) 1 min.; wash, and pass section through 1% sodium thiosulfate (0.5–1.0 min.); wash thoroughly and pass sections through graded alcohols and xylene (3 changes); cover in neutral synthetic resin.
810 citations
TL;DR: Receptive fields of geniculate receptive fields resembled those of retinal ganglion cells, having an excitatory ('on') centre and inhibitory preriphery, or reverse, and cells with receptive fields within or near the area centralis tended to have smaller field centres and stronger suppression by the receptive field periphery than cells with their fields situated in more peripheral regions of the retina.
Abstract: : Cells were recorded with tungsten electrodes in the dorsal lateral geniculate body of the cat Receptive fields of these units were mapped out, in the light-adapted state, with small sports of light In their general arrangement geniculate receptive fields resembled those of retinal ganglion cells, having an excitatory ('on') centre and inhibitory ('off') preriphery, or reverse The two portions of a receptive field were mutually antagonistic; the decrease in centre responses cauded by inclusion of peripheral portions of receptive fields was termed peripheral suppression Cells recorded in layers A and B of the lateral geniculate body were driven from the contralateral eye; cells in layer A1 from the ipsilateral eye In penetrations normal to the layers receptive fields of cells in a single layer were close together or superimposed, and from one layer to the next occupied exactly homologous positions in the two retinas Binocular interaction was not observed in any of the cells studied All three layers of the lateral geniculate contained both 'on'-centre and 'off'-centre units Cells in layers A and A1 were similar both in their firing patterns and in average receptive field size Cells in layer B were more sluggish in their responses to light stimuli, and tended to have larger receptive field centres Cells with receptive fields within or near the area centralis tended to have smaller field centres and stronger suppression by the receptive field periphery than cells with their fields situated in more peripheral regions of the retina
771 citations