Large Ganglion Cells Research Articles

Birth dates of retinal ganglion cells giving rise to the crossed and uncrossed optic projections in the mouse.

In the mouse, as in most mammals, the crossed optic projections originate from the entire extent of the retina, whereas ganglion cells giving rise to the uncrossed (ipsilateral) projection are restricted to the temporal and ventral retina. The nasal border of this bilaterally projecting region in the retina corresponds to the midline of the visual field. Here the birth dates of ipsilaterally and contralaterally projecting ganglion cells were determined by combining tritiated thymidine labelling in the embryo with horseradish peroxidase tracings from the optic tract in the adult. Contralaterally projecting ganglion cells were found to be generated from embryonic day E11 to about E19 in a crude concentric fashion with the oldest cells in central and youngest ones in peripheral retina. Ipsilaterally projecting cells were born from E11 to E16, that is, during the earlier part of the period in which the contralateral projection was born. At the earliest time of ganglion cell generation (E11-12) ipsi- and contralaterally projecting cells were born within separate retinal regions, with the future midline representation forming the border between the two zones. This distinction became lost after E13, when both ipsi- and contralaterally projecting cells were born in the bilaterally projecting region. Hence at E11-12 the retina was found to have a bipartite organization that may allow the specification of the two maps of opposite topographical polarity in which the crossed and uncrossed projections are organized. Since in the adult retina this bipartite organization is preserved only in the large ganglion cells that project to the lateral geniculate nucleus, and since large ganglion cells are known to be the earliest ones formed in the mouse, these cells may be the ones that establish the early and bilateral projections of the retina. The conclusion that the bilateral projection system in the retina reflects an early developmental programme, and not the result of competition between the two eyes at later stages, was reinforced by observing a practically normal retinal origin of ipsilateral projections in mice which had only one normal eye from the earliest stages of eye development.

Structural asymmetry in the frog retinal ganglion cell layer

The density of distribution and topographical features of small and large ganglion cells were investigated in total silver-impregnated preparations of the retina from two species of frogs (Rana ridibunda andR. temporaria). A horizontal band of increased density of ganglion cells was located in both species above the nasotemporal axis passing through the blind spot. Outside this band the density of the small cell population was maximal in the central zone of the retina, decreasing toward the periphery. In the upper halves of the retina the density of small cells was on average 26% greater than in the lower halves. Large ganglion cells, on the other hand, were more densely distributed in the lower half of the retina than in the upper half; this difference was particularly marked inR. temporaria (by 116%). The large cells were asymmetrically distributed relative to the dorsoventral axis also: In the nasal quadrants their density was 40–55% greater than in the temporal. Large cells were more densely distributed in the middle zone of the retina. Signs of asymmetry in the organization of the retinal output raster may be of adaptive ecologic importance and may determine the characteristics of formation of visually controlled food and avoidance behavioral reflexes.

The histochemical localization of cytochrome oxidase in the retina and lateral geniculate nucleus of the ferret, cat, and monkey, with particular reference to retinal mosaics and ON/OFF-center visual channels

The histochemical localization of cytochrome oxidase within the normal retina and lateral geniculate nucleus (LGN) of cats, ferrets, and monkeys revealed that distinct layers, types of cells, and portions of neurons are more intensely stained than others. The dark staining of photoreceptor inner segments and cone pedicles and the light staining of photoreceptor outer segments, somata, and rod spherules demonstrates that different segments of the same cell may have disparate but distinct levels of oxidative enzyme activity. In tangential sections of retina, regular mosaic arrays were evident for each of several darkly reactive retinal components, such as cone inner segments, cone pedicles, and horizontal cells. In the cat and ferret, regular mosaic arrays were also formed by metabolically distinguishable populations of ganglion cells. Ia and IIa ganglion cells (OFF-; Nelson, R., E. V. Famiglietti, Jr., and H. Kolb (1978) J. Neurophysiol. 41: 472-483) were more darkly reactive than the other classes. The darker staining of sublamina a of the inner plexiform layer (OFF-; Famiglietti, E. V., Jr., and H. Kolb (1976) Science 194: 193-195) in the cat and ferret retina, as well as sublamina A' and A1' of the ferret LGN (OFF-; Stryker, M.P., and K.R. Zahs (1983a) J. Neurosci. 3: 1943-1951) suggest that, under typical rearing conditions, the OFF-channels may be metabolically more active than the ON-channels in these species. In Macaca and Saimiri, darker staining was observed in sublamina b of the inner plexiform layer (ON-; Famiglietti, E.V., Jr., and H. Kolb (1976) Science 194: 193-195) and laminae 1, 2, and 6 of the LGN, implying that, under similar rearing conditions, a different pattern is observed. The dark staining of many large retinal ganglion cells, as well as most of the larger LGN neurons (presumed Y/Y-like), in all species studied is evidence that the Y/Y-like pathway is also highly active.

Antibodies against filamentous components in discrete cell types of the mouse retina

Three monoclonal antibodies have been raised against the ganglion cell layer of the adult mouse retina. The first antibody, R3, labeled optic axons in the inner retina, and with colchicine pretreatment somata and dendrites of large ganglion cells could be seen. A small number of other processes, including fibers projecting to the retina from elsewhere (efferent fibers), were also labeled in the inner retina. In the outer plexiform layer R3 stained the axonless class of horizontal cells. R3 recognized a 185,000- to 200,000-dalton polypeptide which is most probably the heaviest of the neurofilament subunits. Antibodies R4 and R5 labeled filamentous components mainly in glia and cells of mesenchymal origin. The antigens appeared in most but not quite all locations morphologically closely related to the intermediate filament protein vimentin. In the retina both antibodies labeled strongly the regularly spaced Müller glia. The astroglia of the optic fiber layer was stained with R5 but not R4. Although the two antigens were in general not expressed in neurons, they were both present in axonless horizontal cells in the outer plexiform layer, coexisting with neurofilaments in this neuron.

The neural substrate for the pupillary light reflex in the pigeon (Columba livia).

The neural substrate of the pupillary light reflex in the pigeon was investigated using anatomical, stimulation, and lesion techniques. In birds, as in mammals, the sphincter pupillae muscle (which constricts the iris) is innervated by cells in the ciliary ganglion (Pilar and Tuttle, '82). These cells are in turn innervated by cells in the Edinger-Westphal nucleus (EW) (Cowan and Wenger, '68; Narayanan and Narayanan, '76; Lyman and Mugnaini, '80). The efferent link of the pupillary light reflex must therefore involve cells in EW. To study the central course of this reflex pathway, injections of horseradish peroxidase (HRP) were placed in EW. These injections labeled cells in a number of regions including a contralateral pretectal nucleus, area pretectalis (AP). Only a limited number of cells in AP project to EW. Injections of tritiated amino acids into AP labeled a discrete region of the contralateral EW. This projection is confined to a dorsolateral region of caudal EW and overlies the somata of approximately 100 cells. Tritiated proline was injected into the eye, and the results confirmed an earlier report (Reperant, '73) that AP receives retinal input from the contralateral eye. Immunohistochemical studies demonstrated fibers in AP that stained positively for substance-P-like, enkephalin-like and tyrosine-hydroxylase-like immunoreactivity. Injections of HRP were placed in AP to examine the retinal ganglion cells mediating the reflex. Cells with an average diameter of approximately 14 microns (5-25 microns range) were labeled and averaged approximately 6 microns greater in diameter than the retinal ganglion cells (mean = 7.3 microns) labeled by an optic chiasm injection. The cells labeled by AP injections were distributed unevenly throughout the retina with a higher concentration in the central and temporal retina and a paucity in the red field and fovea. Our results demonstrate that AP receives input from a distinct subpopulation of large retinal ganglion cells that comprises a very small percentage of the total population of retinal ganglion cells. Unilateral lesions of AP abolished the pupillary light reflex in the eye contralateral to the lesion; stimulation of AP elicited pupilloconstriction in the eye contralateral to the stimulation site. These results delineate the central course of the pupillary light reflex pathway in the pigeon and identify the retinal ganglion cells that subserve this reflex. They show that, at every point in the pathway, only a few cells mediate this simple reflex.(ABSTRACT TRUNCATED AT 400 WORDS)

Antibodies to heavy neurofilament subunit detect a subpopulation of damaged ganglion cells in retina.

Neurofilaments ( NFs ) consist of three protein subunits with apparent molecular weights of 68,000 ( 68K ), 145K and 200K , which are found closely associated in most but not all locations in the nervous system. One of these exceptions is the inner retina of the mouse, where antibodies to 145K NFs label large ganglion cells throughout the extent of the cells, while antibodies to 200K NFs label only more distal portions of the optic axons but usually fail to label the ganglion cell somata and proximal axons. Very rarely, however, and more often in old mice, anti- 200K NF antibodies do label a ganglion cell completely. To determine whether these rare, completely labelled cells reflect a pathological alteration, we cut the optic axons, and report here that after a few days some of the axotomized cells could be labelled completely, in a Golgi-like fashion, by anti- 200K NF antibodies. These cells seem to represent the population that forms the projection to the bulk of the lateral geniculate nucleus, as suggested by their size, distribution and projection pattern. Hence, antibodies to the heavy NF subunit in combination with lesions may allow selective retrograde tracing of a subpopulation of ganglion cells, and such antibodies can be used to detect damage in NF-rich neurones at a very early stage, long before they eventually degenerate.

The cardio-regulator nerves of the hermit crabs: anatomical and electrophysiological identification of their distribution inside the heart

1. The cardiac ganglion and the routes of the cardio-regulator nerves inside the heart were investigated anatomically and electrophysiologically in the hermit crabs (Aniculus aniculus andDardanus crassimanus). It was proved that the dorsal cardiac nerve containing three regulator axons on each side, one inhibitor and two accelerators, pierced the heart wall and connected with the cardiac ganglion. 2. The cardiac ganglion consisted of five large neurons and four small neurons. Configuration of the cardiac ganglion was analogous to the crab (Cancer orPortunus) cardiac ganglion in having a pair of circular trunks. However, arrangement of the large cells and the small cells was analogous to the lobster (Homarus, Panulirus orPalinurus) cardiac ganglion in alignment of the ganglionic cells. 3. The two acceleratory nerves had almost identical innervating routes. The route of the inhibitory nerve was significantly different from the routes of the acceleratory nerves inside the heart. 4. The inhibitory axon had the route only along the main trunk of the cardiac ganglion. IPSPs were recorded from large ganglionic cell bodies, one-toone to inhibitory impulses. 5. The acceleratory axons were carried not only in the main trunk but also in the circular trunk. There were acceleratory branches extending toward the periphery away from both the trunks. 6. EPSPs were recorded from large cell bodies in a one-to-one relationship to acceleratory stimuli. This provided direct evidence for ordinary synapses of the accelerator on the large ganglionic cells.

Effect of impulse blockage on cytochrome oxidase activity in monkey visual system.

Cytochrome oxidase (cytochrome c oxidase; ferrocytochrome c: oxygen oxidoreductase, EC 1.9.2.1) has been introduced as an oxidative metabolic marker for neurones in the central nervous system. Previous studies have shown that mature neurones remained sensitive to altered functional demands, and that both developing and adult neurones responded to sensory deprivation or deafferentation by reducing their cytochrome oxidase (Cyt. Ox.) activity. More recently, we showed that the blockage of retinal impulse transmission with tetrodotoxin led to a reversible reduction in Cyt. Ox. staining of affected lateral geniculate (LGN) and striate neurones in adult cats. The present study sought to extend these findings to adult monkeys, where Cyt. Ox. 'puffs' or 'blobs' are uniquely present in the visual cortex. We found that, while the retina remained histologically intact, with only moderate decreases in Cyt. Ox. staining of large ganglion cells and the two plexiform layers, subtle changes occurred in the LGN as early as 1 day post-tetrodotoxin injection, and clear reduction in enzyme levels was evident in both the LGN and the visual cortex by 3 days. Changes became progressively more severe up to 4 weeks post-injection. Within area 17, alternating bands of high and low Cyt. Ox. staining occurred in lamina IV, with alternating rows of dark and lightly reactive puffs superimposed in exact register. Thus, the mature visual neurones in the primate remain extremely sensitive to the cessation of retinal impulse transmission, and plastic metabolic changes occur through several synapses along the sensory pathway.

Time course of morphological differentiation of cat retinal ganglion cells: influences on soma size.

We have examined the growth of ganglion cell somas during development of the cat's retina. Until approximately E (embryonic day) 50, ganglion cell somas show no sign of the several variations in their size apparent in the adult. At about E50, the somas begin to accumulate granular cytoplasm. The accumulation proceeds first among area centralis cells which, for a few days, are the largest ganglion cells in the retina (whereas in the adult they are the smallest). By E57 three of the adult soma size trends have become apparent: the differentiation of soma size related to functional class, the nasal-temporal difference in soma size, and the small mean size of somas in the visual streak. The early appearance of these trends in soma size suggests that individual cells may be intrinsically programmed to develop as cells of a particular class, such as alpha-, beta-, or gamma-cells, even before their morphological differentiation begins. A fourth trend in soma size, the centro-peripheral difference, appears only after an initial period of ganglion cell growth; the small size of ganglion cells at the area centralis seems to be determined, at least partly, by a local "environmental" factor, the crowding of ganglion cells.

Neurofilaments contain alpha-melanocyte-stimulating hormone (alpha-MSH)-like immunoreactivity.

An antiserum to alpha-melanocyte-stimulating hormone (alpha-MSH) was found to contain antibodies to at least two types of determinants on the alpha-MSH peptide: one is present only on the free peptide, the other is shared with neurofilaments. Immunoblots from mouse brain showed the neurofilament crossreactivity to be located on proteins in the Mr 140,000 range. The neurofilament-crossreactive portion of the antiserum could be selectively absorbed out with a cytoskeletal preparation, which abolished all affinity of the antiserum to the retina but did not affect the labeling pattern in the pituitary. Absorptions with desacetyl-alpha-MSH and corticotropin seemed to indicate that the determinant shared with neurofilaments is not located at either end of the alpha-MSH peptide, but somewhere in between. The immunohistochemical labeling of the retina with the alpha-MSH antiserum was compared to the labeling with monoclonal antibodies against Mr 200,000 neurofilaments. In the adult retina the alpha-MSH-like immunoreactivity was found to be slightly more widespread; most consistently it was detectable in cell bodies of large ganglion cells, whereas the heavy neurofilament subunit was absent from somata and proximal axons of these cells. In the developing mouse brain, expression of the heavy subunit was found to lag 2-3 wk behind expression of the Mr 140,000 proteins. This confirms previous reports of a more restricted distribution and late expression of high molecular weight neurofilaments as compared to the lower subunits.

The number of synaptic boutons terminating on Xenopus cardiac ganglion cells is directly correlated with cell size.

The relationship between the size of parasympathetic neurones and the number of synaptic boutons terminating upon them has been studied in the cardiac ganglion of Xenopus laevis. Synaptic boutons were visualized by impregnation with zinc iodide and osmium (ZIO), which by electron microscopy was shown to stain heavily all synaptic boutons in six preparations. Light microscopic examination of the unipolar ganglion cells in intact tissue reveals that larger neurones have more synaptic boutons. The number of boutons terminating on the cell body is significantly correlated with its surface area. By statistical means it was possible to demonstrate that the relation between bouton number and surface area is linear and that the regression line has a y-intercept not significantly different from zero. Therefore the density of synaptic boutons, one per 127 micron2 of cell body surface, is independent of cell size. The size of synaptic boutons, measured as the area of apposition between bouton and cell body, is similar for small and for large ganglion cells; thus a constant fraction (2%) of the cell body on average is covered by synaptic boutons, regardless of cell size. The correlation between bouton number and cell body surface area is not the result of interaction between boutons. The frequency distribution of boutons per normalized cell was found to be similar to that expected from the Poisson distribution. Thus the probability that a bouton will be 'assigned' to a particular cell is independent of how many other boutons are present. The only factor that appears to influence the number of boutons on the cell body is its size.

Das Spiralganglion des Rhesusaffen*,**

Four temporal bones of rhesus monkeys were investigated in respect of composition and morphology of the spiral ganglion cells. Using light and electron microscopic technique two main types of ganglion cells could be distinguished, namely 90% large (type I) and 10% small (type II) cells. Both small and large ganglion cells are surrounded by myelin sheaths: 90% of the large neurons are surrounded by myelin sheaths, whereas only 15% of the small neurons have a myelin sheath. The small neurons are exclusively connected with unmyelinated nerve-endings forming synaptic contact with the cell surface. These nerve endings contain vesicles similar to synaptic vesicles; the cytoplasm of the adjacent small ganglion cells contains dense core vesicles. Similar dense core vesicles are, however, also found in the cytoplasm of the large ganglion cells and in the axoplasm of the corresponding nerve axons. It is only in the cytoplasm of the small ganglion cells that dense bundles of neurofilaments are present. It seems that the nerve endings resembling synapses and contacting the small ganglion cells belong to the efferent, olivo-cochlear spiral bundle.

α-Bungarotoxin binding sites on sensory neurones and their axonal transport in sensory afferents

The autoradiographic localization of [ 125I]α-bungarotoxin binding sites on primary sensory fibres was investigated. Nicotinic α-bungarotoxin binding sites were localized to a small sub-population of large dorsal root ganglion cells in the rat, monkey, cat and human dorsal root ganglia. Ligation of the sciatic nerve or dorsal root in the rat resulted in an anterograde accumulation of binding sites proximal to the dorsal root ganglion, and a small retrograde accumulation. Unilateral dorsal root section in the rat produced a loss of toxin binding sites mainly within lamina III of the dorsal horn. These results suggest that nicotinic α-bungarotoxin binding sites manufactured in large dorsal root ganglion cell bodies are transported both centrally to the spinal cord and also peripherally.

Morphology and location of tectal projection neurons in frogs: a study with HRP and cobalt-filling.

Tectal projection neurons were labeled by retrograde transport of horseradish peroxidase (HRP) or cobaltic-lysine. The tracer substances were delivered iontophoretically or by pressure injection or diffusion into various regions of the brain or spinal cord. Histochemical procedures allowed identification of labeled cells projecting to the injected regions. Many neurons were filled with cobaltic-lysine, resulting in a Golgi-like staining. After cobalt injections in the diencephalon most of the labeled cells, identified as small piriform neurons, were located in layer 8 of the tectum. Two types of small piriform neurons were distinguished. Type 1 neurons have flat dendritic arborizations confined to lamina D, while the dendrites of type 2 cells may span all of the superficial tectal strata. In smaller numbers large piriform, pyramidal, and ganglionic cells of the periventricular tectal layers were labeled after diencephalic injections. Rhombencephalic cobalt and HRP injections labeled cells whose axons form the tectobulbospinal tract. The neurons most frequently labeled were large ganglionic cells. Ipsilaterally, the majority of their somata were located in layer 7, and their dendrites arborized mainly in lamina F. Contralaterally, labeled ganglionic cell somata occupied the top of layer 6, and most of their dendritic end-branches entered lamina B. The possible functional significance of this anatomical arrangement is discussed. After tectal cobalt injections the topography of the tectoisthmic projection and the terminals of tectal efferent fibers in the diencephalon and brainstem were observed. It is concluded that the organization of frog tectofugal pathways is very similar to that of mammals.

The distribution of displaced ganglion cells in the retina of the pigeon.

Displaced ganglion cells in the pigeon's retina, at the inner margin of the inner nuclear layer, were labelled by retrograde axonal transport of horseradish peroxidase (HRP). Large HRP injections were made in order to fill all the retinal projection sites in the thalamus and midbrain. The distribution of labelled cells was studied in retinal whole mounts incubated with tetramethyl benzidine (TMB) substrate for HRP. A maximum of 5,300 HRP labelled displaced ganglion cells was found. They were concentrated in a band of retina centred on the horizontal meridian, with high density areas (of about 110 cells/mm2) near the area centralis and in the mid-temporal retina. This is a different distribution to that of ganglion and inner nuclear layer cells; these are concentrated in the area centralis and red field. The orientation of retinal maps was checked by ophthalmoscopic measurements of the angle of the pecten to the horizontal in alert pigeons; this was found to be approximately 70 degrees. The array of displaced ganglion cells, studied by nearest neighbour distributions, was irregular and nearly random, which is consistent with a system of low spatial acuity. In the central retina only the cell bodies and not the dendrites of small displaced ganglion cells (7.5 microns diameter) were labelled; towards the periphery large displaced ganglion cells (16 microns diameter) with 2-5 radially arranged primary dendrites were found.

Reduction in numbers of large ganglion cells in cat retina following intravitreous injection of antibodies

Antibodies were prepared against large ganglion cells isolated from bovine retina and injected into the vitreous chamber of 1 eye in 6 adult cats. The other eye of each cat received either a control pre-immune γ-globulin injection or was untreated. After a survival time of 9–86 days, ganglion cell density was assessed from Nissl-stained retinal whole-mounts. In each cat, there were fewer large ganglion cells (α-cells) in the immunoglobulin-injected retina than in the control retina. The reduction in large ganglion cells occurred in patches adjacent to areas of approximately normal large ganglion cell density. Counts of the number of large ganglion cells in both eyes of the 6 cats indicated that the immunoglobulin injected eyes had from 8% to 61% (mean 32%) fewer large ganglion cells than the paired control eyes. This was significantly greater than the difference in the number of large ganglion cells between pairs of normal or control-injected eyes. The magnitude of the effect was not related to the survival time following the immunoglobulin injection. Cell size measures of all ganglion cells in selected areas of retina indicated that the small ganglion cells were unaffected by the antibodies. However, there was a suggestion that the largest of the medium size ganglion cells were affected in addition to the large ganglion cells. Counts of total ganglion cells per unit area in affected regions of retina revealed a reduced overall density, suggesting that the ganglion cells were lost rather than decreased in size. These results indicate that antibodies to the large ganglion cells can be used to reduce the number of large ganglion cells (α-cells) in the cat retina. Since these cells correspond to the Y-cell functional class of ganglion cells in the cat retina, the antibodies may provide a useful tool for studying Y-cell function in the visual pathways.

An electron microscopic study of autonomic nerve cells in the cloacal region of the lamprey, Lampetra japonica.

Two types of autonomic nerve cell in the cloacal region of lamprey, Lampetra japonica have been studied by electron microscopy. Large ganglion cells (LGC) were unipolar and individually invested with a satellite cell sheath. The LGC-satellite cell complex measured 24 microns X 38 microns on average. Granular endoplasmic reticulum and cored vesicles (80-140 nm in diameter) were scattered in the perikaryon. Two kinds of peculiar cytoplasmic filament were seen in LGC: one type was about 20 nm in diameter with periodic dense material on the surface and the other had a diameter of about 8 nm and showed an undulating profile. Nerve endings containing abundant small clear vesicles (30-50 nm in diameter) and a few larger cored vesicles (50-100 nm in diameter) were found in synaptic contact with LGC. Small ganglion cells (SGC) were also unipolar and covered incompletely by a satellite cell sheath. The SGC-satellite cell complex measured 6 and 12 microns on average. The SGC was packed with organelles and the perikaryon appeared more electron dense than that of LGC. SGC perikaryonal cytoplasm contained dispersed granular endoplasmic reticulum and numerous large cored vesicles (55-220 nm in diameter). Nerve endings containing numerous large cored vesicles (70-170 nm in diameter) and variable numbers of small clear vesicles (30-50 nm in diameter) were seen on the surface of SGC.

Effects of antibodies to large ganglion cells on the cat's retinogeniculate pathway.

Effects of antibodies to large ganglion cells on the cat's retinogeniculate pathway.

Organization of visual pathways in normal and visually deprived cats.

Organization of visual pathways in normal and visually deprived cats.

Retinal ganglion cell projections to individual layers of the lateral geniculate body in Galago crassicaudatus

The genus Galago provides an unique opportunity to study the relation between layers of the lateral geniculate body and classes of retinal ganglion cells. In the present experiments HRP was restricted to individual layers of the lateral geniculate body with the following results: After injections of the magnocellular layers, layers 1 and 2, labeled retinal ganglion cells ranged in size from 8 to 20 micrometers. After injections of the parvocellular layers, layers 3 and 6, labeled retinal ganglion cells ranged in size from 6 to 12 micrometers. After injections involving layers 4 and 5, which layers contain only very small, pale cells, labeled retinal ganglion cells ranged in size from 5 to 14 micrometers. Thus, the very largest ganglion cells were labeled only after injections of magnocellular layers 1 and 2, while small and medium retinal ganglion cells were labeled after HRP injections in every layers of the lateral geniculate body. Because the magnocellular layers actually contain a mixture of large, medium, and small-sized cells, we suggest that retinal ganglion cells of different size-classes project to geniculate relay cells of the corresponding size-class.