Morphology and topography of on- and off-alpha cells in the cat retina

1981 ◽  
Vol 212 (1187) ◽  
pp. 157-175 ◽  
Keyword(s):  
Central Area ◽  
Plexiform Layer ◽  
Preceding Paper ◽  
Alpha Cell ◽  
Inner Plexiform Layer ◽  
Alpha Cells ◽  
Cat Retina ◽  
Topographical Distribution ◽  
Retinal Point ◽  
Dendritic Branches

Neurofibrillar staining methods were found to stain all alpha cells of the cat retina completely, that is the perikaryon, the axon and the dendritic branches. The dendrites of the alpha cells in vertical sections were found to be unistratified and to occupy two narrow strata in the outer half of the inner plexiform layer. This difference in branching level could also be observed in whole-mount preparations and it has been demon­strated in the preceding paper (Peichl & Wässle 1981) that it corre­sponds to the physiological on‒off dichotomy. Thus the topographical distribution of on- and off-alpha cells could be studied. They were found to occur in about equal numbers. Both on- and off-alpha cell perikarya form a regular lattice and both lattices are superimposed independently. The dendritic branches of neighbouring alpha cells overlap and each retinal point is covered by the dendritic field of at least one on- and one off-alpha cell. The dendritic trees of on-alpha cells seem to have more small branches and are on the average smaller than those of off-alpha cells. The density of alpha cells was found to peak in the central area whence it continuously decreased towards the retinal periphery.

Convergence and divergence of cones onto bipolar cells in the central area of cat retina

1990 ◽  
Vol 330 (1258) ◽  
pp. 323-328 ◽  
Keyword(s):  
Bipolar Cell ◽  
Central Area ◽  
Plexiform Layer ◽  
Preceding Paper ◽  
Bipolar Cells ◽  
Visual Signal ◽  
Wide Field ◽  
Inner Plexiform Layer ◽  
Type B ◽  
Cat Retina

In the central area of cat retina the cone bipolar cells that innervate sublamina b of the inner plexiform layer comprise five types, four with narrow dendritic fields and one with a wide dendritic field. This was shown in the preceding paper (Cohen & Sterling 1990 a ) by reconstruction from electron micrographs of serial sections. Here we show by further analysis of the same material that the coverage factor (dendritic spread x cell density) is about one for each of the narrow-field types (b 1 , b 2 , and b 4 ). The same is probably true for the other narrow-field type (b 3 ), but this could not be proved because its dendrites were too fine to trace. The dendrites of types b 1 , b 2 , and b 4 collect from all the cone pedicles within their reach and do not bypass local pedicles in favour of more distant ones. The dendrites of type b 5 , the wide-field cell, bypass many pedicles. On average 5.1±1.0 pedicles converge on a b 1 bipolar cell; 6.0±1.2 converge on a b 2 cell and 5.7±1.5 converge on a b 4 cell. Divergence within a type is minimal: one pedicle contacts only 1.2 b 1 cells, 1.0 b 2 cells, and 1.0 b 4 cells. Divergence across types is broad : each pedicle apparently contacts all four types of the narrow-field bipolar cells that innervate sublamina b . Each pedicle probably also contacts an additional 4—5 types of narrow-field bipolar cell that innervate sublamina a . There are several possible advantages to encoding the cone signal into multiple, parallel, narrow-field pathways. These include: tuning of pathways to transmit different temporal frequencies, use of ion channels with widely separated equilibrium potentials (to increase gain), and formation of different regulatory circuits in the inner plexiform layer. The latter possibility would permit different operations (e.g linear or nonlinear) to be performed on the visual signal on its way towards different types of ganglion cell.

Morphological identification of on- and off-centre brisk transient (Y) cells in the cat retina

1981 ◽  
Vol 212 (1187) ◽  
pp. 139-153 ◽  
Keyword(s):  
Ganglion Cell Layer ◽  
Plexiform Layer ◽  
Alpha Cell ◽  
Morphological Identification ◽  
Inner Plexiform Layer ◽  
Alpha Cells ◽  
Dendritic Trees ◽  
Cat Retina ◽  
Large Populations ◽  
Y Cells

Brisk transient (Y) cells were recorded extracellularly in the cat retina. The position and shape of their receptive field centres were plotted on a tangent screen, together with retinal landmarks, such as blood vessels adjacent to the recording area. After recording the retina was processed as a whole mount and stained with a reduced-silver method (see appendix). This technique stains the entire alpha cell population including the dendritic trees. Alpha cells are the morphological correlate of the brisk transient cells (Boycott & Wässle 1974; Cleland et al . 1975). Maps of the screen plot and the histological preparation could be accurately superimposed by means of the retinal landmarks and each recorded brisk transient unit could unequivocally be attributed to a particular alpha cell. Alpha cell dendritic trees are unistratified in either of two laminae within the inner plexiform layer: (1) close to the inner nuclear layer border, ‘outer alpha cells’, or (2) about 10 μm further towards the ganglion cell layer, ‘inner alpha cells’. This stratification difference can be observed in whole mounts for large populations of cells (Wässle et al . 1981). Of the recorded brisk transient cells, all on-centre units were inner alphas and all off-centre units outer alphas.

The morphology and topographic distribution of AII amacrine cells in the cat retina

1985 ◽  
Vol 224 (1237) ◽  
pp. 475-488 ◽  
Keyword(s):  
Ganglion Cells ◽  
Lucifer Yellow ◽  
Central Area ◽  
Plexiform Layer ◽  
Amacrine Cells ◽  
Dendritic Morphology ◽  
Inner Plexiform Layer ◽  
Cat Retina ◽  
Superior Margin ◽  
Aii Amacrine Cells

When cat retina is incubated in vitro with the fluorescent dye, 4',6- diamidino-2-phenyl-indole (DAPI), a uniform population of neurons is brightly labelled at the inner border of the inner nuclear layer. The dendritic morphology of the DAPI-labelled cells was defined by iontophoretic injection of Lucifer yellow under direct microscopic control: all the filled cells had the narrow-field bistratified morphology that is distinctive of the A ll amacrine cells previously described from Golgistained retinae. Although the A ll amacrines are principal interneurons in the rod-signal pathway, their density distribution does not follow the topography of the rod receptors, but peaks in the central area like the cone receptors and the ganglion cells. There are some 512000 A ll amacrines in the cat retina and their density ranges from 500 cells per square millimetre at the superior margin to 5300 cells per square millimetre in the centre (retinal area is 450 mm2). The isodensity contours are kite-shaped, particularly at intermediate densities, with a horizontal elongation towards nasal retina. The cell body size and the dendritic dimensions of A ll amacrines increase with decreasing cell density. The lobular dendrites in sublamina a of the inner plexiform layer span a restricted field of 16—45 pm diameter, while the arboreal dendrites in sublamina b form a varicose tree of 18—95 pm diameter. The dendritic field coverage of the lobular appendages is close to 1.0 (+ 0.2) at all eccentricities whereas the coverage of the arboreal dendrites doubles within the first 1.5 mm and then remains constant at 3.8 ( + 0.7) throughout the periphery.

Rod bipolar cells in the cone-dominated retina of the tree shrew Tupaia belangeri

1991 ◽  
Vol 6 (6) ◽  
pp. 629-639 ◽  
Author(s):  
Brigitte Müller ◽  
Leo Peichl
Keyword(s):  
Bipolar Cell ◽  
Tree Shrew ◽  
Light And Electron Microscopy ◽  
Plexiform Layer ◽  
Bipolar Cells ◽  
Peripheral Retina ◽  
Inner Plexiform Layer ◽  
Cat Retina ◽  
Topographical Distribution ◽  
Rod Bipolar Cells

AbstractThe tree shrew has a cone-dominated retina with a rod proportion of 5%, in contrast to the common mammalian pattern of rod-dominated retinae. As a first step to elucidate the rod pathway in the tree shrew retina, we have demonstrated the presence of rod bipolar cells and studied their morphology and distribution by light and electron microscopy.Rod bipolar cells were labeled with an antiserum against the protein kinase C (PKC), a phosphorylating enzyme. Intense PKC immunoreactivity was found in perikarya, axons, and dendrites of rod bipolar cells. The cell bodies are located in the sclerad part of the inner nuclear layer, the dendrites ascend to the outer plexiform layer where they are postsynaptic to rod spherules, and an axon descends towards the inner plexiform layer (IPL). The axons branch, and terminate in the vitread third of the IPL where mammalian rod bipolar cells are known to terminate. Two amacrine cell processes are always seen as the postsynaptic elements (dyads). Dendritic and axonal arbors of rod bipolar cells are rather large, up to 100 μm in diameter. The topographical distribution of the rod bipolar cells was analyzed quantitatively in tangential sections.Their density ranges from 300 cells/mm2 in peripheral retina to 900 cells/mm2 more centrally. The distribution is rather flat with no local extremes. Consistent with the low rod proportion in tree shrew, the rod bipolar cell density is low compared to the rod-dominated cat retina for example (36,000-47,000 rod bipolar cells/mm2). Rod-to-rod bipolar cell ratios in the tree shrew retina range from smaller than 1 to about 7, and thus are also lower than in cat.

Calcium gradients and light-evoked calcium changes outside rods in the intact cat retina

1994 ◽  
Vol 11 (4) ◽  
pp. 753-761 ◽  
Author(s):  
Ron P. Gallemore ◽  
Jian-Dong Li ◽  
Victor I. Govardovskii ◽  
Roy H. Steinberg
Keyword(s):  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Plexiform Layer ◽  
Rapid Onset ◽  
Subretinal Space ◽  
Inner Plexiform Layer ◽  
Rod Outer Segments ◽  
Volume Increase ◽  
Cat Retina ◽  
Dependent Sources

AbstractWe have studied light-evoked changes in extracellular Ca2+ concentration in the intact cat eye using ion-sensitive double-barreled microelectrodes. Two prominent changes in Ca2+ concentration were observed that differed in retinal location. There was a light-evoked increase in accompanied by brief ON and OFF transients, which was maximal in the inner plexiform layer and was not further studied. There was an unexpected sustained light-evoked decrease in of relatively rapid onset and offset, which was maximal in the distalmost region of the subretinal space (SRS). in the SRS was 1.0 mM higher than in the vitreous humor during dark adaptation and this transretinal gradient disappeared during rod-saturating illumination. After correcting for the light-evoked increase in the volume of the SRS, an increase in the total Ca2+ content of the SRS during illumination was revealed, which presumably represents the Ca2+ released by rods. To explain the light-evoked changes, we used the diffusion model described in the accompanying paper (Li et al., 1994b), with the addition of light-dependent sources of Ca2+ at the retina/retinal pigment epithelium (RPE) border and rod outer segments. We conclude that a drop in around photoreceptors, which persists during illumination and reduces a transretinal Ca2+ gradient, is the combined effect of the light-evoked SRS volume increase, Ca2+ release from photoreceptors, and an unidentified mechanism(s), which is presumably Ca2+ transport by the RPE. The relatively rapid onset and offset of the decrease remains unexplained. These steady-state shifts in should have significant effects on photoreceptor function, especially adaptation.

The morphology and topographic distribution of substance- P-like immunoreactive amacrine cells in the cat retina

1989 ◽  
Vol 237 (1289) ◽  
pp. 471-488 ◽  
Keyword(s):  
Substance P ◽  
Ganglion Cell ◽  
Plexiform Layer ◽  
Amacrine Cells ◽  
Maximum Density ◽  
Peripheral Retina ◽  
Inner Plexiform Layer ◽  
Cat Retina ◽  
Area Centralis ◽  
Topographic Distribution

In cat retinal wholemounts, substance-P-like immunoreactivity (SP-IR) was localized in a distinct population of amacrines whose cell bodies were normally placed in the ganglion cell layer. Although displaced amacrines accounted for 80-95% of the SP-IR amacrines in peripheral retina, this proportion decreased considerably within the area centralis, accounting for 50-80% of the labelled cells at maximum density. The SP-IR cells in both the inner nuclear and ganglion cell layers gave rise to well-defined varicose dendrites of uniform appearance that stratified around 60% depth (S3/S4) of the inner plexiform layer. In addition, sparse fine dendrites in stratum 1 (S1) could sometimes be traced to inner nuclear cells and occasionally to displaced amacrines. The combined SP-IR cell density ranged from less than 50 cells mm -2 in the far periphery to more than 500 cells mm -2 in the area centralis; the maximum density showed little individual variation despite wide differences in the proportion of displaced cells. The 39000 SP-IR amacrines in a mapped retina had a triangular topographic distribution, with intermediate isodensity lines extending vertically in superior retina and horizontally along both arms of the visual streak. Colocalization experiments established that all SP-IR cells in cat retina showed GABA-like immunoreactivity, and that the SP-IR amacrines were quite distinct from the cholinergic amacrines identified by choline acetyltransferase immunohistochemistry.

Glycine receptor immunoreactivity is localized at amacrine synapses in cat retina

1991 ◽  
Vol 7 (6) ◽  
pp. 611-618 ◽  
Author(s):  
Roberta G. Pourcho ◽  
Michael T. Owczarzak
Keyword(s):  
Ganglion Cells ◽  
Glycine Receptor ◽  
Plexiform Layer ◽  
Amacrine Cells ◽  
Bipolar Cells ◽  
Electron Microscopic Level ◽  
Inner Plexiform Layer ◽  
Glycine Receptors ◽  
Electron Microscopic ◽  
Cat Retina

AbstractImmunocytochemical techniques were used to localize strychnine-sensitive glycine receptors in cat retina. Light microscopy showed staining in processes ramifying throughout the inner plexiform layer and in cell bodies of both amacrine and ganglion cells. At the electron-microscopic level, receptor immunoreactivity was seen to be clustered at sites postsynaptic to amacrine cells. In contrast, bipolar cells were neither presynaptic nor postsynaptic elements at sites of glycine receptor staining. Double-label studies verified the presence of glycine immunoreactivity in amacrine terminals presynaptic to glycine receptors. These findings support a role for glycine as an inhibitory neurotransmitter in amacrine cells.

scholarly journals Temporal and mosaic distribution of large ganglion cells in the retina of a daggertooth aulopiform deep–sea fish ( Anotopterus pharao )

2000 ◽  
Vol 355 (1401) ◽  
pp. 1161-1166 ◽  
Author(s):  
M. Uemura ◽  
H. Somiya ◽  
M. Moku ◽  
K. Kawaguchi
Keyword(s):  
Ganglion Cells ◽  
Outer Part ◽  
Plexiform Layer ◽  
Inner Plexiform Layer ◽  
Retinal Ganglion ◽  
Cat Retina ◽  
Epipelagic Zone ◽  
Area Centralis ◽  
Mean Size ◽  
Mosaic Distribution

The daggertooth Anotopteruspharao (Aulopiformes: Anotopteridae) is a large, piscivorous predator that lives within the epipelagic zone at night. In this species, the distribution of retinal ganglion cells has been examined. An isodensity contour map of ganglion cells shows that the cells concentrate in a slightly ventral region of the temporal retina. The region of high ganglion cell density contains 4.07 × 10 3 cells mm −2 , and the resulting visual acuity is 3.5 cycles deg −1 . Outside the area centralis, conspicuously large ganglion cells (LGCs) are observed in the temporal margin of the retina. The LGCs are regularly arrayed, and displaced into the inner plexiform layer. Thick dendrites extend into the outer part (sublamina a) of the inner plexiform layer. In the retinal whole mount, the total number of LGCs is 1590 (90.7cm specimen), and the mean size of the LGCs is about four times larger than that of the ordinary ganglion cells. The morphological appearance of the LGCs was similar to the off–type alpha cells of the cat retina. The function of these distinctive LGCs is discussed in relation to specific head–up feeding behaviour.

Morphology and mosaic of on- and off-beta cells in the cat retina and some functional considerations

1981 ◽  
Vol 212 (1187) ◽  
pp. 177-195 ◽  
Keyword(s):  
Beta Cells ◽  
Visual Discrimination ◽  
Ganglion Cells ◽  
Plexiform Layer ◽  
Inner Plexiform Layer ◽  
Fine Detail ◽  
Cat Retina ◽  
Retinal Topography ◽  
Dendritic Branching ◽  
Whole Mounts

The beta type of ganglion cell can be subdivided in Golgi-stained whole mounts of the cat retina according to the branching level of the den­dritic tree in the inner plexiform layer. The dendritic branching level of on-beta cells is nearer to the cell body; that of off-beta cells is about 10 μm further outwards. After horseradish peroxidase (HRP) injection into the lateral geniculate nucleus all beta cells were labelled. In this way it is shown that about 55% of all ganglion cells, irrespective of retinal topography, are beta cells. The spatial distribution of on- and off-beta cells was studied from the HRP-labelled material. On-beta cells form a lattice with regular inter-cell spacings ; off-beta cells are also regularly arrayed. The two lattices are superimposed independently of each other. Beta cells are commonly assumed to be associated with the resolution of fine detail in the cat visual system. The mosaic of beta cells imposes some constraints and permits some predictions to be made with respect to the cat’s visual discrimination.

NADPH-diaphorase neurones of human retinae have a uniform topographical distribution

1990 ◽  
Vol 4 (6) ◽  
pp. 619-623 ◽  
Author(s):  
Jan M. Provis ◽  
John Mitrofanis
Keyword(s):  
Ganglion Cell ◽  
Nicotinamide Adenine Dinucleotide ◽  
Ganglion Cell Layer ◽  
Cell Layer ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Plexiform Layer ◽  
Amacrine Cells ◽  
Nadph Diaphorase ◽  
Inner Plexiform Layer ◽  
Topographical Distribution

AbstractWe have examined the morphology and distribution of neurones that contain nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase in human retinae. NADPH-diaphorase reactivity was observed in three different classes of amacrine cells (ND1, ND2, ND3 cells) and in the cone photoreceptors. ND1 cells had relatively large somata (mean, 12.3 ¼m) located in the inner nuclear layer (INL) and in the ganglion cell layer (GCL). Their dendrites were often strongly labeled and spread into either the middle or outer strata of the inner plexiform layer (IPL). The somata of ND2 cells were medium-sized (mean, 8.2 ¼m) and located in the INL and in the GCL; their dendrites were usually beaded and often spread in either the middle or outer strata of the IPL. ND3 cells had small, round somata (mean, 5.2 ¼m) located in either the INL or GCL, and were without labeled processes. The total number of NADPH-diaphorase cells (all classes) was estimated at 118,000, with a mean density of about 100/mm2. The most striking fea ture of NADPH-diaphorase cells in humans was that their distribution was relatively uniform across the retina, with no evidence of a peak in density at the foveal rim.

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