Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “GANGLION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources
PubMed1990

Topography of ganglion cells in human retina.

We quantified the spatial distribution of presumed ganglion cells and displaced amacrine cells in unstained whole mounts of six young normal human retinas whose photoreceptor distributions had previously been characterized. Cells with large somata compared to their nuclei were considered ganglion cells; cells with small somata relative to their nuclei were considered displaced amacrine cells. Within the central area, ganglion cell densities reach 32,000-38,000 cells/mm2 in a horizontally oriented elliptical ring 0.4-2.0 mm from the foveal center. In peripheral retina, densities in nasal retina exceed those at corresponding eccentricities in temporal retina by more than 300%; superior exceeds inferior by 60%. Displaced amacrine cells represented 3% of the total cells in central retina and nearly 80% in the far periphery. A twofold range in the total number of ganglion cells (0.7 to 1.5 million) was largely explained by a similar range in ganglion cell density in different eyes. Cone and ganglion cell number were not correlated, and the overall cone:ganglion cell ratio ranged from 2.9 to 7.5 in different eyes. Peripheral cones and ganglion cells have different topographies, thus suggesting meridianal differences in convergence onto individual ganglion cells. Low convergence of foveal cones onto individual ganglion cells is an important mechanism for preserving high resolution at later stages of neural processing. Our improved estimates for the density of central ganglion cells allowed us to ask whether there are enough ganglion cells for each cone at the foveal center to have a direct line to the brain. Our calculations indicate that 1) there are so many ganglion cells relative to cones that a ratio of only one ganglion cell per foveal cone would require fibers of Henle radiating toward rather than away from the foveal center; and 2) like the macaque, the human retina may have enough ganglion cells to transmit the information afforded by closely spaced foveal cones to both ON- and OFF-channels. Comparison of ganglion cell topography with the visual field representation in V1 reveals similarities consistent with the idea that cortical magnification is proportional to ganglion cell density throughout the visual field.

Adult↗
PubMed1988

Dissection of the neuron network in the catfish inner retina. II. Interactions between ganglion cells.

1. To characterize signal interactions between ganglion cells, extrinsic current, either sinusoidally or white-noise modulated, was injected into a ganglion cell and the resulting extracellular spike discharges were recorded from a neighboring ganglion cell. 2. Current injected into an ON-ganglion (GA) cell modulated the spike discharges of a neighboring ON-ganglion cell (GA). Similarly, a current injected into an OFF-ganglion (GB) cell modulated the spike discharges of a neighboring OFF-ganglion (GB) cell. The signal transmission between ganglion cells of the same response polarity was fast and sign-noninverting. The transfer function was lowpass with a cutoff frequency of 30 Hz. The efficacy of the transmission was comparable to that from bipolar or amacrine to ganglion cells of the same polarity. 3. Current injected into an ON-ganglion (GA) cell modulated the spike discharges of a neighboring OFF-ganglion (GB) cell; the signal transmission was slow and sign-noninverting. Correspondingly, current injected into an OFF-ganglion (GB) cell modulated the spike discharges of a neighboring ON-ganglion (GA) cell; transmission was slow and sign-inverting. 4. A brief electrical stimulation of the optic nerve activated a single antidromic ganglion cell spike at threshold. With suprathreshold stimulation, multiple spikes appeared, which probably were activated orthodromically. Changes in membrane potential of ganglion and amacrine cells induced by optic nerve stimulation usually lasted 50-80 ms, with an initial depolarization followed by hyperpolarization. We interpret such long-lasting responses to be mediated by reciprocal circuits that include amacrine, bipolar, and ganglion cells. 5. Together with the observations made by Sakai and Naka, we conclude that virtually almost all amacrine, bipolar, and ganglion cells are functionally interconnected; direct and fast connections are established among ON-cells and similarly among OFF-cells, and complex, indirect connections are established between ON- and OFF-cells.

Animals↗
PubMed1982

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 gamma-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 (alpha-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 (alpha-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.

Animals↗
PubMed1991

Analysis of the horizontal cell contribution to the receptive field surround of ganglion cells in the rabbit retina.

1. The influence of horizontal cells on ganglion cells, the output neuron of the retina, was examined in an in vitro rabbit eyecup preparation. The extracellular spike activity of ganglion cells was monitored while pulsatile DC or sinusoidally modulated current was injected intracellularly into nearby horizontal cells. Interactions between the effects of light stimulation and horizontal cell current injections on ganglion cell responses were also examined. 2. Horizontal cells were found to contribute to the receptive field surround of ganglion cells. In particular, horizontal cells contributed to surround excitability and to surround antagonism of the centre light response. 3. Brisk, sluggish and direction-selective ganglion cells were all affected by current injections into horizontal cells. However, brisk ganglion cells responded to lower amplitude currents than did sluggish or direction-selective cells. 4. Horizontal cells with receptive fields that overlap those of ganglion cells were able to affect ganglion cell discharge. Moreover, the closer a horizontal cell was to the receptive field centre of a ganglion cell, the more effective were current injections in modulating ganglion cell discharge rate. The length constant of the horizontal cell contribution to the ganglion cell receptive field was approximately 200 microns. These results indicate that horizontal cells which are located within or outside of a ganglion cell's receptive field centre can influence that ganglion cell's activity. 5. The influence of horizontal cells on ganglion cell discharges was relatively weak at low temporal frequencies of sinusoidally modulated current. 6. Application of 2-amino-4-phosphonobutyrate (APB), a glutamate analogue, blocked the modulation of spike activity of on-centre ganglion cells that was induced by sinusoidally modulated current injected into nearby horizontal cells. The spike activity of off-centre ganglion cells was not blocked. 7. These findings suggest that horizontal cells contribute to the surround of ganglion cells and bipolar cells primarily through a feedback pathway onto cone photoreceptor cells.

Action Potentials↗
PubMed1989

Satellite cells as blood-ganglion cell barrier in autonomic ganglia.

In a preliminary study a difference in the uptake and transport of wheat germ agglutinin-horseradish peroxidase (WGA-HRP) between the trigeminal ganglion and the superior cervical ganglion was observed. After injection of WGA-HRP and HRP into the trigeminal ganglion, peroxidase was found in the space between the satellite cell processes and the ganglion cells. The ganglion cells showed pinocytosis and uptake of WGA-HRP and HRP. In the superior cervical ganglion WGA-HRP and HRP were found alongside the satellite cells but were absent in the space between satellite cells and ganglion cells. Intravenous injection revealed the presence of HRP in the space between sensory ganglion cells and their satellite cells of the trigeminal and nodose ganglion whereas HRP was absent in the space between autonomic ganglion cells and their satellite cells of the superior cervical, medial cervical and pterygopalatine ganglion although HRP lined the satellite cell membranes. By means of electron microscopy, satellite cell processes in the superior cervical ganglion were found to enwrap ganglion cells very tightly with a marginal space between both cell types. Satellite cells and their processes were mutually anchored by numerous tight junctions. In the trigeminal ganglion the extracellular space between ganglion cells and satellite cells was larger and satellite cells were found to be more loosely arranged around the ganglion cells. Satellite cell processes were only occasionally linked by tight junctions. It is concluded that satellite cells in autonomic ganglia comprise an effective barrier for WGA-HRP and HRP and probably large molecules in general. This barrier is absent in sensory ganglia.

Animals↗
PubMedDate not supplied

A structural basis for omnidirectional connections between starburst amacrine cells and directionally selective ganglion cells in rabbit retina, with associated bipolar cells.

Directionally selective (DS) ganglion cells of rabbit retina are of two principal types. ON DS ganglion cells prefer low velocity in one of three directions of movement and project axons to the accessory optic system (AOS), whereas ON-OFF DS ganglion cells prefer higher velocity in one of four directions and project to tectum and thalamus. Each has a distinct, recognizable dendritic morphology, based upon the correlation of form, physiology, and central projections. In previous Golgi studies, ON and ON-OFF DS cells were found to be partly co-stratified, and ON-OFF DS cells were found to co-stratify with starburst amacrine (SA) cells, the cholinergic amacrine cells of the retina, which also contain elevated levels of GABA. SA cells are radially symmetrical, have synaptic boutons in a distal annular zone of its dendritic tree, are presynaptic primarily to ganglion cell dendrites, co-stratify with ON-OFF DS ganglion cells, and contain the neurotransmitters shown pharmacologically to be involved in DS responses. For these reasons, SA cells are thought to play a role in the DS mechanism. Several models of this mechanism have utilized SA cell dendritic geometry in a centrifugal, radial format to impose directional inputs on DS ganglion cells. The opportunity to examine Golgi preparations containing ON DS ganglion cells that exhibit dendritic field overlap with both starburst amacrine cells and ON-OFF DS ganglion cells has resulted in several new findings. Co-stratification of ON DS ganglion cells and SA cells was demonstrated directly. Secondly, the boutons of single starburst amacrine cells make close contact in different lamellae of the starburst substratum in sublamina b of the inner plexiform layer (IPL) with three adjacent ON-OFF DS ganglion cells, which because of their considerable dendritic-field overlap must prefer different directions of motion. Thirdly, nearby presynaptic boutons of single SA cells make close contact with both ON and ON-OFF directionally selective ganglion cells. Single SA cells thus traverse all the lamellae of the starburst/cholinergic substratum. Fourthly, no directional bias is shown by vectors connecting the origins of dendritic sectors and distal synaptic boutons of starburst amacrine cells in those sectors that are in close contact with the dendrites of single ON or ON-OFF directionally selective ganglion cells. Fifthly, at least two distinct types of cone bipolar cell, nb1 and nb2, participate in the neural circuitry of directional selectivity for ON and ON-OFF DS ganglion cells, and nb1 cells co-stratify with ON DS cells. As a consequence of the second, third, and fourth points, starburst amacrine cells appear to be indiscriminate in their connections with DS ganglion cells, and therefore are unlikely to be the primary conduits for directionally selective information to retinal ganglion cells. This result is consistent with pharmacological studies showing that cholinergic antagonists do not block directional selectivity and a study showing that laser-ablation of SA cells does not reduce the directional selectivity of overlapping ON-OFF DS ganglion cells.

Amacrine Cells↗
PubMed2004

Somatotopic organization of the trigeminal ganglion cells in a cichlid fish, Oreochromis (Tilapia) niloticus.

Somatotopic organization of the trigeminal ganglion is known in some vertebrates. The precise pattern of somatotopy, however, seems to vary in different vertebrate groups. Furthermore, the somatotopic organization remains to be studied in teleosts. From an evolutionary point of view, the morphology and somatotopic organization of the trigeminal ganglion of a percomorph teleost, Tilapia, were investigated by means of the tract-tracing method using biocytin and three-dimensional reconstruction models with a computer. The trigeminal ganglion was one cell aggregate elongated in the dorsoventral direction, which was separate from the facial and anterior lateral line ganglia. Biocytin applications to the trigeminal nerve root labeled ordinary ganglion cells in the trigeminal ganglion and a few displaced trigeminal ganglion cells in the facial ganglion. Biocytin applications to three primary branches (the ophthalmic, maxillary, and mandibular nerves) revealed that trigeminal ganglion cells were somatotopically distributed in the ganglion reflecting the dorsoventral order of the three branches. Ganglion cells of the ophthalmic nerve were distributed in the dorsal part of the trigeminal ganglion, those of the mandibular nerve in the ventral part, and those of the maxillary nerve in the intermediate part. Some of maxillary and mandibular ganglion cells appear to overlap in their boundary region, whereas ophthalmic ganglion cells did not intermingle with ganglion cells of other branches. Labeled-primary fibers terminated in the sensory trigeminal nucleus, descending trigeminal nucleus, medial funicular nucleus, a ventral part of the facial lobe, reticular formation, and trigeminal motor nucleus. Labeled cells were observed in the mesencephalic trigeminal nucleus and the trigeminal motor nucleus. The results suggest that the morphology and somatotopic organization of the trigeminal ganglion of tilapia are similar to those of mammals, except that the axis of the somatotopic organization of the ganglion in mammals is a mediolateral direction reflecting the mediolateral order of the ophthalmic, maxillary, and mandibular nerves.

Animals↗
PubMed2000

Ganglion cells in the human prostate.

Prostate carcinoma infiltrating around ganglion cells is claimed to be diagnostic of extracapsular extension because ganglion cells are only found in periprostatic soft tissue. However, the presence of autonomic ganglion cells in the fibrous capsule of the prostate has been reported. In this study, we aimed to define the exact localization of the ganglion cells in radical prostatectomy specimens. Slides of 64 totally embedded radical prostatectomies were reviewed. The ganglion cells were noted as outside the gland if no relation could be defined with prostate capsule or prostatic glands. They were noted as in the capsule when ganglion cells were observed inside the capsule, which was easily and definitely discerned. Ganglion cells were noted as in the prostate when ganglion cells were observed beneath the capsule and in close proximity to the prostatic glands. Also, the ganglion cells were noted as in the capsule if they were observed inside the capsule but not adjacent to the prostatic glands, and as outside the prostate when the capsule could not be easily defined and distant from the prostatic glands. Ganglion cells were observed in the prostate in 12 cases (18.75%). There was no relationship of these ganglion cells with the tumor in the prostatectomy specimens. Ganglion cells were located in the capsule in 14 cases (21.9%). The ganglion cells were observed outside the prostate in the other 38 cases (59.4%). These results show that there may be ganglion cells in the prostate. Therefore, defining ganglion cell invasion by the tumor as extracapsular invasion may lead to staging error and cause erroneous management of the disease. Presence of carcinoma in ganglion cells should be recorded by defining whether these structures are within or outside the prostate gland. Prostate Cancer and Prostatic diseases (2000) 3, 34-36

Journal Article↗
PubMed1990

Target dependence of chick retinal ganglion cells during embryogenesis: cell survival and dendritic development.

The survival of retinal ganglion cells and the dendritic development were investigated a) in normal chick embryos, b) in embryos whose primordial optic lobes and adjacent areas were removed (target reduced embryos), and c) in embryos whose optic nerves were transected (target deprived embryos) in order to study the influences of central targets on developing ganglion cells. The ganglion cells were stained postmortem with the carbocyanine dye DiI. Cell body and dendritic field diameters were measured in whole-mounted retinae before and after the period of cell death at embryonic day 10 (E10) and E16. The cell densities within the ganglion cell layer were counted in cresyl violet/thionine stained retinae. The central retinal projection in target reduced embryos was studied with the anterogradely transported fluorescent marker rhodamine-B-isothiocyanate (RITC). In normal embryos, the earliest dendritic processes were observed at E6 in the central retina, whereas at E10 elaborate dendritic branching was found across the retina. Different morphological types of ganglion cells could be identified at E16. In both, target reduced embryos and target deprived embryos, the initial dendritic growth and pattern of ramification were indistinguishable from those of normal embryos up to E10. Cell body diameters, dendritic tree diameters, and cell densities were not significantly different. At the end of the naturally occurring cell death period (E16), the ganglion cell density was strongly reduced in both experimental groups compared to controls. In particular, when the optic nerve was transected, it resulted in the almost complete degeneration of ganglion cells. In target reduced embryos, a small population (about 5% of the normal number) of ganglion cells survived. The proportion of large cells was increased within the total population compared to normal retinae. Displaced ganglion cells were not affected by partial target removal but strongly affected by transection of the optic nerve. Anterograde labelling from the retina revealed that in target reduced embryos the remaining ganglion cells innervated non-tectal primary visual nuclei. The present results suggest the following: a) Before the onset of the cell death period, the growth and ramification of ganglion cell dendrites occur independently of central visual targets. b) In target reduced embryos, a small population of ganglion cells survives, namely, those cells that project to remaining central areas. Complete disconnection from central targets by transecting the optic nerve leads to the degeneration of almost all ganglion cells. c) The surviving ganglion cell population consists mainly of large ganglion cells.

Animals↗