| Cell type (class) | Nomenclature (Acronym) |
Definition | Relation of SCN-projecting retinal ganglion cell |
| Annotation | Reference |
Collator |
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| photosensitive SCN-projecting retinal ganglion cell | Berson, Hattar et al (BH) | In isolated retinas, whole-cell recordings were made of the responses of labeled ganglion cells to light (10) (Fig. 1, A to E). In most of these cells (n = 150), light evoked large depolarizations with superimposed fast action potentials (Fig. 1, E to G) (11). Photosensitive ganglion cells shared a common morphology (Fig. 4, A and B), as revealed by intracellular staining with LY (28). Somata were intermediate in diameter among neurons of the ganglion cell layer (14.7 ± 1.2 micrometers,mean 6 SD; n= 18). Many cells sent an axon into the optic fiber layer; those lacking one had presumably lost it during mechanical exposure of the soma before recording. The sparsely branching, tortuous dendrites of these cells arborized primarily in the outer part (OFF sublayer)
of the inner plexiform layer (IPL; Fig. 4B). Although some dendrites coursed within the inner IPL (ON sublayer) for 100 to 200 micrometers, nearly all terminated in the OFF sublayer. Such stratification is highly unusual for ganglion cells depolarized by light [but see (29, 30)]. Dendritic fields were large (diameter 497 ± 115 micrometers; mean ± SD; n = 21). Stimuli illuminating the dendrites but not the soma consistently evoked light responses (31). | includes | | With Flurogold injections into the SCN that do not appear to extend into the optic chiasm, the labeled ganglion cells have a median area of 100 micrometers square. The mean area is 109.7 micrometers square and the mean diameter is 14.3 micrometers square. In addition ot the large numbers of small ganglion cells labeled there is a small number of larger cells with areas ranging from 160 to 250 micrometers square and diameters ranging from 18 to 22 micrometers. The data for the PRV injections in intact animals appear similar except that the median area (70 micrometers square), mediam diameter (12 micrometers), mean area (96.2 micrometers square) and mean diameter (13.7 micrometers) are all smaller than in the Fluorogold group. ... Collator note: retinal projections to the SCN are part of the RHT. | Moore R.Y., Speh J.C. & Card J.P. | Mihail Bota | | The accompanying report (12) shows that RGCs projecting to the SCN are directly sensitive to the light. Collator note: retinal projections to the SCN are part of the RHT. | Hattar S., Liao H.-W., Takao M., Berson D.M. & Yau K.-W. | Mihail Bota | |
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| LHA-projecting retinal ganglion cell | Moore (Moore) | ...FluoroGold injections restricted to the LHA (n = 7) label a small population of cells found almost exclusively in one quadrant of the retina (Fig. 2). Although there is some variability in fiducial mark placementsm this appears to be the superior temporal quadrant of the retina. The size and morphology of these cells are consistent with the type III classification of Perry [24]. They have one to four thin radiating dendrites (Fig. 3A and B) which can be followed only for short distances, usually not more than a few cell diameters. Within these limits, the dendrites appaear to give off few branches. Retinas ipsilateral to LHA injections contain only a few labeled cells. The ipsilateral cells have a similar distribution and morphology. ...a homogenous population of cells with a mean area of 92.3 ± 23.3 micromenters2 and a mean diameter of 12.6 ± 1.6 micrometers. | different | | Injections of FluoroGold restricted to the LHA label a small population of cells located almost exclusively in the superior temporal retina. This is in contrast with the retinal ganglion cells projecting to the SCN, which are distributed across the whole retina with a slighter higher density in temporal quadrants [22]. Both have a fairly similar mean diameter and area as sparse, fine primary dendrites, as one would expect for type III cells [22]. However, the unique distribution of LHA afferent cells suggests that they may comprise a group separate from the ganglion cells projecting to the SCN. This is supported by studies using the transynaptic tracer pseudorabies virus, Bartha strain [1, 22]. Following injections of PRV Bartha into one eye, the virus is taken up by retinal ganglion cells and trasnported anterogradely to the hypothalamus. There it is released and taken up and replicated by cells in the SCN and adjacent medial hypothalamic areas. However, neurons in the LHA are not infected until late timepoints. | Leak R.H. & Moore R.Y. | Mihail Bota |
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| retinal ganglion cell type III | Perry (Perry) | Type III cells have small bodies but they have the largest range of dendritic field sizes (see table 1). The dendrites of this cell class branch less frequently than those of the other classes. This group of cells encompasses a slightly wider variety of dendritic morphology, than the other three classes. | is included | | The major group that is labeled in all of the experimental paradigms, SCN injection od FluoroGold and HRP and intravitreal PRV-Bartha injections, is the type III retinal ganglion cell (Perry, 1979; Dreher et al. 1985). | Moore R.Y., Speh J.C. & Card J.P. | Mihail Bota |
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| retinal ganglion cell Class III | Dreher (Dreher) | Class III cells, have small to medium perikarya (6-20 micrometers) and large dendritic trees (up to 510 micrometers). The primary dendrites are fine and have only a few branches (fig. 1F), while the intraretinal axons of fine to medium calibre (0.3-0.8 micrometers in diameter; fig 3B). Although Class III cells project to the contralateral SC and DLG, as well as to the ipsilateral DLG, those projecting to SC tend to have smaller somata. | is included | | The major group that is labeled in all of the experimental paradigms, SCN injection od FluoroGold and HRP and intravitreal PRV-Bartha injeciotns, is the type III retinal ganglion cell (Perry, 1979; Dreher et al. 1985). | Moore R.Y., Speh J.C. & Card J.P. | Mihail Bota |
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