Wide-field ganglion cells in macaque retinas

Abstract

To describe the wide-field ganglion cells, they were injected intracellularly with Neurobiotin using an in vitro preparation of macaque retina and labeled with streptavidin-Cy3. The retinas were then labeled with antibodies to choline acetyltransferase and other markers to indicate the depth of the dendrites within the inner plexiform layer (IPL) and analyzed by confocal microscopy. There were eight different subtypes of narrowly unistratified cells that ramified in each of the 5 strata, S1-5, including narrow thorny, large sparse, large moderate, large dense, large radiate, narrow wavy, large very sparse, and fine very sparse. There were four types of broadly stratified cells with dendritic trees extending from S4 to S2. One type resembled the parvocellular giant cell and another the broad thorny type described previously in primates. Another broadly stratified cell was called multi-tufted based on its distinctive dendritic branching pattern. The fourth type had been described previously, but not named; we called it broad wavy. There was a bistratified type with its major arbor in S5, the same level as the blue cone bipolar cell; it resembled the large, bistratified cell with blue ON-yellow OFF responses described recently. Two wide-field ganglion cell types were classified as diffuse because they had dendrites throughout the IPL. One had many small branches and was named thorny diffuse. The second was named smooth diffuse because it had straighter dendrites that lacked these processes. Dendrites of the large moderate and multi-tufted cells cofasciculated with ON-starburst cell dendrites and were, therefore, candidates to be ON- and ON-OFF direction-selective ganglion cells, respectively. We concluded that there are at least 15 morphoplogical types of wide-field ganglion cells in macaque retinas.

Stratification of alpha ganglion cells and ON/OFF directionally selective ganglion cells in the rabbit retina

“…They have branches in both sublamina a and sublamina b and a characteristic retroflexive branching pattern. Morphologically similar types have been reported in other species including primate (Yamada et al, 2005) and mouse (Weng et al, 2005). The depth of stratification in the IPL, which can be accurately visualized by confocal microscopy (Masland & Raviola, 2000), is a primary diagnostic feature to differentiate between different ganglion cell types (Watanabe & Rodieck, 1989).…”

“…The number of cone bipolar cell types in the mammalian retina is usually given between 10 and 12, plus one for the rod bipolar cells (Haverkamp et al, 2003;Ghosh et al, 2004;MacNeil et al, 2004), and there is strong evidence that different bipolar cell types have different physiological properties, thus splitting the photoreceptor signals into different channels (DeVries, 2000). The number of ganglion cell types has been estimated as 13 or 14, but there is usually an unclassified remainder which could include a number of sparse or low-density cell types (Rockhill et al, 2002;Marc & Jones, 2002;Dacey et al, 2003;Yamada et al, 2005). This may boost the total number of types to between 15 and 20.…”

Identification and Characterization of a Y-Like Primate Retinal Ganglion Cell Type

“…Furthermore, because the ratio of the RF diameter of the OFF upsilon cells to the RF diameter of OFF parasol cells is ϳ2.9, the ratio of the dendritic arbor diameter of the upsilon cells to the dendritic arbor diameter of the parasol cells is expected to also be ϳ2.9 [assuming the same ratio of the RF to the dendritic arbor diameters for both cell types (Peichl and Wassle, 1983)]. Given these constraints, the most plausible morphological candidate(s) corresponding to the upsilon cells are the smooth (Dacey, 2004) and large radiate (Yamada et al, 2005) ganglion cells recently identified in the primate retina.…”

“…Based on the measured upsilon cell properties, we can speculate as to which morphological RGC type (Rodieck and Watanabe, 1993;Dacey et al, , 2005Dacey, 2004;Yamada et al, 2005) they may correspond to. Because the upsilon cells are OFF-type cells with no evidence for ON-OFF responses (i.e., no significant responses to both light intensity increments and decrements) (Fig.…”

“…Although decades of work have been devoted to the study of primate retinal architecture, fewer than one-half of the 22 or more anatomically identified types of retinal ganglion cells (RGCs) (Rodieck and Watanabe, 1993;Dacey et al, , 2005Dacey, 2004;Yamada et al, 2005) have been characterized physiologically, namely the ON and OFF midget and parasol cells (Dacey, 1999;Chichilnisky and Kalmar, 2002), the small bistratified cells (Dacey and Lee, 1994;Chichilnisky and Baylor, 1999), the recently discovered giant sparse (melanopsin-expressing) cells (Dacey et al, , 2005Dacey, 2004), and, to some extent, the large bistratified cells and the cells of type "sparse" Dacey, 2004). One of the possible reasons for this discrepancy is that the morphological RGC types awaiting physiological characterization constitute only a small fraction of all the primate ganglion cells (1-4%) [see Dacey (2004), their table 20.1].…”