## Abstract The central projections of different groups of cat retinal ganglion cells were studied following small iontophoretic injections of horseradish peroxidase (HRP) into physiologically characterized sites. Analysis was restricted to labeled cells in the upper periphery of the nasal retina,
Dendritic morphology of cat retinal ganglion cells projecting to suprachiasmatic nucleus
โ Scribed by Pu, Mingliang
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 331 KB
- Volume
- 414
- Category
- Article
- ISSN
- 0021-9967
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โฆ Synopsis
The morphological properties of cat retinal ganglion cells projecting to the suprachiasmatic nucleus (SCN) of the hypothalamus were studied by using retrograde labeling, in vitro intracellular injection, confocal optical section, and computer three-dimensional reconstruction techniques. A total of 218 stained cells were studied. Neither the dendritic fields nor soma diameters of SCN-projecting cells varied with eccentricity. Approximately 50% of cells were concentrated not in the area centralis, but rather in the visual streak. SCN-projecting cells showed large and symmetrical dendritic fields (596 ฯฎ 159 ยตm) and medium to small sized somas (17.2 ฯฎ 3.3 ยตm). The ramification patterns of SCN-projecting cells were similar. Most cells primarily ramify in either sublamina A or B. Evidence from quantitatively analyzed cells (n ฯญ 39) suggests that these cells ramified more frequently in sublamina A (n ฯญ 17) than in sublamina B (n ฯญ 8). A large number of cells, on the other hand, showed diffuse ramification (n ฯญ 14) throughout the inner plexiform layer (IPL). The functional roles of these cells and the corresponding retinal neurocircuitry in circadian entrainment remain to be studied.
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