RT Journal Article SR Electronic T1 Local order among the dendrites of an amacrine cell population JF The Journal of Neuroscience JO J. Neurosci. FD Society for Neuroscience SP 2494 OP 2501 DO 10.1523/JNEUROSCI.05-09-02494.1985 VO 5 IS 9 A1 M Tauchi A1 RH Masland YR 1985 UL http://www.jneurosci.org/content/5/9/2494.abstract AB The cholinergic amacrine cells of the rabbit retina branch within a narrow stratum of the retina's inner synaptic layer, and their dendritic fields overlap as much as 70-fold. Because each cell's dendrites have many branches, the overlap must create a dense meshwork of cholinergic dendrites. To learn how the overlapping dendrites are positioned with respect to each other, we filled the dendrites of groups of neighboring cells with Lucifer Yellow CH. The cholinergic amacrine cells were selectively stained by intraocular injection of the fluorescent molecule 4,6-diamidino-2-phenylindole. The retinas were then fixed with 2% paraformaldehyde and 0.01% glutaraldehyde. The stained cells were penetrated under visual control by Lucifer Yellow- filled micropipettes. A systematic arrangement of the dendrites was observed. When a pair of cells was injected, their dendrites were often seen to lie alongside each other. In the terminal dendritic region, there are virtually no dendrites that do not end in apposition to a dendrite of a neighboring cholinergic amacrine cell. When small clusters of nearby cells were injected, an ordered microstructure appeared. The dendrites of the cells join together to form curving bundles, which enclose spaces that rarely contain any cholinergic dendrites: the appearance of the dendritic mosaic is that of a lattice with a repeating unit roughly 10 microns in diameter. The significance of this ordering is not certain, but it is possible that the repeating structural unit participates in a modular functional arrangement.