The topographical relationship between two neuronal mosaics in the short wavelength-sensitive system of the primate retina.

The short wavelength-sensitive (blue) cone bipolar cells was found to have a nonrandom distribution by analyzing the nearest neighbors and by calculating the density recovery profile (DRP). Blue cones had been shown previously to have a nonrandom distribution (Curcio et al., 1991). The relationship between the two arrays was then analyzed by calculating the cross-correlational density recovery profile (cDRP), which indicates the local density of blue cones around each blue cone bipolar cell. Although both cell types appeared to be distributed uniformly at the macroscopic level, the cDRP was 1.7 times higher within 15 microns of each bipolar cell perikaryon than in the surrounding area. The area of higher density was approximately the same as that in which the blue cone bipolar cells made synaptic contacts with blue ones. The finding that the blue cones and the blue cone bipolar cells were closer together than expected suggested that the positions of the perikarya of these neurons were influenced by their synaptic connections or other developmental interactions.