Figure 4

Three selected sections with labeling of different cell types showing original data for reconstruction. Position of sections indicated in three-dimensional reconstruction bottom right; note cells with high electron density identified as retinula axon terminals surrounded by cells with low electron density identified as postsynaptic neurons. A, beginning of visual neuropil 1 (slice number 23); neuropil surrounded by cell bodies of descending unipolar neurons. Bar 5 μm. B, medium range of visual neuropil 1 (slice number 523); arrows indicate subdivision of neuropil into two hemineuropils. C, low range of visual neuropil 1 (slice number 1,017); arrows indicate subdivision of neuropil.