Takemura et al. (2013)
The right part of the brain of a wild-type Oregon R female fly was serially sectioned into 40-nm slices. A total of 1,769 sections, traversing the medulla and downstream neuropils, were imaged at a magnification of 35,000.
S. Takemura et al. A visual motion detection circuit suggested by Drosophila connectomics. Nature, 2013.