I'm planning to perform immunohistochemical analysis on adult zebrafish brain slices. Is there are standard for the orientation of the brain slices? I found an article where they analysed 14 transversal slices across the whole brain, in another article 3 transversal, 2 parasagittal, 2 coronal. Does the selection of the orientation and level always depend on the aim of the experiment or are there also standards, when investigating growth abnormalities?