Fig. 1.

Key tables in the database. Information about each source (publication or repository) is stored in the “Sources” table. Each source may have one or more related record in the “Experiments” table. An experiment may have one or more specimens, information about which is stored in the “Specimens” table. Specimens are not defined at the level of individual animals, but rather at the level of different types of specimen, e.g. a brain, serial sections, etc. The specimens are organised in levels, i.e. the whole brain is the primary specimen, and if a series of sections are cut from that brain it would be a secondary specimen. A specimen may have one or more derived data records, information about which is stored in the derived data records table. A derived data record can relate to one or more records in either the “Quantitations” or “Cell morphologies” table. A record in the quantitations table may or may not have a related record in the “Stereology details” table, depending on whether such procedures have been used; if similar parameters were used for stereological counting, several quantitations may relate to the same record in this table. The “Region records” table stores information about the location of one or more quantitation or morphology in standard EBRAINS atlas terms; in addition, information is stored about the accuracy of the translation from the original term used by the authors, as well as the documentation provided to support location information. For more information about each field in all tables of the database, including those not shown in this figure, see Supplementary File 1. *Primary key; **Foreign key.