Figure 4.

Circular symbols are used to represent cortical lamination on the rat and mouse brain flatmaps. A representative example for the rat brain flatmap is shown in (a) for 5 gray matter regions (red text) and 2 subregions (blue text to the left of two layer indicator series), including the olfactory bulb and some adjacent regions of the cerebral cortex. For sequentially numbered layers (for example, 1-2, 1-4, or 1-6, as shown), the layer indicators (white disks with blue outlines) are arranged in a corresponding left-to-right sequence. For individually named layers, each layer name abbreviation is placed next to its layer indicator. The rat and mouse brain flatmaps (Supporting Information 1) include layer indicators for all layered gray matter regions and subregions of the cerebral and cerebellar cortices. As shown in (b), the layer indicator symbols can be individually altered to represent data. In the example, a color scale is applied that corresponds to binned percentage tertiles. A zero value is indicated by a black symbol fill color, and the default white fill color indicates no data. To facilitate selection of layer markers to adapt, in the brain flatmap Adobe Illustrator file (Supporting Information 1) they are organized in layers named by the abbreviation of their corresponding gray matter region and arranged alphabetically. Abbreviations: AOA, anterior olfactory area; AOB, accessory olfactory bulb; e, external part; gl, glomerular layer; gr, granular layer; ILA, infralimbic area; ipl, inner plexiform layer; mi, mitral layer; MOB, main olfactory bulb; opl, outer plexiform layer; pr, principal part; TTd, tenia tecta dorsal part.