Regional Functional Molecular Profiles Within the Mammalian Cortex: A Commentary on Limbic Mesocortex

Two lateral mouse brain sagittal sections labeled, respectively, for Lypd1 (A) and Kcnab3 (B). (A) Lypd1 labels positively cortical Layers 2 and 5 (less heavily), but only at limbic mesocortical sites, forming the limbic ring that separates the unlabeled isocortex (IsoCx) from the unlabeled hippocampal and olfactory allocortex (Hi, Sub, ERh; OlfCx). The limbic ring is marked twice as the insula (Ins, MCx) and the postrhinal area (PoRh, MCx). (B) Kcnab3, contrarily, labels selectively various layers of the isocortex (IsoCx) and the hippocampal allocortex (Hi, Sub, ERh) but leaves unlabeled selectively the insula (Ins, MCx) and postrhinal (PoRh, MCx) areas of the limbic mesocortical ring, being thus a negative marker for this sort of cortex.