Drawn, ‘flattened’ neocortex images, reconstructed from coronal sections of three different HC (a1–3) and LC (b1–3) brains illustrating the retrograde connections of ACC (red) and S1 (green) at postnatal day 1. A standard cortical outline with dorsal, ventral, rostral, and caudal limits was applied to all cases for the transformation of serial coronal sections into reconstructed flattened cortical image. Black lines: Cortical outline; arrow/red patches: DiI anterior cingulate dye placement locations (DPLs); arrow/green patches: DiA somatosensory DPLs; green/red dots: Retrogradely labeled cell bodies. Reconstructions are oriented medial (M) up and caudal (C) to the right. Scale bar =1,000 μm.