Fig. 4.

Homotopic and heterotopic commissural neurons in marsupials resemble the callosal connectome of eutherians. (A) Coronal sections of dunnart brains showing a summary of retrograde tracer injection sites (DAPI and color-coded in the Left) and the contralateral position of cell bodies (dots). (B) Connectivity matrix combining injection sites (columns; approximate brain positions on Top Left) and percentage of labeled neurons per brain area (rows). aMed, anterior medial cortex; aSom, anterior somatosensory cortex; Fr/Orb, frontal/orbital cortices; Lat, lateral cortex; pMed, posterior medial cortex; pSom, posterior somatosensory cortex; Olf/Pir, olfactory/piriform cortices; Occip, occipital cortex. (Scale bar, 1 mm.)