Figure 4. Expression patterns of four neuropeptides/calcium binding proteins.

A–C. In situ hybridization with each probe was conducted in the sSC at ~P10 (left) and ~P18 (right). The positions of pSGS and pSO are indicated by brackets. A. Expression of substance P (SP) was predominantly found in a superficial layer of sSC. B. Expression of somatostatin (SST) was found in middle and deep layers. C. Expression of vasoactive intestinal polypeptide (VIP) was barely detectable at ~P10 but was found in a superficial layer at ~P18. D. Expression of parvalbumin (PV), detected by immunostaining, was sparse at ~P10 but became abundant in a superficial layer, well below the pial surface, at ~P18. Scale bar: 200 μm.