Figure 10. Regional and cellular distribution of sst2A receptor immunoreactivity in the human developing cortex.

A,B) Embryonic sagittal sections at GW 8 at the level of the medial cerebral cortex (A) reveals numerous receptor immunoreactive cell bodies (purple color) in the preplate (PP) (inset box) and in the subventricular zone (SVZ). By contrast the ventricular zone (VZ) is devoid of receptor immunoreactivity. The red color is due to the counterstaining of sections with neutral red. In the lateral part of the medial cerebral cortex (B), sst2A receptor immunoreactivity is detected in the marginal zone (MZ), cortical plate (CP), subplate/intermediate zone (SP/IZ) and SVZ (inset box). C–E) At GW 12 in coronal sections, albeit less intense, the pattern of receptor immunoreactivity is comparable to that observed at GW 8 with higher signals in the MZ (C,D) and SVZ (C,E). D and E are magnifications of boxed areas in C at the level of the MZ and the SVZ, respectively. Note in D that some bipolar neurons expressing the sst2A receptor are visible in the CP and in E that patches of labeling are observed in the SVZ contiguous to the VZ. F, G) In coronal sections at GW 23, the labeling is present in neurons of CP (F) as well as in presumably post-mitotic migrating neurons in the IZ (G). H–J) In coronal sections at birth, the labeling is diffusely distributed in layers II–III and V. In this latter layer some neurons positive for the sst2A receptor are also observed (I,J). Scale bars: A, B, D, E, G, 25 µm; C, F, H, 100 µm; Inset in A,B and I,J, 10 µm.