Immunofluorescence of the sst2A receptor in coronal sections through the rat neocortical wall between E14 and P5.

<p>A–A″′) At E14, the sst2A receptor immunoreactivity is detected in the preplate (PP). Receptor immunoreactivity is observed in cell bodies and basal processes perpendicular to the pial surface (A″′). B–B″′) At E16, intense receptor immunoreactivity is confined to neuronal cells located in the subplate/intermediate zone (SP/IZ; defined by arrowheads). Immunolabeling is located in cell bodies and small processes of closely packed and presumably migrating neurons (B″′). C–C″′) At E18, the sst2A receptor immunoreactivity is confined to cells in the intermediate zone but absent from the adjacent subplate (defined by arrowheads). D–D″′) At E21, sst2A receptor immunoreactivity is concentrated in the subventricular zone (SVZ) and the adjacent deep part of IZ. Immunoreactivity is apparent in cell bodies and radially oriented processes (D, D″′). E) At P5, the sst2A receptor immunoreactivity is diffusely distributed over the neuropil. The labeling intensity decreases towards the deep layers. At high magnification, receptor immunoreactivity appears diffusely distributed within the neuropil (E″′). A″′, B″′, C″′, D″′ and E″′ represent magnifications of boxed areas on A″, B″, C″, D″ and E″, respectively. CP/MZ, cortical plate/marginal zone; CP, cortical plate; MZ, marginal zone; VZ, ventricular zone; I–VI, cortical layers I to VI; WM, white matter. Scale bars: A–A″, B–B″, 50 µm; C–C″, D–D″, E–E″, 100 µm; A″′–E″′,10 µm.