Fig. 1. Expression of Pdgfra, Shh and Ptc1 in the embryonic rat forebrain. (A-C), E13.5 anterior forebrain, coronal sections. Pdgfra is expressed in the neuroepithelium and adjacent SVZ at the boundary between anterior hypothalamus and MGE (arrowhead in A) within broader domains of Shh (B) and Ptc1 (C) expression. There is an additional domain of Shh and Ptc1 expression in the preoptic recess (arrow in B), but there is no Pdgfra expression in this region. (D) Coronal and (E) parasagittal sections of E14.5 anterior forebrain. Pdgfra is widely expressed outside the nervous system (D). In the ventral forebrain, Pdgfra is strongly expressed in the VZ and SVZ of the anterior hypothalamus, extending dorsally into the MGE (D), but is not expressed in the LGE or cortex at this stage. Strong expression is also observed in the primordia of the choroid plexus (arrow in D). In the SVZ, two categories of Pdgfra+ cells are intermingled: closely packed cells that express relatively low levels of Pdgfra and smaller cells that are more intensely labelled (arrowheads in E). (F) Diagram to show the plane of section of A-D and the location of the field shown in E. MGE and LGE, medial and lateral ganglionic eminences; Cx, cerebral cortex; Tel, telencephalon; Di, diencephalon; 3V, third ventricle.
