Fig. 4.

Double-immunofluorescent labeling of the rat median eminence. sst₁ is visualized by fluorescein (green) and somatostatin with Texas Red (red). A strong labeling was observed in the external layer for sst₁ (A) and somatostatin (B). A double-exposure micrograph is shown (C) displaying colocalization of somatostatin and sst₁. Arrows mark the border between the internal and external layers of the median eminence. Double-exposure micrograph of high magnification of the median eminence (D) shows nerve fibers with boutons containing both sst₁ and somatostatin (arrowheads) or somatostatin alone (arrows). itl marks the position of the internal layer. A periventricular nerve fiber endowed with large boutons shows colocalization of sst₁(E) and somatostatin (F). Note the perikaryon exhibiting a positive immunoreaction for somatostatin (arrow) but not for sst₁. Scale bars: A–C, 200 μm;D–F, 25 μm.