FIGURE 2

FIGURE 2

Cellular organization of zebrafish TL. (A–F) Micrographs of semithin transverse sections of zebrafish TL stained with toluidine blue-borax (A–E) and cryostat transverse sections immunostained against GAD67 (F). (A) Section through the rostral TL. Note that at this level, TL sits on top of the posterior commissure. Midline is indicated by dashed line. Area squared is shown in detail in (D). (B) Section through the intermediate region of the TL showing the peripheral band of cells and internal cell clusters. Black dashed line marks the approximate limit between both populations. Note also the presence of a group of large neurons (black thick arrow) in dorsal TL and the nuclei of ependymal cells (arrowheads). White dashed line marks the midline. (C) Detail of the peripheral band of cells below the ventricular surface showing small (Nu₂, black arrowheads) and medium size (Nu₁, white arrowheads) round nuclei, as well as more irregular nuclei with paler chromatin (Nu₃, white arrows). Midline is to the right. (D) Detail of the area squared in (A) showing small (Nu₂, black arrowheads) and medium size nuclei (Nu₁, white arrowheads), as well as slightly larger nuclei (Nu₃, arrows) with paler chromatin. Dashed line marks the OT border. (E) Section showing the location of large (C₃) cells in the dorsal region of TL (thick black arrows). Thin arrows: axons of the intertectal commissure. Midline is to the right. (F) Section through rostral TL showing GAD67-positive cell bodies (thick black arrows) in dorsal areas, as well as immunopositive fibers (white arrowheads). Asterisks, ventricle; Stars, blood vessels. For abbreviations, see the list. Scale bars: 50 μm (A–B, F); 20 μm (C,E); 10 μm (D).