Chromogenic in situ hybridization showing GAD67 mRNA expression throughout the rostrocaudal extent of the BST. A, Low-power image of a coronal section through the anterior division of the BST. B–E, High-power images from the anterior (B–D) to the posterior (E) division of the BST. C is an enlarged view of A. The BST is surrounded by the caudate–putamen (CP), lateral septum (LS), preoptic area (PO), and ventral pallidum (VP). The anterior division of the BST is subdivided into the dorsal (d) and ventral (v) parts by the anterior commissure (ac). Cx, Cerebral cortex; fx, fornix; ic, internal capsule; lv, lateral ventricle; OT, olfactory tubercle; sm, stria medullaris; st, stria terminalis. Scale bars: A, 1 mm; B–E, 200 μm.