Alteration of the RMS in adult Tuba1a-mutant mice. (A and B) Low-magnification image of sagittal brain sections after Nissl staining in control (A) and mutant (B) brains. Note that the RMS is enlarged in the Tuba1a-mutant brain (red arrowheads). (C and D) Higher magnification of the RMS in the sagittal view is shown in control (C) and Tuba1a-mutant (D) brains, revealing an increase in RMS size in the mutant brain. (E and F) Low-magnification image of coronal brain sections after Nissl staining in control (E) and mutant (F) brains. Note that the RMS is enlarged in the mutant condition (F) at different rostral levels, and OB neurons are reduced. The GCL is outlined with white dashed lines. Arrowheads indicate the RMS. (G) RMS thickness was measured at three different rostrocaudal levels (RMS1, RMS2, and RMS3 according to the schema). Note the increased thickness of mutant RMS2 and RMS3. (H) The overall OB surface was measured in control and Tuba1a-mutant brains. Note the decreased OB size in the mutant. (I) The GCL surface was measured in control and Tuba1a-mutant brains. Note the decreased surface in the mutant. (G–I) **, P < 0.01; ***, P < 0.001. n = 5. Data are represented as mean ± SEM. LV, lateral ventricle. Bars: (A) 437 µm; (C) 87 µm; (E) 650 µm; (E and F, right) 175 µm.