Figure 6.

Subchronic HAL treatment after METH on NeuN immunostaining in the SNr. Rats were administered METH (10 mg/kg 4 times, every 2 h) or 0.9% saline (1 ml/kg 4 times, every 2 h) on day 0 and then HAL (0.5 mg/kg) or vehicle (VEH) once daily on days 3–7. Rats were killed on day 14. NeuN-positive profiles, which were counted by an observer blind to the treatment conditions, are expressed as NeuN-positive profiles per square millimeter. Data shown represent the average of three consecutive slices and are mean ± SEM. A, Coronal view of a mature brain illustrating the SNr region that was sampled (dotted lines; −5.3 mm from bregma). Representative high-magnification images are shown from the SNr of rats treated with SAL–VEH (B), SAL–HAL (C), METH–VEH (D), and METH–HAL (E). F, NeuN-positive profile counts in the SNr showed that there was a significant decrease in the SAL–HAL treatment group compared with the SAL–VEH group. Arrows indicate representative NeuN-labeled cells. Scale bar: B–E, 100 μm. Significance was determined via a one-way ANOVA; *p < 0.05 compared with SAL–VEH. n = 9 for SAL–VEH; n = 4 for SAL–HAL; n = 9 for METH–VEH; n = 10 for METH–HAL.