Figure 2.

Histological examination of the CA1 region of rat hippocampus following DA administration. Rats were treated intraperitoneally with either the control (vehicle) or DA (1 mg/kg). Tissues were collected at 24 hours (A-D, F-I) and 5 days (E) after treatment and prepared for histology. Images are shown at × 50 (A, B) and × 100 (C-I) magnification. To clarify cell type-specific staining and subcellular staining, insets show the same samples (indicated by arrowheads) at × 400 magnification. (A, B) Hematoxylin-Eosin staining (A) 24 hours after vehicle administration and (B) 24 hours after DA administration. Arrow indicates neuronal shrinkage; asterisk indicates cell dropout. (C-E) TUNEL staining (C) 24 hours after vehicle administration, (D) 24 hours after DA administration, and (E) 5 days after DA administration. Arrow indicates TUNEL-positive neuron. (F, G) In situ hybridization (F) 24 hours after vehicle administration and (G) 24 hours after DA administration. Arrow indicates positive staining for WDR35 mRNA. (H, I) Immunohistochemical staining for WDR35 (H) 24 hours after vehicle administration and (I) 24 hours after DA administration. Positive staining neurons are enclosed by dotted lines.