Fig. 1.

Histology of VH lesions. a, Small neonatal VH lesions resulted in cell loss and structural alteration in the remaining hippocampus (arrows). b, One of the largest neonatal VH lesions showing profound cell loss in the VH and enlarged ventricles. c, Brain section of a neonatal sham rat at the same level as in b; no hippocampal loss is observed. d, Brain section of an adult VH lesion. e, Schematic diagrams illustrating neonatal VH lesions. Gray and black areas show the largest and smallest extent of VH lesions, respectively.f, Schematic diagrams showing extent of adult VH lesions.