Figure 2. Representative histology of neonatal rat pup terminal ileum.

Histological changes were graded as described in the methods section. Briefly: 0, normal ileum; 1–3, mild, moderate, or severe damage reflecting degrees of separation of submucosa and/or lamina propria, regional villous sloughing and initial necrosis; 4, necrosis. Pups were considered to have NEC if their histological score was ≥2. Magnification: 200×.