Isolated right testes obtained from EAO-affected mice and control mice were fixed with Bouin’s solution and then embedded in plastic (Technovit 7100; Kulzer & Co., Wehrheim, Germany) without cutting the organs to prevent artificial damage to the testicular tissue. Sections (3–4-μm thick) were obtained at 15–20-μm intervals, stained with Gill No. 3 hematoxylin and 2% eosin Y (HE stained), and observed with a light microscope (BX51; Olympus, Shinjuku, Japan).