Anatomical study of the brain of the African ostrich

摘要

The anatomical characteristics of the African ostrich brain were investigated in this study. The average weight, length, and width of the total brain are 26.34 g, 59.26 mm, and 42.30 mm, respectively. The cerebellum appears relatively well developed and obviously protrudes dorsally. The posterior superior part of the cerebellar vermis almost forms an angle of 130°. The ostrich brain has many more transverse fissures of the cerebellar vermis than do the brains of domestic fowls. Therefore, the surface area of the African ostrich's cerebellum is larger. The formation of the cerebrum is an obtuse triangle. Its surface is smooth, without any gyrus or sulcus. The gray matter is very thin. There is an arcuated telencephalic vallecula on the dorsal surface, and the sagittal eminence is elliptic. The olfactory bulbs are quite small. The hypophysis is spherical. The whole brain represents only 0.015% of the total body weight, and it is 17 times lighter than the brain of domestic fowls. Statistical analysisshowed that the ratio of brain weight to body weight is significantly smaller (P < 0.01) in the African ostrich than in the 3 domestic fowls investigated. The present study suggests that the brain of the African ostrich is underdeveloped.