A cytoarchitectonic volumetric comparison of the area gigantopyramidalis in wild and domestic sheep.

The area gigantopyramidalis has been circumscribed on frontal serial sections of brains of mouflons (Ovis ammon musimon) and domestic sheep (Ovis ammon f. aries). A brief description of the topography and lamination of the area 4 is given. By means of intraspecific-allometric methods this area has shown a decrease in volume by 29.9% in domestic sheep compared with wild sheep. In view of the close relationship between size and function of a structure the reduction rates of the area gigantopyramidalis, the cerebellum and the basal ganglia are discussed as due to the special environmental changes caused by domestication.