Functional morphology of the brain of the African giant pouched rat (Cricetomys gambianus) Waterhouse, 1840).

Abstract

A gross morphological study of the brain of the African giant pouched rat (Cricetomys gambianusWaterhouse, 1840) was undertaken in order to document its normal features and assess thestructure-function paradigm. The study was conducted by direct observation of 29 adultAfrican giant pouched rats' brains. In the telencephalon, the cerebral cortex was devoidof prominent gyri and sulci, but the large olfactory bulb and tract relaying impulses to theolfactory cortex were very prominent. The large size of the olfactory bulb correlated withthe established sharp olfactory acuity of the rodent. In the mesencephalic tectum, the caudalcolliculi were bigger than the rostral colliculi, indicating a more acute sense of hearing thansight. In the metencephalon, the cerebellar vermis, the flocculus and the paraflocculus werehighly coiled and, thus, well developed. The myelencephalon revealed a better organisedventral surface than dorsal surface; the cuneate fascicle, the intermediate sulcus and the lateralsulcus were not evident on the dorsal surface, but there were clearly visible pyramids andolivary prominence on the ventral surface. In conclusion, the highly coiled cerebellar vermis,flocculus and paraflocculus, as well as the conspicuous pyramids and olivary prominence areindicative of a good motor coordination and balance in the African giant pouched rat.