European Journal of Biomedical and Pharmaceutical Sciences

COMPARATIVE STUDIES ON THE BRAINS OF CRICETOMYS GAMBIANUS AND THRYONOMYS SWINDERIANUS

George I. O.*, Fawehinmi H. B., Oyakhire M. O., Musa S. A. Agu I.

ABSTRACT

Scientific research in the biomedical sciences requires research animals as laboratory models for these purposes. The development of indigenous research animals such as Grasscutter (GC) and African Giant Rat (AGR) which do not need to be placed in rigidly controlled facilities and are readily available is essential for research in an environment with limited resources for carrying out scientific investigations. It is crucial to understand the neuroanatomical basis of the different behaviors of these animals. Therefore, this work compared the gross brain morphology and morphometry, prefrontal cortex, olfactory bulb, hippocampus, and flocculonodular lobe of the cerebellum of AGR and GC, and related the findings to their behavioural/functional differences. Five adult AGR and GC each were used for this study. Gross morphometry and morphology were carried out on fixed tissues of whole brain specimens of AGR and GC. Histological analysis was done on some brain structures. Both brains of AGR and GC were lissencephalic. The brain of AGR was oval in shape while that of GC was globe-like. There was a Y-shaped posterior cerebral artery emerging from the dorsal surface of each cerebral hemisphere of the GC, making a prominent depression on the caudal aspect of the cerebrum. Also, the anterior cerebral artery could be seen radiating from the parietofrontal aspect of the medial longitudinal fissure of each cerebral hemisphere. There were differences in the gross morphology and morphometry, and histology of brain structures of AGR and GC which could be related to their behavioral differences.

Keywords: Morphology, Morphometry, Histology, African Giant Rat, Grasscutter.