Lobulation pattern of the of the cerebellum of African grasscutter (<i>Thryonomys swinderianus</i>)

Abstract

Grasscutter is one of the largest species of rodents in Africa whose basic cerebellar folding pattern has not been documented. The aim of the research was to provide reference data on the lobulation morphometric of its cerebellar cortex. A quantitative analysis was conducted on the cerebella of seven African grasscutters. The results showed that the head weight had strong positive correlation with the cerebellar weight (r = 0.8954, P < 0.001). In the rostral lobe, the mean size of declive was significntly larger than Lingula cerebelli (P < 0.01) and culmen (Pars caudalis) (P < 0.001). Also, the culmen Pars rostralis differed signigifcantly with Pas caudalis (P < 0.01). For the Lobus caudalis, the mean folium vermis was significantly higher than those of the tuber vermis and nodulus (Ps < 0.001). The ovula vermis was the broadest lobule in this lobe, was significantly larger than the tuber vermis the pyramis, and nodulus (Ps < 0.001). The mean internal perimeter, including all primary and secondary sublobules (4643.3 ± 341.69 μm) was higher than the external perimeter (1621 ± 42.43 μm) significantly (P < 0.0001). The mean cerebellar foliation index was 2.86 ± 0.18; suggesting a relatively increased in length of cerebellum in form of a folded structure. In conclusion, some of the structural development and behaviours in the grasscutter may likely be correlated with the relative sizes of individual cerebellar lobules.

Keywords: Cerebellum, lobes, lobules, morphometric, T. swinderianus