International Journal of Brain and Cognitive Sciences 2015, 4(2): 28-32 DOI: 10.5923/j.ijbcs.20150402.02 Topography of Deep Cerebellar Nuclei of the African Giant Pouched Rat (Cricetomys gambianus) Byanet Obadiah Department of Veterinary Anatomy, College of Veterinary Medicine, University of Agriculture, Makurdi, Nigeria Abstract The deep cerebellar nuclei form the major structures that cerebellum communicates with other brain components to execute its functional role of coordination of voluntary movement, posture and balancing. The major objective of this study was to identify as well as relating the deep cerebellar nuclei to the zonal distributions in the cerebellum. A histomorphological analysis was conducted on twelve cerebella of African giant pouched rats. Three nuclei were identified to be associated with the corresponding zone of the cortex; the dentate were noted in the bilateral cerebellar hemispheres, interpose nuclei were found in the paravermis and the fastigial nuclei in the central vermis. The dentate nuclei were the largest of the three, average 90 µm, composed of multipolar, bipolar neurons and some characteristic cellular bands in form of a folded bag shaped cells. The interposed nuclei were next in size to dentate, averaged 50 µm composed mainly of multipolar and bipolar neurones. The smallest was fastigial nuclei, averaged 43 µm and composed of small and medium-sized bipolar neurones. In conclusion, the relatively well-developed deeper cerebellar nuclei, particularly the dentate nucleus in this species may be correlated with the animals’ ability to use their extremities in movement and in reaching and grasping of grasses and other food materials in the wild and / or captivity. Keywords Morphology, Deep cerebellar nuclei, C. gambianus 1. Introduction The African giant pouched rat (Cricetomys gambianus) is one of Africa's largest rodents found mostly in savannas, around the edges of forests and within the human settlements. Their burrows can be complex are commonly seen inside termite mounds and at the base of trees. They are nocturnal animals and usually lead solitary lives and forage alone [1]. The search for alternative animal protein source has popularized attempts to domesticate and breed wild rodents such as African giant pouched rat (AGR) in African sub region (National Research Council [1]. The AGR has almost the same capacity to produce animal protein comparable to those produce by rabbits in tropical countries [2]. The basic biology, particularly nervous system among others is considered as the research need for their effective domestication. Cerebellum is an important part of the brain that is responsible for coordination of complex movements [3]. The early anatomical studies proposed a concept for morphological organization of the cerebellum based on the efferent relationship between the cerebellar cortex and the deep cerebellar nuclei (DCN) of the cat, rabbit and monkey * Corresponding author: byaneto@yahoo.com (Byanet Obadiah) Published online at http://journal.sapub.org/ijbcs Copyright © 2015 Scientific & Academic Publishing. All Rights Reserved [4]. Furthermore, these authors found that cerebellum was organized into zones; the vermis, paravermis and lateral hemispheres cortex. It has been shown that the mouse DCN comprises of three distinct nuclei (dentate, interposed and fastigial) and each has neurones of various sizes [5]. Also, each pair of DCN is associated with a corresponding zone of the cerebellar cortex, such that the dentate nuclei are placed in the lateral hemispheres; the interposed nuclei are located in the paravermis and the fastigial nuclei in the central vermis [6]. These structural relationships are generally maintained in the neuronal connections between the nuclei and associated cerebellar cortex [5]. The dentate nuclei (DN) are found to be the largest and laterally placed on both sides of the cerebellar hemispheres in man and animals [7]. In transverse section, some DN neurons appear as convoluted band of gray matter, with folded bag -like shaped and opening or hilus directed medially [8]. In addition, the DN neurones are composed mainly of large multipolar cell types with branching dendrites [9]. Comparative studies revealed that DN is large in great apes and humans relative to the other cerebellar nuclei, due to its relative expansion in size on the ventral region [10-11]. This implies that the non-motor (ventral) region of the dentate is of importance in great apes and humans [12]. Generally, cerebellar nuclei control the non-motor such as cognitive events and motor activity that concerned with voluntary movements of the extremities, including reaching and grasping [13-15].