A comparative study of the lateral geniculate body of rat (Rattus norvegicus), bat (Eidolon helvum) and pangolin (Manis tricuspis).

Abstract

In this study, the lateral geniculate bodies (LGB) of rats, bats and pangolins were compared using histological and quantitative histochemical parameters to observe possible modifications that enable these mammals to cope with their habitation particularly with respect to their diet. The study was conducted using ten adult Wistar rats, ten fruit bats and eight pangolins comprising of both sexes. After being sacrificed by cervical dislocation, their skulls were opened using bone forceps to expose the brains. The lateral geniculate bodies were excised from each brain tissue, homogenized and homogenate studied spectrophotometrically for the activities of lactate dehydrogenase (LDH), glucose-6-phosphate dehydrogenase (G-6-PDH), acid phosphatase (ACP), alkaline phosphatase (ALP) and acetylcholinesterase (AChE). The LGB tissue samples meant for histological studies were fixed in 10% formol calcium and processed for paraffin wax embedding. Serial sections of 3?m thickness were stained with Hematoxylin and Eosin (H & E) and Cresyl fast violet (CFV) stains. The stained tissues were studied under the light microscope. Application of one-way ANOVA statistical method showed that there were significant differences (p<0.05) in the activities of LDH, G-6-PDH, ACP, ALP and AChE of the LGB of the three mammals as revealed in the quantitative histochemistry of these enzymes and markers. Histological observations revealed no observable differences in the relative distribution of neurons and their supporting glial cells within the LGB of the three mammalian species. The comparison of the differences observed in the histological and the quantitative histochemical activities in these mammalian species revealed a variation in the visual perception and their individual peculiarities in relation to their mode and pattern of living.