Glial cell mapping in the camel cerebellar cortex: a histochemical and immunohistochemical study

Abstract

The cerebellum is involved in numerous motor functions, the adaptation and execution of smooth complex voluntary and fine movements. Glial cells are essential for maintaining healthy neurons. Studying the camel cerebellum was neglected even in recent research even in the Middle East and Asia where camels are reared. Therefore, we investigated the glia in camel cerebellum employing histochemical and immunohistochemical staining using GFAP, Olig2, S-100 and Iba1 for astrocytes, oligodendrocytes, Bergmann glia and fibrous astrocytes, and microglia, respectively. The camel cerebellum was collected from ten clinically healthy mature camel’s (Camelus dromedarius) heads. GFAP immunoreactivity was not detected in the molecular layer, suggesting that this astrocytic population does not express GFAP. The distribution of astrocytes is heterogeneous between different layers and within the same layer. Bergmann glia was arranged into 4–6 rows in the Purkinje cell layer. Their processes extend radially through the molecular layer and reach the pial surface. Its mean density was 5126 cells/1 mm2. Oligodendrocytes were observed in the white matter and granular layer. The oligodendrocytes were either solitary or aligned in rows like beads along the nerve fascicles. Microglia were heterogeneous in both morphology and distribution in different layers and within the same layer. The white matter contains the highest mean density and they were elliptical and most processes run parallel to the nerve fibers. In the granular layer, elliptical- and oval bodies and their processes emerge from all over the cell bodies. The molecular layer contained oval microglia with short processes. Abundant Iba1 positive puncta distributed all over the molecular layer. The current study in camel is considered a step of comparative neuroglial biology across species.