Structural Insights of the Glycogen Body in Domestic Chicken

Abstract

There is a special unusual cellular mass in birds’ spinal cords known as glycogen body (corpus gelatinosum). Because of the specific topographical situation of this circumventricular organ, the structure of this organ on the cellular and subcellular level is of special interest with respect to the still unsolved functional problems aiming to find a relation between the structure and the function of this organ. Twenty domestic chickens were used in this study to demonstrate the structural peculiarities of this body from the histological point of view. Our results revealed that the glycogen body is a very delicate, small, ovoid circumventricular, transparent and gelatinous consistency structure embedded in the dorsal part of the lumbosacral region of spinal cord. The body has two cell zones; Peripheral one had regularly arranged large cells with metachromatic faint red cytoplasm and peripheral basophilic nuclei and central one with irregularly arranged cells that had different basophilic degrees, variable sizes, and peripheral nuclei. By transmission electron microscope, the cells of both zones showed deeply infolded electron dense peripherally located nuclei with prominent nucleoli that were rounded in the outer zone and ovoid in the central one. The cytoplasm was almost occupied with large dense masses of glycogen. No connective tissue was observed in the body except in the vicinity of the blood vessels that were more distributed in the center of the body than in its periphery. Conclusion