The regional distribution of neuronal glycogen in the opossum brain, with special reference to hypothalamic systems

Neurons that accumulate glycogen have been identified in the opossum brain stem and diencephalon by a modified histochemical method using alcoholic solutions and fuchsin proper (pararosanilin) rather than the Schiff reagent (leucosulphite derivative). Several of the glycogen-positive cell groups such as the mesencephalic trigeminal nucleus and the brainstem somatic and special visceral efferent nuclei have been previously detected in the developing brain of small, common laboratory mammals. Scattered glycogen-containing neurons also appear in the dorsal thalamus and basal forebrain. A conspicuous, often Golgi-like accumulation of glycogen has been found in neurons of the magnocellular and parvocellular hypothalamic systems. Together with available data on the metabolic rate of marsupials, our results suggest that the patterns of glycogen deposition may be common to several vertebrates and may be a constant although not exclusive property of cells with axonal endings outside the blood-brain barrier.