Immunocytochemical localization of glycogen phosphorylase in primary sensory ganglia of the peripheral nervous system of the rat

Neuronal localization was investigated of glycogen phosphorylase (GP) in ganglia of the peripheral nervous system of the rat. Immunofluorescence and immunoenzymatic procedures were applied with a monoclonal anti-bovine brain GP antibody on paraformaldehyde-fixed, paraffin-embedded tissues. Immunoreactivity was only present in the somatic neurons of the mesencephalic trigeminal nucleus in the brain stem and in dorsal root ganglia (DRG), but not in the autonomic neurons of the superior cervical ganglia or in the sensory nuclei of the spinal cord. GP immunoreactivity was present as early as day 1 after birth. In the adult rat, staining was present in neurons of different sizes, and to varying intensities. No relationship was apparent between the staining intensities and morphologically distinguishable types of neurons. In DRG, the type of reactivity was the same from cervical to sacral ganglia. The selected occurrence of GP in specific neurons of the peripheral nervous system in contrast to the ubiquitous occurrence in all astrocytes of the central nervous system may indicate a different role of neuronal glycogen compared to astrocytic glycogen.