Cystathionine β-synthase in the CNS of masu salmon Oncorhynchus masou (Salmonidae) and carp Cyprinus carpio (Cyprinidae)

Abstract

Immunohistochemical labeling showed the presence of cystathionine β-synthase in neurons of the ventral spinal column, medulla oblongata, the cells and fibers of the cerebellum, optic tectum, and telencephalon of the masu salmon Oncorhynus masou and the carp Cyprinus carpio. We found considerable interspecies differences in the localization and optical density of immunoreactive structures in brain areas of masu salmon and carp which are presumably related to the specificities of the feeding and behavior of these fishes. In carp, the medulla oblongata and spinal cord had intensely labeled vessels, which were absent in masu salmon. The periventricular area of the medulla oblongata and ventral and lateral areas of the cerebellum of the carp had strongly CBS-positive cells without outgrowths. The sizes of cells and their location in the brain and interrelations with H2S-producing neurons suggest that periventricular area of the carp brain has H2S-producing glia.