Salnikova M.M., Golubev A.I., Malutina L.V., Zabotin Ya.I. 2017. Ultrastructure of the cerebral ganglion of the acanthocephalan Corynosoma strumosum // Invertebrate Zoology. Vol.14. No.2: 182–189 [in English].
Kazan (Volga Region) Federal University, Kremlevskaya str., 18, Kazan, 420008, Russia. E-mail: firstname.lastname@example.org
ABSTRACT: A fine study of the cerebral ganglion of the acanthocephalan Corynosoma strumosum, at the stage of the late acanthella, from the paratenic (reservoir) host the White Sea cod, Gadus morhua, which differs from the sexually mature form only by the proboscis inverted into the sheath, is conducted. Ganglion of Acanthocephala is located in the posterior third of the sheath cavity of the proboscis between the fibers of the retractor muscles, being separated from them only by a thin layer of fibrillar matrix. Ganglion consists of a cortex and a neuropile. The cortex is formed by three types of neurons, which, according to their position in the ganglion, can be divided into the peripheral neurons — located on the periphery; central ones — located around the neuropile, and the intermediate — concentrated between the first two cell types. Each cell type is characterized by a number of cytological features. The integrity of the ganglion is ensured both by numerous and different by the complexity invaginated contacts of the surface membranes of neurons with extracellular material and external fibrillar matrix, and due to a large number of soma-somatic connections. Among the latter ones there are synaptic contacts. According to the structure and nature of the introduction into the soma and into the processes of neighboring neurons, the outgrowths of the partner cells can be single, finger-like curved or branched. The cytoskeleton of the cytoplasm of somatic outgrowth consists of microtubules and neurofibrils. In all cases, the membranes of neuronal outgrowths are postsynaptic. From the side of presynaptic membranes in the contact area the vesicles different in size and structure are present. It is likely that the unusual architectonics of the ganglion of Acanthocephala, the peculiarity of nuclear-cytoplasmic bonds in their neurons and the unique structure of the invaginated contacts are typical features of organization of their nervous system at the cellular level.
KEY WORDS: Acanthocephala, Corynosoma strumosum, cerebral ganglion, ultrastructure, neuron, synapse.