Studies on the neurosecretory activity of the brain in the fresh water Crustacean, Astacus leptodactylus Eschscholz (Decapoda)

Konok, István (1960) Studies on the neurosecretory activity of the brain in the fresh water Crustacean, Astacus leptodactylus Eschscholz (Decapoda). A Magyar Tudományos Akadémia Tihanyi Biológiai Kutatóintézetének évkönyve, 27. pp. 15-28. ISSN 0365-3005

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Abstract

On base of histological investigations and paperchromatographic analysis of the supraoesophageal ganglion of the fresh water crab Astacus leptodactylus Eschscholz, the following could be concluded: 1. Three different types of neurosecretory cells (А, В, C) are located in majority peripherically and grouped around the roots of nerves originating in the brain, in definite number and arrangement. 2. Compared to the investigations of Enami, Matsumoto and Durand, except the А-type giant cells, the other two types of neurosecretory cells are identifiable with Enami’s α-, resp. with Durand Type 3 secretory cells, on the other hand with Enami γ- and Durand Type 4 neurosecretory cells resp. with Matsumoto’s D-cells. 3. The А-type giant cells can he compared in certain relation to Enami’s giant В-cells, resp. the Durand Type 2 neurosecretory cells. 4. The C-type cells are to be found in great quantity (about 6-800 pcs laterally located only on the surface of the olfactory lobes). These axons proceed into the olfactory lobes. 5. Great neurosecretory activity can be observed in all three types oi cells in the cerebral ganglions of summer and autumn samples.. On the contrary, in the winter, end February samples the C-type cells are in a completely inactive state. In the other two types of cell secretory activity is just beginning about this time. 6. Inside the brain, the transport of neurosecrete in the axon bundles can be well-analysed. We observed the migration of the secretory material through the peduncle lobi optici. We could further observe two little canals (supposed to be giant axons) proceeding from the circumoesophageal ganglion to the brain, in which the transport of neurosecrete was demonstrable. 7. During the summer-autumm active secretory period, among others a lilac fluorescent compound could be isolated from the brain by means of paper chromatography. On base of its Rf value and its absorption spectrum measured in the UV-spectrum and other characteristics, it proved to be identical with the isoxanthopterin isolated from the brain of insects. 8. To clear the role the isoxanthopterin is supposed to have, we made comparisons partly with the conditions found in insects, partly in connection with the neurohormones of chromatophorotropic character which are produced in the brain of crabs and which control moulting. 9. Isoxanthopterin could not be demonstrated in the brain of winter specimens. Owing to this fact, the point of its production can only be brought into correlation with C-type cells which are at this time inactive.

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