|
|
|
|
|
|
|
|
|||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
Quarterly Journal of Microscopical Science, Vol s2-75, 1-47, Copyright © 1932 by Company of Biologists
1 Christopher Welch Scholar, late Senior Demy of Magdalen College. Department of Zoology and Comparative Anatomy, Oxford
1. The neurons of the stellate ganglia of Cephalopods are surrounded by connective tissue which penetrates into canals in the cytoplasm. The nuclei in these canals belong to the connective tissue.
2. The nuclei of the neurons contain a fluid of rather low viscosity, in which are suspended a basophil karyosome, one or more oxyphil plasmosomes, and a number of smaller granules.
3. Around the nucleus there is a mass of bodies, visible in the unstained cells, which stain readily with neutral red, and have been shown to have a definite outer membrane which is permeable to water but impermeable to inorganic ions. These vacuoles maintain their identity when squeezed out of the cells.
4. The vacuoles stain somewhat with osmium tetroxide both when immersed directly in a 0.5 per cent, solution in sea-water and after Kolatschev's method. They often stain deeply with silver after Cajal's and Da Fano's methods.
5. After staining with Kolatschev, Cajal, or Da Fano's techniques a number of granules can be seen in the neighbourhood of the vacuoles. They usually (perhaps always) lie near the surface of the latter, but certainly do not constitute their outer membrane. Not all of the vacuoles are accompanied by such bodies. The term Golgi bodies (or substance) is restricted to these granules.
6. The chondriosomes are smaller bodies scattered throughout the cell; they were not found to stain with osmium or silver.
7. Centrifuging the ganglia produced shifting of the karyosome within the nucleus, but no changes in the positions of any of the substances in the cytoplasm.
8. The region of the vacuoles has been shown to have a higher oxidation potential than the rest of the cell.
9. The Nissl substance forms a homogeneous mass in the outer part of the cell and is not divided up into separate grumes it extends into the axon. It undergoes peculiar post-mortem changes when kept under anaerobic conditions.
10. The Nissl substance of Aplysia lies round the nucleus. It is not divided up into grumes and does not extend into the axon.
11. After section of the mantle connective no changes were seen in the Nissl substance of the stellate ganglion, though the cells were shown to be in an abnormal physiological condition.
12. After section of the stellar nerves marked retrograde degeneration was seen in the cells of the stellate ganglion, and this is described in detail. The Nissl substance later regenerates in situ, and not in connexion with the nucleus; possibly it is formed in connexion with the outer layer of vacuoles.
13. Electrical stimulation of the mantle connective caused no marked changes in the nuclei, Nissl substance, or Golgi bodies of the cells of the stellate ganglion.
