Characterization of crustacean central glia

CHARACTERIZATION OF CRUSTACEAN CENTRAL GLIA^*

SIMONE F. DA SILVA¹, CRISTINE M. BRESSAN^1,2,3, RUBEN BITTENCOURT-NAVARRETE², LENY A. CAVALCANTE²AND SILVANA ALLODI¹

¹

²Instituto de Biofisica Carlos Chagas Filho, 21941-590 Rio de Janeiro, RJ

³Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil

The functions of the nervous system result from the interaction not only among neurons, but also between neurons and glial cells. In some invertebrates, peripheral glial cells show a great variety of types that have been relatively well characterized by ultrastructural and physiological criteria. Less is known about central glia, particularly in superior invertebrates such as crustaceans. In view of differences between the axonal ensheathment in crustaceans and vertebrates, we have tried to use the immunohistochemical detection of 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase), an actin-binding protein detected in non-compacted oligodendroglial and Schwann cells ensheathments, to characterize central glial cells in 2 crustaceans: the crab Ucides cordatus and post-larval stages of the giant prawn Macrobrachium rosenbergii. In the protocerebrum of U. cordatus, CNPase immunoreactivity was observed in cell bodies and processes in the basal membrane, lamina ganglionaris, external, internal and terminal medullae and in the protocerebral tract. The same structures were also immunoreactive in the post-larval stages of M. rosenbergii. CNPase immunohistochemistry was also found in the ganglionic X-organ, including neurosecretory neurons with diameters larger than 30 mm. In the deutocerebrum, CNPase labeling was observed in the olfactory lobe. Glutamine synthetase (GS), also used as a glial cell label in vertebrates, was tested in the same crustaceans. In post-larval prawns, immunohistochemical localization of GS could be observed in the lamina ganglionaris and other subdivisions of the optic lobes. The sites where this enzyme was detected are comparable to the sites where CNPase is expressed although the density of label varies. Our results indicate that both CNPase and glutamine synthetase are phylogenetically conserved and that they could be considered useful labels to identify crustacean central glial cells as well as large diameter neurons of the ganglionic X-organ. — ( June 27, 2000 ).

Publication Dates

• Publication in this collection
  05 Oct 2000
• Date of issue
  Sept 2000