Two forms of cerebellar glial cells interact differently with neurons in vitro.

Abstract

Specific interactions between neurons and glia dissociated from early postnatal mouse cerebellar tissue were studied in vitro by indirect immunocytochemical staining with antisera raised against purified glial filament protein, galactocerebroside and the NILE [nerve growth factor-inducible large external] glycoprotein. Two forms of cells were stained with antisera raised against purified glial filament protein. The 1st, characterized by a cell body 9 .mu.m diameter and processes 130-150 .mu.m long, usually had 2-3 neurons associated with them and resembled Bergmann glia. The 2nd had a slightly larger cell body with markedly shorter arms among which were nestled several dozen neuronal cells and resembled astrocytes of the granular layer. Staining with monoclonal antisera raised against purified galactocerebroside revealed the presence of immature oligodendroglia in the cultures. These glial cells constituted .apprx. 2% of the total cell population in the cultures and, in contrast to astroglia, did not form specific contacts with neurons. Staining with 2 neuronal markers, antisera raised against purified NILE glycoprotein and tetanus toxin, revealed that most cells associated with presumed astroglia were small neurons (5-8 .mu.m). After 1-2 days in culture, some stained neurons had very fine, short processes. Nearly all of the processes > 10-20 .mu.m long were glial in origin. EM also demonstrated the presence of 2 forms of astroglia in the cultures, each with a different organizing influence on cerebellar neurons. Most neurons associated with astroglia were granule neurons, although a few larger neurons sometimes associated with them. Time-lapse video microscopy revealed extensive cell migration (.apprx. 10 .mu.m/h) along the arms of Bergmann-like astroglia. Cells did not migrate along the arms of astrocyte-like astroglia, but remained stationary at or near branch points. Growth cone activity, pulsating movements of cell perikarya, and ruffling of the membranes of glial and neuronal processes were also seen.