The effects of calcium on the surface characteristics of dissociated fetal mouse cerebral cells: morphological aspects.

Abstract

Abstract Trypsin-EDTA dissociated fetal mouse cerebral cells were cultured over a 48 h period in media containing physiological and low levels of Ca 2+ , and also in media lacking Ca 2+ . Quantitative light microscopy studies revealed that 86% of cells grown in the physiological Ca 2+ medium had recognizable cellular processes 1 h after plating and 96% at 48 h. Of the cells grown in media without Ca 2+ , 70–80% failed to establish cellular processes. In the low Ca 2+ medium, 7% of the plated cells had no cellular processes at 1 h. Scanning electron microscopy revealed that cells grown in the physiological Ca 2+ and low Ca 2+ media demonstrated cell types of varying features. One type had rounded cell bodies, with at least one well-defined cell process. A second type demonstrated considerable ruffling on the cell surface, and a third type had flattened cell bodies with numerous cell processes. Cells grown in the low Ca 2+ medium showed considerable proliferation of processes up to 15 h after plating. In contrast, cells grown in the Ca 2+ -free medium had flattened and relatively smooth cell bodies, with few distinct processes. Those cells with processes were unipolar. These results suggest that dissociation with trypsin-EDTA renders the cell surface active, exposing it to the direct effects of the presence or absence of external Ca 2+ . The lack of cell surface features and cellular outgrowth in the Ca 2+ free cells suggests that Ca 2+ plays an important role in the initial dynamic processes of cell membrane activity during early neural cell adhesion and development.