CONSTITUTIVE EXPRESSION OF GLUTAMIC-ACID DECARBOXYLASE (GAD) BY STRIATAL CELL-LINES IMMORTALIZED USING THE TSA58 ALLELE OF THE SV40 LARGE T-ANTIGEN

Rodent striatal cells were immortalized using the A58 temperature-sens itive allele of the SV40 large T antigen. Seventy-eight clones and 10 mixed cultures were characterized at the nonpermissive and permissive temperatures. Based on morphology and expression of proteins, cells we re classified into three primary types, with types b and c expressing some neuronal characteristics. Type a cells have an epithelial-like mo rphology with coarse cytoplasmic extensions and occasional fine proces ses. These cells express vimentin, do not grow well under serum-free c onditions and, when confluent, form a uniform monolayer. Type b cells have a polygonal shape and usually extend multiple thin processes. The se cells possess large nuclei with multiple nucleoli and do not expres s vimentin. Type c cells have a fibroblast-like appearance, are unipol ar or multipolar, and their soma is smaller than that of type b cells. Type c cells do not express vimentin, and when confluent form a unifo rm monolayer. Some type b and c clones express NCAM and MAP-2. Several type b and c cell lines were found to consistently express glutamic a cid decarboxylase (GAD) immunoreactivity under several tissue culture conditions. Selected cell lines were transplanted into the intact adul t rat rain in several locations. Cells survived well for 15 wk and did not form tumors. The proteins expressed in vivo were similar to those expressed in vitro.