As a first step toward identifying the factor(s) that is/are produced by astrocytes and support(s) the survival of cerebellar Purkinje cells in dissociated culture, we compared the effect of astrocytes of cerebellar, hippocampal, and cerebral origin. A feeder coverslip of cerebellar astrocytes, which did not have cell-to-cell contact to neuronal culture, increased the percentage of Purkinje cells to about 8-9 fold with no change in the percentage of astrocytes. On the other hand, astrocytes of hippocampal or cerebral origin did not increase the percentage of Purkinje cells at low plating density, whereas they increased the number of astrocytes in neuronal culture. These results indicate that the factor(s), tentatively named as Purkinje-cell survival factor was/were specifically produced by cerebellar astrocytes and affected directly on Purkinje cells.