5'-Nucleotidase of cerebellar molecular layer: reduction in Purkinje cell-deficient mutant mice.

The molecular layer of the cerebellar cortex contains high levels of the enzyme 5'-nucleotidase (EC 3.1.3.5), localized predominantly to Bergmann glia. In the present study, histochemical methods have been employed to examine the distribution of cerebellar 5'-nucleotidase in mice of two separate mutant strains in which Purkinje cells are eliminated selectively. In homozygous 'Purkinje cell degeneration' (pcd) and 'nervous' (nr) mice, molecular layer 5'-nucleotidase is greatly reduced and residual enzyme activity in colocalized with surviving Purkinje cells. These results suggest strongly that the expression of 5'-nucleotidase activity by Bergmann glia is under the inductive influence of their associated Purkinje cells.