Fig. 7. Glial hypertrophy in the anterior cerebellum and midbrain of adult Abr;Bcr double null mutants. (A,B) In the anterior cerebellum of double null mutants, the ectopic granule cells are surrounded by numerous GFAP-positive glial cells (B), whereas in controls, a similar staining is absent (A). (C,D) Glial hypertrophy is also present in the midbrain of adult Abr;Bcr mutants (D) but not in controls (C). (E) Control midbrains show no detectable glial hypertrophy upon exposure to kainic acid. (F) Treatment of double null mutants with kainic acid results in massive gliosis in the midbrain. Ce, cerebellum; Sc, superior colliculus; KA, kainic acid. Scale bars: 100 µm in A,B; 50 µm in C-F.