title: Bergmann glia require continuous association with Purkinje cells for normal phenotype expression.
abstract: Bergmann glia (Bg) respond to the early postnatal Purkinje cell (Pc) death in Lurcher (Lc) mutant mouse cerebellum by down-regulating expression of the enzyme glycerol-3-phosphate dehydrogenase (GPDH). To determine whether glial GPDH expression requires the continued presence of Pcs in adults, we used single intracerebellar injections of kainic acid to kill Pcs in wild-type mice from 7 weeks to 11 months old. Bg at all ages tested responded to Pc loss by down-regulating GPDH expression. To learn whether a high level of GPDH could be reinduced following down-regulation in Lc Bg, we grafted wild-type fetal Pcs into Lc cerebella. The influence of grafted Pcs on GPDH expression is host-age and implant-position dependent. Only Pcs implanted into hosts less than 6 weeks old were later found to be associated with GPDH-positive Bg. Grafted Pcs that migrated into the anterior folia of young hosts were more likely to be associated with GPDH-positive Bg than Pcs migrating to other positions. EM analysis showed that Bg ensheathment of grafted Pcs is thinner and more discontinuous, but qualitatively similar to normal. The results suggest that the interaction between host Bg and grafted Pcs can sustain elevated GPDH expression in Bg that have not yet down-regulated, but is not adequate to reinduce expression in those cells that have.
authors.affiliation: Department of Anatomy and Cell Biology, University of Virginia School of Medicine, Charlottesville 22908.
authors.forename: M
authors.initials: M
authors.lastname: Fisher
authors.forename: P
authors.initials: P
authors.lastname: Trimmer
authors.forename: G
authors.initials: G
authors.lastname: Ruthel
mesh_terms: D000367:Age Factors; D000818:Animals; D017209:Apoptosis; D016380:Brain Tissue Transplantation; D002450:Cell Communication; D016923:Cell Death; D002531:Cerebellum / Q000473:pathology; D003712:Dendrites / Q000648:ultrastructure; D004790:Enzyme Induction; D016332:Fetal Tissue Transplantation; D005993:Glycerolphosphate Dehydrogenase / Q000096:biosynthesis*; D007608:Kainic Acid / Q000494:pharmacology; D051379:Mice; D008818:Mice, Neurologic Mutants / Q000033:anatomy & histology* / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000096:biosynthesis*; D009457:Neuroglia / Q000166:cytology* / Q000201:enzymology; D010641:Phenotype; D011689:Purkinje Cells / Q000187:drug effects / Q000502:physiology* / Q000637:transplantation
chemical_list: D009419:Nerve Tissue Proteins; D005993:Glycerolphosphate Dehydrogenase; D007608:Kainic Acid