Expression of neurotrophins and neurotrophin receptors in the cerebellum of mutant weaver and lurcher mice.
To test the hypothesis whether a failure to express neurotrophins or a neurotrophin receptor might underlie the pathology observed in mutant mice with degeneration of regionally distinct subpopulations of neurons, the expression of BDNF, NT-3, TrkB, TrkC and synaptophysin mRNA was examined in the cerebellum of mutant lurcher (lc/+) and weaver (wv/+)/(wv/wv) mice. To identify the expression patterns of individual neurons, we used in situ hybridization with digoxigenin labeled ribonucleotide probes. RT-PCR of cerebellar mRNA for BDNF, NT-3, TrkB and TrkC (GAPDH as internal standard) was performed in parallel. Although especially in homozygous (wv/wv) weaver mice the normal anatomical order and number of the cerebellar neurons is grossly disturbed, residual Purkinje and granule neurons of both mutants displayed a normal expression pattern of the neurotrophins examined. Thus, the affected animals showed no significant signal decrease compared to healthy littermates or C3H mice. Our results suggest that the loss of specific neuron populations in the cerebellum of either mutant occurs via mechanisms either independent or downstream of the neurotrophins examined in this study.
Wüllner
U
U
Department of Neurology, Eberhard-Karls-University, Hoppe-Seyler-Str. 3, D-72076 Tübingen, Germany.
Isenmann
S
S
Gleichmann
M
M
Klockgether
T
T
Bähr
M
M
D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics; D002531:Cerebellum / Q000378:metabolism* / Q000473:pathology; D006579:Heterozygote; D006720:Homozygote; D051379:Mice; D008809:Mice, Inbred C3H; D008818:Mice, Neurologic Mutants; D009414:Nerve Growth Factors / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics*; D009474:Neurons / Q000378:metabolism* / Q000473:pathology; D020933:Neurotrophin 3; D011689:Purkinje Cells / Q000378:metabolism / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics; D020801:Receptor, Ciliary Neurotrophic Factor; D020812:Receptor, trkC; D017475:Receptors, Nerve Growth Factor / Q000096:biosynthesis / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic
D019208:Brain-Derived Neurotrophic Factor; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D020933:Neurotrophin 3; D012333:RNA, Messenger; D020801:Receptor, Ciliary Neurotrophic Factor; D017475:Receptors, Nerve Growth Factor; D020794:Receptor Protein-Tyrosine Kinases; D020812:Receptor, trkC