Cerebellar brain-derived neurotrophic factor-TrkB defect associated with impairment of eyeblink conditioning in Stargazer mutant mice.
In the spontaneous ataxic mutant mouse stargazer, there is a selective reduction of brain-derived neurotrophic factor (BDNF) mRNA expression in the cerebellum. BDNF protein levels in the cerebellum are reduced by 70%. Despite normal levels of full-length and truncated TrkB receptor, constitutive and neurotrophin-4/5-induced tyrosine phosphorylation was significantly reduced in several signal transduction molecules, including phospholipase-Cgamma1, erk1, and erk2. Morphological examination revealed an increased number of external granule cells at postnatal day 15 and the presence of abnormal neurons resembling immature granule cells in the adult. These abnormalities are associated with a severe impairment in the acquisition of classical eyeblink conditioning, indicating cerebellar malfunction. Our data suggest that normal BDNF expression and TrkB signal transduction in the cerebellum are necessary for learning and plasticity in this model.
Qiao
X
X
Program for Neural, Informational, and Behavioral Sciences, University of Southern California, Los Angeles, California 90089, USA.
Chen
L
L
Gao
H
H
Bao
S
S
Hefti
F
F
Thompson
R F
RF
Knusel
B
B
D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism*; D002524:Cerebellar Ataxia / Q000235:genetics* / Q000378:metabolism; D002531:Cerebellum / Q000166:cytology / Q000378:metabolism*; D003215:Conditioning, Eyelid / Q000502:physiology*; D006720:Homozygote; D051379:Mice; D008818:Mice, Neurologic Mutants; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism*; D020801:Receptor, Ciliary Neurotrophic Factor; D017475:Receptors, Nerve Growth Factor / Q000378:metabolism*; D012640:Seizures / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D014722:Vestibule, Labyrinth / Q000378:metabolism
D019208:Brain-Derived Neurotrophic Factor; D020801:Receptor, Ciliary Neurotrophic Factor; D017475:Receptors, Nerve Growth Factor; D020794:Receptor Protein-Tyrosine Kinases