Altered synapse formation in the adult somatosensory cortex of brain-derived neurotrophic factor heterozygote mice

Details

Serval ID
serval:BIB_A5B6516DE0EB
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Altered synapse formation in the adult somatosensory cortex of brain-derived neurotrophic factor heterozygote mice
Journal
Journal of Neuroscience
Author(s)
Genoud  C., Knott  G. W., Sakata  K., Lu  B., Welker  E.
ISSN
1529-2401 (Electronic)
Publication state
Published
Issued date
03/2004
Volume
24
Number
10
Pages
2394-400
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Mar 10
Abstract
Increased sensory stimulation in the adult whisker-to-barrel pathway induces the expression of BDNF as well as synapse formation in cortical layer IV. Here, we investigated whether BDNF plays a role in the alterations of connectivity between neurons by analyzing the ultrastructure of the BDNF heterozygote mouse, characterized by a reduced level of BDNF expression. Using serial section electron microscopy, we measured synapse density, spine morphology, and synaptic vesicle distribution to show that mice with a reduced level of BDNF have a barrel neuropil that is indistinguishable from wild-type controls. After 24 hr of whisker stimulation, however, there is no indication of synapse formation in the heterozygous mouse. Whereas the balance between excitatory and inhibitory synapses is modified in the controls, it remains constant in the heterozygotes. The distribution of synaptic vesicles in excitatory synapses is the same in heterozygous and wild-type mice and is not influenced by the stimulation paradigm. Spine volume, however, is unchanged by stimulation in the wild-type animals, but does increase significantly in the heterozygous animal. These results provide evidence that, in vivo, BDNF plays an important role in the structural rearrangement of adult cortical circuitry as a consequence of an increased sensory input.
Keywords
Animals Brain-Derived Neurotrophic Factor/biosynthesis/deficiency/*genetics Dendrites/ultrastructure Gene Expression/genetics Heterozygote Mice Mice, Mutant Strains Physical Stimulation/methods Somatosensory Cortex/metabolism/*physiology/ultrastructure Synapses/*physiology/ultrastructure Synaptic Vesicles/ultrastructure Vibrissae/physiology
Pubmed
Web of science
Open Access
Yes
Create date
24/01/2008 15:40
Last modification date
14/01/2021 10:33
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