Prominent Postsynaptic and Dendritic Exocytosis of Endogenous BDNF Vesicles in BDNF-GFP Knock-in Mice.
Mol Neurobiol
; 56(10): 6833-6855, 2019 Oct.
Article
em En
| MEDLINE
| ID: mdl-30929164
ABSTRACT
Brain-derived neurotrophic factor (BDNF) is a secreted messenger molecule that is crucial for neuronal function and induction of synaptic plasticity. Although altered availability of BDNF underlies many neurological deficits and neurodegenerative disorders, secretion dynamics of endogenous BDNF are unexplored. We generated a BDNF-GFP knock-in (KiBE) mouse, in which GFP-labeled BDNF is expressed under the control of the unaltered endogenous mouse BDNF gene regulatory elements. This KiBE mouse model enables for the first time live cell imaging analysis of endogenous BDNF dynamics. We show that BDNF-GFP release and biological activity in vivo are unaffected by the GFP tag, since homozygous KiBE mice, which lack wild-type BDNF, are healthy and have a normal life expectancy. STED superresolution microscopy shows that 70% of BDNF-GFP vesicles in KiBE mouse neurites are localized in dendrites, being typically 200 nm away from synaptic release sites. Live cell imaging in hippocampal slices also reveals prominent targeting of endogenous BDNF-GFP vesicles to dendrites. Fusion pore opening and cargo release of dendritic BDNF vesicles start within 30 s after a strong depolarizing stimulus and continue for > 100 s thereafter, revealing an astonishingly delayed and prolonged release of endogenous BDNF.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Vesículas Sinápticas
/
Fator Neurotrófico Derivado do Encéfalo
/
Dendritos
/
Proteínas de Fluorescência Verde
/
Exocitose
/
Técnicas de Introdução de Genes
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Mol Neurobiol
Assunto da revista:
BIOLOGIA MOLECULAR
/
NEUROLOGIA
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Alemanha