Efferent function of vestibular afferent endings? Similar localization of N-type calcium channels, synaptic vesicle and synaptic membrane-associated proteins.
Neuroscience
; 98(2): 377-84, 2000.
Article
em En
| MEDLINE
| ID: mdl-10854771
ABSTRACT
We investigated the distribution of N-type voltage-dependent calcium channels that mediate Ca(2+) entry initiating transmitter release in the rat vestibular sensory epithelium. We used confocal microscopy to assess the in vitro labeling by fluorescent specific ligand binding, omega-conotoxin-GVIA and also the immunolabeling of presynaptic soluble N-ethylmaleimide-sensitive fusion factor attachment protein receptor (SNARE) proteins, syntaxin, 25,000 mol. wt synaptosome-associated protein and synaptotagmin components of the neurotransmitter exocytosis machinery. We found that there was a close anatomical association between the voltage-gated calcium channels, the synaptic vesicle and synaptic membrane-associated proteins on the afferent nerve calyces and probably afferent boutons, which are postsynaptic compartments. Our data suggest that these peripheral afferent endings possess the presynaptic Ca(2+) channels and the components of the presynaptic SNARE proteins involved in synaptic vesicle docking and calcium-dependent exocytosis. They provide additional evidence for a secretory function and efferent role of these endings in hair cell neurotransmission.
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Base de dados:
MEDLINE
Assunto principal:
Membranas Sinápticas
/
Vesículas Sinápticas
/
Nervo Vestibular
/
Proteínas de Ligação ao Cálcio
/
Vias Aferentes
/
Terminações Pré-Sinápticas
/
Células Ciliadas Vestibulares
/
Canais de Cálcio Tipo N
/
Proteínas de Transporte Vesicular
Tipo de estudo:
Risk_factors_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
2000
Tipo de documento:
Article