Release probability of hippocampal glutamatergic terminals scales with the size of the active zone.
Nat Neurosci
; 15(7): 988-97, 2012 Jun 10.
Article
em En
| MEDLINE
| ID: mdl-22683683
ABSTRACT
Cortical synapses have structural, molecular and functional heterogeneity; our knowledge regarding the relationship between their ultrastructural and functional parameters is still fragmented. Here we asked how the neurotransmitter release probability and presynaptic [Ca(2+)] transients relate to the ultrastructure of rat hippocampal glutamatergic axon terminals. Two-photon Ca(2+) imaging-derived optical quantal analysis and correlated electron microscopic reconstructions revealed a tight correlation between the release probability and the active-zone area. Peak amplitude of [Ca(2+)] transients in single boutons also positively correlated with the active-zone area. Freeze-fracture immunogold labeling revealed that the voltage-gated calcium channel subunit Cav2.1 and the presynaptic protein Rim1/2 are confined to the active zone and their numbers scale linearly with the active-zone area. Gold particles labeling Cav2.1 were nonrandomly distributed in the active zones. Our results demonstrate that the numbers of several active-zone proteins, including presynaptic calcium channels, as well as the number of docked vesicles and the release probability, scale linearly with the active-zone area.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Vesículas Sinápticas
/
Potenciais de Ação
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Terminações Pré-Sinápticas
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Hipocampo
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article