Presynaptic CaV1.3 channels regulate synaptic ribbon size and are required for synaptic maintenance in sensory hair cells.
J Neurosci
; 32(48): 17273-86, 2012 Nov 28.
Article
em En
| MEDLINE
| ID: mdl-23197719
ABSTRACT
L-type calcium channels (Ca(V)1) are involved in diverse processes, such as neurotransmission, hormone secretion, muscle contraction, and gene expression. In this study, we uncover a role for Ca(V)1.3a in regulating the architecture of a cellular structure, the ribbon synapse, in developing zebrafish sensory hair cells. By combining in vivo calcium imaging with confocal and super-resolution structured illumination microscopy, we found that genetic disruption or acute block of Ca(V)1.3a channels led to enlargement of synaptic ribbons in hair cells. Conversely, activating channels reduced both synaptic-ribbon size and the number of intact synapses. Along with enlarged presynaptic ribbons in ca(V)1.3a mutants, we observed a profound loss of juxtaposition between presynaptic and postsynaptic components. These synaptic defects are not attributable to loss of neurotransmission, because vglut3 mutants lacking neurotransmitter release develop relatively normal hair-cell synapses. Moreover, regulation of synaptic-ribbon size by Ca(2+) influx may be used by other cell types, because we observed similar pharmacological effects on pinealocyte synaptic ribbons. Our results indicate that Ca(2+) influx through Ca(V)1.3 fine tunes synaptic ribbon size during hair-cell maturation and that Ca(V)1.3 is required for synaptic maintenance.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Sinapses
/
Peixe-Zebra
/
Transmissão Sináptica
/
Canais de Cálcio Tipo L
/
Células Ciliadas Auditivas
Limite:
Animals
Idioma:
En
Revista:
J Neurosci
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Estados Unidos