Exocytosis at the ribbon synapse of retinal bipolar cells studied in patches of presynaptic membrane

The distribution of exocytic sites and ion channels in the synaptic terminal of retinal bipolar cells was investigated by measuring capacitance and conductance changes in cell-attached patches of presynaptic membrane. Patch depolarization evoked capacitance and conductance increases that were inhibi...

Descripción completa

Detalles Bibliográficos
Autores: Llobet Berenguer, Artur, 1972-, Cooke, Anne, Lagnado, Leon
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2003
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/175766
Acceso en línea:https://hdl.handle.net/2445/175766
Access Level:acceso abierto
Palabra clave:Neurones
Fisiologia
Retina
Citologia
Neurons
Physiology
Cytology
id ES_8abfbe6c7024ef4332e893200f367807
oai_identifier_str oai:diposit.ub.edu:2445/175766
network_acronym_str ES
network_name_str España
repository_id_str
spelling Exocytosis at the ribbon synapse of retinal bipolar cells studied in patches of presynaptic membraneLlobet Berenguer, Artur, 1972-Cooke, AnneLagnado, LeonNeuronesFisiologiaRetinaCitologiaNeuronsPhysiologyRetinaCytologyThe distribution of exocytic sites and ion channels in the synaptic terminal of retinal bipolar cells was investigated by measuring capacitance and conductance changes in cell-attached patches of presynaptic membrane. Patch depolarization evoked capacitance and conductance increases that were inhibited by blocking Ca(2+) influx or loading the terminal with EGTA. The increase in capacitance declined as the depolarization approached the reversal potential for Ca(2+), indicating that it was a result of Ca(2+)-dependent exocytosis. The conductance increase was caused by K(Ca) channels that were also activated by Ca(2+) influx. Two observations indicated that sites of exocytosis and endocytosis colocalized with clusters of Ca(2+) channels and K(Ca) channels; the initial rate of exocytosis was correlated with the activation of K(Ca) channels, and exocytosis did not occur in the 41% of patches lacking this conductance. Electron microscopy demonstrated that there were approximately 16 vesicles docked to the plasma membrane at each active zone marked by a ribbon, but vesicles were also attached to the rest of the membrane at a density of 1.5/microm(2). The density of ribbons was 0.10 +/- 0.02/microm(2), predicting that approximately 43% of cell-attached patches would lack an active zone. The density of Ca(2+) channel clusters assayed by capacitance and conductance responses was therefore similar to the density of ribbons. These results are consistent with the idea that Ca(2+) channel clusters were colocalized with ribbons but do not exclude the possibility that calcium channels also occurred at other sites. The wide distribution of vesicles docked to the plasma membrane suggests that exocytosis might also be triggered by the spread of Ca(2+) from Ca(2+) channel clusters.The Society for Neuroscience2003info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://hdl.handle.net/2445/175766Articles publicats en revistes (Patologia i Terapèutica Experimental)reponame:Dipòsit Digital de la UBinstname:Universidad de BarcelonaInglésReproducció del document publicat a: https://doi.org/10.1523/JNEUROSCI.23-07-02706.2003Journal of Neuroscience, 2003, vol. 23, num. 7, p. 2706-2714https://doi.org/10.1523/JNEUROSCI.23-07-02706.2003cc-by-nc-sa (c) Llobet Berenguer, Artur, 1972- et al., 2003http://creativecommons.org/licenses/by-nc-sa/3.0/esinfo:eu-repo/semantics/openAccessoai:diposit.ub.edu:2445/1757662026-05-27T06:46:51Z
dc.title.none.fl_str_mv Exocytosis at the ribbon synapse of retinal bipolar cells studied in patches of presynaptic membrane
title Exocytosis at the ribbon synapse of retinal bipolar cells studied in patches of presynaptic membrane
spellingShingle Exocytosis at the ribbon synapse of retinal bipolar cells studied in patches of presynaptic membrane
Llobet Berenguer, Artur, 1972-
Neurones
Fisiologia
Retina
Citologia
Neurons
Physiology
Retina
Cytology
title_short Exocytosis at the ribbon synapse of retinal bipolar cells studied in patches of presynaptic membrane
title_full Exocytosis at the ribbon synapse of retinal bipolar cells studied in patches of presynaptic membrane
title_fullStr Exocytosis at the ribbon synapse of retinal bipolar cells studied in patches of presynaptic membrane
title_full_unstemmed Exocytosis at the ribbon synapse of retinal bipolar cells studied in patches of presynaptic membrane
title_sort Exocytosis at the ribbon synapse of retinal bipolar cells studied in patches of presynaptic membrane
dc.creator.none.fl_str_mv Llobet Berenguer, Artur, 1972-
Cooke, Anne
Lagnado, Leon
author Llobet Berenguer, Artur, 1972-
author_facet Llobet Berenguer, Artur, 1972-
Cooke, Anne
Lagnado, Leon
author_role author
author2 Cooke, Anne
Lagnado, Leon
author2_role author
author
dc.subject.none.fl_str_mv Neurones
Fisiologia
Retina
Citologia
Neurons
Physiology
Retina
Cytology
topic Neurones
Fisiologia
Retina
Citologia
Neurons
Physiology
Retina
Cytology
description The distribution of exocytic sites and ion channels in the synaptic terminal of retinal bipolar cells was investigated by measuring capacitance and conductance changes in cell-attached patches of presynaptic membrane. Patch depolarization evoked capacitance and conductance increases that were inhibited by blocking Ca(2+) influx or loading the terminal with EGTA. The increase in capacitance declined as the depolarization approached the reversal potential for Ca(2+), indicating that it was a result of Ca(2+)-dependent exocytosis. The conductance increase was caused by K(Ca) channels that were also activated by Ca(2+) influx. Two observations indicated that sites of exocytosis and endocytosis colocalized with clusters of Ca(2+) channels and K(Ca) channels; the initial rate of exocytosis was correlated with the activation of K(Ca) channels, and exocytosis did not occur in the 41% of patches lacking this conductance. Electron microscopy demonstrated that there were approximately 16 vesicles docked to the plasma membrane at each active zone marked by a ribbon, but vesicles were also attached to the rest of the membrane at a density of 1.5/microm(2). The density of ribbons was 0.10 +/- 0.02/microm(2), predicting that approximately 43% of cell-attached patches would lack an active zone. The density of Ca(2+) channel clusters assayed by capacitance and conductance responses was therefore similar to the density of ribbons. These results are consistent with the idea that Ca(2+) channel clusters were colocalized with ribbons but do not exclude the possibility that calcium channels also occurred at other sites. The wide distribution of vesicles docked to the plasma membrane suggests that exocytosis might also be triggered by the spread of Ca(2+) from Ca(2+) channel clusters.
publishDate 2003
dc.date.none.fl_str_mv 2003
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv https://hdl.handle.net/2445/175766
url https://hdl.handle.net/2445/175766
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv Reproducció del document publicat a: https://doi.org/10.1523/JNEUROSCI.23-07-02706.2003
Journal of Neuroscience, 2003, vol. 23, num. 7, p. 2706-2714
https://doi.org/10.1523/JNEUROSCI.23-07-02706.2003
dc.rights.none.fl_str_mv cc-by-nc-sa (c) Llobet Berenguer, Artur, 1972- et al., 2003
http://creativecommons.org/licenses/by-nc-sa/3.0/es
info:eu-repo/semantics/openAccess
rights_invalid_str_mv cc-by-nc-sa (c) Llobet Berenguer, Artur, 1972- et al., 2003
http://creativecommons.org/licenses/by-nc-sa/3.0/es
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv The Society for Neuroscience
publisher.none.fl_str_mv The Society for Neuroscience
dc.source.none.fl_str_mv Articles publicats en revistes (Patologia i Terapèutica Experimental)
reponame:Dipòsit Digital de la UB
instname:Universidad de Barcelona
instname_str Universidad de Barcelona
reponame_str Dipòsit Digital de la UB
collection Dipòsit Digital de la UB
repository.name.fl_str_mv
repository.mail.fl_str_mv
_version_ 1869412740386258944
score 15,301603

Similares en LA Referencia