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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
Pt 20
pubmed:dateCreated
2005-10-12
pubmed:abstractText
We have previously shown that retinoic acid (RA), a factor highly expressed in spinal cord, rapidly and specifically enhances the spontaneous acetylcholine release at developing neuromuscular synapses in Xenopus cell culture, using whole-cell patch-clamp recording. We have now further investigated the underlying mechanisms that are involved in RA-induced facilitation on the frequency of spontaneous synaptic currents (SSCs). Buffering the rise of intracellular Ca2+ with BAPTA-AM hampered the facilitation of SSC frequency induced by RA. The prompt RA-enhanced SSC frequency was not abolished when Ca2+ was eliminated from the culture medium or there was bath application of the pharmacological Ca2+ channel inhibitor Cd2+, indicating that Ca2+ influx through voltage-activated Ca2+ channels are not required. Application of membrane-permeable inhibitors of inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] or ryanodine receptors effectively blocked the increase of SSC frequency elicited by RA. Treating cells with either wortmannin or LY294002, two structurally different inhibitors of phosphatidylinositol 3-kinase (PI 3-kinase) and with the phospholipase Cgamma (PLCgamma) inhibitor U73122, abolished RA-induced facilitation of synaptic transmission. Preincubation of the cultures with pharmacological inhibitors, either genistein, a broad-spectrum tyrosine kinase inhibitor, or PP2, which predominantly inhibits the Src family of nonreceptor tyrosine kinase, completely abolished RA-induced synaptic facilitation. Taken collectively, these results suggest that RA elicits Ca2+ release from Ins1,4,5P3 and/or ryanodine-sensitive intracellular Ca2+ stores of the presynaptic nerve terminal. This is done via PLCgamma/PI 3-kinase signaling cascades and Src tyrosine kinase activation, leading to an enhancement of spontaneous transmitter release.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9533
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
118
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4721-30
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
A rapid, nongenomic pathway facilitates the synaptic transmission induced by retinoic acid at the developing synapse.
pubmed:affiliation
Department of Biological Sciences, National Sun Yat-sen University, No. 70, Lein-Hai Rd., Kaohsiung City, 804, Taiwan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't