Linked Life Data

10712480

Source:http://linkedlifedata.com/resource/pubmed/id/10712480

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2000-4-11
pubmed:abstractText
Neuromuscular synapses in buccal muscle I3a of Aplysia are modulated by the small cardioactive peptide (SCP), a peptide cotransmitter that is intrinsic to the motor neurons, and by serotonin (5-HT) released from modulatory neurons that are extrinsic to the motor circuit. Although the modulation of excitatory junction potentials (EJPs) and contractions by 5-HT and SCP has been studied extensively in this muscle, little is known about the mechanisms that underlie the modulation. 5-HT and SCP, at 1 microM, were found to potently increase the level of cAMP in I3a. Therefore we investigated whether the activation of the cAMP pathway was sufficient to modulate EJPs and contractions. The direct activation of adenylyl cyclase with forskolin increased the level of cAMP, facilitated EJPs, and potentiated contractions. Indeed, the short-term effects of forskolin were very similar to all aspects of the short-term effects of 5-HT and SCP. Membrane-permeable cAMP analogues also mimicked the effects of 5-HT and SCP on EJPs and contractions. However, it seems likely that some effects of 5-HT are also mediated through other second-messenger pathways because low concentrations of 5-HT modulate EJPs and contractions but do not significantly increase cAMP levels in I3a. It is possible that lower concentrations of 5-HT function through receptors linked to protein kinase C (PKC) because phorbol, an activator of PKC, modulated EJPs and contractions without increasing the levels of cAMP. In conclusion, we provide evidence that pharmacological agents that activate the cAMP pathway mimicked most of the effects of 5-HT or SCP and that more than one second-messenger system appears to be involved in the modulation of the I3a neuromuscular system.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0022-3077
pubmed:author
pubmed:issnType
Print
pubmed:volume
83
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1567-79
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:10712480-1-Methyl-3-isobutylxanthine, pubmed-meshheading:10712480-Adenylate Cyclase, pubmed-meshheading:10712480-Animals, pubmed-meshheading:10712480-Aplysia, pubmed-meshheading:10712480-Cyclic AMP, pubmed-meshheading:10712480-Cyclic AMP-Dependent Protein Kinases, pubmed-meshheading:10712480-Electric Stimulation, pubmed-meshheading:10712480-Enzyme Inhibitors, pubmed-meshheading:10712480-Forskolin, pubmed-meshheading:10712480-Invertebrate Hormones, pubmed-meshheading:10712480-Motor Neurons, pubmed-meshheading:10712480-Muscle Contraction, pubmed-meshheading:10712480-Muscles, pubmed-meshheading:10712480-Neural Pathways, pubmed-meshheading:10712480-Neuromuscular Junction, pubmed-meshheading:10712480-Neuropeptides, pubmed-meshheading:10712480-Phorbol Esters, pubmed-meshheading:10712480-Serotonin
pubmed:year
2000
pubmed:articleTitle
Role of cAMP in the short-term modulation of a neuromuscular system in aplysia.
pubmed:affiliation
Committee on Neurobiology and Department of Neurobiology, Pharmacology and Physiology, University of Chicago, Chicago, Illinois 60637, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.