Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2010-1-21
pubmed:abstractText
Low levels of survival motor neuron (SMN) protein result in spinal muscular atrophy (SMA), a severe genetic disease characterized by motor impairment and premature lethality. Although SMN is a ubiquitous protein, motor neurons are much more vulnerable to low levels of SMN than other cells. To gain insight into the pathogenesis of SMA, we have compared synaptic function of motor terminals in wild-type and severe SMA mice at different ages and in two proximal muscles. Our results show that mutant muscle fibers fire normal action potentials and that multi-innervated terminals are functional. By studying the characteristics of the three main components of synaptic transmission in nerve terminals (spontaneous, evoked, and asynchronous release), we found that the kinetics of the postsynaptic potentials are slowed and evoked neurotransmitter release is decreased by approximately 55%. In addition, asynchronous release is increased approximately 300%, indicating an anomalous augmentation of intraterminal bulk Ca(2+) during repetitive stimulation. Together, these results show that the reduction of SMN affects synaptic maturation, evoked release, and regulation of intraterminal Ca(2+) levels.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1529-2401
pubmed:author
pubmed:issnType
Electronic
pubmed:day
20
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
849-57
pubmed:meshHeading
pubmed-meshheading:20089893-Action Potentials, pubmed-meshheading:20089893-Animals, pubmed-meshheading:20089893-Animals, Newborn, pubmed-meshheading:20089893-Calcium, pubmed-meshheading:20089893-Disease Models, Animal, pubmed-meshheading:20089893-Electric Stimulation, pubmed-meshheading:20089893-Extracellular Fluid, pubmed-meshheading:20089893-Homeostasis, pubmed-meshheading:20089893-Mice, pubmed-meshheading:20089893-Mice, Transgenic, pubmed-meshheading:20089893-Models, Biological, pubmed-meshheading:20089893-Muscle, Skeletal, pubmed-meshheading:20089893-Muscular Atrophy, Spinal, pubmed-meshheading:20089893-Mutation, pubmed-meshheading:20089893-Neuromuscular Junction, pubmed-meshheading:20089893-Neurotransmitter Agents, pubmed-meshheading:20089893-Presynaptic Terminals, pubmed-meshheading:20089893-Reaction Time, pubmed-meshheading:20089893-Survival of Motor Neuron 1 Protein
pubmed:year
2010
pubmed:articleTitle
Altered intracellular Ca2+ homeostasis in nerve terminals of severe spinal muscular atrophy mice.
pubmed:affiliation
Department of Medical Physiology and Biophysics, School of Medicine, University of Seville, 41009 Seville, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't