Linked Life Data

10601005

Source:http://linkedlifedata.com/resource/pubmed/id/10601005

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2000-1-31
pubmed:abstractText
We have analyzed in organotypic rat visual cortex cultures the way in which expression of brain-derived neurotrophic factor (BDNF) mRNA depends on synaptically generated spontaneous bioelectric activity (SBA) as monitored by recordings of pyramidal cells. SBA was initially low, but from the fourth week onwards 83% of the neurons fired action potentials at 0.2-1.2 impulses/s in a well-balanced state of excitation and inhibition. BDNF mRNA expression increased during the second week to a level surprisingly similar to the adult visual cortex in vivo, despite the fact that activity rates in vitro were approximately 10-fold lower than rates reported in vivo. Thus, SBA generated by a cortical neuronal network in the absence of sensory input is sufficient to elicit and maintain BDNF expression. The transient BDNF peak occurring after eye opening in vivo did not occur in vitro. A blockade of SBA seems not to alter the expression of neurotrophin (NT)-3 and -4/5, and tyrosine kinase receptor C and B mRNA. However, BDNF expression remained extremely low. A recovery of SBA after a period of blockade concurred with a transient hyperexcitability. BDNF immediately increased, driven by calcium influx through voltage-gated channels in synergy with NMDA receptors. Expression transiently reached high levels in neurons of supragranular layers. Infragranular neurons, although firing action potentials, recovered BDNF expression much slower. After 5 days in vitro recovery, the network had de novo established a balanced state of excitation and inhibition. Distribution and expression level of BDNF mRNA had returned to control. Even in 'adult' cultures an acute blockade of SBA downregulated BDNF, and a subsequent recovery of SBA restored BDNF expression. We conclude that BDNF mRNA expression depends on and responds with a fast kinetic to changes of the SBA. Steady-state levels do not depend on the absolute levels of activity, but more likely on the balance between excitation and inhibition, suggesting a role for BDNF in activity homeostasis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1047-3211
pubmed:author
pubmed:issnType
Print
pubmed:volume
9
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
864-77
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Development of neuronal activity and activity-dependent expression of brain-derived neurotrophic factor mRNA in organotypic cultures of rat visual cortex.
pubmed:affiliation
AG Entwicklungsneurobiologie, Fakultät für Biologie, Ruhr-Universität, Bochum, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't