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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2009-4-1
pubmed:abstractText
Plasma membrane chloride (Cl(-)) pathways play an important role in neuronal physiology. Here, we investigated the role of NKCC1 cotransporters (a secondary active Cl(-) uptake mechanism) in Cl(-) handling in cultured rat dorsal root ganglion neurons (DRGNs) and motor neurons (MNs) derived from fetal stage embryonic day 14. Gramicidin-perforated patch-clamp recordings revealed that DRGNs accumulate intracellular Cl(-) through a bumetanide- and Na(+)-sensitive mechanism, indicative of the functional expression of NKCC1. Western blotting confirmed the expression of NKCC1 in both DRGNs and MNs, but immunocytochemistry experiments showed a restricted expression in dendrites of MNs, which contrasts with a homogeneous expression in DRGNs. Both MNs and DRGNs could be readily loaded with or depleted of Cl(-) during GABA(A) receptor activation at depolarizing or hyperpolarizing membrane potentials. After loading, the rate of recovery to the resting Cl(-) concentration (i.e., [Cl(-)](i) decrease) was similar in both cell types and was unaffected by lowering the extracellular Na(+) concentration. In contrast, the recovery on depletion (i.e., [Cl(-)](i) increase) was significantly faster in DRGNs in control conditions but not in low extracellular Na(+). The experimental observations could be reproduced by a mathematical model for intracellular Cl(-) kinetics, in which DRGNs show higher NKCC1 activity and smaller Cl(-)-handling volume than MNs. On the basis of these results, we conclude that embryonic DRGNs show a higher somatic functional expression of NKCC1 than embryonic MNs. The high NKCC1 activity in DRGNs is important for maintaining high [Cl(-)](i), whereas lower NKCC1 activity in MNs allows large [Cl(-)](i) variations during neuronal activity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1530-6860
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
23
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1168-76
pubmed:meshHeading
pubmed-meshheading:19103648-Animals, pubmed-meshheading:19103648-Anti-Bacterial Agents, pubmed-meshheading:19103648-Bumetanide, pubmed-meshheading:19103648-Cells, Cultured, pubmed-meshheading:19103648-Chlorides, pubmed-meshheading:19103648-Electrophysiology, pubmed-meshheading:19103648-Embryo, Mammalian, pubmed-meshheading:19103648-Ganglia, Spinal, pubmed-meshheading:19103648-Gramicidin, pubmed-meshheading:19103648-Immunohistochemistry, pubmed-meshheading:19103648-Kinetics, pubmed-meshheading:19103648-Models, Statistical, pubmed-meshheading:19103648-Motor Neurons, pubmed-meshheading:19103648-Patch-Clamp Techniques, pubmed-meshheading:19103648-Rats, pubmed-meshheading:19103648-Rats, Inbred Strains, pubmed-meshheading:19103648-Receptors, GABA, pubmed-meshheading:19103648-Receptors, GABA-A, pubmed-meshheading:19103648-Sodium-Potassium-Chloride Symporters, pubmed-meshheading:19103648-gamma-Aminobutyric Acid
pubmed:year
2009
pubmed:articleTitle
Differential contribution of the Na(+)-K(+)-2Cl(-) cotransporter NKCC1 to chloride handling in rat embryonic dorsal root ganglion neurons and motor neurons.
pubmed:affiliation
Department of Molecular and Cell Biology, Katholieke Universiteit Leuven, Leuven, Belgium. jo.nsimy@gmail.com
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't