Nonsynaptic glycine release is involved in the early KCC2 expression.
The cation-chloride co-transporters are important regulators of the cellular Cl(-) homeostasis. Among them the Na(+) -K(+) -2Cl(-) co-transporter (NKCC1) is responsible for intracellular chloride accumulation in most immature brain structures, whereas the K(+) -Cl(-) co-transporter (KCC2) extrudes chloride from mature neurons, ensuring chloride-mediated inhibitory effects of GABA/glycine. We have shown that both KCC2 and NKCC1 are expressed at early embryonic stages (E11.5) in the ventral spinal cord (SC). The mechanisms by which KCC2 is prematurely expressed are unknown. In this study, we found that chronically blocking glycine receptors (GlyR) by strychnine led to a loss of KCC2 expression, without affecting NKCC1 level. This effect was not dependent on the firing of Na(+) action potentials but was mimicked by a Ca(2+) -dependent PKC blocker. Blocking the vesicular release of neurotransmitters did not impinge on strychnine effect whereas blocking volume-sensitive outwardly rectifying (VSOR) chloride channels reproduced the GlyR blockade, suggesting that KCC2 is controlled by a glycine release from progenitor radial cells in immature ventral spinal networks. Finally, we showed that the strychnine treatment prevented the maturation of rhythmic spontaneous activity. Thereby, the GlyR-activation is a necessary developmental process for the expression of functional spinal motor networks. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 764-779, 2016.
Univ. Bordeaux, INCIA, UMR 5287, Site Talence, F33615 Pessac cedex, France. CNRS, INCIA, UMR 5287, Site Talence, F33615 Pessac cedex, France.
Anne-Emilie
AE
Allain
Univ. Bordeaux, INCIA, UMR 5287, Site Talence, F33615 Pessac cedex, France. CNRS, INCIA, UMR 5287, Site Talence, F33615 Pessac cedex, France.
William
W
Cazenave
Univ. Bordeaux, INCIA, UMR 5287, Site Talence, F33615 Pessac cedex, France. CNRS, INCIA, UMR 5287, Site Talence, F33615 Pessac cedex, France.
Alain
A
Delpy
Univ. Bordeaux, INCIA, UMR 5287, Site Talence, F33615 Pessac cedex, France. CNRS, INCIA, UMR 5287, Site Talence, F33615 Pessac cedex, France.
Prisca
P
Exertier
Univ. Bordeaux, Laboratoire De Biotechnologie Des Protéines Recombinantes À Visée Santé, EA 4135, Bordeaux, F-33076, Bordeaux.
Christophe
C
Barthe
Univ. Bordeaux, IMN, UMR 5293, Site Talence, F33615 Pessac cedex, France. CNRS, IMN, UMR 5293, Site Talence, F33615, Pessac cedex, France.
Pierre
P
Meyrand
Univ. Bordeaux, INCIA, UMR 5287, Site Talence, F33615 Pessac cedex, France. CNRS, INCIA, UMR 5287, Site Talence, F33615 Pessac cedex, France.
Daniel
D
Cattaert
Univ. Bordeaux, INCIA, UMR 5287, Site Talence, F33615 Pessac cedex, France. CNRS, INCIA, UMR 5287, Site Talence, F33615 Pessac cedex, France.
Pascal
P
Branchereau
D000818:Animals; D015220:Calcium Channels / Q000378:metabolism*; D055724:Electrophysiological Phenomena; D005260:Female; D005998:Glycine / Q000378:metabolism*; D018684:Glycine Agents / Q000494:pharmacology; D051379:Mice; D058953:Neural Stem Cells / Q000378:metabolism*; D011247:Pregnancy; D011493:Protein Kinase C / Q000378:metabolism*; D018009:Receptors, Glycine / Q000187:drug effects / Q000378:metabolism*; D066151:Spinal Cord Ventral Horn / Q000196:embryology / Q000378:metabolism / Q000502:physiology*; D013331:Strychnine / Q000494:pharmacology; D027981:Symporters / Q000378:metabolism*; D000096922:K Cl- Cotransporters
D015220:Calcium Channels; D005998:Glycine; D018684:Glycine Agents; D011493:Protein Kinase C; D018009:Receptors, Glycine; D013331:Strychnine; D027981:Symporters; D000096922:K Cl- Cotransporters
chloride co-transporter; development; embryo; glycine receptor; motor network; radial cell; rhythmic spontaneous activity; spinal cord