Developmental up-regulation of the potassium–chloride cotransporter type 2 in the rat lumbar spinal cord

Stil, Aurélie; Liabeuf, Sylvie; Jean-Xavier, Céline; Brocard, Cécile; Viemari, Jean‐Charles; Vinay, Laurent

doi:10.1016/j.neuroscience.2009.08.035

Cited by 69 publications

(74 citation statements)

References 69 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Because IPSPs are still depolarizing from rest in neonatal rat MNs and are able to facilitate action potential generation when paired with EPSPs (Jean-Xavier et al, 2007), a possible explanation of the latter result could be that chloride homeostasis in MNs and possibly interneurons is involved. However, at such a low concentration, bumetanide has no effect on the reversal potential of IPSPs in neonatal rat motoneurons (Jean-Xavier et al, 2006), in agreement with the observation that NKCC1 does not appear to play a significant role in chloride homeostasis in those neurons at that age (Stil et al, 2009). In addition, DIOA, which shifts the reversal potential for IPSPs toward more positive values and should thereby enhance the facilitation of subthreshold EPSPs (Jean-Xavier et al, 2007), had no effect on VR bursts.…”

Section: Discussionsupporting

confidence: 84%

Primary Afferent Terminals Acting as Excitatory Interneurons Contribute to Spontaneous Motor Activities in the Immature Spinal Cord

Bos¹,

Brocard²,

Vinay³

2011

Journal of Neuroscience

Self Cite

View full text Add to dashboard Cite

Patterned, spontaneous activity plays a critical role in the development of neuronal networks. A robust spontaneous activity is observed in vitro in spinal cord preparations isolated from immature rats. The rhythmic ventral root discharges rely mainly on the depolarizing/ excitatory action of GABA and glycine early during development, whereas at later stages glutamate drive is primarily responsible for the rhythmic activity and GABA/glycine are thought to play an inhibitory role. However, rhythmic discharges mediated by the activation of GABA A receptors are recorded from dorsal roots (DRs). In the present study, we used the in vitro spinal cord preparation of neonatal rats to identify the relationship between discharges that are conducted antidromically along DRs and the spontaneous activity recorded from lumbar motoneurons. We show that discharges in DRs precede those in ventral roots and that primary afferent depolarizations (PADs) start earlier than EPSPs in motoneurons. EPSP-triggered averaging revealed that the action potentials propagate not only antidromically in the DR but also centrally and trigger EPSPs in motoneurons. Potentiating GABAergic antidromic discharges by diazepam increased the EPSPs recorded from motoneurons; conversely, blocking DR bursts markedly reduced these EPSPs. High intracellular concentrations of chloride are maintained in primary afferent terminals by the sodium-potassium-chloride cotransporter NKCC1. Blocking these cotransporters by bumetanide decreased both dorsal and ventral root discharges. We conclude that primary afferent fibers act as excitatory interneurons and that GABA, through PADs reaching firing threshold, is still playing a key role in promoting spontaneous activity in neonates.

show abstract

Section: Discussionsupporting

confidence: 84%

Primary Afferent Terminals Acting as Excitatory Interneurons Contribute to Spontaneous Motor Activities in the Immature Spinal Cord

Bos¹,

Brocard²,

Vinay³

2011

Journal of Neuroscience

Self Cite

View full text Add to dashboard Cite

show abstract

“…The parallel alterations of KCC2 and GABA polarity have been confirmed in a large variety of animal species from invertebrates to humans (Rivera et al, 1999(Rivera et al, , 2005Delpire, 2000;Payne et al, 2003;Sernagor et al, 2003;Dzhala et al, 2005;Akerman and Cline, 2006;Liu et al, 2006;Ben-Ari et al, 2007;Howard et al, 2007;Kahle et al, 2008;Reynolds et al, 2008;Blaesse et al, 2009;Glykys et al, 2009;Stil et al, 2009;Tanis et al, 2009;Boulenguez et al, 2010). KCC2 and E GABA developmental sequences are unlikely to depend on global metabolic diets because they are cell and sex specific (Kandler and Friauf, 1995;Kandler et al, 2002;Balakrishnan et al, 2003 izing do not express KCC2 (Price et al, 2005;Gilbert et al, 2007;Pozas et al, 2008), and early overexpression of KCC2 in zebra fish embryos (Reynolds et al, 2008) or cortical neurons (Chudotvorova et al, 2005;Lee et al, 2005;Ben-Ari et al, 2007;Cancedda et al, 2007;Wang and Kriegstein, 2008) alter GABA polarity, GABA synapse formation, and neuronal development in vivo.…”

Section: The Nkcc1/kcc2 Sequence In Brain Maturationmentioning

confidence: 95%

Depolarizing Actions of GABA in Immature Neurons Depend Neither on Ketone Bodies Nor on Pyruvate

Tyzio¹,

Allène²,

Nardou³

et al. 2011

J. Neurosci.

View full text Add to dashboard Cite

show abstract

“…We next addressed the question of suppressing descending afferences several days after birth, when the levels of GABA A Rs are already low in the lumbar cord, and when the reversal potential of IPSPs is significantly more negative than at birth (Stil et al, 2009). Four rats were transected at P5 and the spinal cords were processed for immunohistochemistry 7 d later (SCT-P12) together with tissues from 3 control-P12 animals.…”

Section: A Sct Performed At P5 Upregulates Gaba a Rsmentioning

confidence: 99%

Differential Plasticity of the GABAergic and Glycinergic Synaptic Transmission to Rat Lumbar Motoneurons after Spinal Cord Injury

Sadlaoud

Tazerart²,

Brocard³

et al. 2010

J. Neurosci.

Self Cite

View full text Add to dashboard Cite

Maturation of inhibitory postsynaptic transmission onto motoneurons in the rat occurs during the perinatal period, a time window during which pathways arising from the brainstem reach the lumbar enlargement of the spinal cord. There is a developmental switch in miniature IPSCs (mIPSCs) from predominantly long-duration GABAergic to short-duration glycinergic events. We investigated the effects of a complete neonatal [postnatal day 0 (P0)] spinal cord transection (SCT) on the expression of Glycine and GABA A receptor subunits (GlyR and GABA A R subunits) in lumbar motoneurons. In control rats, the density of GlyR increased from P1 to P7 to reach a plateau, whereas that of GABA A R subunits dropped during the same period. In P7 animals with neonatal SCT (SCT-P7), the GlyR densities were unchanged compared with controls of the same age, while the developmental downregulation of GABA A R was prevented. Whole-cell patch-clamp recordings of mIPSCs performed in lumbar motoneurons at P7 revealed that the decay time constant of miniature IPSCs and the proportion of GABAergic events significantly increased after SCT. After daily injections of the 5-HT 2 R agonist DOI, GABA A R immunolabeling on SCT-P7 motoneurons dropped down to values reported in control-P7, while GlyR labeling remained stable. A SCT made at P5 significantly upregulated the expression of GABA A R 1 week later with little, if any, influence on GlyR. We conclude that the plasticity of GlyR is independent of supraspinal influences whereas that of GABA A R is markedly influenced by descending pathways, in particular serotoninergic projections.

show abstract

Developmental up-regulation of the potassium–chloride cotransporter type 2 in the rat lumbar spinal cord

Cited by 69 publications

References 69 publications

Primary Afferent Terminals Acting as Excitatory Interneurons Contribute to Spontaneous Motor Activities in the Immature Spinal Cord

Primary Afferent Terminals Acting as Excitatory Interneurons Contribute to Spontaneous Motor Activities in the Immature Spinal Cord

Depolarizing Actions of GABA in Immature Neurons Depend Neither on Ketone Bodies Nor on Pyruvate

Differential Plasticity of the GABAergic and Glycinergic Synaptic Transmission to Rat Lumbar Motoneurons after Spinal Cord Injury

Contact Info

Product

Resources

About