Electroneutral Na-Cl, Na-K-2Cl, and K-Cl cotransporters participate in the movement of salt and fluid across epithelia and play a major role in the maintenance and regulation of the volume of a wide variety of cells. While these transporters have been studied extensively during the past 15 years, it is only recently that their molecular identity has been revealed. We have recently shown that two of these cotransporters, the Na-K-2Cl cotransporter and the K-Cl cotransporter, are expressed highly in the brain. Their role in the nervous system is incompletely understood. Growing evidence suggests that besides playing an important role in regulating the composition of the CSF, they may also play a major role in neuronal function. In fact, Na-K-2CI cotransporter expression in neurons has been suggested to determine the effect of GABA on membrane potential, which in turn may be important during neuronal maturation and response to neuronal injury. This proposal is aimed at understanding the physiology of these cotransporters in neuronal cells. Through detailed quantitative studies we will investigate 1) the role of the secretory Na-K-2Cl cotransporter (BSC2), an inward transport mechanism, and the neuronal-specific K-Cl cotransporter (KCC2), an outward transport mechanism, in establishing the steady-state intracellular Cl- concentration in neurons, and 2) the developmental regulation of these two cotransporter mechanisms. These studies, by involving functional and molecular approaches, will lead to a better understanding of the role of these electroneutral cation-chloride cotransporters in neuronal function. Regulation of intracellular and extracellular ion composition has important implications for the physiology and pathophysiology of the brain. For instance, regulation of intracellular Cl- concentration is crucial for controlling the function of GABA in the CNS. The GABA response in turn is an important feature of the normal function of the neuron, e.g. for the control of slow wave sleep in the thalamus, or the control of diurnal rhythmicity in the hypothalamus, a critical feature of neuronal plasticity during development, and a critical feature in various pathologies such as cerebral trauma, cerebral ischemia, where neuronal damage involves changes in GABA-induced excitability properties, potentially due to significant changes in intracellular Cl- concentration.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS036758-03
Application #
6393572
Study Section
Special Emphasis Panel (ZRG1-MDCN-4 (01))
Program Officer
Nichols, Paul L
Project Start
1999-07-30
Project End
2003-04-30
Budget Start
2001-05-01
Budget End
2002-04-30
Support Year
3
Fiscal Year
2001
Total Cost
$276,403
Indirect Cost
Name
Vanderbilt University Medical Center
Department
Anesthesiology
Type
Schools of Medicine
DUNS #
004413456
City
Nashville
State
TN
Country
United States
Zip Code
37212
Lee, Hanmi; Bach, Eva; Noh, Jihyun et al. (2016) Hyperpolarization-independent maturation and refinement of GABA/glycinergic connections in the auditory brain stem. J Neurophysiol 115:1170-82
Ding, Jinlong; Delpire, Eric (2014) Deletion of KCC3 in parvalbumin neurons leads to locomotor deficit in a conditional mouse model of peripheral neuropathy associated with agenesis of the corpus callosum. Behav Brain Res 274:128-36
Gagnon, Kenneth B; Delpire, Eric (2013) Physiology of SLC12 transporters: lessons from inherited human genetic mutations and genetically engineered mouse knockouts. Am J Physiol Cell Physiol 304:C693-714
Gagnon, Kenneth B; Delpire, Eric (2012) Molecular physiology of SPAK and OSR1: two Ste20-related protein kinases regulating ion transport. Physiol Rev 92:1577-617
Stil, Aurélie; Jean-Xavier, Céline; Liabeuf, Sylvie et al. (2011) Contribution of the potassium-chloride co-transporter KCC2 to the modulation of lumbar spinal networks in mice. Eur J Neurosci 33:1212-22
Garbarini, Nicole; Delpire, Eric (2008) The RCC1 domain of protein associated with Myc (PAM) interacts with and regulates KCC2. Cell Physiol Biochem 22:31-44
Zhu, Lei; Polley, Nathan; Mathews, Gregory C et al. (2008) NKCC1 and KCC2 prevent hyperexcitability in the mouse hippocampus. Epilepsy Res 79:201-12
Zhang, Ling-Li; Delpire, Eric; Vardi, Noga (2007) NKCC1 does not accumulate chloride in developing retinal neurons. J Neurophysiol 98:266-77
Byun, Nellie; Delpire, Eric (2007) Axonal and periaxonal swelling precede peripheral neurodegeneration in KCC3 knockout mice. Neurobiol Dis 28:39-51
Pieraut, Simon; Laurent-Matha, Valerie; Sar, Chamroeun et al. (2007) NKCC1 phosphorylation stimulates neurite growth of injured adult sensory neurons. J Neurosci 27:6751-9

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