Abstract
Electrophysiologically, astrocytes are characterized by a high K+ resting conductance and a hyperpolarized resting membrane potential. Both features are due to the activity of astrocytic potassium channels. Astrocytes express a variety of voltage-dependent and leak potassium channels on the plasma membrane that contribute to the hyperpolarized resting membrane potential and other cellular processes. This chapter focuses on measuring K+ channel function in astrocytes, focusing on Kir4.1, an inwardly rectifying potassium channel. We and others have demonstrated that Kir4.1 contributes significantly to the high-resting K+ conductance and the hyperpolarized resting membrane potential. This channel is also implicated in channel-mediated regulation of extracellular potassium.
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References
Kuffler SW, Potter DD (1964) Glia in the leach central nervous system: Physiological properties and neuron-glia relationship. J Neurophysiol 27: 290–320
Ransom BR, Goldring S (1973) Slow depolarization in cells presumed to be glia in cerebral cortex of cat. J Neurophysiol 36:869–878
Neusch C, Papadopoulos N, Muller M et al (2006) Lack of the Kir4.1 channel subunit abolishes K+ buffering properties of astrocytes in the ventral respiratory group: impact on extracellular K+ regulation. J Neurophysiol 95:1843–1852
Djukic B, Casper KB, Philpot BD et al (2007) Conditional knock-out of Kir4.1 leads to glial membrane depolarization, inhibition of potassium and glutamate uptake, and enhanced short-term synaptic potentiation. J Neurosci 27:11354–11365
Kucheryavykh YV, Kucheryavykh LY, Nichols CG et al (2007) Downregulation of Kir4.1 inward rectifying potassium channel subunits by RNAi impairs potassium transfer and glutamate uptake by cultured cortical astrocytes. Glia 55: 274–81
Olsen ML, Higashimori H, Campbell SC et al (2006) Functional expression of Kir4.1 channels in spinal cord astrocytes. Glia 53:516–28
De Biase L M, Nishiyama A, Bergles DE (2010) Excitability and synaptic communication within the oligodendrocyte lineage. J Neurosci 30: 3600–3611
Chen PH, Cai WQ, Wang LY, Deng QY (2008) A morphological and electrophysiological study on the postnatal development of oligodendrocyte precursor cells in the rat brain. Brain Res 1243: 27–37
Sontheimer H. and Olsen ML (2007) Whole-cell patch clamp recordings In: Walz W (ed) Patch Clamp Analysis Advanced Techniques, 2nd edn. Humana Press, New Jersey
Olsen ML, Campbell SL, Sontheimer H. (2007) Differential distribution of Kir4.1 in spinal cord astrocytes suggests regional differences in K+ homeostasis. J Neurophys 98: 786–93
Sakmann B. Trube G. (1984) Voltage-dependent inactivation of inward-rectifying single-channel currents in the guinea-pig heart cell membrane. J Physiol. (London) 347: 659–683
Ransom CB, Sontheimer H (1995) Biophysical and pharmacological characterization of inwardly rectifying K+ currents in rat spinal cord astrocytes. J Neurophysiol 73: 333–345
Sarantopoulos C (2007) Perforated Patch Clamp Techniques. In: Walz W (ed) Patch Clamp Analysis Advanced Techniques, 2nd edn. Humana Press, New Jersey
Seifert G, Huttmann K, Binder DK et al (2009) Analysis of astroglial K+ channel expression in the developing hippocampus reveals a predominant role of the Kir4.1 subunit J Neurosci 29: 7474–7488
Kimelberg HK (2004) The problem of astrocyte identity. Neurochem Int 45, 191–202
Kafitz KW, Meier SD, Stephan J, Rose CR (2008) Developmental profile and properties of sulforhodamine 101--Labeled glial cells in acute brain slices of rat hippocampus. J Neurosci Methods 169:84–92
Kang J, Kang N, Yu Y et al (2010) Sulforhodamine 101 induces long-term potentiation of intrinsic excitability and synaptic efficacy in hippocampal CA1 pyramidal neurons. Neurosci 169:1601–1609
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Olsen, M. (2012). Examining Potassium Channel Function in Astrocytes. In: Milner, R. (eds) Astrocytes. Methods in Molecular Biology, vol 814. Humana Press. https://doi.org/10.1007/978-1-61779-452-0_18
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DOI: https://doi.org/10.1007/978-1-61779-452-0_18
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