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Differential Distribution of Three Ca2+-Activated K+ Channel Subunits, SK1, SK2, and SK3, in the Adult Rat Central Nervous System

https://doi.org/10.1006/mcne.2000.0842Get rights and content

Abstract

Ca2+-activated, voltage-independent K+ channels are present in most neurons and mediate the afterhyperpolarizations (AHPs) following action potentials. They present distinct physiological and pharmacological properties and play an important role in controlling neuronal firing frequency and spike frequency adaptation. We used in situ hybridization to characterize the distribution patterns of the three cloned SK channel subunits (SK1–3), the prime candidates likely to underlie Ca2+-dependent AHPs in the central nervous system. We found high levels of expression in regions presenting prominent AHP currents, such as, for example, neocortex and CA1–3 layers of the hippocampus (SK1 and SK2), reticularis thalami (SK1 and SK2), supraoptic nucleus (SK3), and inferior olivary nucleus (SK2 and SK3). Our results reveal the functional role of SK channels with defined subunit compositions in some neurons and open the way to the identification of the molecular determinants of AHP currents in many brain regions.

References (44)

  • P.N. Strong

    Potassium channel toxins

    Pharmacol. Ther.

    (1990)
  • C. Vergara et al.

    Calcium-activated potassium channels

    Curr. Opin. Neurobiol.

    (1998)
  • M.D. Womble et al.

    Muscarinic modulation of conductances underlying the afterhyperpolarization in neurons of the rat basolateral amygdala

    Brain Res.

    (1993)
  • G.K. Aghajanian et al.

    Intracellular studies in the facial nucleus illustrating a simple new method for obtaining viable motor neurons in adult rat brain slices

    Synapse

    (1989)
  • G. Avanzini et al.

    Intrinsic properties of nucleus reticularis thalami neurones of the rat studied in vitro

    J. Physiol. (London)

    (1989)
  • T. Bal et al.

    Mechanisms of oscillatory activity in guinea-pig nucleus reticularis thalami in vitro: A mammalian pacemaker

    J. Physiol. (London)

    (1993)
  • T. Bal et al.

    Synchronized oscillations in the inferior olive are controlled by the hyperpolarization-activated cation current Ih

    J. Neurophysiol.

    (1997)
  • H.G. Baumgarten et al.

    Anatomy of central serotoninergic projection systems

  • F.E. Bloom et al.

    Catecholamines and behaviour

  • K.G. Chandy et al.

    Isolation of a novel potassium channel gene hSKCa3 containing a polymorphic CAG repeat: A candidate for schizophrenia and bipolar disorder?

    Mol. Psychiatry

    (1998)
  • A. Constanti et al.

    Calcium-dependent potassium conductance in guinea-pig olfactory cortex neurones in vitro

    J. Physiol. (London)

    (1987)
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    To whom correspondence should be addressed at Molekulare Biologie Neuronaler Signale, Max-Planck-Institut für Experimentelle Medizin, Hermann-Rein-Strasse 3, 37075 Göttingen, Germany. Fax: ++49-551-3899644. E-mail: [email protected].

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