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SK channels regulate excitatory synaptic transmission and plasticity in the lateral amygdala

Nature Neuroscience volume 8, pages 635–641 (2005)Cite this article

Abstract

At glutamatergic synapses, calcium influx through NMDA receptors (NMDARs) is required for long-term potentiation (LTP); this is a proposed cellular mechanism underlying memory and learning. Here we show that in lateral amygdala pyramidal neurons, SK channels are also activated by calcium influx through synaptically activated NMDARs, resulting in depression of the synaptic potential. Thus, blockade of SK channels by apamin potentiates fast glutamatergic synaptic potentials. This potentiation is blocked by the NMDAR antagonist AP5 (D(-)-2-amino-5-phosphono-valeric acid) or by buffering cytosolic calcium with BAPTA. Blockade of SK channels greatly enhances LTP of cortical inputs to lateral amygdala pyramidal neurons. These results show that NMDARs and SK channels are colocalized at glutamatergic synapses in the lateral amygdala. Calcium influx through NMDARs activates SK channels and shunts the resultant excitatory postsynaptic potential. These results demonstrate a new role for SK channels as postsynaptic regulators of synaptic efficacy.

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Figure 1: NMDARs activate SK channels that contribute to the synaptic potential.
Figure 2: EPSP amplification requires an increase in postsynaptic calcium concentration and activation of postsynaptic potassium channels.
Figure 3: Calcium influx through NMDARs activates SK channels.
Figure 4: Calcium influx through postsynaptic NMDARs activates SK channels.
Figure 5: SK channel activation follows the time course of calcium influx through NMDARs.
Figure 6: Blockade of SK channels potentiates LTP.

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Acknowledgements

This work was supported by grants from the National Heath and Medical Research Council of Australia and the Australian Research Council.

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  1. The Queensland Brain Institute, University of Queensland, Brisbane, 4072, Queensland, Australia

    E S Louise Faber, Andrew J Delaney & Pankaj Sah

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  1. E S Louise Faber
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Correspondence to Pankaj Sah.

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Faber, E., Delaney, A. & Sah, P. SK channels regulate excitatory synaptic transmission and plasticity in the lateral amygdala. Nat Neurosci 8, 635–641 (2005). https://doi.org/10.1038/nn1450

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