The subthreshold-active K V 7 current regulates neurotransmission by limiting spike-induced Ca 2+ influx in hippocampal mossy fiber synaptic terminals.

Autor: Martinello K; 1UCL School of Pharmacy University College London, London, WC1N 1AX UK., Giacalone E; 2Institute of Biophysics, National Research Council, 90146 Palermo, Italy., Migliore M; 2Institute of Biophysics, National Research Council, 90146 Palermo, Italy., Brown DA; 3Department of Neuroscience, Physiology and Pharmacology, University College London, London, WC1E 6BT UK., Shah MM; 1UCL School of Pharmacy University College London, London, WC1N 1AX UK.
Jazyk: angličtina
Zdroj: Communications biology [Commun Biol] 2019 Apr 26; Vol. 2, pp. 145. Date of Electronic Publication: 2019 Apr 26 (Print Publication: 2019).
DOI: 10.1038/s42003-019-0408-4
Abstrakt: Little is known about the properties and function of ion channels that affect synaptic terminal-resting properties. One particular subthreshold-active ion channel, the Kv7 potassium channel, is highly localized to axons, but its role in regulating synaptic terminal intrinsic excitability and release is largely unexplored. Using electrophysiological recordings together with computational modeling, we found that the K V 7 current was active at rest in adult hippocampal mossy fiber synaptic terminals and enhanced their membrane conductance. The current also restrained action potential-induced Ca 2+ influx via N- and P/Q-type Ca 2+ channels in boutons. This was associated with a substantial reduction in the spike half-width and afterdepolarization following presynaptic spikes. Further, by constraining spike-induced Ca 2+ influx, the presynaptic K V 7 current decreased neurotransmission onto CA3 pyramidal neurons and short-term synaptic plasticity at the mossy fiber-CA3 synapse. This is a distinctive mechanism by which K V 7 channels influence hippocampal neuronal excitability and synaptic plasticity.
Competing Interests: The authors declare no competing interests.
Databáze: MEDLINE
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