Neuronal adaptation involves rapid expansion of the action potential initiation site
| Autor: | Scott, Ricardo S., Henneberger, Christian, Padmashri, Ragunathan, Anders, Stefanie, Jensen, Thomas P., Rusakov, Dmitri A. |
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| Přispěvatelé: | Wellcome Trust, Medical Research Council (UK), Biotechnology and Biological Sciences Research Council (UK), European Research Council, Ministerio de Ciencia e Innovación (España), Human Frontier Science Program |
| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Popis: | Action potential (AP) generation is the key to information-processing in the brain. Although APs are normally initiated in the axonal initial segment, developmental adaptation or prolonged network activity may alter the initiation site geometry thus affecting cell excitability. Here we find that hippocampal dentate granule cells adapt their spiking threshold to the kinetics of the ongoing dendrosomatic excitatory input by expanding the AP-initiation area away from the soma while also decelerating local axonal spikes. Dual-patch soma–axon recordings combined with axonal Na+ and Ca2+ imaging and biophysical modelling show that the underlying mechanism involves distance-dependent inactivation of axonal Na+ channels due to somatic depolarization propagating into the axon. Thus, the ensuing changes in the AP-initiation zone and local AP propagation could provide activity-dependent control of cell excitability and spiking on a relatively rapid timescale. This work was supported by the Wellcome Trust Principal Fellowship, Medical Research Council (UK), Biology and Biotechnology Research Council (UK), European Research Council Advanced Grant, FP7 BM1001 COST Action (D.A.R.); Ramon y Cajal Fellowship and Spanish Ministerio de Ciencia e Innovación Grant, SAF2010-20604 (R.S.S.); Human Frontier Science Program, UCL Excellence Fellowship, and the NRW-Rückkehrerprogramm (C.H.). |
| Databáze: | OpenAIRE |
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