Dendritic calcium activity precedes inspiratory bursts in preBotzinger complex neurons

Christopher A Del Negro, John A Hayes, Jens C Rekling

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37 Citationer (Scopus)

Abstract

Medullary interneurons of the preBötzinger complex assemble excitatory networks that produce inspiratory-related neural rhythms, but the importance of somatodendritic conductances in rhythm generation is still incompletely understood. Synaptic input may cause Ca(2+) accumulation postsynaptically to evoke a Ca(2+)-activated inward current that contributes to inspiratory burst generation. We measured Ca(2+) transients by two-photon imaging dendrites while recording neuronal somata electrophysiologically. Dendritic Ca(2+) accumulation frequently precedes inspiratory bursts, particularly at recording sites 50-300 µm distal from the soma. Preinspiratory Ca(2+) transients occur in hotspots, not ubiquitously, in dendrites. Ca(2+) activity propagates orthodromically toward the soma (and antidromically to more distal regions of the dendrite) at rapid rates (300-700 µm/s). These high propagation rates suggest that dendritic Ca(2+) activates an inward current to electrotonically depolarize the soma, rather than propagate as a regenerative Ca(2+) wave. These data provide new evidence that respiratory rhythmogenesis may depend on dendritic burst-generating conductances activated in the context of network activity.
OriginalsprogEngelsk
TidsskriftJournal of Neuroscience
Vol/bind31
Udgave nummer3
Sider (fra-til)1017-22
Antal sider6
ISSN0270-6474
DOI
StatusUdgivet - 19 jan. 2011

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