Control of firing patterns through modulation of axon initial segment T-type calcium channels

Kevin J. Bender, Victor N. Uebele, John J. Renger, Laurence O. Trussell

Research output: Contribution to journalArticle

32 Scopus citations


Spontaneously active neurons typically fire either in a regular pattern or in bursts. While much is known about the subcellular location and biophysical properties of conductances that underlie regular spontaneous activity, less is known about those that underlie bursts. Here, we show that T-type Ca 2+ channels localized to the site of action potential initiation in the axon initial segment play a pivotal role in spontaneous burst generation. In auditory brainstem interneurons, axon initial segment Ca 2+ influx is selectively downregulated by dopaminergic signalling. This regulation has marked effects on spontaneous activity, converting the predominant mode of spontaneous activity from bursts to regular spiking. Thus, the axon initial segment is a key site, and dopamine a key regulator, of spontaneous bursting activity.

Original languageEnglish (US)
Pages (from-to)109-118
Number of pages10
JournalJournal of Physiology
Issue number1
StatePublished - Jan 1 2012


ASJC Scopus subject areas

  • Physiology

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