Position-dependent patterning of spontaneous action potentials in immature cochlear inner hair cells.

Saved in:

Bibliographic Details
Title:	Position-dependent patterning of spontaneous action potentials in immature cochlear inner hair cells.
Authors:	Johnson, Stuart L., Eckrich, Tobias, Kuhn, Stephanie, Zampini, Valeria, Franz, Christoph, Ranatunga, Kishani M., Roberts, Terri P., Masetto, Sergio, Knipper, Marlies, Kros, Corné J., Marcotti, Walter
Source:	Nature Neuroscience. Jun2011, Vol. 14 Issue 6, p711-717. 7p. 7 Graphs.
Subjects:	Hair cells, Auditory pathways, Action potentials, Sensory neurons, Sensory ganglia, Acetylcholine, Laboratory rodents, Physiology
Abstract:	Spontaneous action potential activity is crucial for mammalian sensory system development. In the auditory system, patterned firing activity has been observed in immature spiral ganglion and brain-stem neurons and is likely to depend on cochlear inner hair cell (IHC) action potentials. It remains uncertain whether spiking activity is intrinsic to developing IHCs and whether it shows patterning. We found that action potentials were intrinsically generated by immature IHCs of altricial rodents and that apical IHCs showed bursting activity as opposed to more sustained firing in basal cells. We show that the efferent neurotransmitter acetylcholine fine-tunes the IHC's resting membrane potential (Vm), and as such is crucial for the bursting pattern in apical cells. Endogenous extracellular ATP also contributes to the Vm of apical and basal IHCs by triggering small-conductance Ca2+-activated K+ (SK2) channels. We propose that the difference in firing pattern along the cochlea instructs the tonotopic differentiation of IHCs and auditory pathway. [ABSTRACT FROM AUTHOR]
	Copyright of Nature Neuroscience is the property of Springer Nature and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database:	Psychology and Behavioral Sciences Collection

Description
Abstract:	Spontaneous action potential activity is crucial for mammalian sensory system development. In the auditory system, patterned firing activity has been observed in immature spiral ganglion and brain-stem neurons and is likely to depend on cochlear inner hair cell (IHC) action potentials. It remains uncertain whether spiking activity is intrinsic to developing IHCs and whether it shows patterning. We found that action potentials were intrinsically generated by immature IHCs of altricial rodents and that apical IHCs showed bursting activity as opposed to more sustained firing in basal cells. We show that the efferent neurotransmitter acetylcholine fine-tunes the IHC's resting membrane potential (Vm), and as such is crucial for the bursting pattern in apical cells. Endogenous extracellular ATP also contributes to the Vm of apical and basal IHCs by triggering small-conductance Ca2+-activated K+ (SK2) channels. We propose that the difference in firing pattern along the cochlea instructs the tonotopic differentiation of IHCs and auditory pathway. [ABSTRACT FROM AUTHOR]
ISSN:	10976256
DOI:	10.1038/nn.2803