Development and regeneration of hair cells share common functional features.
The structural phenotype of neural connections in the auditory brainstem is sculpted by spontaneous and stimulus-induced neural activities during development. However, functional and molecular mechanisms of spontaneous action potentials (SAPs) in the developing cochlea are unknown. Additionally, it is unclear how regenerating hair cells establish their neural ranking in the constellation of neurons in the brainstem. We have demonstrated that a transient Ca(2+) current produced by the Ca(v)3.1 channel is expressed early in development to initiate spontaneous Ca(2+) spikes. Ca(v)1.3 currents, typical of mature hair cells, appeared later in development. Moreover, there is a surprising disappearance of the Ca(v)3.1 current that coincides with the attenuation of the transient Ca(2+) current as the electrical properties of hair cells transition to the mature phenotype. Remarkably, this process is recapitulated during hair-cell regeneration, suggesting that the transient expression of Ca(v)3.1 and the ensuing SAPs are signatures of hair cell development and regeneration.
Levic
Snezana
S
Department of Otolaryngology, Program in Communication Science, Center for Neuroscience, University of California, 1544 Newton Court, Davis, CA 95616, USA.
Nie
Liping
L
Tuteja
Dipika
D
Harvey
Margaret
M
Sokolowski
Bernd H A
BH
Yamoah
Ebenezer N
EN
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D020746:Calcium Channels, L-Type / Q000502:physiology*; D020747:Calcium Channels, T-Type / Q000502:physiology*; D020013:Calcium Signaling; D002642:Chick Embryo; D002645:Chickens; D003051:Cochlea / Q000187:drug effects / Q000196:embryology / Q000254:growth & development / Q000502:physiology*; D005839:Gentamicins / Q000633:toxicity; D006198:Hair Cells, Auditory / Q000166:cytology* / Q000187:drug effects; D020748:Mibefradil / Q000494:pharmacology; D009532:Nickel / Q000494:pharmacology; D018408:Patch-Clamp Techniques; D012038:Regeneration; D012604:Scorpion Venoms / Q000494:pharmacology
D002121:Calcium Channel Blockers; D020746:Calcium Channels, L-Type; D020747:Calcium Channels, T-Type; D005839:Gentamicins; D012604:Scorpion Venoms; C118444:kurtoxin; D020748:Mibefradil; D009532:Nickel