Developmental regulation of nicotinic synapses on cochlear inner hair cells

In the mature cochlea, inner hair cells (IHCs) transduce acoustic signals into receptor potentials, communicating to the brain by synaptic contacts with afferent fibers. Before the onset of hearing, a transient efferent innervation is found on IHCs, mediated by a nicotinic cholinergic receptor that...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Katz, Eleonora, Gómez Casati, María Eugenia
Publicado:	2004
Materias:	α9α10 nAChR Ca2+-activated K+ channel Cholinergic Efferent innervation IHC Mammalian cochlea Neonatal development Transient synapse acetylcholine calcium calcium activated potassium channel messenger RNA nicotine nicotinic receptor nicotinic receptor alpha10 subunit nicotinic receptor alpha9 subunit potassium receptor subunit unclassified drug Alpha10 gene Alpha9 gene animal cell animal tissue article auditory stimulation calcium transport cochlea Corti organ depolarization efferent nerve gene hair cell hearing in situ hybridization ion current knockout gene newborn nonhuman postnatal development priority journal protein expression rat receptor potential sensory nerve signal transduction sk2 gene synapse synaptogenesis Acetylcholine Action Potentials Age Factors Animals Cochlea Gene Expression Regulation, Developmental Hair Cells, Inner Hearing Patch-Clamp Techniques Potassium Potassium Channels, Calcium-Activated Protein Subunits Rats Rats, Sprague-Dawley Receptors, Nicotinic Small-Conductance Calcium-Activated Potassium Channels Synaptic Transmission
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_02706474_v24_n36_p7814_Katz http://hdl.handle.net/20.500.12110/paper_02706474_v24_n36_p7814_Katz
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_02706474_v24_n36_p7814_Katz
record_format	dspace
spelling	paper:paper_02706474_v24_n36_p7814_Katz2023-06-08T15:24:45Z Developmental regulation of nicotinic synapses on cochlear inner hair cells Katz, Eleonora Gómez Casati, María Eugenia α9α10 nAChR Ca2+-activated K+ channel Cholinergic Efferent innervation IHC Mammalian cochlea Neonatal development Transient synapse acetylcholine calcium calcium activated potassium channel messenger RNA nicotine nicotinic receptor nicotinic receptor alpha10 subunit nicotinic receptor alpha9 subunit potassium receptor subunit unclassified drug Alpha10 gene Alpha9 gene animal cell animal tissue article auditory stimulation calcium transport cochlea Corti organ depolarization efferent nerve gene hair cell hearing in situ hybridization ion current knockout gene newborn nonhuman postnatal development priority journal protein expression rat receptor potential sensory nerve signal transduction sk2 gene synapse synaptogenesis Acetylcholine Action Potentials Age Factors Animals Cochlea Gene Expression Regulation, Developmental Hair Cells, Inner Hearing Patch-Clamp Techniques Potassium Potassium Channels, Calcium-Activated Protein Subunits Rats Rats, Sprague-Dawley Receptors, Nicotinic Small-Conductance Calcium-Activated Potassium Channels Synaptic Transmission In the mature cochlea, inner hair cells (IHCs) transduce acoustic signals into receptor potentials, communicating to the brain by synaptic contacts with afferent fibers. Before the onset of hearing, a transient efferent innervation is found on IHCs, mediated by a nicotinic cholinergic receptor that may contain both α9 and α10 subunits. Calcium influx through that receptor activates calcium-dependent (SK2-containing) potassium channels. This inhibitory synapse is thought to disappear after the onset of hearing [after postnatal day 12 (P12)]. We documented this developmental transition using whole-cell recordings from IHCs in apical turns of the rat organ of Corti. Acetylcholine elicited ionic currents in 88-100% of IHCs between P3 and P14, but in only 1 of 11 IHCs at P16-P22. Potassium depolarization of efferent terminals caused IPSCs in 67% of IHCs at P3, in 100% at P7-P9, in 93% at P10-P12, but in only 40% at P13-P14 and in none of the IHCs tested between P16 and P22. Earlier work had shown by in situ hybridization that α9 mRNA is expressed in adult IHCs but that α10 mRNA disappears after the onset of hearing. In the present study, antibodies to α10 and to the associated calcium-dependent (SK2) potassium channel showed a similar developmental loss. The correlated expression of these gene products with functional innervation suggests that Alpha10 and SK2, but not Alpha9, are regulated by synaptic activity. Furthermore, this developmental knock-out of α10, but not α9, supports the hypothesis that functional nicotinic acetylcholine receptors in hair cells are heteromers containing both these subunits. Fil:Katz, E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Gómez-Casati, M.E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2004 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_02706474_v24_n36_p7814_Katz http://hdl.handle.net/20.500.12110/paper_02706474_v24_n36_p7814_Katz
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	α9α10 nAChR Ca2+-activated K+ channel Cholinergic Efferent innervation IHC Mammalian cochlea Neonatal development Transient synapse acetylcholine calcium calcium activated potassium channel messenger RNA nicotine nicotinic receptor nicotinic receptor alpha10 subunit nicotinic receptor alpha9 subunit potassium receptor subunit unclassified drug Alpha10 gene Alpha9 gene animal cell animal tissue article auditory stimulation calcium transport cochlea Corti organ depolarization efferent nerve gene hair cell hearing in situ hybridization ion current knockout gene newborn nonhuman postnatal development priority journal protein expression rat receptor potential sensory nerve signal transduction sk2 gene synapse synaptogenesis Acetylcholine Action Potentials Age Factors Animals Cochlea Gene Expression Regulation, Developmental Hair Cells, Inner Hearing Patch-Clamp Techniques Potassium Potassium Channels, Calcium-Activated Protein Subunits Rats Rats, Sprague-Dawley Receptors, Nicotinic Small-Conductance Calcium-Activated Potassium Channels Synaptic Transmission
spellingShingle	α9α10 nAChR Ca2+-activated K+ channel Cholinergic Efferent innervation IHC Mammalian cochlea Neonatal development Transient synapse acetylcholine calcium calcium activated potassium channel messenger RNA nicotine nicotinic receptor nicotinic receptor alpha10 subunit nicotinic receptor alpha9 subunit potassium receptor subunit unclassified drug Alpha10 gene Alpha9 gene animal cell animal tissue article auditory stimulation calcium transport cochlea Corti organ depolarization efferent nerve gene hair cell hearing in situ hybridization ion current knockout gene newborn nonhuman postnatal development priority journal protein expression rat receptor potential sensory nerve signal transduction sk2 gene synapse synaptogenesis Acetylcholine Action Potentials Age Factors Animals Cochlea Gene Expression Regulation, Developmental Hair Cells, Inner Hearing Patch-Clamp Techniques Potassium Potassium Channels, Calcium-Activated Protein Subunits Rats Rats, Sprague-Dawley Receptors, Nicotinic Small-Conductance Calcium-Activated Potassium Channels Synaptic Transmission Katz, Eleonora Gómez Casati, María Eugenia Developmental regulation of nicotinic synapses on cochlear inner hair cells
topic_facet	α9α10 nAChR Ca2+-activated K+ channel Cholinergic Efferent innervation IHC Mammalian cochlea Neonatal development Transient synapse acetylcholine calcium calcium activated potassium channel messenger RNA nicotine nicotinic receptor nicotinic receptor alpha10 subunit nicotinic receptor alpha9 subunit potassium receptor subunit unclassified drug Alpha10 gene Alpha9 gene animal cell animal tissue article auditory stimulation calcium transport cochlea Corti organ depolarization efferent nerve gene hair cell hearing in situ hybridization ion current knockout gene newborn nonhuman postnatal development priority journal protein expression rat receptor potential sensory nerve signal transduction sk2 gene synapse synaptogenesis Acetylcholine Action Potentials Age Factors Animals Cochlea Gene Expression Regulation, Developmental Hair Cells, Inner Hearing Patch-Clamp Techniques Potassium Potassium Channels, Calcium-Activated Protein Subunits Rats Rats, Sprague-Dawley Receptors, Nicotinic Small-Conductance Calcium-Activated Potassium Channels Synaptic Transmission
description	In the mature cochlea, inner hair cells (IHCs) transduce acoustic signals into receptor potentials, communicating to the brain by synaptic contacts with afferent fibers. Before the onset of hearing, a transient efferent innervation is found on IHCs, mediated by a nicotinic cholinergic receptor that may contain both α9 and α10 subunits. Calcium influx through that receptor activates calcium-dependent (SK2-containing) potassium channels. This inhibitory synapse is thought to disappear after the onset of hearing [after postnatal day 12 (P12)]. We documented this developmental transition using whole-cell recordings from IHCs in apical turns of the rat organ of Corti. Acetylcholine elicited ionic currents in 88-100% of IHCs between P3 and P14, but in only 1 of 11 IHCs at P16-P22. Potassium depolarization of efferent terminals caused IPSCs in 67% of IHCs at P3, in 100% at P7-P9, in 93% at P10-P12, but in only 40% at P13-P14 and in none of the IHCs tested between P16 and P22. Earlier work had shown by in situ hybridization that α9 mRNA is expressed in adult IHCs but that α10 mRNA disappears after the onset of hearing. In the present study, antibodies to α10 and to the associated calcium-dependent (SK2) potassium channel showed a similar developmental loss. The correlated expression of these gene products with functional innervation suggests that Alpha10 and SK2, but not Alpha9, are regulated by synaptic activity. Furthermore, this developmental knock-out of α10, but not α9, supports the hypothesis that functional nicotinic acetylcholine receptors in hair cells are heteromers containing both these subunits.
author	Katz, Eleonora Gómez Casati, María Eugenia
author_facet	Katz, Eleonora Gómez Casati, María Eugenia
author_sort	Katz, Eleonora
title	Developmental regulation of nicotinic synapses on cochlear inner hair cells
title_short	Developmental regulation of nicotinic synapses on cochlear inner hair cells
title_full	Developmental regulation of nicotinic synapses on cochlear inner hair cells
title_fullStr	Developmental regulation of nicotinic synapses on cochlear inner hair cells
title_full_unstemmed	Developmental regulation of nicotinic synapses on cochlear inner hair cells
title_sort	developmental regulation of nicotinic synapses on cochlear inner hair cells
publishDate	2004
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_02706474_v24_n36_p7814_Katz http://hdl.handle.net/20.500.12110/paper_02706474_v24_n36_p7814_Katz
work_keys_str_mv	AT katzeleonora developmentalregulationofnicotinicsynapsesoncochlearinnerhaircells AT gomezcasatimariaeugenia developmentalregulationofnicotinicsynapsesoncochlearinnerhaircells
_version_	1768542034944065536

Developmental regulation of nicotinic synapses on cochlear inner hair cells

Ejemplares similares