Differential expression of the α9 nicotinic acetylcholine receptor subunit in neonatal and adult cochlear hair cells

Simmons, Dwayne D.; Morley, Barbara J.

doi:10.1016/s0169-328x(98)00056-4

Cited by 58 publications

(73 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Current evidence suggests that ␣9 expression in hair cells occurs before synaptogenesis, whereas ␣10 expression is concomitant with the presence of efferent fibers (Simmons and Morley, 1998;Simmons, 2002). It is thus possible that this correlation relates to the protein-protein interaction we have identified between prosaposin and ␣10, and suggests an additional role for ␣10 along with prosaposin in establishment of neural connections.…”

Section: Discussionmentioning

confidence: 75%

Progressive Deafness and Altered Cochlear Innervation in Knock-Out Mice Lacking Prosaposin

Akil¹,

Chang²,

Hiel³

et al. 2006

J. Neurosci.

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 75%

Progressive Deafness and Altered Cochlear Innervation in Knock-Out Mice Lacking Prosaposin

Akil¹,

Chang²,

Hiel³

et al. 2006

J. Neurosci.

View full text Add to dashboard Cite

“…Such a synaptic scaffold could be critical for the transient assembly and clustering of nAChRs in IHCs prior to the onset of hearing. Previous studies have suggested that IHCs may at least transiently express α9 containing nAChR subunits and may be inhibited by ACh (Glowatzki and Fuchs, 2000;Morley and Simmons, 2002;Simmons and Morley, 1998). The inhibition of IHCs could be important for the maturation of IHC and auditory nerve responses such as the generation of low frequency bursts of action potentials (Simmons, 2002).…”

Section: Discussionmentioning

confidence: 99%

Muscle-like nicotinic receptor accessory molecules in sensory hair cells of the inner ear

Osman

Schrader

Hawkes

et al. 2008

Molecular and Cellular Neuroscience

View full text Add to dashboard Cite

Nothing is known about the regulation of nicotinic acetylcholine receptors (nAChRs) in hair cells of the inner ear. MuSK, rapsyn and RIC-3 are accessory molecules associated with muscle and brain nAChR function. We demonstrate that these accessory molecules are expressed in the inner ear raising the possibility of a muscle-like mechanism for clustering and assembly of nAChRs in hair cells. We focused our investigations on rapsyn and RIC-3. Rapsyn interacts with the cytoplasmic loop of nAChR α9 subunits but not nAChR α10 subunits. Although rapsyn and RIC-3 increase nAChR α9 expression, rapsyn plays a greater role in receptor clustering while RIC-3 is important for acetylcholine-induced calcium responses. Our data suggest that RIC-3 facilitates receptor function, while rapsyn enhances receptor clustering at the cell surface.

show abstract

“…We cannot preclude the possibility that, under different experimental conditions or at extreme differences in the rate of transcription of the genes coding for the ␣9 and ␣10 subunits, alternate stoichiometries might exist. However, because both ␣9 and ␣10 subunits are expressed at high levels in outer hair cells (Elgoyhen et al, 1994(Elgoyhen et al, , 2001Simmons and Morley, 1998;Morley and Simmons, 2002), it is unlikely that one subunit might be a limiting factor for the assembly of the more abundant representative form of the receptor. In addition, although the transcription of the gene coding for the ␣10 (but not the ␣9) gene undergoes drastic developmental changes before the onset of hearing (second postnatal week) in rats (Morley and Simmons, 2002;Katz et al, 2004), the properties of the native ␣9␣10-containing inner hair cell receptor highly resemble those of heteromeric ␣9␣10 expressed in Xenopus oocytes .…”

Section: Discussionmentioning

confidence: 99%

Stoichiometry of the α9α10 Nicotinic Cholinergic Receptor

Plazas¹,

Katz²,

Gómez-Casati³

et al. 2005

J. Neurosci.

View full text Add to dashboard Cite

The ␣9 and ␣10 nicotinic cholinergic subunits assemble to form the receptor that mediates synaptic transmission between efferent olivocochlear fibers and hair cells of the cochlea. They are the latest vertebrate nicotinic cholinergic receptor (nAChR) subunits that have been cloned, and their identification has established a distant early divergent branch within the nAChR gene family. The ␣10 subunit serves as a "structural" component leading to heteromeric ␣9␣10 nAChRs with distinct properties. We now have probed the stoichiometry of recombinant ␣9␣10 nAChRs expressed in Xenopus oocytes. We have made use of the analysis of the population of receptors assembled from a wild-type subunit and its partner ␣9 or ␣10 subunit bearing a reporter mutation of a valine to threonine at position 13Ј of the second transmembrane domain (TM2). Because the mutation increased the sensitivity of the receptor for acetylcholine (ACh) but mutations at different subunits were not equivalent, the number of ␣9 and ␣10 subunits could be inferred from the number of components in compound concentration-response curves to ACh. The results were confirmed via the analysis of the effects of a mutation to threonine at position 17Ј of TM2. Because at this position the mutations at different subunits were equivalent, the stoichiometry was inferred directly from the shifts in the ACh EC 50 values. We conclude that the recombinant ␣9␣10 receptor is a pentamer with a (␣9) 2 (␣10) 3 stoichiometry.

show abstract

Differential expression of the α9 nicotinic acetylcholine receptor subunit in neonatal and adult cochlear hair cells

Cited by 58 publications

References 25 publications

Progressive Deafness and Altered Cochlear Innervation in Knock-Out Mice Lacking Prosaposin

Progressive Deafness and Altered Cochlear Innervation in Knock-Out Mice Lacking Prosaposin

Muscle-like nicotinic receptor accessory molecules in sensory hair cells of the inner ear

Stoichiometry of the α9α10 Nicotinic Cholinergic Receptor

Contact Info

Product

Resources

About