TY - JOUR
T1 - Requirement of nicotinic acetylcholine receptor subunit β2 in the maintenance of spiral ganglion neurons during aging
AU - Bao, Jianxin
AU - Lei, Debin
AU - Du, Yafei
AU - Ohlemiller, Kevin K.
AU - Beaudet, Arthur L.
AU - Role, Lorna W.
PY - 2005/3/23
Y1 - 2005/3/23
N2 - Age-related hearing loss (presbycusis) is a major health concern for the elderly. Loss of spiral ganglion neurons (SGNs), the primary sensory relay of the auditory system, is associated consistently with presbycusis. The causative molecular events responsible for age-related loss of SGNs are unknown. Recent reports directly link age-related neuronal loss in cerebral cortex with the loss of high-affinity nicotine acetylcholine receptors (nAChRs). In cochlea, cholinergic synapses are made by olivocochlear efferent fibers on the outer hair cells that express α9 nAChR subunits and on the peripheral projections of SGNs that express α2, α4-7, and β2-3 nAChR subunits. A significantly decreased expression of the β2 nAChR subunit in SGNs was found specifically in mice susceptible to presbycusis. Furthermore, mice lacking the β2 nAChR subunit (β2-/-), but not mice lacking the α5 nAChR subunit (α5-/-), have dramatic hearing loss and significant reduction in the number of SGNs. Our findings clearly established a requirement for β2 nAChR subunit in the maintenance of SGNs during aging.
AB - Age-related hearing loss (presbycusis) is a major health concern for the elderly. Loss of spiral ganglion neurons (SGNs), the primary sensory relay of the auditory system, is associated consistently with presbycusis. The causative molecular events responsible for age-related loss of SGNs are unknown. Recent reports directly link age-related neuronal loss in cerebral cortex with the loss of high-affinity nicotine acetylcholine receptors (nAChRs). In cochlea, cholinergic synapses are made by olivocochlear efferent fibers on the outer hair cells that express α9 nAChR subunits and on the peripheral projections of SGNs that express α2, α4-7, and β2-3 nAChR subunits. A significantly decreased expression of the β2 nAChR subunit in SGNs was found specifically in mice susceptible to presbycusis. Furthermore, mice lacking the β2 nAChR subunit (β2-/-), but not mice lacking the α5 nAChR subunit (α5-/-), have dramatic hearing loss and significant reduction in the number of SGNs. Our findings clearly established a requirement for β2 nAChR subunit in the maintenance of SGNs during aging.
KW - Aging
KW - Hearing loss
KW - Neurodegeneration
KW - Nicotinic receptors
KW - Presbycusis
KW - Spiral ganglion neurons
UR - http://www.scopus.com/inward/record.url?scp=16244414845&partnerID=8YFLogxK
U2 - 10.1523/JNEUROSCI.5277-04.2005
DO - 10.1523/JNEUROSCI.5277-04.2005
M3 - Article
C2 - 15788760
AN - SCOPUS:16244414845
VL - 25
SP - 3041
EP - 3045
JO - Journal of Neuroscience
JF - Journal of Neuroscience
SN - 0270-6474
IS - 12
ER -