Expression of glycine receptors and gephyrin in the rat cochlea.
The cochlear efferent feedback system exerts direct impact on cochlear nerve activity and balances interaural sensitivity. So far, acetylcholine, GABA and dopamine are known to be transmitters of the inhibitory efferent system. Despite the wealth of information about glycinergic neurotransmission in the central auditory system, the inhibitory glycine receptor (GlyR) has not yet been regarded as a target molecule of efferent transmission in the cochlea. Using RT-PCR, in situ hybridization and immunohistochemistry, we show that GlyRalpha3, GlyRbeta and gephyrin are expressed in the organ of Corti and spiral ganglion neurons. Furthermore, two alternative splice variants of GlyRalpha3, corresponding to the long (alpha3_L) and short (alpha3_K) human isoforms, could be distinguished. The localization of glycine receptors below inner hair cells and in outer hair cells of the adult cochlea suggests that these inhibitory receptors may serve as target molecules of the efferent olivocochlear bundle.
Dlugaiczyk
Julia
J
Department of Otorhinolaryngology, Head and Neck Surgery, University of Erlangen-Nürnberg, 91054, Erlangen, Germany. julia_dlugaiczyk@yahoo.de
Singer
Wibke
W
Schick
Bernhard
B
Iro
Heinrich
H
Becker
Kristina
K
Becker
Cord-Michael
CM
Zimmermann
Ulrike
U
Rohbock
Karin
K
Knipper
Marlies
M
D017398:Alternative Splicing; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000378:metabolism*; D003051:Cochlea / Q000378:metabolism*; D018076:DNA, Complementary; D005456:Fluorescent Dyes / Q000378:metabolism; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007211:Indoles / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D018009:Receptors, Glycine / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D002352:Carrier Proteins; D018076:DNA, Complementary; D005456:Fluorescent Dyes; D007211:Indoles; D008565:Membrane Proteins; D012333:RNA, Messenger; D018009:Receptors, Glycine; C073441:gephyrin; C007293:DAPI