Spiral ganglion

After a global brain ischemia of 30 min followed by reperfusion for 3 and 6 days, a progressive accumu- 

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Hall DB Michigan State University, Chicago, IL After describing the properties of the young spiral ganglion cells within the mammalian auditory system then investigate the neurotoxic effects of lead on the sodium current National Institute on Deafness Other Communication Disorders... 

Kimnra N, Nishizaki K, Orita Y, Masnda Y. 4-methyl-catechol, a potent inducer of nerve growth factor synthesis, protects spiral ganglion neurons from aminoglycoside ototoxicity—preliminary report. Acta Otolaryngol Suppl 1999 540 12-15. 

Histological examination of the temporal bones from two individuals with ototoxicity due to tobramycin showed reductions in the numbers of both ganglion cells and hair cells (21). Spiral ganglion cell loss was not necessarily subadjacent to areas of hair cell loss in cases of aminoglycoside ototoxicity. Instead, there may be a reduction in the number of ganglion cells in segments of the cochlea with normal-appearing hair cells. 

Sone M, Schachern PA, Paparella MM. Loss of spiral ganglion cells as primary manifestation of aminoglycoside ototoxicity. Hear Res 1998 115(l-2) 217-23. 

We can thus conclude from the immunoelectron microscopical data that AMPA receptors composed of GluR2/3 and GluR4 subunits are likely to be involved in afferent hair cell transmission. This would be in line with physiological studies. Patch-clamp analyses have identified functional AMPA receptors in isolated spiral ganglion cells (Nakagawa et al.. 

Nakagawa T, Komune S, Uemura T, Akaike N (1991b) Excitatory amino acid response in isolated spiral ganglion cells of guinea pig cochlea. J Neurophysiol 65 715-723. 

In the auditory system, FGF-2 (immunoreactivity) has been localized to developing inner hair cells, spiral ganglion cells (Despres et al, 1991), and distinct neuron populations of auditory relay nuclei (Riedel et al, 1995 cf Luo et al, 1995, however). Localization of FGF-2 to the cochlea might be arte-factual, since its mRNA was not detected there at any age (Luo et al, 1993). However, both developing hair cells and spiral ganglionic neurons have been shown to express FGF-1 mRNA (Luo et al, 1993, 1995), suggesting that FGF-1 may be involved in the establishment of cochlear innervation. 

P.C. Roehm and M.R. Hansen, Strategies to preserve or regenerate spiral ganglion neurons, Curr. Opin. Otolaryngol. Head Neck Surg., 13(5), 294—300 (2005). 

Current cochlear implant technology allows many device recipients to perform very well in tests of speech recognition and to function normally in daily life. However, cochlear implantees have displayed a wide range of scores in tests evaluating speech perception abilities [12,13]. One potential source of variation in speech perception abilities is deviation from the assumptions about how cochlear implants transmit speech information under ideal conditions. In any particular cochlear implant patient, researchers and clinicians cannot be certain about the number of surviving spiral ganglion or how the... 

Zappia JJ, Altschuler R (1989) Evaluation of the effect of ototopical neomycin on spiral ganglion cell density in the guinea pig. Hear Res 40(l-2) 29-37. doi 10.1016/0378-5955(89)90096-8... 

Human hearing arises from airborne waves alternating 50 to 20,000 times a second about the mean atmospheric pressure. These pressure variations induce vibrations of the tympanic membrane, movement of the middle-ear ossicles connected to it, and subsequent displacements of the fluids and tissues of the cochlea in the inner ear. Biomechanical processes in the cochlea analyze sounds to frequency-mapped vibrations along the basilar membrane, and approximately 3,500 inner hair cells modulate transmitter release and spike generation in 30,000 spiral ganglion cells whose proximal processes make up the auditory nerve. This neural activity enters the central auditory system and reflects sound patterns as temporal and spatial spike patterns. The nerve branches and synapses extensively in the cochlear nuclei, the first of the central auditory nuclei. Subsequent brainstem nuclei pass auditory information to the medial geniculate and auditory cortex (AC) of the thalamocortical system. 

SGCs (spiral ganglion cells), 5 3 Shah, C.S., 53-2 Shannon, C.E., 78-2-78-5 Shannon, G.E, 29-8 Shannon s information theory,... 

Spiral ganglion cells, S-6-5-7 Spirometry, 7-12-7-14 Springer, T.A., 62-7 Squid axon, 22-10 Stachowiak, G.W., 50-10 Stainless steels, 38-2-38-4 manufacturing, 38-18 Stanciu, C., 6-7... 

Pettingill, LN, Minter, RL, and Shepherd, RK. 2008. Schwann cells genetically modified to express neurotrophins promote spiral ganglion neuron survival in vitro. Neuroscience 152(3) 821-828. 

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