title: Effects of neonatal partial deafness and chronic intracochlear electrical stimulation on auditory and electrical response characteristics in primary auditory cortex.
abstract: The use of cochlear implants in patients with severe hearing losses but residual low-frequency hearing raises questions concerning the effects of chronic intracochlear electrical stimulation (ICES) on cortical responses to auditory and electrical stimuli. We investigated these questions by studying responses to tonal and electrical stimuli in primary auditory cortex (AI) of two groups of neonatally deafened cats with residual high-threshold, low-frequency hearing. One group were implanted with a multi-channel intracochlear electrode at 8 weeks of age, and received chronic ICES for up to 9 months before cortical recording. Cats in the other group were implanted immediately prior to cortical recording as adults. In all cats in both groups, multi-neuron responses throughout the rostro-caudal extent of AI had low characteristic frequencies (CFs), in the frequency range of the residual hearing, and high-thresholds. Threshold and minimum latency at CF did not differ between the groups, but in the chronic ICES animals there was a higher proportion of electrically but not acoustically excited recording sites. Electrical response thresholds were higher and latencies shorter in the chronically stimulated animals. Thus, chronic implantation and ICES affected the extent of AI that could be activated by acoustic stimuli and resulted in changes in electrical response characteristics.
authors.affiliation: The Bionic Ear Institute, Melbourne, Vic. 3002, Australia. jfallon@bionicear.org
authors.forename: James B
authors.initials: JB
authors.lastname: Fallon
authors.forename: Robert K
authors.initials: RK
authors.lastname: Shepherd
authors.forename: Mel
authors.initials: M
authors.lastname: Brown
authors.forename: Dexter R F
authors.initials: DR
authors.lastname: Irvine
mesh_terms: D000161:Acoustic Stimulation; D000367:Age Factors; D000375:Aging; D000818:Animals; D000831:Animals, Newborn; D001303:Auditory Cortex / Q000473:pathology / Q000503:physiopathology*; D001307:Auditory Perception; D001309:Auditory Threshold; D002415:Cats; D019929:Cochlear Implantation; D003054:Cochlear Implants; D004195:Disease Models, Animal; D004558:Electric Stimulation; D004976:Ethacrynic Acid; D005072:Evoked Potentials, Auditory; D006316:Hearing Loss, High-Frequency / Q000139:chemically induced / Q000503:physiopathology / Q000628:therapy*; D007612:Kanamycin; D009473:Neuronal Plasticity; D011930:Reaction Time; D013997:Time Factors
chemical_list: D007612:Kanamycin; D004976:Ethacrynic Acid
references.citation: IEEE Trans Biomed Eng. 1999 Apr;46(4):461-70
references.pmid: 10217884
references.citation: Am J Otol. 1997 Nov;18(6 Suppl):S17-8
references.pmid: 9391580
references.citation: J Neurophysiol. 1999 Dec;82(6):3506-26
references.pmid: 10601478
references.citation: J Neurophysiol. 1994 Nov;72(5):2334-59
references.pmid: 7884463
references.citation: J Comp Neurol. 2003 May 12;459(4):355-67
references.pmid: 12687704
references.citation: Hear Res. 2008 Aug;242(1-2):3-21
references.pmid: 18616994
references.citation: J Neurophysiol. 1975 Mar;38(2):231-49
references.pmid: 1092814
references.citation: Hear Res. 2000 Apr;142(1-2):89-101
references.pmid: 10748332
references.citation: Int Rev Neurobiol. 2005;70:473-509
references.pmid: 16472643
references.citation: Acta Otolaryngol Suppl. 1983;399:19-31
references.pmid: 6316712
references.citation: Annu Rev Neurosci. 2001;24:139-66
references.pmid: 11283308
references.citation: Hear Res. 1991 Jul;54(1):11-9
references.pmid: 1917710
references.citation: Brain. 2003 Oct;126(Pt 10):2235-45
references.pmid: 12847078
references.citation: J Neurophysiol. 2005 Jun;93(6):3339-55
references.pmid: 15659529
references.citation: Hear Res. 1998 Nov;125(1-2):98-108
references.pmid: 9833964
references.citation: Hear Res. 2005 Jul;205(1-2):184-92
references.pmid: 15953527
references.citation: Hear Res. 2008 Apr;238(1-2):110-7
references.pmid: 17910997
references.citation: Brain. 2009 Feb;132(Pt 2):524-36
references.pmid: 19036764
references.citation: J Neurophysiol. 2002 Jan;87(1):434-52
references.pmid: 11784761
references.citation: Hear Res. 2008 Aug;242(1-2):164-71
references.pmid: 18164883
references.citation: Hear Res. 2006 Dec;222(1-2):1-15
references.pmid: 17071031
references.citation: Hear Res. 2007 Nov;233(1-2):14-22
references.pmid: 17658232
references.citation: Hear Res. 1995 Dec;92(1-2):131-42
references.pmid: 8647736
references.citation: J Acoust Soc Am. 1974 Dec;56(6):1835-47
references.pmid: 4443483
references.citation: J Neurophysiol. 1995 Feb;73(2):449-67
references.pmid: 7760111
references.citation: J Acoust Soc Am. 1998 Oct;104(4):2314-25
references.pmid: 10491696
references.citation: Hear Res. 2007 Mar;225(1-2):60-70
references.pmid: 17258411
references.citation: Cereb Cortex. 2004 Sep;14(9):952-65
references.pmid: 15115736
references.citation: Prog Brain Res. 2006;157:283-313
references.pmid: 17167917
references.citation: J Neurosci. 2009 Jan 21;29(3):811-27
references.pmid: 19158306
references.citation: Hear Res. 2001 Aug;158(1-2):95-101
references.pmid: 11506941
references.citation: Int J Audiol. 2009 Feb;48(2):63-73
references.pmid: 19219690
references.citation: Audiol Neurootol. 2005 May-Jun;10(3):134-44
references.pmid: 15724084
references.citation: Hear Res. 1992 May;59(2):224-40
references.pmid: 1618713
references.citation: Hear Res. 1990 Dec;50(1-2):7-33
references.pmid: 2076984
references.citation: J Comp Neurol. 1998 Sep 14;399(1):35-46
references.pmid: 9725699
references.citation: J Comp Neurol. 1980 Jul 15;192(2):265-91
references.pmid: 7400399
references.citation: Audiol Neurootol. 1998 Mar-Jun;3(2-3):123-44
references.pmid: 9575381
references.citation: Adv Otorhinolaryngol. 2006;64:89-108
references.pmid: 16891838
references.citation: Audiol Neurootol. 2001 Jul-Aug;6(4):203-6
references.pmid: 11694728
references.citation: Audiol Neurootol. 1996 Sep-Oct;1(5):293-306
references.pmid: 9390810
references.citation: J Comp Neurol. 1989 Apr 15;282(3):456-71
references.pmid: 2715393
references.citation: Hear Res. 2000 Sep;147(1-2):188-99
references.pmid: 10962185
references.citation: J Otolaryngol. 1993 Feb;22(1):4-11
references.pmid: 8445702
references.citation: Acta Otolaryngol Suppl. 1983;399:5-17
references.pmid: 6316713
references.citation: Science. 2003 Apr 18;300(5618):498-502
references.pmid: 12702879
references.citation: J Comp Neurol. 1993 Dec 1;338(1):17-49
references.pmid: 8300898
references.citation: Hear Res. 1991 May;53(1):153-8
references.pmid: 2066283
references.citation: Laryngoscope. 2003 Oct;113(10):1726-30
references.pmid: 14520097
references.citation: Hear Res. 1997 Mar;105(1-2):1-29
references.pmid: 9083801
references.citation: J Comp Neurol. 2009 Jan 1;512(1):101-14
references.pmid: 18972570
references.citation: Hear Res. 2002 Nov;173(1-2):172-86
references.pmid: 12372645
references.citation: J Assoc Res Otolaryngol. 2007 Jun;8(2):241-57
references.pmid: 17347777
references.citation: J Comp Neurol. 2003 Dec 15;467(3):354-74
references.pmid: 14608599
references.citation: Audiol Neurootol. 2009;14 Suppl 1:2-7
references.pmid: 19390169
references.citation: Cereb Cortex. 2002 Aug;12(8):797-807
references.pmid: 12122028
references.citation: J Neurophysiol. 2003 Oct;90(4):2387-401
references.pmid: 12773493
references.citation: J Neurophysiol. 1999 Dec;82(6):2883-902
references.pmid: 10601427