title: Task-dependent V1 responses in human retinitis pigmentosa.
abstract: OBJECTIVE
  During measurement with functional MRI (fMRI) during passive viewing, subjects with macular degeneration (MD) have a large unresponsive lesion projection zone (LPZ) in V1. fMRI responses can be evoked from the LPZ when subjects engage in a stimulus-related task. The authors report fMRI measurements on a different class of subjects, those with retinitis pigmentosa (RP), who have intact foveal vision but peripheral visual field loss.
  
  
  METHODS
  The authors measured three RP subjects and two control subjects. fMRI was performed while the subjects viewed drifting contrast pattern stimuli. The subjects passively viewed the stimuli or performed a stimulus-related task.
  
  
  RESULTS
  During passive viewing, the BOLD response in the posterior calcarine cortex of all RP subjects was in phase with the stimulus. A bordering, anterior LPZ could be identified by responses that were in opposite phase to the stimulus. When the RP subjects made stimulus-related judgments, however, the LPZ responses changed: the responses modulated in phase with the stimulus and task. In control subjects, the responses in a simulated V1 LPZ were unchanged between the passive and the stimulus-related judgment conditions.
  
  
  CONCLUSIONS
  Task-dependent LPZ responses are present in RP subjects, similar to responses measured in MD subjects. The results are consistent with the hypothesis that deleting the retinal input to the LPZ unmasks preexisting extrastriate feedback signals that are present across V1. The authors discuss the implications of this hypothesis for visual therapy designed to replace the missing V1 LPZ inputs and to restore vision.
authors.affiliation: Department of Ophthalmology, Jikei University, School of Medicine, Tokyo, Japan. massuuu@gmail.com
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Masuda
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Horiguchi
authors.forename: Serge O
authors.initials: SO
authors.lastname: Dumoulin
authors.forename: Ayumu
authors.initials: A
authors.lastname: Furuta
authors.forename: Satoru
authors.initials: S
authors.lastname: Miyauchi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nakadomari
authors.forename: Brian A
authors.initials: BA
authors.lastname: Wandell
mesh_terms: D000328:Adult; D015350:Contrast Sensitivity / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009473:Neuronal Plasticity / Q000502:physiology; D012174:Retinitis Pigmentosa / Q000503:physiopathology*; D012607:Scotoma / Q000503:physiopathology; D013647:Task Performance and Analysis; D014792:Visual Acuity / Q000502:physiology; D014793:Visual Cortex / Q000503:physiopathology*; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology; D014796:Visual Perception / Q000502:physiology
references.citation: Artif Organs. 2003 Nov;27(11):1005-15
references.pmid: 14616519
references.citation: Proc Natl Acad Sci U S A. 2006 Jul 11;103(28):10805-10
references.pmid: 16818873
references.citation: Nature. 2009 Jan 22;457(7228):475-9
references.pmid: 19158795
references.citation: J Physiol. 1968 May;196(2):479-93
references.pmid: 4871047
references.citation: Hum Mol Genet. 2009 Mar 1;18(5):931-41
references.pmid: 19074458
references.citation: Prog Brain Res. 2002;136:373-88
references.pmid: 12143395
references.citation: Ophthalmology. 2007 May;114(5):895-8
references.pmid: 17306875
references.citation: Cereb Cortex. 1996 May-Jun;6(3):388-405
references.pmid: 8670666
references.citation: Magn Reson Med. 1993 Aug;30(2):161-73
references.pmid: 8366797
references.citation: Nat Neurosci. 1999 Apr;2(4):370-4
references.pmid: 10204545
references.citation: J Neurosci. 2005 Mar 30;25(13):3459-68
references.pmid: 15800201
references.citation: Nature. 1982 Sep 30;299(5882):442-4
references.pmid: 7121581
references.citation: Cell Stem Cell. 2009 Jan 9;4(1):73-9
references.pmid: 19128794
references.citation: J Cogn Neurosci. 2000 Sep;12(5):739-52
references.pmid: 11054917
references.citation: J Neurosurg. 1974 Jun;40(6):747-55
references.pmid: 4826600
references.citation: Orphanet J Rare Dis. 2007 Feb 01;2:7
references.pmid: 17270046
references.citation: Nat Neurosci. 2001 May;4(5):455-6
references.pmid: 11319548
references.citation: Arch Ophthalmol. 2004 Apr;122(4):460-9
references.pmid: 15078662
references.citation: Vis Neurosci. 1997 Jan-Feb;14(1):89-101
references.pmid: 9057272
references.citation: Surv Ophthalmol. 2002 Jul-Aug;47(4):335-56
references.pmid: 12161210
references.citation: Hum Gene Ther. 2008 Oct;19(10):979-90
references.pmid: 18774912
references.citation: Proc Natl Acad Sci U S A. 2008 Sep 30;105(39):15112-7
references.pmid: 18809924
references.citation: Trends Genet. 2009 Apr;25(4):156-65
references.pmid: 19303164
references.citation: Vision Res. 2003 Nov;43(24):2573-81
references.pmid: 13129543
references.citation: Magn Reson Med. 2000 May;43(5):705-15
references.pmid: 10800036
references.citation: Science. 1990 Apr 13;248(4952):229-31
references.pmid: 2326637
references.citation: Nat Rev Neurosci. 2009 Dec;10(12):873-84
references.pmid: 19904279
references.citation: Brain Res. 1981 Jan 5;204(1):189-93
references.pmid: 7248745
references.citation: Neuroreport. 1995 Jun 19;6(9):1349-53
references.pmid: 7670002
references.citation: Annu Rev Neurosci. 2004;27:649-77
references.pmid: 15217346
references.citation: Vision Res. 2003 Apr;43(9):1091-102
references.pmid: 12676250
references.citation: IEEE Trans Med Imaging. 1997 Dec;16(6):852-63
references.pmid: 9533585
references.citation: Graefes Arch Clin Exp Ophthalmol. 2007 Oct;245(10):1411-9
references.pmid: 17342502
references.citation: Artif Organs. 2003 Nov;27(11):996-1004
references.pmid: 14616518
references.citation: J Neural Eng. 2009 Jun;6(3):035002
references.pmid: 19458405
references.citation: Neuron. 1997 Apr;18(4):591-8
references.pmid: 9136768
references.citation: Neurosci Lett. 1984 Aug 24;49(1-2):181-6
references.pmid: 6493590
references.citation: Nature. 1992 Mar 12;356(6365):150-2
references.pmid: 1545866
references.citation: Philos Trans R Soc Lond B Biol Sci. 2002 Aug 29;357(1424):963-73
references.pmid: 12217168
references.citation: Prog Brain Res. 2006;154:93-120
references.pmid: 17010705
references.citation: Vision Res. 2008 Aug;48(18):1910-9
references.pmid: 18620725
references.citation: Arch Ophthalmol. 2007 Feb;125(2):151-8
references.pmid: 17296890
references.citation: Brain Res. 1979 Apr 27;166(2):259-71
references.pmid: 218692
references.citation: J Neurophysiol. 2002 Nov;88(5):2530-46
references.pmid: 12424292
references.citation: N Engl J Med. 2008 May 22;358(21):2240-8
references.pmid: 18441370
references.citation: Spat Vis. 1997;10(4):437-42
references.pmid: 9176953
references.citation: Vision Res. 1992 May;32(5):789-96
references.pmid: 1604848
references.citation: Exp Brain Res. 1991;83(3):670-4
references.pmid: 2026207
references.citation: Lancet. 2006 Nov 18;368(9549):1795-809
references.pmid: 17113430
references.citation: ASAIO J. 2000 Jan-Feb;46(1):3-9
references.pmid: 10667705
references.citation: J Physiol. 2000 Apr 15;524 Pt 2:587-602
references.pmid: 10767137
references.citation: Ophthalmology. 2004 Aug;111(8):1595-8
references.pmid: 15288993
references.citation: J Vis. 2003;3(10):586-98
references.pmid: 14640882
references.citation: Nat Neurosci. 2000 Sep;3(9):940-5
references.pmid: 10966626
references.citation: J Biomater Sci Polym Ed. 2007;18(8):1031-55
references.pmid: 17705997
references.citation: N Engl J Med. 2008 May 22;358(21):2231-9
references.pmid: 18441371
references.citation: Curr Neurol Neurosci Rep. 2006 Sep;6(5):403-13
references.pmid: 16928351
references.citation: Brain Res. 1998 Nov 30;813(1):181-6
references.pmid: 9824694
references.citation: Clin Exp Optom. 2008 Jan;91(1):78-84
references.pmid: 18045253
references.citation: Spat Vis. 1997;10(4):433-6
references.pmid: 9176952
references.citation: Annu Rev Physiol. 2004;66:735-69
references.pmid: 14977420
references.citation: Magn Reson Med. 1999 Aug;42(2):412-5
references.pmid: 10440968
references.citation: Brain Res. 1980 Jan 13;181(2):285-300
references.pmid: 7350967
references.citation: Magn Reson Med. 1998 Mar;39(3):361-8
references.pmid: 9498591
references.citation: Nat Neurosci. 2005 Aug;8(8):1102-9
references.pmid: 16025108
references.citation: Neuroimage. 2007 Feb 1;34(3):1199-208
references.pmid: 17169579
references.citation: J Neurosci. 2002 Oct 1;22(19):8633-46
references.pmid: 12351737
references.citation: J Neurosci. 2005 Jan 19;25(3):614-8
references.pmid: 15659597
references.citation: Proc Biol Sci. 1999 Mar 7;266(1418):499-507
references.pmid: 10189714
references.citation: J Neurosci. 1995 Mar;15(3 Pt 2):2417-33
references.pmid: 7891177
references.citation: J Neurosci. 1995 Mar;15(3 Pt 1):1631-47
references.pmid: 7891124
references.citation: Cereb Cortex. 2008 Nov;18(11):2483-93
references.pmid: 18250083
references.citation: Science. 1974 Feb 1;183(4123):440-4
references.pmid: 4808973